New Polk Ultra Compact Amps (Class D Fullrange)

arun1963

Yes they will as long as your gains are set properly.

You're right that one will hear the amp clipping / distotortion in the upper mids and highs, not at the lower end.

BeefJerky

arun1963 wrote: »

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.

I agree with all this.

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.

I agree that they have differences, and car audio is harder to get right. I never denied that. However, I still disagree with your "95%" figure. The basics are still exactly the same between the two, however, the car audio side requires more advanced work past the basics. I'd put it closer to 40% different. However, I think this is more of an opinion, and as such I suggest we agree to disagree on this.

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?

Once an amp starts to get over 0.5% THD, longer listening sessions become less tolerable. As such, something in my body is clearly noticing the difference. As to whether you consider that "hearing a difference," I don't know. As for the difference between a class-AB and class-D amp, it will depend on the THD for the specific amps. However, class-D amps generally have a higher rated THD than their class-AB counterparts, though the gap seems to be narrowing as time goes on. This a good thing, and I think that class-D is where the future is headed. I just think there is still further improvement to be seen in the technology before it can really replace class-AB amps.

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.

I apologize if I came off in a snobbish manner, as that was never my intention. I've been known to have strong viewpoints and tend to express them in a very blunt manner. They aren't intended to come off in a rude way, however, I understand why they may be taken that way sometimes. I hope we can move on and continue to have a civil discussion.

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.

In understand where you are coming from on this. Not only are different people more or less sensitive to these artifacts, but lossy codecs respond differently to different material.

This just shows the range of hearing in different people. You are clearly very sensitive and can hear artifacts very easily even at higher bitrates. On the other hand, I have some friends who can't hear them at all. I'm somewhere in the middle, in that it depends on the particular bitrate as well as the source material as to whether I will hear artifacts.

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.

Sounds right to me. I have no experience with tube amps aside from what I've read around the internet.

MacLeod

We're getting back to this THD misconception again. THD is not a static measurement and to say one amp has higher distortion than another based on it is wrong.

To go back to our automotive analogy, its the same as RPM's. Saying car A makes 300 horsepower at 2500 RPM's and car B makes 350 horsepower at 4500 RPM's is the same as saying amp A makes 300 watts at .5% THD and amp B makes 350 watts at 1% THD. To say that amp B is a lesser amp because it makes 1% THD is the same as saying car B is the lesser car because it makes more RPM's. THD is simply a measurement of how hard an amp is being pushed at that particular power rating not how much it makes all the time.

Also, there is not only any way you can hear when an amp is at .5% THD but there is also no way you can tell it because its fluid and will increase and decrease with the demands and intensity of the music. Its like saying "I can tell when my car is making 300 horsepower and when its making 325".

arun1963

The difference between speaker level response and ear level is NOT the same as THD. It is merely the affect of the environment. In real terms things like THD+N, slew rates, damping factor etc are all fairly irrelevant in a car. Why? because most decent brands would have these numbers at a level where the values are beyond the threshold of your hearing, in a car.

Although I like Mac's analogy on the car hp.

arun1963

BeefJerky wrote: »

I agree with all this.

Good at least we are beginning to agree on some things.

BeefJerky wrote: »

I agree that they have differences, and car audio is harder to get right. I never denied that. However, I still disagree with your "95%" figure. The basics are still exactly the same between the two, however, the car audio side requires more advanced work past the basics. I'd put it closer to 40% different. However, I think this is more of an opinion, and as such I suggest we agree to disagree on this.

Agree to disagree. BTW what would you count as 60% similarities?

BeefJerky wrote: »

Once an amp starts to get over 0.5% THD, longer listening sessions become less tolerable. As such, something in my body is clearly noticing the difference. As to whether you consider that "hearing a difference," I don't know. As for the difference between a class-AB and class-D amp, it will depend on the THD for the specific amps. However, class-D amps generally have a higher rated THD than their class-AB counterparts, though the gap seems to be narrowing as time goes on. This a good thing, and I think that class-D is where the future is headed. I just think there is still further improvement to be seen in the technology before it can really replace class-AB amps.

