Amp for my MM6's and dB650's?

AustinKP

So I finally got my new HU and speakers installed. I got an Alpine 9815 w/ the MM6's in the front and the dB650's for the rear. I'm definitely a newbie to aftermarket car audio, but I've been following a lot of the posts in here for a few months now.

As I suspected, my HU isn't nearly powerful enough for my speakers. My MM6's can take 150W RMS and the dB650's can take 60W. I believe my HU is only good for 27W or so RMS. I'm looking for a good SQ amp that I'll normally keep at "safe" listening levels, but that I can turn way up when I'm in the mood. I guess the plan is to power the coaxials until I get a sub, then I can just bridge the rear channel for the sub, and run them off the HU again. Is that a good idea? I know that PBDodge has often recommended the Hifonics NX880 and ZX6400 for less powerful speakers. I don't know why the Zeus is a lot more expensive, but has less RMS power. I'd like to spend less than $300 for the amp, hopefully closer to $200 if I can get it online somewhere, but I realize that might not be possible.

In short, I guess I'd really like to know:
1. How much power do I need to make my MM6's sound like the quality components they are? (The coaxes are just for rear fill, and I suspect when I get some real power to my fronts, I won't even need them hardly at all for sound)
2. Staying under $300, what is the best 4 channel SQ amp I can get that puts out a decent amount of power? I don't care what the amp looks like, since I'm trying to keep this as hidden as possible. No need to advertise "Steal Me"

I really appreciate all your guys advice. This is one of my favorite forums to visit, as I can always count on solidly founded, objective advice. You guys are great. Thanks in advance

MrDHEJ

I just got done with my system, and i'm using the US AMPS TU-600 tube amp (150x2@4ohm) on a set of Polk MM6's. If your looking for SQ it's the way to go. You'll spend around $350 to $400 but your getting allot for a little more money.

The US AMPS 200x i got running a pair of MM460 plate speakers (50x2@4ohm) is another good choice for rears for $200

MacLeod

My 2 cents would be an amp Ive recommeded a few times before. A very high end amp for an awesome price.

The Phoenix Gold Tantrum 600.4 is offered at Sound Domain.com for $280 and puts out an underrated 75x4 but you can bet its more like 85-90. These are competition level amps and are worth $550+ in shops. For the money Ive not seen a better amp anywhere on the net. Im working up enough scratch to upgrade my speakers right now but if theyre still selling this baby at this price by the time I get around to upgrading amps I can assure you Ill be all over one of these!

sntnsupermen131

i normally dont help longhorns, but i guess ill make an exception
i wouldnt get a 4 channel
id get a 3 channel
run your rears off your deck
a 3 channel has 2 channels to run your front speakers, and 1 channel to run a sub
you wont use the 1 channel for a while, which is fine, its not going to hurt it at all...when i get some time ill look some up and see what i can find
-Cody
aggies are the best--just not in sports...or building fires...

AustinKP

Originally posted by sntnsupermen131
i normally dont help longhorns, but i guess ill make an exception

Now wait a minute here...who's a longhorn? I thought YOU were the one from TX? Actually, I'm from Missouri. I'm just in UT for school. In fact, right now I'm taking an electronics class, so I'm learning what all this hocus pocus really means, i.e. impedance, amps, volts, resistance. I even know how a speaker works. It's all pretty cool

So why a tube amp vs. a normal transistor(?) amp? I've heard in other posts that they have a more sterile sound? Whatever that means... Are they more fragile than a normal amp/more expensive to repair?

