What to look for in an Amp?

[Irish Pride]

One of my pre-convention goals is to get my sound system sounding a little better. Currently i'm running an Alpine deck with 50W per channel to 4 Alpine speakers in the doors and rear deck lid. I have a 12" Kenwood in a custom trunk box that i want to install but the last time i hooked up a "system" i was in high school so i'm a little clueless at this point.

What do i need to look for in an Amp or Amps to power this stuff. If i just want to power the sub do i just go with a mono amp? If i want to power everything is there a single amp that can do that or do i need to look into getting 2 amps? What power ranges should i be looking at?

 

[intimdatr]

Well it all starts out with how much money you want to spend.
The more pricey route (and the one i would take) is running two separate amps: A single channel for the sub and another 4 or 6 channel for the speakers. The Amp for the sub should peak around what the sub is rated to peak at maybe even a little higher so your not worrying about having enough power to run or pound your brains out . This amp can usually be pretty run of the mill because all it needs to do is pound, spend about 30mins tuning and your good. But for the 4 or 6 channel amp for the speakers Is where i would spend more money and research and find the style of amp that fits your needs. If your going for "good" sound i would pick a soild 4 channel and wire in your speakers to it no problem and cut the highs through your head unit the way you want them and for the mids you tune the amp till its what you like.(THIS IS IF YOU HAVE 2 or 3 WAY SPEAKERS INSTALLED IF NOT IGNORE) If you want "Amazing" i would go a 6 channel and wire you the mids to 4 and the front (or rears depends on the acoustics of your ears car speakers etc.) Highs to the other 2 channels and and tune them accordingly.

If you just want a better sound you can several amps out there that are 5 channels (4 mains and a sub) that will work great for you purpose but will not offer the tuning of running separate amps.

 

[SuperHO]

Not much has changed in system installs over the years. Remeber, when you hook up an amp, all you're doing is boosting the existing signal. If the source sounds like shit, it'll sound even worse when you boost the output.

i guess the big questions are what exactly are you looking for sound-wise and how much are you willing to spend?

 

[vortex2450]

As they said, you need to set a concise budget and goal. Me?

I'm planning to running dedicated digital Alpine amps (M50,F30) with component polk audio component 6.5s in the front and 6x9s in the rear. I was looking at a 12" DVC Type-R but think I am going with a more high fidelity driver.

Anyways, it all depends, if you jsut want some boomy "thump in the trunk" go with something cheap, if your aiming at better sound, then save up and make clear goals.

Things to look for in good amps are: Class, Effeciency, RMS (not peak) channel ratings, THD noise ratio (lower is better), signal sweep range, internal corssovers, low/high pass. Also, don't pick out a no name amp, find something with a good reputation, look up reviews, etc,etc.


Also, installing amps is a great excuse for a batt relocation.

-Josh

 

[Irish Pride]

Money isnt an issue. I'll get the best available once i know what i'm looking for. Back when i hooked up my last system a 200W amp was a big deal. Now they're 1000W plus. You had to have an external crossover and filters. This is where i'm lost. I didnt keep up with the technology. I'm not looking for trunk thumping bass. I want to be able to hear good crisp sound and feel the added bass, but not wake the neighbors. My brand of choice is Alpine. My sound system right now sounds very nice. I just want it to sound better. Do they make amps solely for subs? If so, what do i look for?

 

[hawkeye18]

I'm not looking for trunk thumping bass. I want to be able to hear good crisp sound and feel the added bass, but not wake the neighbors.

So what you're saying is, you're going for SQL, not SPL. This is generally a good thing.

In that case, I'd recommend going with one or two 10" subs vice a 12" sub. The blue '95 has 2 JL 10W3s in a sealed enclosure in it, and the bass is very powerful, but still very tight and controlled. The bigger the sub gets, the more boomey the bass, but the less controlled. Something about it being easier to control a rapier than a broadsword... though a 12" in a sealed enclosure is not too bad. 15"s and above just totally toss out SQL.

Anyway, as far as amps go, I echo most of what's been said above; if an amp advertises its peak wattage and doesn't show its RMS wattage, keep looking. Good amps will advertise their RMS watts. Peak wattage is wholly unimportant.

