amp selection

spicer81

Member
2008-02-19 11:13 pm
I just recently got into wanting to know about car stereos and all that good stuff and I have a 12" Alpine Type-R and Two 10" Alpine Type-E Subs I wanted to know how much amp power would I need to push these speakers and what would be the best brand at a good price? If anybody could help me with this I would really appreciate it. I heard Rockford Fosgate was the way to go. Is that true?

Spicer
 

jol50

Member
2007-11-08 2:14 am
There are a lot of good amps out there, what kind of power in rms are they good for? Also running different subs together may not be a good idea if you don't run them at separate frequencies....but I have seen it work. Also need to know what ohms the ones you will run are and single or dual VC.

Personally most of my amps I get used, but that is up to you. I like older amps, but don't care so much on subs because I like the lower power draw of class D amps for that...and quality is not as much an issue with subs for me if there is a difference. Then again I will try anything just about.
 

jol50

Member
2007-11-08 2:14 am
The two sets of subs will have a different response curve, what can happen is they cancel each other out at certain frequencies. It would work if you say, ran the 12 at under 40Hz and the 10s over 40 for example. Otherwise, you can try it and see but it is hard to say how they will interact without testing. Even the same subs in different boxes can do this. Sometimes it can come out good and work fine, but in general it is not recommended just so you know.

So you could run a 1Kw amp at 1 ohm, or something at 4 ohms or 2 x 2ohms for a 2 channel but most 2ch are class AB that take more power to run. I have three 1kw at 1ohm amps but not selling any just yet. If you like alpine there are an assortment of old to new 350-800w amps on ebay. I have some to try in my car but too cold to do that yet. Or like you said two 2 ohm amps would work, I tested a newer M450 on the bench and it seemed to work nice (400wrms), but they are smaller economy type amps compared to old ones. They are small in size and class D. I have a couple older ones I want to try, the mrv class d type. If they don't get it I will drop the 1kw in and not worry about power on my 4 12s IB. They should not need over 600wrms but the current 420 is not quite enough if I keep these same subs.

Or, you may not need that much power depending on your use/needs. You don't need to go to max rating, also the enclosure can affect how much they can handle. Sealed you can run them hard, ported you may need subsonic and they will put out more sound. I would say a 500wrms sub would run good on anything over half that, unless you want to see how much you can get out of them. I want to try a bigger amp on my IB subs because they can have more control and sound different, it has tons of bass for my use. Its a kicker on there now.

As far as brand, many make good amps including RF. New amps tend to not be as durable in vibration and abuse depending on quality, and are not as easy to fix inside with miniature components. Few amps are made in US anymore, most in China and some Korean.
 

jol50

Member
2007-11-08 2:14 am
Depending on your setup you can go either way; the AB you can use for other things in the future unlike a mono sub amp (is the advantage). It is hard to find efficiency ratings on a lot of amps though, it can range from 10% with some I just looked at to over 30% between D and AB. I have a little car so I'm going D with the limited power, if I had a larger car or truck I would not worry so much at < 1Kw. Maybe someone else here knows of some guidelines or alternator levels required for X watts of amps. I don't crank in it at night that much either.
 

jol50

Member
2007-11-08 2:14 am
Cap will help the alternator live longer, will help dimming some, but if you overrun the alternator nothing can get your 14v back. Extra battery will keep it from going under 12v if it drops that much, and help play it with car off. Some say caps are worthless. They are kind of like a tiny battery I guess, to put it simple. I got one for $15 shipped so I'm going to use it...I figure pushing the stock alt I will take any help I can get. Also have a booster pack battery to try with it. So IMHO, I'd recommend not investing a lot of funds into caps when other things can help more. It must be mounted close to the amp also. They can help power the amp for the moment it takes for the alternator to react to a big draw, that is why they help dimming some and life of alternator some....but if you draw too much the number of milliseconds the cap works runs out, its only for a hit of sound. So like with a bass track of nonstop bass they will do less for you.
 

jol50

Member
2007-11-08 2:14 am
Four 10s is great, I used to run that all the time. 12s can get a little deeper easier but I liked the 10s. It is more what area I have to mount them in now and I had room in this car for 4 12s so in they went. I think 4 10s have more cone area than 2 12s right?