need amp help plz

**jgibson34** · 03-01-2007, 07:27 AM

i need to find a powerful amp to power my system (not an expert) Rear Deck

speakers- Infinity 5-1/4" 2-Way Car Speakers with Plus One Cones (Pair)

Handles up to 135 watts peak power (45 watts RMS) H.U - JVC 50W x 4

MOSFET 50 watts peak (20 watts RMS) x 4 channels 2 pairs of preamp

outputs (front and rear/ sub switchable) Subs - Alpine 12" Dual-Voice-Coil 4-

Ohm Subwoofer Handles up to 1500W peak power (500W RMS) Sub box - Q-

Logic 12" Dual-Chamber Sealed Subwoofer Enclosure im also going to add two

speakers to the front doors as well (highs) can someone help

**XC-C30** · 03-01-2007, 07:30 AM

you're gonna need 2 separate amps if you wanna power it all.

What's your budget?

**cbevis** · 03-01-2007, 08:17 AM

so basically you've got a pair of 45 RMS speakers and a 12" 500 RMS sub? I don't think you're going to need two amps. I'd get a 760 watt class D amp for the sub and throw the speakers on an EQ...call it a day.

**XC-C30** · 03-01-2007, 08:32 AM

Originally Posted by cbevis

so basically you've got a pair of 45 RMS speakers and a 12" 500 RMS sub? I don't think you're going to need two amps. I'd get a 760 watt class D amp for the sub and throw the speakers on an EQ...call it a day.

And how do you think those speakers are gonna keep up with the sub? I'd sugest for you to do some more reading

Oh and why a 760watts amp specificaly?

**cbevis** · 03-01-2007, 09:00 AM

Originally Posted by IC-C30

And how do you think those speakers are gonna keep up with the sub? I'd sugest for you to do some more reading

Oh and why a 760watts amp specificaly?

relax....I'm not new to this whole scene. These are just suggestions based on all the systems I've ever built. I'm using my current system for a basis of comparison here.

Throwing those speakers on an EQ will allow him amplify the HU's 20 RMS per channel rating bringing it pretty close to the speakers 45 RMS. It's a good sollution to save on unecessary power draw and it'll allow him to more effectivly tune those speakers to better cover the sound levels left out by the sub.

The 760 number I threw out is just a standard wattage "rating" that most brand names with a class D amp spec out. It'll have a fairly decent RMS that'll be able to push that sub. As far as keeping up with the sub...IMO, probably won't happen with just two speakers. He'll probably end up turning down the vollumn in the sub preset on his HU. Of coarse, there may be more than just the two speakers in this system...in which case it'll fine.

**XC-C30** · 03-01-2007, 09:20 AM

there's more to it than just output. A car-amp of 15watts per channel will likely put out more than the 15watts per channel of a radio-amp. The efficiency of a built-in amp is just too low to feed any speakers well, not to mention the sound-quality that lacks with a HU.... Powering the speakers of an external amp with 2x50watts will be more benefitical in that case. And as far as the sub goes, you have to be carefull when you're overpowering that much. It's a task, a noob shouldn't take care of himself. So I'd rathr stick with a lower output amp, like 550 or 600 or something. or if the sub is pretty effeicient, he could even do with a 400watt amp. Same goes fot the speakers though. The more efficient, the better.

Oh and, sorry I came across atacking, I didn't mean to.

**cbevis** · 03-01-2007, 09:38 AM

Originally Posted by IC-C30

Oh and, sorry I came across atacking, I didn't mean to.

no problem...posts are often misinturpreted 9 times out of 10. Thank god for emoticons eh?

I guess where I'm coming from on those speakers is if he's only going to amp two of them then a 200 watt EQ in tandem with his HU will push more than enough. I like putting speakers on EQs instead of amps because i can filter out all the bass...where most of the amps are sapped. Beside, that's what the sub is for.

I hear you on the over powered amp though...it's not for the ill informed. However, I'd rather him tune the amp's gain based on an over abundance of power than to have him clip the hell out of his sub with not enough power....lower powered amps blow more subs than overpowered ones. Also, lets not forget he say's he's got a 500 watt RMS rating on that sub....760 watts at best translates to 680 watts...even with a class D amp, and that's a peak performance number. The RMS on something like that is only about 400 watts....bridged

**jgibson34** · 03-01-2007, 08:38 PM

so im not sure whose advice to go with ....

does putting it on an equalizer meaning powering it with my deck.. i will have front speakers and rear speakers will there be enough power for them both

**david69leonard** · 03-02-2007, 02:29 PM

here is a good EQ that will work wonders for your carpc:

http://cgi.ebay.com/From-Japan-Pione...QQcmdZViewItem

I had one of these back in the day and i loved it, with this you can hook up a 4ch amp for your components, and a two channel for your subs, it also has volume control and several other different useful features...

**cbevis** · 03-02-2007, 05:41 PM

Originally Posted by jgibson34

so im not sure whose advice to go with ....

does putting it on an equalizer meaning powering it with my deck.. i will have front speakers and rear speakers will there be enough power for them both

to be honest...it'll be personal preference....you'll end up spending the same amount of money either way you go. Here's how I see it...An amp will give you more push and an EQ will give you more tunability. I've had both set ups in my car and in all honesty I was the only one who could hear the difference.

Think of an EQ as a smaller amp that has 12 bands of adjustibility. 12 bands (or however many) are nice to have if you're OCD like I am...but can be a pain in the *** if you listen to different types of music. The advantage is you can tune down the bass which will reserve more of the EQs power for the highend...which doesn't require all that much to begin with. In the end, that's the biggest advantage...less draw on the vehicles' electronic systems.