If you want a single-channel amp (and you probably will), go for a class D monoblock amp. Class D transistors have the least fidelity but the highest efficiency, and since you're only amplifying a very small subset of frequencies, none of which involve vocals, fidelity is rather unimportant.

Do not skimp on the wiring to the amp, either. Don't feed a 1200WRMS amp with 8ga cable. Not that you'll need that much power, but I'd recommend stringing 4ga cable at a minimum in case you want to upgrade later (and you will). And keep that ground cable as short as possible.

 

[Phoenix]

If you find one that interests you , post it up.

The wattage is complete BS in the cheap stuff , it looks like its not regulated and anyone will advertise it as mega power and it has tiny balls in reality. A 4000W pyramid can be less powerful then my old school phoenix gold 4X50w. (btw dont buy the new phoenix gold ones , the old ones are good and written made in the USA with the flag).

The more high end sub you will get , the more they are stiff and they will need more power to push them , but they are more powerful in the end.

Another thing , brands are changing in quality ALOT. Be careful on choosing it only cause of the name. One year they can be kickass , the other complete crap cause they moved to china.

Pioneer and kenwood makes good ones and they are not to pricey.

BTW: if you want to run only one sub , you only need a X1 mono amp. 2 subs grab a X2 or X4. But be careful certain amps runs on certain OHMS , so does the subs.

If you grab a X4 with 2 subs , you can bridge it for full power but it will change the OHMS and your sub might not take it.

EDIT: here is the diagrams to help you out with the ohms , whats possible to plug with what.
http://www.crutchfield.com/S-R1pm0I5u5zs/learn/learningcenter/car/subwoofers_wiring.html

 

[93rev2sev]

RMS wattage is much more important than advertised wattage.

Advertised wattage is a "momentary maximum". If your bass hits, your amp will use more juice, but it will only be able to provide the power for a split second, then it falls back to the RMS number...which is what you're using 95% of the time.

Manufacturers can increase the maximum wattage simply by using more capacitors in the amp. When the bass hits, the caps are discharged immediately and then you're left with the amps ability to make power with it's transistors (the RMS number). That's how these el-cheapo amps are able to advertise 50 gagillion watts - they only make 50 gagillion watts for 1 microsecond.

As for how many amps you need?
You already have a pretty decent 200 watt 4 channel amp - right behind the face of your radio.

If you have one sub and 4 speakers, then you will use 2 amps- The four channel built into the deck and another to drive the sub...unless you want to buy an amp that's a lot better than a 200 watt, 4 channel Alpine (which doesn't make much sense).

I don't think they really make single channel amps, so just get a decent 2 channel amp, matched to the sub you've got, bridge it, and be done.

Spend the rest of your efforts making the cabin quiet. Creating a quiet environment is the most overlooked process in the "system builds" that I've seen.


All of the information you've just received is about 20 years old, but I'll bet it's still 100% relevent.

 

[SHOhopefull]

To kind of piggyback on Chad's thread here..

For my Silver SHO, I had been thinking running the 4 regular speakers off the HU, and just doing a mono amp and sub.

Would the 4 interior speakers still sound decent with just a 50x4 HU?

And Chad, are you looking at just the overall music, or do you have some old 80's and 90's basshead moments like I do? Reason asking is I'm still up in the air on the sub. 2 10's as Jason said or just a single 12...

Edit:I think 93rev2sev just answered most of my question lol

 

[Irish Pride]

To kind of piggyback on Chad's thread here..

For my Silver SHO, I had been thinking running the 4 regular speakers off the HU, and just doing a mono amp and sub.

Would the 4 interior speakers still sound decent with just a 50x4 HU?

And Chad, are you looking at just the overall music, or do you have some old 80's and 90's basshead moments like I do? Reason asking is I'm still up in the air on the sub. 2 10's as Jason said or just a single 12...

Edit:I think 93rev2sev just answered most of my question lol

I want to rock out to GNR and Motley in style!!

I'm looking for good quality sound. Thats it. For my enjoyment and not the car next to me. Like i said, i've already got a good Alpine HU and 2 Alpine 6.5s in the doors and 2 Alpine 6x9s in the rear. My system already sounds good.

I'm commited to the 12" sub. I bought Dillons custom trunk box at the BBQ and it already has a 12" Kinwood in it. All i need now is the power supply to bring it all together.