In a car which has a much higher noise floor than a 2ch room, you are not going to hear the effects of THD below say 0.7-8%. Even if you have bat ears. You may hear it in a room but I don't know for sure, since my amp at home is way below that figure.

BeefJerky wrote: »

I apologize if I came off in a snobbish manner, as that was never my intention. I've been known to have strong viewpoints and tend to express them in a very blunt manner. They aren't intended to come off in a rude way, however, I understand why they may be taken that way sometimes. I hope we can move on and continue to have a civil discussion.

Done and dusted. Let's move on.

BeefJerky wrote: »

In understand where you are coming from on this. Not only are different people more or less sensitive to these artifacts, but lossy codecs respond differently to different material.

This just shows the range of hearing in different people. You are clearly very sensitive and can hear artifacts very easily even at higher bitrates. On the other hand, I have some friends who can't hear them at all. I'm somewhere in the middle, in that it depends on the particular bitrate as well as the source material as to whether I will hear artifacts.

When you're compressing the original file to 320kbps you will lose a ton of dynamics that were there on the cd. This loss of dynamics is what will make the burnt version sound sound hollow and just not right. The difference is night and day IF the original recording is not too hot and has good dynamics. I've tried this with some well recorded cd's Floyd / Doors / Led Zep / Fleetwood Mac etc and there is a big difference. Now if the original recording was real hot and recorded well into clipping (my daughters Miley Cyrus cd ) you may not hear a significant difference. I haven't tried this so I'm not going to comment one way or the other.

BeefJerky wrote: »

Sounds right to me. I have no experience with tube amps aside from what I've read around the internet.

Even in a car if you cut down a bit at 12-20khz it will make the lower end more prominent hence that 'warmer' sound of tubes.

arun1963

Ok here's my summation to this thread.

There have been and will be multiple threads on THD in a system. So lets break this distortion down. In any sound chain, (home or car) there are three variables that affect total distortion level.

1. Your source/amps/cables
2. Your speakers
3. Your environment.

In home audio the weightage is as follows:

1. Speakers - 70%
2. Environment - 20%
3. Amps/cables/source - 10%

In a car:

1. Environment - 80%
2. Speakers - 15%
3. Amps/source/cables - 5%

KaosTsoc

All I can say about this thread is WOW... What a mouthful. However very informative, and well.. gives good advice/information for any of us who have a hard time understanding how it all works (like my self). Good job guys...


Thanks.

alienagneda

Hey, I was just wondering if I should buy those new PA D amps vs the older PA amps? :eek:

good read and I am buying the PA D's. I fear I am paying more for just a smaller package though.

MacLeod

Cant go wrong with either bro.

Now just make sure you dont buy those stupid expensive cables. {runs and hides} :biggrin:

BeefJerky

MacLeod wrote: »

We're getting back to this THD misconception again. THD is not a static measurement and to say one amp has higher distortion than another based on it is wrong.

To go back to our automotive analogy, its the same as RPM's. Saying car A makes 300 horsepower at 2500 RPM's and car B makes 350 horsepower at 4500 RPM's is the same as saying amp A makes 300 watts at .5% THD and amp B makes 350 watts at 1% THD. To say that amp B is a lesser amp because it makes 1% THD is the same as saying car B is the lesser car because it makes more RPM's. THD is simply a measurement of how hard an amp is being pushed at that particular power rating not how much it makes all the time.

Agreed. However, the reality is that an amp with a higher relative THD at full rated power is likely to have a higher relative THD at lower power as well. It's certainly not going to be linear, but more along the lines of a logarithmic curve.

Also, there is not only any way you can hear when an amp is at .5% THD but there is also no way you can tell it because its fluid and will increase and decrease with the demands and intensity of the music. Its like saying "I can tell when my car is making 300 horsepower and when its making 325".

I find it interesting how you claim that no one can hear .5% THD as if it is fact. Besides the fact that everyone's hearing is different, I've seen no hard data to say that no one can detect it. To put it another way, maybe you can explain why my ears hurt under longer listening sessions (at moderate volume levels) with an amp with a rated THD around 0.5% (or higher) at full rated power. I'd be very curious to hear your explanation of that.

arun1963 wrote: »

Good at least we are beginning to agree on some things.