You think I should leave the rears alone for now? They get OK loud, but only if I turn the X-over pretty high so they don't distort on any kind of bass. I'm afraid the amped MM6's would overpower them a lot. Thanks for the responses so far...

sntnsupermen131

ok no one really makes 3 channels anymore...so here are my 4 channel choices
PPI amp
its reconditioned...ie.-90 day warranty, but its a PPI, which is an awesome amp, its 125x4 rms...which is what you need
hifonics amp
this is a new hifonics amp, great amp...i like hifonics a lot...1 yr warranty
those are my picks of the litter...
only thing...125 is a little much for those db's...so keep the gain WAY down, or just not even use 2 channels, then bridge it when you get a sub...and you can put 250 watts to it
as far as tube amps...theyre more expensive, more fragile...not sure about how hard to fix...i know jstas actually made his own
they have an AWESOME sound though
its very warm..sounds REALLY good
your fronts are SUPPOSED to over power your rears...and as far as crossing them over high...mine are crossed over at 100Hz...which is high
i have 200 watts going to my mm6's and about 80 going to my rear speakers...blends perfect
-Cody

MacLeod

You know what they do with A & M students that cant cut it?

They cut off their 2 middle fingers and send them to Austin!!!!

Thank you, Ill be here all week.

sntnsupermen131

so what youre saying is...if youre a reject with 6 fingers...you go to ut?

-Cody

MacLeod

Exactly! How do you think the "horns" thing came about? They gotta do something with their hands besides using them to count with.

Im from Tennessee, home of the real UT. Ya know, the multi-national champs UT!

sntnsupermen131

real UT or not...everyone knows Texas is better
-Cody

MacLeod

I lived in Texas for 5 years and my folks are still there so Ill always have a sweet spot for TX. Temple is my adopted home town.

sntnsupermen131

tennessee isnt that bad...after all, they are home of the former houston oilers
i could never live "up north"
too cold...
-Cody

Jstas

Originally posted by AustinKP
So why a tube amp vs. a normal transistor(?) amp? I've heard in other posts that they have a more sterile sound? Whatever that means... Are they more fragile than a normal amp/more expensive to repair?

Sterile? A tube amp? No. No way man. Tubes have a very rich and smooth sound. The do have some drawbacks like a small amount of hiss and interference. They will also cook, hotter than most solid state amps but that is the nature of a tube amp. They are far from any kind of sterile sound though.

As far as what sterile means, it's just trying to describe the indescibable. The difference between sterile and rich as I have used the terms can't be given justice by mere words. I'd have to line up two similar amps, one being a tube amp and the other being a solid state and play the exact same speakers and signal source through them for you to hear the difference. Mainly it has to do with a digital vs. analog signal, sampling rates for the digital side along with bit-rates of the D/A converter. A digital signal, eventhough the human ear cannot hear it, will have some small amount of original signal degradation due to the way the signal sine curve is constructed by the DAC. A tube amp runs an analog signal, start to finish, so it doesn't have the stepped curve of the digital signal. On cheap equipment, it's hard to hear. On moderate to high end equipment, you can clearly hear the difference.

It's like a solid state sound is comparable to sitting in a white room with a table, some chairs, a window and a door. A tube sound is like sitting in that same room but the walls are maybe tan or have paintings hung, the chairs have cushions and arms on them, the table has flowers on it, there are curtains on the window and the floor has a nice carpet on it. The room is pretty much the same but there is more to the experience.

Don't get me wrong, some people prefer solid state over tubes and that is just fine. There is a horde or excellent equipment out there in solid state form and it is mostly much less expensive than comparable tube based stuff. Tubes are just from another time. Some think it is a simpler time and maybe it was, can't say for sure. But mated with modern technology, tubes are just as clean and clear as the solid state stuff. Add to that the richness in the sound of a tube amp and for me, tubes win out over solid state.

As far as durability and expense, it's a double edged sword. The amps are initially expensive. Mainly because of volume. If Sony was churning out 500 watt 5 channel tubes amps on a daily basis you could probably pick one up for 300 bucks. But they aren't and I'm glad 'cause that amp would sound like total dog poo. The older you get with the tube technology though, the more fragile and susceptible to environmental changes it is. Modern technology has vastly improved and refined tube technology. Consequently, the more modern you get, the more durable things get. However, due to limited production of replacement tubes and such, they can be very expensive to a few dollars a tube.

