New Polk Ultra Compact Amps (Class D Fullrange)

arun1963

Vital wrote: »

According to him there's sq literally coming out of the amp. I don't think he even needs speakers to hear the absurd amount of sound quality, pdx takes car of that lol.

They need to do a case study titled "SQ Amps", at Harvard Biz School. The biggest success story of marketing mixed with technical mumbo jumbo. 90% of folks actually believe and get worked up about the sq qualities of an amp.

alienagneda

It seems sonix now has these units available.
I was going to go with the PA 1200.1 and a PA 500.4 given polk audio on ebay is dumping them as "refurbished" units for cheap.
However, their combined foot print is over 30" so I would need to buy a trailer just to locate them without turning my trunk into a Polk Audio showroom.
I still have a month or better before I will be ready for the amps.


Sooo. Given the product dumping of the PA series over the PA D1000.1 and PA D4000.4 unknown goodness I cant decide if I should jump on the cheap tried and true PA or just go with the PA D assuming Polk wont disappoint and the small footprint that would make my install so much more pleasing to the eye.

Any thoughts?

dorokusai

I'd get whatever is priced the best as you can't really lose here.

MacLeod

Get the D's.

More powerful, more efficient and smaller. The 1200.1 and 500.4 are huge and about the only way to mount them is on the floor of your trunk which takes up valuable space.

If I didn't already have a a full compliment of PA's, I'd opt for the D's in a second.

Vital

I have PA500.4 and 1200.1, bought all the material to build an amprack to house them real nice and now these D's come out lol. Now idk if i should just built it and basically commit to 500.4 and 1200.1 since amprack will be custom sized/built or sell them, get Ds and hope they will not sound any worse then what i have now....and then built the same rack for them with materials i already have..

I'll need to see some reviews of D's first thou as i love PAs i have now in no way would sacrifize it for something unknown.

MacLeod

The D's will sound slightly better because they're more powerful. Not only do they make more power per channel but since they're more efficient they'll make more power with less input voltage. It wont be a night and day difference but they will be a bit better

That being said, if you can fit the PA's I'm not sure its worth the loss you'd take on selling them in order to get the D's. In fact I'm pretty sure its not.

Vital

That's PA200.4 and 500.4 pictured but current 1200.1 fits perfectly fine instead of 200.4.
Pic is old but since then i went active and got rid of rear fill so there's no passive xovers so all i have are just 2 amps that fit perfectly fine next to each other all the way down the trunk's floor..... still want smaller amps just for the hell of it lol.

alienagneda

Thanks for the quick replies. I could save about $125 buying the PA's over the PA D's. But I am going to take Macs advice and jump on the new technology - fingers crossed Polk keeps with their excellent product quality.
My SR6500's and dual SR124DVC's should love this new setup.

On another note. Does anyone else find in bothersome that Polk allows BestBuy to distribute their product. I know its a great brick and mortar for more sales volume. But the BB buying experience always made me feel dirty somehow - having some oily teenager babbling on about SonyXPlode subs with Polk amps! Such an unholy union.

Thanks again.
Fiberglass work this weekend for my SR124VDC's new homes.

EndersShadow

Vital wrote: »

That's PA200.4 and 500.4 pictured but current 1200.1 fits perfectly fine instead of 200.4.

Thanks for that pic, it gives me a possible idea for my car with its 2 amps + 4 crossovers (2 sets of db6501's)

Vital

EndersShadow wrote: »

Thanks for that pic, it gives me a possible idea for my car with its 2 amps + 4 crossovers (2 sets of db6501's)

here's a few more since i'm bored at work lol









might wanna think of ventilation but since this was done September of last year right before winter i didn't have to worry about overheating

arun1963

alienagneda wrote: »

On another note. Does anyone else find in bothersome that Polk allows BestBuy to distribute their product. I know its a great brick and mortar for more sales volume. But the BB buying experience always made me feel dirty somehow - having some oily teenager babbling on about SonyXPlode subs with Polk amps! Such an unholy union.

Not really. It gives them a distribution network of 1500 stores world wide. It's true that 90% of BM stores selling mobile audio equipment have no clue on good sound and neither do 99% of the customers who go there. For the remaining 1% of customers, chances are they will already know what they want, so you can ingnore what the saleskid says.

One of the supposedly best BM stores here was pushing me to upgrade my polk amps sometime back, to some $ 4000 amps. I do most of my install tweaks here since I'm all thumbs. On every visit he would give me his sales pitch, how his amps had great sq etc.

So finally I sat the owner of the shop in my car and made him listen to some Floyd. After about 10 mts he turns to me and says, 'you'll actually need to upgrade the amps and speakers.' I must have looked shocked, so he explained, 'your car doesn't get as loud as mine and your speakers are weak. There's no sound comming from them, you've got the sound comming from the windshield'!!!!

arun1963

Vital wrote: »

here's a few more since i'm bored at work lol

Tsk tsk..... get back to work

Vital wrote: »

might wanna think of ventilation but since this was done September of last year right before winter i didn't have to worry about overheating

I was going to ask about that........but then again NYC doesn't hit 115 for 100 days straight.

MacLeod

@Vital

Dude I like that amp rack. Enclosed so you can set your sub on it or whatever. You're not really losing any real storage space. One thing tho, those amps get hot and the covers are really detrimental to their cooling. If they're not going to be on display, take those covers off so the heatsinks can radiate unrestricted. That's how I ran mine when I mounted them under the back seat

Vital

MacLeod wrote: »

@Vital

Dude I like that amp rack. Enclosed so you can set your sub on it or whatever. You're not really losing any real storage space. One thing tho, those amps get hot and the covers are really detrimental to their cooling. If they're not going to be on display, take those covers off so the heatsinks can radiate unrestricted. That's how I ran mine when I mounted them under the back seat

Sub is in fg stealth corner enclosure taking up very minimum usefull space.
Every amp i've had in this rack was with beauty cover off just to make sure i don't put a single scratch or piece of dirt on it.
Now that i'm ready to have this rack made to be a combo of practicality (basic size/shape it is now) and show (leds, plexiglass, carpet...) i will need to use these beauty covers BUT before i even put them back on and make a single cut into re-desinged amprack i'll wait to make up my mind on these new D amps. For some reason even thou PA amps fit ust fine i'd rather have my rack even smaller... idk, i quess i'll wait for reviews on these D amps.