:biggrin:

Agree to disagree. BTW what would you count as 60% similarities?

The basics: wiring, source and amp setup, crossover design/setup and basic speaker setup. It is the more advanced things that set it apart: speaker placement, eliminating resonances and advanced EQ tuning (if need be).

Don't get me wrong, I absolutely respect those who are able to tune a car audio system to the max. It takes a lot of knowledge and experience to do so.

In a car which has a much higher noise floor than a 2ch room, you are not going to hear the effects of THD below say 0.7-8%. Even if you have bat ears. You may hear it in a room but I don't know for sure, since my amp at home is way below that figure.

I think you do have a valid point here, since there will always be more background noise in a car versus a home setup. However, I don't believe you can make it a set number as to what someone would be able to hear in terms of THD. One big variable is how quiet the particular car is.

In addition you need to factor in how long the person generally spends in the car during their travels. Also, it will depend on how loud the person is likely to play their music. The longer the time spent listening and the louder the system is played, the more likely the person will be able to detect a certain level of THD.

For example, my car is a CR-V, which is not a particularly quiet car. My Kenwood class-D amp is rated for 1% THD, and I have not been bothered by it. However, I generally only drive distances around 30-45 minutes at a time and listen at moderate volumes.

On the other hand, if it was in an extremely quiet car (think along the lines of Mercedes), the situation might be different due the lower noise floor. It might also be different if I blasted it and/or took a road trip.

Done and dusted. Let's move on.

Sounds good to me.

When you're compressing the original file to 320kbps you will lose a ton of dynamics that were there on the cd. This loss of dynamics is what will make the burnt version sound sound hollow and just not right. The difference is night and day IF the original recording is not too hot and has good dynamics. I've tried this with some well recorded cd's Floyd / Doors / Led Zep / Fleetwood Mac etc and there is a big difference. Now if the original recording was real hot and recorded well into clipping (my daughters Miley Cyrus cd ) you may not hear a significant difference. I haven't tried this so I'm not going to comment one way or the other.

I agree with all this. A lot of newer music falls under this category of being recorded highly compressed and at the loudest volume possible. This sucks, but that is for another discussion. At any rate, that is part of the reason I can detect it more on something like classical music. That kind of music tends to be very dynamic. Also certain instruments seem to artifact easier, such as cymbals.

arun1963 wrote: »

Ok here's my summation to this thread.

There have been and will be multiple threads on THD in a system. So lets break this distortion down. In any sound chain, (home or car) there are three variables that affect total distortion level.

1. Your source/amps/cables
2. Your speakers
3. Your environment.

In home audio the weightage is as follows:

1. Speakers - 70%
2. Environment - 20%
3. Amps/cables/source - 10%

In a car:

1. Environment - 80%
2. Speakers - 15%
3. Amps/source/cables - 5%

I would change 1 and 2 in the car to 60% and 35% respectively. However, that is just my opinion and I certainly respect yours.

MacLeod

I find it interesting how you claim that no one can hear .5% THD as if it is fact. Besides the fact that everyone's hearing is different, I've seen no hard data to say that no one can detect it. To put it another way, maybe you can explain why my ears hurt under longer listening sessions (at moderate volume levels) with an amp with a rated THD around 0.5% (or higher) at full rated power. I'd be very curious to hear your explanation of that.

Id be glad to but you're not gonna like it. Its your imagination.

For one, distortion isn't an ear screeching scream that would hurt your ears. Its simply a distortion of the signal and since its the lower frequencies that draw more power, it'll be those that distort the most. A distorted kick drum isn't going to last very long nor would it hurt your ears.

Second, the THD is going to rise and fall with the intensity of the music so its going to range from .005% to 1% all the time. It work be very hard for it to maintain over 1% for a period long enough to make your ears hurt unless you were listening to a continuous test tone.

Third, yeah everybody's hearing is different but most people can't hear above 18K Hz but some can hear up to 20K maybe. But .5% is half the amount of the audible distortion level so that would be the same as being able to hear 40K Hz which is ridiculous.

Fourth, like I said, THD is going to rise and fall just like the horsepower or a car. You can't tell when your care is making 300 and then 325.