I just got a Heathkit AA-32 working again and replacement tubes cost me 135 dollars. Keep in mind that tubes do wear out eventually and need to be replaced. Good thing is though, if you buy in bulk, they are cheaper. They will last a good long time in storage as long as it is a dry and clean storage to prevent contact corrosion. To me though, the benefits of a tube amp far outweigh the cost of maintenance. Hell, I'd be running the USAmps tube amps in my truck if I wasn't strapped for space. Maybe one day, I will go that route. Right now though, my 5 channel Kenwood eXcelon is doing just fine.

MrDHEJ

Jstas, i like your compairison of the tube amps... room with carpet

Did you check out my thread where i just put the US AMPS TU-600 in my 99 silverado? The sound is beautiful.

Jstas

Yes, I did see it. It is what reminded me of this thread and that I wanted to respond.

I'm almost jealous. I'd love to have tube amps in my truck but I don't have the money and room for a 4 channel and seperate sub amp let alone 2 stereo amps and a sub amp. Ah well, maybe one day when the truck gets retired to weekend duty, I'll take out the current setup (designed with every day use in mind) and redo the amps and sub. Maybe I'll have a 2nd dB104 by then too.

MacLeod

Just curious Jstas, what is your current system?

MrDHEJ

What kind of truck do you have? I fit all 3 behind the rear seat in mine.

AustinKP

Ok, so I think I figured out why you thought I was a longhorn? Is it because my name is Austin, and you thought that was my location? That whole thing still doesn't make sense to me...maybe I'm just missing something.
Man, I don't check this post for a few hours and all of a sudden I have 11 new replies. Then I read them and find that they're all about how TX is the coolest and nowhere else. And by the way, thanks for the finger offer, but it's hard enough to type with 10.

Originally posted by Jstas
Sterile? A tube amp? No. No way man. Tubes have a very rich and smooth sound. The do have some drawbacks like a small amount of hiss and interference. They will also cook, hotter than most solid state amps but that is the nature of a tube amp. They are far from any kind of sterile sound though.

Ok, so a tube amp has a hiss and interference? How much are we talking here? Is it audible? If I understand correctly, a tube amp is "warmer" while a solid state is "cleaner"? How much bigger are tube compared to solid state? I have a 2000 Ford Mustang V6. Will a 4 channel amp fit under the rear deck between my rear speakers? If not, will it maybe fit under the passenger seat? Is that even a good location? Thanks for the replies so far...

Jstas

It's just an F-150 standard cab, short bed. Not a whole lot of room behind the seat and since I drive it all the time, I need some storage space back there too. Lining it with amps and speakers isn't practical.

The stereo, I don't really brag about it. It sounds nice and stuff but I hate listing it all out. But here it goes:

Kenwood eXcelon KRC-858 head unit
Kenwood C-610 10 disc changer (very old but still works)
Kenwood eXcelon KAC-X650D 5 channel amp
Polk Audio db3650 6.5" components (1 inch tweeter/6.5 inch woofer + crossovers)
Polk Audio db6510 6.5" seperates (just woofers)
Polk Audio db10 10 inch subwoofer

That's about it. Nothing really fancy, just good, solid components and a decent amount of power. No caps, no crossovers (aside from the components), nothing exhorbitant or flashy. It's all wired with Streetwires and Esoteric Audio wires and such and it's all hidden behind stock panels. Except for the sub, amp and CD changer which are all tucked back in the corners behind the seats, out of view. It looks like a bone stock F-150 with a radio delete panel in the dash from the outside. The only giveaway is the surface mounted tweeters on the door panels but they are black and non-descript.

But according to some people here, it's all junk.

Oh, those are the original db's, basically equivalent to what can be found in the older RT series Polk Audio home speakers. Not the newer ones just released late last year.

Jstas

Originally posted by AustinKP
Ok, so a tube amp has a hiss and interference? How much are we talking here? Is it audible? If I understand correctly, a tube amp is "warmer" while a solid state is "cleaner"? How much bigger are tube compared to solid state? I have a 2000 Ford Mustang V6. Will a 4 channel amp fit under the rear deck between my rear speakers? If not, will it maybe fit under the passenger seat? Is that even a good location? Thanks for the replies so far...