You can actually see there's no beauty covers on these amps here:

BeefJerky

MacLeod wrote: »

The D's will sound slightly better because they're more powerful.

Okay, I have to correct you on this. "More powerful" does not equate to "sounding better" in any way, shape or form. In fact, the class-AB PA-series should be the better of the two in terms of sound quality. They would most certainly measure better, but the differences may or may not be heard. This can depend on the listener as well as the exact implementation of the class-D amps.

This is not a knock against Polk's PA-D series of amps, nor class-D amps in general. As I've mentioned elsewhere, I run a full range class-D amp in my car and am very happy with it. However, if I had the room, I would have considered putting in a class-AB amp for the better sound quality.

MacLeod wrote:

Not only do they make more power per channel but since they're more efficient they'll make more power with less input voltage. It wont be a night and day difference but they will be a bit better

That being said, if you can fit the PA's I'm not sure its worth the loss you'd take on selling them in order to get the D's. In fact I'm pretty sure its not.

I can agree with this part.

@Vital: Nice work on the amp racks!

arun1963

BeefJerky wrote: »

Okay, I have to correct you on this. "More powerful" does not equate to "sounding better" in any way, shape or form. In fact, the class-AB PA-series should be the better of the two in terms of sound quality. They would most certainly measure better, but the differences may or may not be heard. This can depend on the listener as well as the exact implementation of the class-D amps.

This is not a knock against Polk's PA-D series of amps, nor class-D amps in general. As I've mentioned elsewhere, I run a full range class-D amp in my car and am very happy with it. However, if I had the room, I would have considered putting in a class-AB amp for the better sound quality.

More watts will give you better dynamics and more head room, hence more watts will sound better. I swapped the pa500.4 that I ran for 3 years, to the Genesis ultra four. 4x85 watts to 4x130 watts. Big difference in dynamics and more headroom. The Genesis is rated for 4x100 but measured 4x128.

In a car you are not going to hear the difference between A/B and D. Assuming of course both topologies are of decent build quality.

BeefJerky

arun1963 wrote: »

More watts will give you better dynamics and more head room, hence more watts will sound better. I swapped the pa500.4 that I ran for 3 years, to the Genesis ultra four. 4x85 watts to 4x130 watts. Big difference in dynamics and more headroom. The Genesis is rated for 4x100 but measured 4x128.

Yes, more watts may give you better dynamics and headroom, but it still does not equal sound quality. I've heard both good and bad class-AB and class-D amps and there are differences. For instance, let's use a professional Peavey amp that puts out 1000+ watts as an example. It sure has lots of power, but it sounds like garbage; much worse than a significantly lower powered (~110w/ch) Pioneer Elite amplifier. I can say this from experience, and anyone with ears can confirm this. More watts does not equate to better sound quality.

Or, we can use tube amplifiers as an example. They are generally very low wattage, but can still sound fantastic. Number of watts aren't everything - not even close.

Dynamics and sound quality are independent of one another. To illustrate this, I will state that any of the following combinations are possible:
1) High power amp with a lot of dynamics, but poor sound quality
2) Low power amp with little dynamics, but great sound quality
3) Low power amp with little dynamics, as well bad sound quality
4) High power amp with a lot of dynamics, as well as great sound quality
5) High power amp with little dynamics, as well as poor sound quality

arun1963 wrote:

In a car you are not going to hear the difference between A/B and D. Assuming of course both topologies are of decent build quality.

Again, I disagree here, but realize that some peoples ears are more sensitive to these things than others. In fact, I already stated this in my prior post.

MacLeod

There is no such thing as a "class D sound" or any other. One set of circuits doesnt sound different than another. Even if it did, why would you want an amp that changed the sound? If a class a/b amp has a ruler flat response from 20 to 20K how can a class d with the same response sound different? Does it have a flaterrer response? If there were a difference, somebody would've won Richard Clark's amp challenge in the near 30 years its been up. Just like a Duracell battery wont produce a different color light in your flashlight than an Energizer battery.

And yes, more power does mean better SQ. Of course common sense plays a role so spare me the "well then why not put 1000 watts on a tweeter" response I know is coming. But a system being powered by a 50 watt per channel amp will absolutely sound better if he swaps out to a 150 watt per channel amp. That is assuming everything is installed properly, gains set right and so on.

BeefJerky

MacLeod wrote: »

There is no such thing as a "class D sound" or any other. One set of circuits doesnt sound different than another. Even if it did, why would you want an amp that changed the sound? If a class a/b amp has a ruler flat response from 20 to 20K how can a class d with the same response sound different? Does it have a flaterrer response? If there were a difference, somebody would've won Richard Clark's amp challenge in the near 30 years its been up. Just like a Duracell battery wont produce a different color light in your flashlight than an Energizer battery.

It's not about flatness of response, but distortion. Every amplifier introduces distortion to some extent, however, the distortion from class-AB amps is generally less offensive than that from class-D amplifiers. However, that is becoming less of a distinction with the improvements in class-D amps. There is a reason that class-D amps were only used for subs in the old days - too much distortion that would make the mids and highs offensive. Again, there has been quite a bit of improvement in this over the years, and I'm sure it will continue to improve.

And as far as distortion goes, it's not always so much that you can immediately hear it, but it will be very fatiguing to listen to for longer periods. This is proven.

I won't go into more detail since a quick Google search will tell you more than you need to know. That, and you seem pretty steadfast on your opinion regardless of the facts.

Your flashlight "analogy" is completely irrelevant and has no bearing on amplifiers and speakers.