BeefJerky

MacLeod wrote: »

Id be glad to but you're not gonna like it. Its your imagination.

I'd be more inclined to believe that if I always knew the THD of an amp prior to listening to it. However, I have experienced cases of having listener fatigue (or not having it) without knowing the specs of an amp. I only asked and found out after listening.

For one, distortion isn't an ear screeching scream that would hurt your ears.

Of course it's not. That's why it happens during longer listening sessions rather than short ones.

Its simply a distortion of the signal and since its the lower frequencies that draw more power, it'll be those that distort the most. A distorted kick drum isn't going to last very long nor would it hurt your ears.

It is correct that lower frequencies will produce more distortion, but unless your amp is clipping, its THD is irrelevant. Studies show that it takes ~100% THD for most listeners to hear it in the lower frequencies. It is the THD in the higher frequencies that we are sensitive to. Even if that THD is relatively lower, we will still be more sensitive to it, and more likely to be affected by it. As such, the length of the kick drum is irrelevant.

Second, the THD is going to rise and fall with the intensity of the music so its going to range from .005% to 1% all the time. It work be very hard for it to maintain over 1% for a period long enough to make your ears hurt unless you were listening to a continuous test tone.

Indeed it does constantly change during music. However, just like many stimuli to the human body (including pain), it is cumulative. Take for example, the Chinese water torture, or someone repeatedly poking you in the arm. It doesn't hurt or bother you at first, but it will after a longer session of it. It is the same in regards to THD and your ears.

It is also similar to how there are different recommended maximum sound exposure levels based on length of time exposed to it. You may be able to tolerate a certain amount of decibels for 30 minutes, but if you increase it you won't be able to tolerate it for as long.

Third, yeah everybody's hearing is different but most people can't hear above 18K Hz but some can hear up to 20K maybe. But .5% is half the amount of the audible distortion level so that would be the same as being able to hear 40K Hz which is ridiculous.

I'm pretty sure that math is incorrect. Frequency is not linear in regards to human hearing. It is closer to a logarithmic scale, but even that is not exact. There are actually a couple of specific scales that were created based on scientific data that are more accurate.

As for the THD, I'm quite sure that it is not a linear scale either in regards to human hearing.

Either way, I don't think this math is even close to being accurate.

Fourth, like I said, THD is going to rise and fall just like the horsepower or a car. You can't tell when your care is making 300 and then 325.

It depends on what you are doing with the car. If you are racing, pulling a heavy load, or simply trying to pass someone, that 25 HP can certainly make a difference.

arun1963

give me 10 mts to wolf down my dinner.......

MacLeod

BeefJerky wrote: »

I'd be more inclined to believe that if I always knew the THD of an amp prior to listening to it. However, I have experienced cases of having listener fatigue (or not having it) without knowing the specs of an amp. I only asked and found out after listening.

What specs would those be? I dont understand why you dont get this. One amp being rated at .5% THD and another being rated at 1% THD doesn't tell you which is the cleanest. All it tells you is that they'll both make 100 watts, just that one makes it a little easier. The cleanest amp in the world could be rated at 1% THD. All amps will make .5% THD at some point. Its like a car rated at 300 horsepower at 2000 RPM'S doesn't mean it wont do 4000 RPM's. Plus ratings aren't that reliable as there isn't a set way to rate each spec from brand to brand. One brands 100 watts could be a lot different from another brands 100 watts.

Ito is correct that lower frequencies will produce more distortion, but unless your amp is clipping, its THD is irrelevant. Studies show that it takes ~100% THD for most listeners to hear it in the lower frequencies. It is the THD in the higher frequencies that we are sensitive to. Even if that THD is relatively lower, we will still be more sensitive to it, and more likely to be affected by it. As such, the length of the kick drum is irrelevant.

What?! You can hear distortion of .5 but studies show it has to be 100% to hear? Which studies? That would be an interesting read

It takes far less power to reproduce high frequencies so for them to be demanding enough to push an amp into audible distortion would be so loud that the distortion wouldnt matter cause your ears would be bleeding already from the volume.