Settle down now Beavis you are going to an extreme here. A tube amp doesn't have the kind of interference you are thinking of. Any piece of electronics can have that kind of interference. A tube amp, being an analog piece of equipment, can pick up out side stuff like a radio signal or EM interference. It's the main reason you don't see too many automotive tube amps. It's a hostile environment to electronics. Solid state is more stable in that respect so obviously an easier choice to live with.

The interference and hissing can be audible. The hissing is caused by the electricity moving across teh plates in teh tubes, diodes and resistors. Quality parts eliminate that but as they grow old and wear out, they can degrade in performance. Then the hissing and interference can become a greater problem. Simple solution, get new tubes.

The tube amp from USAmps that was being discussed is the same size as any other amp. Go to USAmps website and check out the info. They have several models in the line with all kinds of specs listed. You'll have to take measurements and compare the numbers to see what will fit your application.

Lastly, a solid state amp is not cleaner in any respect. A tube amp vs. a solid state amp on even footing (same power levels, same quality levels) you will not be able to tell decisivly which one is cleaner. A tube amp is warmer both sonically and physically. A tube amp will have a more natural sound because it is an analog signal which is a natural signal path.

Probably a better comparison would be a Mercedes AMG E55 vs. the new Pontiac GTO. Both will have comparable performance (barring the luxury aspect) and achive very similar results. That AMG, while fun to drive and with lots of power, is sort of detached because of it's ride quality standards. It is also very conservative in design. It has a mellow yet powerful exhaust note and under stated styling. Very sterile, conservative German performance. Now, look at the GTO. Even if it is Aussie based, it's balls to the wall American V8 performance in a fairly flashy package and it makes no bones about it. It has a throaty exhaust note, doesn't believe in traction control and when you sit in the car you know you aren't in the typical jellybean family car. Even if the GTO is slightly bland.

The Mercedes is a solid state amp. Very refined, very predictable, very reliable, lots of good power and a nice look and sound. The GTO is a tube amp. Still has lots of power, its a little more robust in it's operation and while the quality is still there, it may need service sooner than the Mercedes. The experiance in a GTO is more visceral, more raw because it isn't as detached from the environment as the Mercedes feels. There is no traction control and steering assist or electronic shocks. It's hard performance that feels more powerful than the AMG because there is more of an experience there for your senses to feel. But the two cars really aren't that different in thier final goal which is all out perfomance in a comfotable package. It's just that the two get to that point in different ways.

All I'm saying is that some people don't like teh sound of a tube amp because they find th little buzzes and hisses that you can (not always do though) experience with using tube equipment. But that is the nature of the beast. I think that you would be pleased with a tube amp though. Especially since tube power is different that solid state power. 120 watts of tube power is going to out perform 120 watts of solid state power. Tube power supplies and input and output stages are usually more roust than solid state stuff so the tube stuff will have more headroom than the solid state. If you do get a tube amp, you will get alot of clean power and a very pleasant, smooth sound that isn't fatiguing to listen to at all. It's very detailed and clear and usually not as bright as a solid state amp. I still recommend it but in teh end it is your money and you do with it as you see fit. I don't think you would be disappointed though.

AustinKP

Jstas - you make some nice analogies man. Carpeted room, GTO vs AMG E55. Did you get these from someone, or are you thinking these up on the fly, cause that's pretty cool.
My only concern is the buzzing/hissing...just how noticable is it? I'm shooting for the cleanest system I can get, and I'd hate to have a small buzz all the time. Is it so quiet that if I had a song playing that I couldn't even hear it? Do tube amps ever win SQ competitions? Does anyone that has a tube amp have an opinion? MrDHEJ, how is yours? Do you notice any extra noise?

MrDHEJ

My TU-600 is super clean. I hear no hiss, and theres some music i have never heard before in my songs. It really brings it out. It provides plenty of power to the MM6's, and i've only clipped the bass once, but set my head unit's high pass filter to 80Hz and no problems. I have not turned this system up all the way yet, it gets so loud it starts to hurt, theres no distortion but nothing is reaching it's max. If i open the passenger door and 3rd door the sound gets projected out and it's like my own little rock concert.