MacLeod wrote:

And yes, more power does mean better SQ. Of course common sense plays a role so spare me the "well then why not put 1000 watts on a tweeter" response I know is coming. But a system being powered by a 50 watt per channel amp will absolutely sound better if he swaps out to a 150 watt per channel amp. That is assuming everything is installed properly, gains set right and so on.

So, let me get this straight. If I compare an utterly atrocious 150 watt amp (i.e. Sparkomatic or Pyramid) versus a high quality 50 watt amp (i.e. Eclipse), the 150 watt will still sound better? You're deluding yourself here. Poor sound quality is still poor regardless of how many watts are produced.

MacLeod

BeefJerky wrote: »

It's not about flatness of response, but distortion. Every amplifier introduces distortion to some extent, however, the distortion from class-AB amps is generally less offensive than that from class-D amplifiers. However, that is becoming less of a distinction with the improvements in class-D amps. There is a reason that class-D amps were only used for subs in the old days - too much distortion that would make the mids and highs offensive. Again, there has been quite a bit of improvement in this over the years, and I'm sure it will continue to improve.

That is true if youre talking about the first Class D amps to come out years ago. They were for subs only because they had a high amount of distortion and werent fit for full range applications. Xtant was the first I believe to come out with a full range Class D amp that had low enough distortion that it was inaudible. You cant hear THD below 1% so as long as its below that, its fine.

Distortion isnt a set thing, its more like an RPM gauge. Any amp can make .05% THD but it might only be making 3 watts when it does. What you want to look at is how much power its making below the audible level of 1%, thats what matters and thats what tells you how much power youre going to actually be able to use. So any amp can be used to where its making zero audible distortion, its just a matter of how hard you can crank on it before you get into that level.

And as far as distortion goes, it's not always so much that you can immediately hear it, but it will be very fatiguing to listen to for longer periods. This is proven.

Yes and no. Obviously more distortion is going to get old a lot faster but since virtually all brand name amps are making distortion lower than the audible level, it doesnt matter.

So, let me get this straight. If I compare an utterly atrocious 150 watt amp (i.e. Sparkomatic or Pyramid) versus a high quality 50 watt amp (i.e. Eclipse), the 150 watt will still sound better? You're deluding yourself here. Poor sound quality is still poor regardless of how many watts are produced.

I never said that a flea market amp rated at 150 watts will sound better than a Zapco that conservatively making 50 watts. The flea market amp isnt making anywhere near its rated power so that "150 watt" amp is more like 50 watts if youre lucky. Im sure it would hit 150 watts but youd have to push it WELL into the audible distortion level.

What Im saying is that if you take a system powered by 50 watts per channel and then upgrade it to 150 watts per channel, it will sound better. No other way around it.

I never said the brand of amp is not important. A Zapco amp is going to be well built and noise free and will easily make its rated power far beyond the level of audible distortion. A flea market amp will be the opposite. Itll have pops and buzzes and will maybe make half its rated power if youre lucky. So you have to buy an amp that is well made, will be free of noise like turn on/off pops, and will make the power you require and are paying for well below the level of audible distortion.

arun1963

BeefJerky wrote: »

Yes, more watts may give you better dynamics and headroom, but it still does not equal sound quality. I've heard both good and bad class-AB and class-D amps and there are differences. For instance, let's use a professional Peavey amp that puts out 1000+ watts as an example. It sure has lots of power, but it sounds like garbage; much worse than a significantly lower powered (~110w/ch) Pioneer Elite amplifier. I can say this from experience, and anyone with ears can confirm this. More watts does not equate to better sound quality.

Or, we can use tube amplifiers as an example. They are generally very low wattage, but can still sound fantastic. Number of watts aren't everything - not even close.

Dynamics and sound quality are independent of one another. To illustrate this, I will state that any of the following combinations are possible:
1) High power amp with a lot of dynamics, but poor sound quality
2) Low power amp with little dynamics, but great sound quality
3) Low power amp with little dynamics, as well bad sound quality
4) High power amp with a lot of dynamics, as well as great sound quality
5) High power amp with little dynamics, as well as poor sound quality


Again, I disagree here, but realize that some peoples ears are more sensitive to these things than others. In fact, I already stated this in my prior post.

1. Home audio and car audio are totally different. Different environment, different rules and challenges. Hence your experience with 2ch stuff is of little relevance on this side.

2. Class D amps have come a long way at least you agree on that.

3. Golden Ears? Please spare us that crap.

4. Compare like with like.

5. Does your car sound anything remotely like your 2 ch rig?

I think those five points cover pretty much everything in your post.

BeefJerky

MacLeod wrote: »

That is true if youre talking about the first Class D amps to come out years ago. They were for subs only because they had a high amount of distortion and werent fit for full range applications. Xtant was the first I believe to come out with a full range Class D amp that had low enough distortion that it was inaudible. You cant hear THD below 1% so as long as its below that, its fine.

Except that everybody's ears are different, and some are more sensitive to distortion than others. 1% may be a general rule, but some people will be more or less sensitive. For instance, 1% is too much THD for me, and will make my ears hurt with a longer listening session. Around 0.5% is the cutoff for me.

Distortion isnt a set thing, its more like an RPM gauge. Any amp can make .05% THD but it might only be making 3 watts when it does. What you want to look at is how much power its making below the audible level of 1%, thats what matters and thats what tells you how much power youre going to actually be able to use. So any amp can be used to where its making zero audible distortion, its just a matter of how hard you can crank on it before you get into that level.

Actually, many higher powered amps have more distortion at lower levels than a similar lower powered amp. So, for lower listening volumes, a higher powered amp may not always be better.

Yes and no. Obviously more distortion is going to get old a lot faster but since virtually all brand name amps are making distortion lower than the audible level, it doesnt matter.

Again, there is a general rule, but it doesn't actually apply to 100% of the population. This can be said for any "general rule" out there, though.