 

[Irish Pride]

RMS wattage is much more important than advertised wattage.

Advertised wattage is a "momentary maximum". If your bass hits, your amp will use more juice, but it will only be able to provide the power for a split second, then it falls back to the RMS number...which is what you're using 95% of the time.

Manufacturers can increase the maximum wattage simply by using more capacitors in the amp. When the bass hits, the caps are discharged immediately and then you're left with the amps ability to make power with it's transistors (the RMS number). That's how these el-cheapo amps are able to advertise 50 gagillion watts - they only make 50 gagillion watts for 1 microsecond.

As for how many amps you need?
You already have a pretty decent 200 watt 4 channel amp - right behind the face of your radio.

If you have one sub and 4 speakers, then you will use 2 amps- The four channel built into the deck and another to drive the sub...unless you want to buy an amp that's a lot better than a 200 watt, 4 channel Alpine (which doesn't make much sense).
I don't think they really make single channel amps, so just get a decent 2 channel amp, matched to the sub you've got, bridge it, and be done.

Spend the rest of your efforts making the cabin quiet. Creating a quiet environment is the most overlooked process in the "system builds" that I've seen.


All of the information you've just received is about 20 years old, but I'll bet it's still 100% relevent.

That was my original thinking. Didnt know if powering a 12" sub would make my 4 speakers up front seem underpowered. I guess the best way to go is to do like you say and find the best amp to go with the sub and then go from there. I can always add power to the fronts later.

Next question - if i have the sub hooked up will my front 4 still be putting out HIs, MIDs, and LOWs? My HU has a sub output, so will this eliminate the LOWs to the front 4?

 

[intimdatr]

Next question - if i have the sub hooked up will my front 4 still be putting out HIs, MIDs, and LOWs?

Yes because of how the car is wired. You would have to re wire it to purely eliminate it. What ive done is Tune my subs up a bit and the lows down in the head unit. Which really helps with getting a crisp my out 5x7's in the rear. The issue is with the 3in fronts im running they are biased high in my head unit and with the small size and 3 way design the highs are SCREAMERS. But What i plan to do is simply cut the wires to the highs and run the main speakers as the highs.

If you want to have Mid be mids and Highs be highs your going to have to run your highs as components wired separately into either your head unit or amp with a high pass.

My HU has a sub output, so will this eliminate the LOWs to the front 4?

It will run the subs as Lows and will still put low frequencies to the speakers. Because the head unit puts the entire range of sound (usually) to the amp and expects the amp to sort it out. Which these 20 year old ones dont. If you run a really high end amp they will have a All pass a Lo Pass a Mid pass and a Hi pass (and on the $$$ ones they will all be adjustable) and then from there you run new wire to the speakers accordingly. Most people that do this are running 2 amps. One mono block or bridge 2 channel for subs this amp can be pretty normal because all it needs to do is drive subs. And a 6 channel amp - 4 mids and 2 highs.

If you wont the BEST sound possible out of your setup you really need to re wire the speakers with better wire and a different setup to allow for highs to highs and mids to mids in 2/3 way speakers.



The highs you see pictured are normally wire into the speaker and have to cut and rewired in to the amp(sorta sucks to do). Unless you plan to run tweeters separately. Cool but lots of work.

But as you can see you have the 4 channels coming out of the head unit as Front left Rear left Front right and Rear right and when they hit the amp they are split into 6 channels 4 mids that are Front left, Rear left Etc. and 2 highs (called components) that can be front or rears depending on how you like it.
You also the lines for subs coming out and going directly to subs to allow for the best bass adjustment.

Running the HU to power your speakers will work but will really limit the tunning of systems leaving you with shrill highs and low mids.

This is the best route to take for the BEST sound quality. granted its a lot more work and a lot more money but honestly i dont think doing anything less would be worth it.

Hope this helps!

 

[intimdatr]

To kind of piggyback on Chad's thread here..

For my Silver SHO, I had been thinking running the 4 regular speakers off the HU, and just doing a mono amp and sub.

Would the 4 interior speakers still sound decent with just a 50x4 HU?

And Chad, are you looking at just the overall music, or do you have some old 80's and 90's basshead moments like I do? Reason asking is I'm still up in the air on the sub. 2 10's as Jason said or just a single 12...