The only "Extra" noise i heard was a small amount of alternator whine at very low volume level's when playing a cd, but moving the head unit ground from the factory harness to the chassis solved that.

Hiss can come from allot of things though. I'm using streetwires ZN6 patch cables "$50 a peice" and twisted speaker wire.

If i ever do it again i WILL get another tube amp.

sntnsupermen131

id get the tube amp as well, they win many a SQ competitions, but sometimes it depends on what the judges like to hear
Jstas, correct me if im wrong, but isnt that "warm" sound produced by the tube amp in fact a type of distortion?
Ive heard that before, but wasnt sure if it was true
-Cody

Jstas

Originally posted by AustinKP
Jstas - you make some nice analogies man. Carpeted room, GTO vs AMG E55. Did you get these from someone, or are you thinking these up on the fly, cause that's pretty cool.
My only concern is the buzzing/hissing...just how noticable is it? I'm shooting for the cleanest system I can get, and I'd hate to have a small buzz all the time. Is it so quiet that if I had a song playing that I couldn't even hear it? Do tube amps ever win SQ competitions? Does anyone that has a tube amp have an opinion? MrDHEJ, how is yours? Do you notice any extra noise?

The hissing I am referring to, you willmost likely only hear when there is no sound playing and the stereo is on but sitting idle. If there is sound playing, unless the tubes or power supplies for the various stages are on thier way out, the hissing will be completely inaudible except at maybe very low listening levels.

As far as clean goes, USAmps are very clean amps. I don't think they woud make crappy tube amps and stellar solid state. It would just be bad business. As far as winning SQ competitions, I don't know. I don't follow that stuff a whole lot anymore and when I did, tube amps were available but insanely expensive and extremely fragile so no one had them.

Originally posted by sntnsupermen131
Jstas, correct me if im wrong, but isnt that "warm" sound produced by the tube amp in fact a type of distortion?

Uhh...not that I know of. The hissing is just the movement of the electrons. The "warmness" has to do with the fact that it is an analog signal and not a digital signal.

When you look at a digital sine wave, you see a series of steps going up and down the slopes of the wavelength. Just like an escalator in the mall. The number of steps between two points in a given time is the sampling rate which is measured in bits. When you have a 24 bit Digital/Analog converter, that means that it has 24 bits to make up that sampling. Now if you went and got your self a 48 bit D/A Converter, you will have twice as many bits in that sampling. What that does for you is it reduces the rise and run between the sampling points (the leading edge or corner of the step) and creates a higher density of sampling points. The smaller the rise and run in the digital signal, the closer it gets to resembling an analog signal. The digital signals can sound very manufactured and "sterile" to use a term loosely. That is because in the sampling they can pull out extraneous sounds but they also have to reconstruct a sound in an analog signal. It doesn't always sound natural because it has been futzed around with by all the circuitry in your components.

A tube amp does not have the extra D/A Converter stage in it because it is an analog piece of equipment. So, the sound that comes from a tube amp sounds more natural because it isn't missing track information due to a low sampling rate or a D/A Converter with a poor sensitivity level. The warmness refers to a more natural sound because it has more of the original sound in it.

Now, modern solid state stuff is good. The higher up the lines you go, the better it gets. It is hard for the human ear to differentiate the sounds because it can't hear the steps in the sampling. What we do hear is something we have a hard time describing. Easiest way to say it is, compare a live performance with a recorded performance being played on the best equipment money can buy. The stereo sounds great! Just like the live performance. But no matter how high you turn the volume up or how much money you spend on the stereo, it is just missing something compared to the live performance. Aside from the audience and the ambience of the concert venue, the sound of the performance has something more. You can't put your finger on it and it's hard to describe but you know it when you hear it and feel it. Kinda like ****.