Indeed it does constantly change during music. However, just like many stimuli to the human body (including pain), it is cumulative. Take for example, the Chinese water torture, or someone repeatedly poking you in the arm. It doesn't hurt or bother you at first, but it will after a longer session of it. It is the same in regards to THD and your ears.

It is also similar to how there are different recommended maximum sound exposure levels based on length of time exposed to it. You may be able to tolerate a certain amount of decibels for 30 minutes, but if you increase it you won't be able to tolerate it for as long.

If your amp is hitting audible distortion enough that its hurting your ears, you're in a desperate need for a new amp. A car audio head unit has enough power to play any music at a decent level without getting into audible distortion.

I'm pretty sure that math is incorrect.

I'm pretty sure its not too. It was an analogy/example and not meant to be a statement of scientific fact. My point was that you hearing half the level of distortion that is widely considered inaudible is akin to hearing frequencies twice as high as what is widely considered as inaudible

arun1963

?The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.?

Alvin Toffler.

Before you get all twisted out of shape, this quote is NOT meant to run you down. If you've read Toffler, the quote above is based on his point of view that everytime there is a pardigm shift in the environment, rules, accepted norms etc, one has to unlearn and re-learn. Your statement that that home audio and car audio are 65% simmilar prevents you from unlearning and re-learning. Look at the big picture son, you're thinking about car audio with your feet firmly rooted in 2ch home.

BeefJerky wrote: »

I find it interesting how you claim that no one can hear .5% THD as if it is fact. Besides the fact that everyone's hearing is different, I've seen no hard data to say that no one can detect it. To put it another way, maybe you can explain why my ears hurt under longer listening sessions (at moderate volume levels) with an amp with a rated THD around 0.5% (or higher) at full rated power. I'd be very curious to hear your explanation of that.

:biggrin:

BeefJerky wrote: »

The basics: wiring, source and amp setup, crossover design/setup and basic speaker setup. .

Ok that's about 2%.

BeefJerky wrote: »

Don't get me wrong, I absolutely respect those who are able to tune a car audio system to the max. It takes a lot of knowledge and experience to do so..

ummm ok

BeefJerky wrote: »

However, I don't believe you can make it a set number as to what someone would be able to hear in terms of THD. One big variable is how quiet the particular car is. ..

Wrong. You can have a car quiet as a doormouse and you would have only eliminated about 20% of the impact of your environment. A quiet car will do zilch for removing reflection, arrival times, axis response etc.

I

BeefJerky wrote: »

In addition you need to factor in how long the person generally spends in the car during their travels. Also, it will depend on how loud the person is likely to play their music. The longer the time spent listening and the louder the system is played, the more likely the person will be able to detect a certain level of THD...

Wrong again. I spend 4+ hours on a daily basis in the car. The volume knob on my hu maxes out at 64. I normally have the volume at 52 with 0 fatigue factor.

BeefJerky wrote: »

I would change 1 and 2 in the car to 60% and 35% respectively. However, that is just my opinion and I certainly respect yours.

Please trust me you do not know what applies in car audio.

BeefJerky wrote: »

I'd be more inclined to believe that if I always knew the THD of an amp prior to listening to it. However, I have experienced cases of having listener fatigue (or not having it) without knowing the specs of an amp. I only asked and found out after listening..

Can you give a link to your amp? Just curious how a decent car amp can be rated at 1% THD. My Genesis are rated at 0.1% THD+N. Don't think the kennys can be at 1%. Plus like Mac mentioned THD depends on the power being drawn from your amps.

arun1963

If you have listening fatigue in a car, chances are the 1-5khz range is too hot in your car.

MacLeod

Very true. With all the glass and hard surfaces causing wicked reflections, you can easily get listening fatigue in a car if its not set up right.

BeefJerky

MacLeod wrote: »

What specs would those be? I dont understand why you dont get this. One amp being rated at .5% THD and another being rated at 1% THD doesn't tell you which is the cleanest. All it tells you is that they'll both make 100 watts, just that one makes it a little easier. The cleanest amp in the world could be rated at 1% THD. All amps will make .5% THD at some point. Its like a car rated at 300 horsepower at 2000 RPM'S doesn't mean it wont do 4000 RPM's. Plus ratings aren't that reliable as there isn't a set way to rate each spec from brand to brand. One brands 100 watts could be a lot different from another brands 100 watts.

