I'm looking at Phase 2 of my system install.

I'm running a Nakamichi 6 disk changer HU, and 4 Infinity Kappa 5x7s. I am going to add a single 8" sub when I add the amp. Doing my homework, I'm leaning towards the RE8 (but I have not bought it yet).

The question becomes, what amp to power all of this? I don't really crank my radio loud...but I do want a full, rich, clean sound, and I want a lot of control of the sound spectrum.

Any help on what to do as far as an amp goes?

Thanks,
Mike

 

I'd suggest an Alpine digital amp, such as the MRV-F340.
Digital amps give you a broad range of adjustments.

You could pair it with an alpine MRD-M300 or the like for the sub.

Good luck!

 

You want to run 2 amps, a 4 channel for your highs/mids and a mono for the sub. not many 5 channel amps out there. Alpine, Rockford Fosgate, JL Audio, pheonix gold (Tantrum amps are a good choice if you can find them, they're being discont'd so they're really cheap, about 1/2 price. look on ebay)

Just get something mid level about 50 watts per channel for the kappa's and 150 - 200 watts for the sub.

 

The RE8 is RMS 175, Max 250, with a dual voice coil, 4 ohm.

The MRD-M300 is listed as 300W x 1 (2ohm 14.4V), with 600W max power.

Is this gonna fry the sub? If so, does anyone know of a mono amp that will push a the single RE8?

Thanks,
Mike

 

That's a bit too much, especially considering that alpines are generally underrated.

I found this phoenix gold (150Wx1 @ 2): http://www.cardomain.com/item/PHOR201

I've had a hard time finding a mono amp with that little power.
You might also try a 2-channel, with one channel for each voice coil.

Better yet, get a 4 channel and use 2 channels for your sub, leave the other two for your door speakers.

 

Crud. Lost my first attempt at this post...Is this a good amp? To my admittedly amateur eyes, it would seem to fit the bill...but I know zilch about amps.Which would be the better setup? The amp you just suggested, or this?Hmmm...I replaced all four door speakers, though...would I still have enough juice to run those Kappas well doing this? I was thinking I'd be better off running one channel to each. But, like I said, I'm an amateur at this.

Thanks a lot for your help.

Mike

 

Ah, I was thinking you just replaced 2 speakers.

Yeah, you need a 4-channel there. That'll allow you to retain all balance / fade adjustments.

For your sub:
Mono amps are usually class-D, which provide the best bass you can get. One reason is they are more efficient power converters, so they drain your electrical system less, which means you have more power available for bone-rattling bass.

Most multi-channel amps are Class AB or class A. They offer a broad range of frequencies (low and high). You can use them for tweets, subs, whatever. They are not near as efficient though, so big bass will drain your system even more.

That's about as much as I know on the advantages of mono over multi-channel.

Multi-channel amps are probably going to be much cheaper. So, it all depends on your target.

 

Ok.

Time to check my math. I did a little more digging and this is what I have come up with as a possible system. Please tell me if I am doing this correctly, and/or if I am doing something boneheaded that I don't need to do.

Subwoofer:

RE8 RMS 175 Max 250 Dual voice coil 4 ohm

Sub's Amp:

MTX Thunder251D Class D Amplifier

RMS
2 Ohm Load 160 w x 1
4 Ohm Load 80 w x 1

Dynamic Power 14.4 VDC
2 Ohm Load 250 w x 1
4 Ohm Load 125 w x 1

I figure that by running the dual coils in parallel it will be 2 ohm, right? If I'm misunderstanding, or if this is gonna fry my sub, please let me know.

Speakers:

4 Infinity Kappas: RMS 100 Max 300 @ 4 ohm

Amp: MTX Thunder1004 4-Channel Amplifier

2 Ohm Load 180 w x 4
4 Ohm Load 90 w x 4
Bridged 4 Ohm Load 360 w x 2
Dynamic Power 14.4 VDC
2 Ohm Load 250 w x 4
4 Ohm Load 125 w x 4

Thanks again!
Mike

 

Coronach:
Assuming that all of your equipment spec numbers are correct, I think you can look forward to a successful installation. Enjoy.


NOTE: I know of ZERO amplifier manufacturer's that underrate their equipment. If anybody has knowledge otherwise, I suggest they provide some sort of reference when making that claim.

 

Well, I pulled the numbers from the manufacturer's websites, so they better be right. I was mostly concerned about whether or not I was understanding the 4 ohm vs 2 ohm when wiring the dual-coiled sub in parallel. This really seemed like something where I could misunderstand and fry my brand new sub.

Also, how correct am I in this assumption:

I don't really listen to my stereo that loud, but I figured that it was still a good idea to get something close to 100 W RMS per channel, just for sake of sound clarity, as the Inifinities are rated at 100 RMS.

If the juice going to each channel really only matters if the stereo is cranked, I can get by with a smaller amp, probably.

Thanks!
Mike