Edit:I think 93rev2sev just answered most of my question lol

In a word yes. Theyre going to sound a million times better simply because newer head units, are newer! If all you are looking for is some pretty good sound and randomly want to crank Bassnectar and pop the trunk latch this setup works very well! And personally i would run 2 10's because theyre faster at reacting. 12's and 15's start getting kinda slow and want to double more in longer bass runs. (sounds terrible).

 

[SHOhopefull]

In a word yes. Theyre going to sound a million times better simply because newer head units, are newer! If all you are looking for is some pretty good sound and randomly want to crank Bassnectar and pop the trunk latch this setup works very well! And personally i would run 2 10's because theyre faster at reacting. 12's and 15's start getting kinda slow and want to double more in longer bass runs. (sounds terrible).

Ok, that's what I was wondering... My bass tastes are along the line of Techmaster PEB, Bass Boy, Bass 305, etc... But I do like listening to everything else, so I don't want just all bass. Thanks!

 

[SuperHO]

There's a lot of misinformation scampering around this thread, so rather than address everything and potentially start a war, I'm gonna direct you to the best place on the web to answer your questions.

www.diymobileaudio.com

Surf the forum there, read what people have to say, examine the myths section, and learn. Some of the industry's best are regular posters there, and the information is abundant. I've learned more on that sight in 18 months than I have in 20 years of car audio enthusiasm.

 

[intimdatr]

There's a lot of misinformation scampering around this thread, so rather than address everything and potentially start a war, I'm gonna direct you to the best place on the web to answer your questions.

www.diymobileaudio.com

Surf the forum there, read what people have to say, examine the myths section, and learn. Some of the industry's best are regular posters there, and the information is abundant. I've learned more on that sight in 18 months than I have in 20 years of car audio enthusiasm.

Cool site! Cleared up some stuff ive thought about! Mostly with the larger sub vs smaller sub stuff! 6 cubic feet for a 15in sub !! Seams like everything works as long as you put the effort in to doing it right. A lot of the info on their site though seams to be a bit of opinion. Or at least in the few threads i read in the myth stuff. Looks like the site agrees with what i posted for a setup...form what i can tell. some of that stuff even has me confused!

 

[hawkeye18]

There is a lot of science in car audio if you want to go that last 20%. Matching speakers with enclosure size, matching wattage ratings, matching wiring, which direction to fire the sub at, etc. etc. etc.

It can get pretty confusing. There is a reason there's a lot of misinformation - it's easy to get confused.

 

[intimdatr]

There is a lot of science in car audio if you want to go that last 20%. Matching speakers with enclosure size, matching wattage ratings, matching wiring, which direction to fire the sub at, etc. etc. etc.

It can get pretty confusing. There is a reason there's a lot of misinformation - it's easy to get confused.

LOL No Kidding!!

 

[QUICKSILVER93]

what 200 watt 4 channel amp are you talking about??? rev2sev? As you correctly stated rms watts are "true" watts because they are what is 99.5% of the time what is available. Your head unit while stating 50x4(mine is also an alpine) is really only between 13-22 rms. even the very high end radio's are not made to run any "real" speakers. Intimidatr has the right set-up idea for what you are looking for I believe. 1 dedicator amp for your mids and high's either 4 channel or six channel and one mono amp for your subs.

My friend set up all my stuff and you can still get as clean and crisp a sound with half the stuff that i have. FWIW ALPINE has no peers when you factor price,quality,and reliability.

as far as suggestions I have three alpine mono m series amps and they r cheap and they pound. 2 m500's and a m1000. as far as subs dual voice coils and overly pricey subs are a waste of money. get a middle of the road model. alpines type s or r and buy the warranty.

my two cents

 

[SuperHO]

Tom, I really need to meet you and let you hear my system. Hearing "Money For Nothing" by Dire Straits is damn near a religious experience with only a pair of 6" components up front and a single 12" sub in the proper sized ported box in the trunk.

Once we're done with that, I'll fire up some Techmaster P.E.B. and see if I can't make your eyes water, cuz it'll definitely make your nose itch.

You don't need massive amounts of power with multiple subs for an awesome sounding system. The reality is most people focus their money and energy into the portion of the system that provides about 2% of the listening experience and skimp out on the other 98%. Put effort into your front soundstage and build the rest around that.