I never said that a flea market amp rated at 150 watts will sound better than a Zapco that conservatively making 50 watts. The flea market amp isnt making anywhere near its rated power so that "150 watt" amp is more like 50 watts if youre lucky. Im sure it would hit 150 watts but youd have to push it WELL into the audible distortion level.

I fully agree that there are differences in quality (and therefore sound quality) in different brands of amplifiers. That goes for both classes of amps of course.

What Im saying is that if you take a system powered by 50 watts per channel and then upgrade it to 150 watts per channel, it will sound better. No other way around it.

It's still not that simple - watts are not everything. However, you can continue to believe so if you choose.

I never said the brand of amp is not important. A Zapco amp is going to be well built and noise free and will easily make its rated power far beyond the level of audible distortion. A flea market amp will be the opposite. Itll have pops and buzzes and will maybe make half its rated power if youre lucky. So you have to buy an amp that is well made, will be free of noise like turn on/off pops, and will make the power you require and are paying for well below the level of audible distortion.

See above.

arun1963 wrote: »

1. Home audio and car audio are totally different. Different environment, different rules and challenges. Hence your experience with 2ch stuff is of little relevance on this side.

2. Class D amps have come a long way at least you agree on that.

3. Golden Ears? Please spare us that crap.

4. Compare like with like.

5. Does your car sound anything remotely like your 2 ch rig?

I think those five points cover pretty much everything in your post.

1) They are certainly differences, but there are also similarities. It seems you choose to ignore these similarities in order to bolster your case.

2) I do agree with that.

3) The whole "Golden Ears" term is just inaccurate and demeaning. It all boils down to simple biology and science, which tells us that everyone's hearing is different. There are many "general rules" when it comes to humans, but no human follows them all exactly. Human hearing can differ quite drastically from one person to another.

For example, the standard definition of the range of human hearing is 20Hz-20kHz, but many can't even hear that high as a child, and it only deteriorates as one ages.

Another example of a difference is how some of my friends cannot hear the difference between a 128kbps MP3 and a CD, but I (and many others) can. However, based on your claims, since it is a "rule" that 128kbps is "CD quality" there must not be an audible difference. Either that, or human hearing differs.

Just because one person can't hear the differences between one amp and another doesn't mean that others can't. To automatically deny that shows how little you know about human biology.

4) Please explain exactly how failed to do so, and how I can meet your standards.

5) Of course not, and I'm happy to acknowledge that the car is a more difficult environment for audio compared to your typical home. However, I will reiterate that this does not mean that knowledge from home audio doesn't apply to the car. Many things can be carried over and applied to a car audio setup.

MacLeod

BeefJerky wrote: »

Except that everybody's ears are different, and some are more sensitive to distortion than others. 1% may be a general rule, but some people will be more or less sensitive. For instance, 1% is too much THD for me, and will make my ears hurt with a longer listening session. Around 0.5% is the cutoff for me.

Actually, many higher powered amps have more distortion at lower levels than a similar lower powered amp. So, for lower listening volumes, a higher powered amp may not always be better.

Let me try this again, the THD rating is not the amount of distortion an amp makes. It is the amount of distortion that amp will make at a certain rated power. For example, an amp that makes 100 watts @ .5% THD could make 150 watts but at 1%THD and maybe make 200 watts but it would be at 3%THD.

Another example would be when an amp clips. An amp that makes 100 watts could push out 200+ watts but the clipped signal would be nearly 10%THD.

One way to hear when an amp pushes into audible distortion is on a vocal track. These need a lot of power to be good and loud and when the singer hits a high and hard note, youll hear the distortion in a lesser powered system because its taking a lot of juice to reproduce that note at the volume that its supposed to and so while the amp can do it, its doing it at 5% THD give or take.

All that being said, that is a matter of not enough power and not an amp with too much distortion. What you want is an amp big enough to be able to hit that one note with the volume youre wanting and be able to do it without dipping into the audible distortion level.

So one more time, more power = better sound quality.

It's still not that simple - watts are not everything. However, you can continue to believe so if you choose.

Watts are everything when youre trying to building a system and trying to determine how loud youre wanting to listen and what kind of music. For heavy metal you dont need a lot of power because those high frequencies are easy to reproduce loud. If you want to listen to Livingston Taylor, youre gonna need a lot of power if you want to listen to it loud and clear.

The whole "Golden Ears" term is just inaccurate and demeaning. It all boils down to simple biology and science, which tells us that everyone's hearing is different. There are many "general rules" when it comes to humans, but no human follows them all exactly. Human hearing can differ quite drastically from one person to another.

For example, the standard definition of the range of human hearing is 20Hz-20kHz, but many can't even hear that high as a child, and it only deteriorates as one ages.

Another example of a difference is how some of my friends cannot hear the difference between a 128kbps MP3 and a CD, but I (and many others) can. However, based on your claims, since it is a "rule" that 128kbps is "CD quality" there must not be an audible difference. Either that, or human hearing differs.

Just because one person can't hear the differences between one amp and another doesn't mean that others can't. To automatically deny that shows how little you know about human biology.

Richard Clark has had his $10,000 amp challenge out for nearly 3 decades. You take any 2 amps you choose, level match them to within 1 db and then pick your own music and then do a blind ABX tesst. If you can pick out the amp, you win $10,000. Should be easy for the golden ears that hear such drastic differences between amp. To date, its not been done. All the golden ears cry foul and say its rigged of course.

Try this out and see how you do. Take the test 15 times and see how many you get right. If you get around 50%, thats the same result as if youd flipped a coin. Hell I just went thru and clicked the same one everytime and got 65%. If you get near 90% Ill concede that you can indeed hear grass grow.

http://mp3ornot.com/

arun1963

BeefJerky wrote: »

1) They are certainly differences, but there are also similarities. It seems you choose to ignore these similarities in order to bolster your case.

2) I do agree with that.

3) The whole "Golden Ears" term is just inaccurate and demeaning. It all boils down to simple biology and science, which tells us that everyone's hearing is different. There are many "general rules" when it comes to humans, but no human follows them all exactly. Human hearing can differ quite drastically from one person to another.