Jstas

Oh, my analogies. Some people think I am an idiot because I try and describe things in ways an average joe can understand. You can teach a person much more by associating and identifying with something they already know and understand rather than forcing a whole new idea down thier throat from the get go.

I learned this quickly while being a rifle range instructor and camp counselor when I was in high school. So when I try and explain a new concept to a person, I use terms, ideas and examples that they already are familiar with or can grasp a better understanding. It may take a little longer but once a person understands the ideas and concepts behind something, they are more apt to understanding the nitty gritty details. They usually get more interested and want to learn more because they are discouraged by things that are involved but they do not easily comprehend. Like calculus. I hate calculus.

As far as my analogies go, I didn't get them from anyone. They are all mine. I try to relate things in ways that I understand so I can describe them better or in ways everyone will just get. Like the tube amp thing, I tried to picture in my head what a tube amp sound vs. a solid state sound woul look like. So I pictured a room, one very bland and clean or sterile, the other equally as clean but no where near as bland. It's an extreme but you got the hint. Sometimes it can get me into trouble because people who do understand go all ///**** on me and harp about how that "it isn't right" or that "it's long winded". What they don't get, in thier social ineptitude, is that the world isn't a recluse just like theem and there are other people out there who care nothing about how a circuit works and just want thier stuff to sound good. To achieve that goal of sounding good though, it is a good thing for the owner to have a basic understanding of how things work and why. It helps them make better choices and decisions when buying gear.

AustinKP

MrDHEJ - Why did you decide to get the tube amp vs a transistor amp? Did you compare it to any other amps head to head? I'm just wondering how much better it sounds - if it's a 'whole new world' or just a subtle difference. If a tube is going to be like $280 difference, I'll probably just go for a normal amp. I looked up the TU-600 on eBay and it was like $500 if I remember correctly. The Hifonics NX880 was only like $220. How much did you pay for yours?

Cody - what does the sntnsupermen stand for?

sntnsupermen131

sntn=sinton, my home town
supermen...umm?...no reason really
-Cody

MrDHEJ

I got the tube amp solely on the remarks from people here that said for all out SQ tube was the way to go. I wasn't disapointed.

For **** N' giggles i hooked up an old carver 4075 to do a sound comparison and the differance was huge. Yeah i know the carver is 1/2 the wattage, and 10 years old, but even at lower lvl's it was still a huge differance. I even hooked the 200x and 600x up to the MM6's and the differance in sound was very noticable.

the TU-600 just gives me that warm fuzzy feeling.

PoweredByDodge

Jastas says "It's just an F-150 short bed..." .........


.... but leaves out....


.......................... "It's just an F-150 -- LIGHTNING -- short bed -- with one of the flattest, most consistent, horse and torque curves over the useable RPM range that you'll ever see."


You are hereby corrected. Naughty, naughty, no cookies for you.

MacLeod

Cody- When I first saw your screen name I thought it was short for "Sunset Superman". Thats an old Dio song from the 80s. I thought maybe you were a long haired headbanger like I used to be back then! LOL

AustinKP - The finger thing doesnt really mean that Texas A&M cuts off peoples fingers. UTs mascot is the longhorn so everybody down there does the little longhorn symbol with their hand. Fold in your 2 middle fingers and it looks like horns. So long time rivals, A&M, claim they cut off the middle fingers and send them to UT as a..........oh to hell with it. I guess if you have to explain a joke this much then it wasnt very funny. Maybe thats why I drive a beer truck for a living rather than making movies alongside Eddie Murphy.

AustinKP

Ok, F-150, and F-150 Lightning? That's almost not even the same truck. Jstas - *just* an F-150 short bed? Seriously...tsk, tsk, tsk. Can't blame your choice of transportation though. I love lightnings.

MacLeod - UT wouldn't happen to stand for Univ of Texas, would it? Because that would start to make a whole lot more sense to me. This whole time, I've thought we were talking about the postal abbreviation for Utah, which is where I am! No wonder I thought you were all crazy!

Which brings me to my next question - why is abbreviation such a long word?