I agree that all ratings are not measured the same, especially when it comes to lower-class brands. However, I'm at least somewhat more trusting of the ratings when it comes to respected manufacturers. As for your claim that THD depends on the loudness and material, I've already agreed with that, so I'm not sure why you continue to try and push that point.

What?! You can hear distortion of .5 but studies show it has to be 100% to hear? Which studies? That would be an interesting read

Okay, it seems you didn't actually read what I typed here. The amount of distortion necessary to be audible depends on frequency. That 100% figure is based on the lower frequencies (~40hz). However, the mids and highs require much less distortion in order to be audible. For example, it is generally over 8kHz before 1% THD is noticeable. The level of THD necessary will continue to drop as the frequency rises. In addition, it depends on the type of harmonic distortion (even/odd/both) in regards to how offensive it is.

Here's the study that I was referring to:
http://www.axiomaudio.com/distortion.html

It takes far less power to reproduce high frequencies so for them to be demanding enough to push an amp into audible distortion would be so loud that the distortion wouldnt matter cause your ears would be bleeding already from the volume.

Right, but since less distortion is necessary at higher frequencies to be audible, it doesn't really work out like that.

If your amp is hitting audible distortion enough that its hurting your ears, you're in a desperate need for a new amp. A car audio head unit has enough power to play any music at a decent level without getting into audible distortion.

Actually, I never claimed that my car amp hurt my ears or bothered me in any way. When I ran them off the head unit, I had issues with moderate to high volumes. However, with the amp I have no issues.

I'm pretty sure its not too. It was an analogy/example and not meant to be a statement of scientific fact. My point was that you hearing half the level of distortion that is widely considered inaudible is akin to hearing frequencies twice as high as what is widely considered as inaudible

Except that since neither are a linear scale the half level thing isn't even close to accurate. In fact, I'd go so far as to say that it is downright misleading.

arun1963 wrote: »

Alvin Toffler.

Before you get all twisted out of shape, this quote is NOT meant to run you down. If you've read Toffler, the quote above is based on his point of view that everytime there is a pardigm shift in the environment, rules, accepted norms etc, one has to unlearn and re-learn. Your statement that that home audio and car audio are 65% simmilar prevents you from unlearning and re-learning. Look at the big picture son, you're thinking about car audio with your feet firmly rooted in 2ch home.

I'm not offended, and I can understand where you are coming from. In fact, I like the quote.

Ok that's about 2%.

Okay, I think that is where we differ. I consider the basics to be a fairly big part, because without them there would be no home audio or car audio. Not to mention, a good knowledge of the basics will help out with the more advanced stuff in my opinion.

ummm ok

Well, I do. :biggrin:

Wrong. You can have a car quiet as a doormouse and you would have only eliminated about 20% of the impact of your environment. A quiet car will do zilch for removing reflection, arrival times, axis response etc.

Wrong again. I spend 4+ hours on a daily basis in the car. The volume knob on my hu maxes out at 64. I normally have the volume at 52 with 0 fatigue factor.

I agree that there is more to it then the three things I mentioned. However, I believe that they are three important variables. As for reflections/timing/axis response, I suspect (and correct me if I'm wrong) that due to the way a car has to be laid out, they are all pretty similar in terms of how much they affect the sound, regardless of the car. In other words, I suspect that choice of speaker placement affects those more than the design of the car or a person's habits. The three I mentioned are directly affected by the design of the car and person's habits.

Please trust me you do not know what applies in car audio.

I think you assume that I have zero car audio experience. I won't claim I'm a professional, but I'm not a newbie either.

Can you give a link to your amp? Just curious how a decent car amp can be rated at 1% THD. My Genesis are rated at 0.1% THD+N. Don't think the kennys can be at 1%. Plus like Mac mentioned THD depends on the power being drawn from your amps.

http://www.kenwoodusa.com/Car_Entertainment/Amplifiers/XR-5S

arun1963 wrote: »

If you have listening fatigue in a car, chances are the 1-5khz range is too hot in your car.