For example, the standard definition of the range of human hearing is 20Hz-20kHz, but many can't even hear that high as a child, and it only deteriorates as one ages.

Another example of a difference is how some of my friends cannot hear the difference between a 128kbps MP3 and a CD, but I (and many others) can. However, based on your claims, since it is a "rule" that 128kbps is "CD quality" there must not be an audible difference. Either that, or human hearing differs.

Just because one person can't hear the differences between one amp and another doesn't mean that others can't. To automatically deny that shows how little you know about human biology.

4) Please explain exactly how failed to do so, and how I can meet your standards.

5) Of course not, and I'm happy to acknowledge that the car is a more difficult environment for audio compared to your typical home. However, I will reiterate that this does not mean that knowledge from home audio doesn't apply to the car. Many things can be carried over and applied to a car audio setup.

1. Car audio is 95% different from home audio. So excuse me for ignoring that 5% cause NOTHING in any of your posts touched upon the common 5%. In case you doubt my statement please refer to my point 5.

3. Yes 'aural' capabilities will vary from person to person. The key is learning to listen, training your ears to hear a difference. Multiple studies suggest that 2db is the threshold where the 'average' human ear can tell the difference between louder/softer, know what? After close to 4K hours of tweaking I can tell the difference at 0.5db. Most of the guys on the car forum here are tweakers. In a car its 60% about tuning and 40% about install, equipment, placement etc. As a first step you have to learn to tune and hear the difference. How does raising 800hz on the right by 0.5db affect 8khz and the tonality over 10 octaves. If you can't hear that difference you'll never get anywhere with car audio.

It pisses me off when ignorant 2ch jocks come here with a condescending attitude. After 4 years of tweaking, my car is close to my home setup comprising Naim pre+power/Nad cdp/ Totem speakers. This, with limited dsp on my deck and 0 reflection mgt. With a processor and some hushing of reflections, I'd get further for sure. You'll never find someone from the car forum here proclaiming they have great ears. Why? cause it's rude and not true.

4. Re-read your posts and you;ll find out.

5. I rest my case.

BeefJerky

MacLeod wrote: »

Let me try this again, the THD rating is not the amount of distortion an amp makes. It is the amount of distortion that amp will make at a certain rated power. For example, an amp that makes 100 watts @ .5% THD could make 150 watts but at 1%THD and maybe make 200 watts but it would be at 3%THD.

Another example would be when an amp clips. An amp that makes 100 watts could push out 200+ watts but the clipped signal would be nearly 10%THD.

One way to hear when an amp pushes into audible distortion is on a vocal track. These need a lot of power to be good and loud and when the singer hits a high and hard note, youll hear the distortion in a lesser powered system because its taking a lot of juice to reproduce that note at the volume that its supposed to and so while the amp can do it, its doing it at 5% THD give or take.

All that being said, that is a matter of not enough power and not an amp with too much distortion. What you want is an amp big enough to be able to hit that one note with the volume youre wanting and be able to do it without dipping into the audible distortion level.

I agree with that for the most part, and have acknowledged it in prior posts. However, you failed to address one issue that I brought up which is more than valid. Many higher powered amps will have higher THD at lower levels than a similar quality lower powered amp. This can make a difference, and clearly shows that higher power is not always better.

So one more time, more power = better sound quality.

Repeating this line won't make it true. See above.

Watts are everything when youre trying to building a system and trying to determine how loud youre wanting to listen and what kind of music. For heavy metal you dont need a lot of power because those high frequencies are easy to reproduce loud. If you want to listen to Livingston Taylor, youre gonna need a lot of power if you want to listen to it loud and clear.

I certainly agree that different types of music can call for different setups for optimal performance. I had to look up Livingston Taylor since I wasn't aware of who he was, but I get your point nonetheless. To throw out another band, Primus would also require some good power (at least for the low end) due to the use of a bass guitar as lead. I still don't believe watts are everything, but I don't deny that they have importance.

In fact, I believe that a higher powered amp is great for the low end, as distortion is much harder to hear in those frequencies, and it is also needed more. However, I believe that going overboard to power the high end is both useless and can detract from the sound quality. Truthfully, if I had the space in my car (which I don't), I would have a good ultra-powerful class-D amp for the sub, and a nice mid-power class-AB amp for the mids and tweeters.

However, I have limited placement options, and want to keep it looking stock. As such, I went with a 5 channel class-D Kenwood amp (XR-5S). It's 80x4 for the fronts and backs, however, I keep the fader all the way up front unless I have people riding in the back (rarely). It also puts out 350w to the sub. Truthfully, this is plenty of power for me. I can drive my system past the point that I would ever want to listen to it and still have plenty of headroom. I can also rattle the car with the sub quite thoroughly when needed.

Richard Clark has had his $10,000 amp challenge out for nearly 3 decades. You take any 2 amps you choose, level match them to within 1 db and then pick your own music and then do a blind ABX tesst. If you can pick out the amp, you win $10,000. Should be easy for the golden ears that hear such drastic differences between amp. To date, its not been done. All the golden ears cry foul and say its rigged of course.

I don't have much faith in his challenge either. Simply, why should I trust him to be fully fair and honest? It is his personal money that is up for grabs, so he has no real motivation to do so. Since there has been no impartial 3rd party to monitor him and his setup (as far as I know), we can't know for sure. In addition, his lack of any sort of actual logs of his supposedly scientific data make me question the validity of it all. Truthfully, I would trust you just as much as I would trust him in this situation.

Try this out and see how you do. Take the test 15 times and see how many you get right. If you get around 50%, thats the same result as if youd flipped a coin. Hell I just went thru and clicked the same one everytime and got 65%. If you get near 90% Ill concede that you can indeed hear grass grow.

http://mp3ornot.com/

I got around 50% as well, however, not all of those clips are equal in terms of showing the difference. The clip Hard Lovin' Woman by Juliette Lewis was obvious and I got that one right every time. The difference was quite noticeable in the vocals especially near the beginning. The clip Beautiful Love by Sophie Milman was less noticeable, but I still got that one correct around 75% of the time. The last clip, Barrio San Miguel by Gino d'Auri was a toss. I couldn't tell the difference between the two encodings at all on that song.

I never claimed that all songs or recordings would show audible differences between a low bitrate MP3 and a higher bitrate MP3 or lossless. Some can certainly encode well enough to be inaudible, and others can show small to drastic differences. To my ears, songs with heavy use of cymbals and classical music show show the most deficiencies in low bitrate MP3s. Also, certain types of vocals can be quite noticeable.

arun1963 wrote: »

1. Car audio is 95% different from home audio. So excuse me for ignoring that 5% cause NOTHING in any of your posts touched upon the common 5%. In case you doubt my statement please refer to my point 5.

3. Yes 'aural' capabilities will vary from person to person. The key is learning to listen, training your ears to hear a difference. Multiple studies suggest that 2db is the threshold where the 'average' human ear can tell the difference between louder/softer, know what? After close to 4K hours of tweaking I can tell the difference at 0.5db. Most of the guys on the car forum here are tweakers. In a car its 60% about tuning and 40% about install, equipment, placement etc. As a first step you have to learn to tune and hear the difference. How does raising 800hz on the right by 0.5db affect 8khz and the tonality over 10 octaves. If you can't hear that difference you'll never get anywhere with car audio.

It pisses me off when ignorant 2ch jocks come here with a condescending attitude. After 4 years of tweaking, my car is close to my home setup comprising Naim pre+power/Nad cdp/ Totem speakers. This, with limited dsp on my deck and 0 reflection mgt. With a processor and some hushing of reflections, I'd get further for sure. You'll never find someone from the car forum here proclaiming they have great ears. Why? cause it's rude and not true.

4. Re-read your posts and you;ll find out.

5. I rest my case.

1) I find your 95% claim absurd, and you haven't provided anything to back it up either. Your point number 5 actually doesn't provide any sort of proof to back up your case either.

3) I agree that training will be necessary for many people. However, there are some natural-born musicians that could match your ear's ability without even trying.

As for you getting pissed off at "ignorant 2ch jocks with a condescending attitude." Your elitist condescending attitude is just as rude and ignorant. It's funny because you actually are that which you hate.

4) This sounds like something my girlfriend would say when she claims I did something wrong but won't tell me what. It's also a weaselly way out of actually answering my valid question.

5) Your case is still unproven.

MacLeod

DSkip wrote: »

Who cares. Just let this crap die already. Nobody is going to budge and everyone wants the last word. There is nothing very informative about the last few posts and they are getting more personal each time.

Feel free to not click on this thread at anytime. This is a discussion forum and we're having a discussion.

BeefJerky wrote: »

I agree with that for the most part, and have acknowledged it in prior posts. However, you failed to address one issue that I brought up which is more than valid. Many higher powered amps will have higher THD at lower levels than a similar quality lower powered amp. This can make a difference, and clearly shows that higher power is not always better.

I disagree that a higher powered amp will make more noise at low volumes. Even if its true, its still well beyond the audible level. Ive heard several systems running 350+ watts PER DRIVER :eek: and theyre as quiet as the wind driven snow.

I certainly agree that different types of music can call for different setups for optimal performance. I had to look up Livingston Taylor since I wasn't aware of who he was, but I get your point nonetheless. To throw out another band, Primus would also require some good power (at least for the low end) due to the use of a bass guitar as lead. I still don't believe watts are everything, but I don't deny that they have importance.

Primus wont need quite as much to get loud, at least not in the mids and highs. The higher treble of the guitars and such dont require big power. Less Claypool's genius comes thru no matter what the volume.

In fact, I believe that a higher powered amp is great for the low end, as distortion is much harder to hear in those frequencies, and it is also needed more. However, I believe that going overboard to power the high end is both useless and can detract from the sound quality. Truthfully, if I had the space in my car (which I don't), I would have a good ultra-powerful class-D amp for the sub, and a nice mid-power class-AB amp for the mids and tweeters.

Im with you on this. I think there is a point of overkill where there is no return on investment. Generally 100-150 watts per driver on the mids and highs (Im talking car not home audio) is the most you need. Like Ive said, Ive heard some massively powered systems and the extra power doesnt separate them from the ones running 150 watts.

However, I have limited placement options, and want to keep it looking stock. As such, I went with a 5 channel class-D Kenwood amp (XR-5S). It's 80x4 for the fronts and backs, however, I keep the fader all the way up front unless I have people riding in the back (rarely). It also puts out 350w to the sub. Truthfully, this is plenty of power for me. I can drive my system past the point that I would ever want to listen to it and still have plenty of headroom. I can also rattle the car with the sub quite thoroughly when needed.

Im with ya here too. Im not saying you have to have a 5,000 watt amp, just like you dont have to have a car that makes 400 horsepower. But that extra horsepower will come in handy when you want to have a little fun. Same with the extra wattage. I mean hell, Im only running 400 watts to my sub and 90 to each driver and thats for SQ competition on a national level! Like I said way earlier, there is a point of common sense and me saying more power is good doesnt equate to me saying put 5000 watts on a tweeter.

I don't have much faith in his challenge either. Simply, why should I trust him to be fully fair and honest? It is his personal money that is up for grabs, so he has no real motivation to do so. Since there has been no impartial 3rd party to monitor him and his setup (as far as I know), we can't know for sure. In addition, his lack of any sort of actual logs of his supposedly scientific data make me question the validity of it all. Truthfully, I would trust you just as much as I would trust him in this situation.

Its as transparent as it can be. You are more than welcome to inspect the entire test setup for as long as you want. He hides nothing. You have 2 amps, both of your choosing and then you have a ABX switcher. You listen to amp A, then to B then to X and you have to say which one X is. Nobody guess right more than 50% of the time which like the MP3 test, is the same result as flipping a coin. It works just like that MP3 test. Blind ABX testing is the only objective and scientific way to test if you truly can hear a difference between product A and product B.