MacLeod wrote: »

Very true. With all the glass and hard surfaces causing wicked reflections, you can easily get listening fatigue in a car if its not set up right.

As stated above, I do not have issues with listening fatigue in my car audio system.

MacLeod

My ADD is kicking in cause these posts are getting too long and to be honest Im not really sure what we're arguing about anymore so:

I'm right and you're wrong.

:biggrin:

BeefJerky

MacLeod wrote: »

My ADD is kicking in cause these posts are getting too long and to be honest Im not really sure what we're arguing about anymore so:

I'm right and you're wrong.

:biggrin:

Actually, none of us are winners in this discussion. My cat (pictured below) is the actual winner. Why? We have no right to question why. Because he is a cat, and we as humans are merely minions in The Great Plan. He sees all and knows all, and he has great contempt for those who are insolent enough to question The Great Plan.


(Yes, he is watching me as I type this...oh crap! Claws! Claws!)

[Deleted User]

I believe the question is really are the "New" PAD amps better than the "Old" PA amps. The truth is they are completely different amps. There is nothing wrong with the PA amps. The PADs are indeed a smaller package. I Beta tested the PAD1000.1. I have not had ANY problems at all. They actually measure more output wattage than stated. if space is your concern go with PAD. I personally prefer the PAD line. That's my 2 cents

MacLeod

Always nice when an engineer agrees with me. :biggrin:

But yes, the PA amps are great amps as (shameless self promotion) I've proven in the competition lanes. The new D amps are an improvement because they're smaller, more efficient and a little more powerful. Can't go wrong with either.

The Carbon series are still my favorite though. One of the best looking amps ever.

Cool cat by the way.

BeefJerky

MacLeod wrote: »

Always nice when an engineer agrees with me. :biggrin:

But yes, the PA amps are great amps as (shameless self promotion) I've proven in the competition lanes. The new D amps are an improvement because they're smaller, more efficient and a little more powerful. Can't go wrong with either.

The Carbon series are still my favorite though. One of the best looking amps ever.

I am genuinely interested to see just how these new Polk PAD series amps compare to the more established class-D amps, such as the Alpine PDX, Kenwood XR and JL Audio XD/HD series amps.

Cool cat by the way.

Thanks. I passed the word on to him, and he seems to have slightly less contempt for the human species. Wait...nevermind...:cool: LOL!

arun1963

A question, your amp puts out 1% THD+N. You can hear the effects of 0.5%. So you must really hate your amp, when you turn it up for extended periods. Yet you claim that you have no listening fatigue in your car......lol

BeefJerky

arun1963 wrote: »

A question, your amp puts out 1% THD+N. You can hear the effects of 0.5%.

Sure, I can...in a home environment (or in a very quiet car environment). However, as you stated, a car environment has a higher noise floor that can help to mask some of that. You are absolutely right on that.

So you must really hate your amp, when you turn it up for extended periods. Yet you claim that you have no listening fatigue in your car......lol

I do not hate my amp, but if I did, I would have already replaced it. It probably helps that I don't tend to listen loudly in my car, so it's rarely being pushed. I will occasionally turn it up for a particular song, but that's about it. In addition, my car (08 CR-V) is not a quiet car. However, if I were to move to a quieter car (or get significant noise reduction work done on my current one, which I am considering), I would likely be able to justify upgrading my amplifier. I would probably go with the JL Audio HD900.

alienagneda

Len wrote: »

I personally prefer the PAD line. That's my 2 cents

so glad you said that. i just bought 2 of the PAD amps.
bummer is i wont have these hooked up for weeks.
still fiberglassing - never never will i do that again!

sold
jbl 1200.1
diamond d4300.2
fogate 600a4
mtx 2400
and broke even on the cost for the new PAD's:biggrin:

Vital

So i've been looking for these D amps since the word on them was out. Speciafiacally for 4000.4 and 1000.1 to replace my current PA500.4 and 1200.1

Can someone tell me why 4000.4 is the only amp that is still not available? Every other amp from D series is out for sale for over a month now (if not more) but 4000.4 is nowhere to find. Why is that???