I got around 50% as well, however, not all of those clips are equal in terms of showing the difference. The clip Hard Lovin' Woman by Juliette Lewis was obvious and I got that one right every time. The difference was quite noticeable in the vocals especially near the beginning. The clip Beautiful Love by Sophie Milman was less noticeable, but I still got that one correct around 75% of the time. The last clip, Barrio San Miguel by Gino d'Auri was a toss. I couldn't tell the difference between the two encodings at all on that song.

I never claimed that all songs or recordings would show audible differences between a low bitrate MP3 and a higher bitrate MP3 or lossless. Some can certainly encode well enough to be inaudible, and others can show small to drastic differences. To my ears, songs with heavy use of cymbals and classical music show show the most deficiencies in low bitrate MP3s. Also, certain types of vocals can be quite noticeable.

This is always the way it goes, you guys claim to hear the difference between amps, bit rates, cables, extension cords and everything else like night and day, but can never show that you can in an objective test. Then when you dont, all of a sudden the differences are extremely subtle and it takes time to pick them out. If there is a difference and its noticeable, you should be able to pick it out 10 out of 10 times. I guarantee I could tell the difference between an amp running 6db of bass boost and one the wasnt and Id get it right every time.

BeefJerky

MacLeod wrote: »

Feel free to not click on this thread at anytime. This is a discussion forum and we're having a discussion.

This. And I think our discussion has been quite civil, despite our disagreements.

I disagree that a higher powered amp will make more noise at low volumes. Even if its true, its still well beyond the audible level. Ive heard several systems running 350+ watts PER DRIVER :eek: and theyre as quiet as the wind driven snow.

I think it depends on the particular amp and how well designed they are. For example, the original Alpine PDX series amps had a high noise floor that was noticeable by many. Other than that they were decent amps, but that was a real drawback. Unfortunately, Alpine never updated the 5-channel PDX amp with their refresh, so that one still has the same noise issue. This is sad, and took it out of my consideration when I was looking for a 5 channel amp.

To clarify my thoughts, moving from a high quality lower wattage amp to a high quality higher wattage amp should absolutely be better in terms of sound quality, especially at higher volumes. However, going from a high quality low wattage amp to a mid quality high wattage amp might not be better. And when I say mid quality, I'm still referring to a decent quality name brand, and not some crap flea market amp. All I'm saying is throwing more watts at a system isn't always going to be better. It certainly can be, but there are exceptions.

Primus wont need quite as much to get loud, at least not in the mids and highs. The higher treble of the guitars and such dont require big power.

To some extent, it will depend on where your crossover is set between your mids and sub. The lower it is set, the more power the mids will need for Les's awesome bass guitar.

Less Claypool's genius comes thru no matter what the volume.

Agreed! I didn't start listening to them until recently. They are very different, and take some getting used to; and, it's probably not for everybody. However, it really is genius, and can be downright amazing to listen to.

Im with you on this. I think there is a point of overkill where there is no return on investment. Generally 100-150 watts per driver on the mids and highs (Im talking car not home audio) is the most you need. Like Ive said, Ive heard some massively powered systems and the extra power doesnt separate them from the ones running 150 watts.

Agreed.

Im with ya here too. Im not saying you have to have a 5,000 watt amp, just like you dont have to have a car that makes 400 horsepower. But that extra horsepower will come in handy when you want to have a little fun. Same with the extra wattage. I mean hell, Im only running 400 watts to my sub and 90 to each driver and thats for SQ competition on a national level! Like I said way earlier, there is a point of common sense and me saying more power is good doesnt equate to me saying put 5000 watts on a tweeter.

I pretty much agree with your car analogy. My CR-V only has 180hp, but it does what I need it to. And, Honda's V-TEC really is amazing when it kicks in. However, I think the 400 extra HP would be more useful than the extra unused wattage; it would also be a helluva lot more fun! I'd love to get a Porsche Cayenne Turbo S. 450 HP under the hood of an SUV would be awesome. However, I would probably get myself in trouble doing stupid things with it, and I'd be spending a lot more on gas, so I'm probably better off without it.

Its as transparent as it can be. You are more than welcome to inspect the entire test setup for as long as you want. He hides nothing. You have 2 amps, both of your choosing and then you have a ABX switcher. You listen to amp A, then to B then to X and you have to say which one X is. Nobody guess right more than 50% of the time which like the MP3 test, is the same result as flipping a coin. It works just like that MP3 test. Blind ABX testing is the only objective and scientific way to test if you truly can hear a difference between product A and product B.

Okay, maybe I need to look into his stuff some more when I have time.

This is always the way it goes, you guys claim to hear the difference between amps, bit rates, cables, extension cords and everything else like night and day, but can never show that you can in an objective test. Then when you dont, all of a sudden the differences are extremely subtle and it takes time to pick them out. If there is a difference and its noticeable, you should be able to pick it out 10 out of 10 times. I guarantee I could tell the difference between an amp running 6db of bass boost and one the wasnt and Id get it right every time.

I don't think I ever claimed that all music would make for a night and day difference when comparing MP3 to lossless (or low to high bitrate MP3). At least I never intended to. I can't speak for all people who make claims about MP3, but the ones I know hold the same beliefs I do; which is that it varies with different types of music. Some types of music show very noticeable MP3 artifacts (even at 320kbps), some show mild artifacts, and some may show no audible difference. As I mentioned regarding your test site, one clip I was able to ID 100% of the time, one 80% and one not at all. That just serves to emphasize my point that MP3 reacts differently depending on the source material.

As for cables, it seems to be a hot subject around here. I've never been able to hear a bit of difference between any properly designed cables. Or, in the case of speaker cables, ones that are of adequate gauge. I use a variety of decent quality interconnects and they all sound the same to me. I use low-voltage lighting cable with monoprice banana plugs on them for my speakers, and those sound the same to me as those high dollar cables that others swear by. I also use generic interconnects and speaker cable in my car system, and it does the job just fine.

All that being said, I'm not going to claim that there is absolutely no difference between them and that others are wrong in what they hear. Maybe their ears are better than mine. However, I consider that a blessing since it saves me money. :biggrin:

Also, note that I am only referring to analog interconnects above. Digital interconnects don't make an audible difference as long as they are put together right. Digital is digital, and it either works or it doesn't. A digital cable cannot in any way affect frequency response, noise or "sound signature."

As for ID'ing a 6dB bass boost, I have no doubt that you could do so reliably. However, I'm sure I could too, as I despise any sort of artificial bass boost in music.

BeefJerky

DSkip wrote: »

Not that my opinion matters much but I enjoyed the last 2 posts. I just didn't want to see it turn into a pissing match. That appeared to be the direction it was heading from this end.

No problem DSkip, thanks for that. Honestly, MacLeod and I seem to be keeping it civil, regardless of our differing opinions. However, Arun1963 seems to be attempting to take the discussion towards a less civil route, and I let him get to me in my last reply to him. Your post has brought that to my attention, and I will not let it go down that route any further.

I've heard subtle differences in cables but not enough to justify big $. Since getting a tube amp I've been somewhat perplexed by the idea of why it sounds different. Since so much DSP is used in Car Audio, I'm curious if it boils down more to tonal qualities of an amp and if those can be replicated with some DSP. I tend to be quiet on these topics now because I'm straddling the fence and can't really "investigate" with my own ears since my camaro is parked w/ a dead battery.

That is a good question, and one that I don't really have any specific knowledge of. I do, however, have some guesses and speculations. As you mentioned, frequency response tends to be less flat on a tube amp. However, I also believe it has to do with how they respond when driven near or past their limit. Unlike solid state, they don't hard clip, which gives them a very different sound near and at their limit.

I also get curious about the image separation of the HK 240 amp vs. the tube amp. The HK is definitely brighter, which could (?) explain the difference in detail. I want to believe that it all boils down to the FR of each processor/amp and how each range plays w/ our ears, but I'm too ignorant to back anything up.

I actually wouldn't be surprised if the greater brightness played a part in the image separation that you hear. The higher the frequency, the more directional the sound is. This is, of course, why subwoofers placed elsewhere in the room can blend with the other speakers.

I imagine that if you could bump up the highs coming from the tube amp, you might hear greater image separation as well. In fact, you could probably try that with an EQ in line before the tube amp. Or, try lowering the level of the highs coming from the HK and see what it does. However, it may also have to do with how the tube amp is designed, and whether there are any interactions between the two channels versus the solid state design. These tests might also affect the detail/crispness that you mention.

As for detail, I tend to equate that more with the higher frequencies. I don't really think that's correct, but it just seems natural for me. I realize that I would also miss detail if the mids were muddy.

I'm sure that has been covered by someone before. If it does, it'd be easy to see why, with extensive DSP, you could get any similarly rated amp to sound like anyother.

I'd LOVE to get the "body" out of the music in my car that I get with the tubes and pair that with the crispness and detail that is already there.

Hmmm, but based on my pure speculation above, you may not be able to get the "body" without losing the crispness/detail and image separation since you would likely be sacrificing the highs. I actually encourage you to try one of the tests I mentioned above and let us know what the results are. I think that could be very interesting.

arun1963

The basic idea in car audio is, to recreate the experience and impact of what you would hear from a decent 2ch setup. The experience and impact are a sum of stuff like tonality, imaging, staging, balance etc. Now, these are subjective variables. Since one can't quantify or measure these attributes/effects, maybe you can measure the cause. The FR of the speaker at driver level.

Suppose we were to measure the frequency response of that 2ch speaker 1" from the speaker and then again at your ear level at the sweet spot, where youre sitting. You would get two sets of FR graphs fairly simmilar to each other. If you have a RTA app on your laptop or phone, do the measurements and see what you come up with.

In a car, this is how a 6.5" driver measures 1" from the cone and this is what you hear at ear level. Of course different drivers will have different speaker level responses, but they will all get crapped up to the same extent. The ear level response in a car factors in the cancellations, summations, reflections of a crappy near field environment. What is not factored in is stuff like arrival times, axis response etc. These readings are for one side the ear level response for the far side speaker would be equally crappy but different due to differences in L/R response. So the primary concern in a car is to get the ear level response close to driver level and then tweak a bit to get the balance, tonality, imaging, staging and impact. DSP, managing reflections and driver placement and angling are critical in a car.

You don't have to deal with any of this crap in a home 2ch cause you're listening in a far field and much less intrusive environment. This is why car audio is 95% different frome home audio. You're not going to hit the similarities, till you're well into sorting out the the ear level FR.

Can you hear the difference between a 0.4% and 0.8% THD of your amp, in this mess? Will you hear a difference between class A/B and D?

Some other points that were raised:

1. I really could not care less if you think I started the flaming. Fact is that beefjerky introduced the typical 2ch snob variable 'I can hear the difference', which by extension means 'my hearing is better than yours'. Thats crap at least as far as car audio goes. I hope my explanation above is proof of that. Don't argue about stuff you have no clue about and you'll keep it objective and civil. Notice the plural.

2. I have yet to hear any 320kbps burnt cd that didn't sound like crap. Lossless is at par with cd's. The focal tuning disks are in lossless AAC format and they are brilliantly recorded and sound better than 90 % of my cd's.

3. The HK 240 is brighter than the tube amp cause all tube amps roll off the highs from about 12khz on. SS amps don't. The SS amp could also have a built in smiley curve, which would further accentuate the highs.

Vital

Maybe I'm simply stuck in the "old era" where mono subs were producing too much distortion to power anything but a subwoofer but here's a question - with these new class D amps can I use mono amps to power speakers/tweeter?

Of course I'm not looking to put 1,000 rms on a tweeter but for the sake of argument and my general understanding of this subject - will the sound/distortion level of new class D mono amps be good enough for a tweeter?