4-Channel amps

[theDRIZZLE]

Im looking for a 4 channel amp to power 2 sets of infinity kappa 6x8s that put out 100 rms at 2 ohms. The 2 im looking at are the rockford fosgate p4004 and the alpine MRP-F450. Does anybody have experience with these amps or have any suggestions? Any input is great. Thanks.

 

[chuyler1]

The MTX Thunder TC 4004 is another option. Both the MTX and the Alpine have speaker-level inputs. If you plan on using the stock stereo those will save you $20-30 because you won't have to buy a LOC. Other than that, all three amps are pretty much the same. The Alpine probably has the best SQ but it is also the most expensive.

Instead of powering 2 sets of 6x8"s you should consider using the rear channels bridged to power a single 8" or 10" 200w RMS subwoofer.

 

[Hughes412]

Im looking for a 4 channel amp to power 2 sets of infinity kappa 6x8s that put out 100 rms at 2 ohms. The 2 im looking at are the rockford fosgate p4004 and the alpine MRP-F450. Does anybody have experience with these amps or have any suggestions? Any input is great. Thanks.

I say go with the P4004. I have that one with the 6x9 kapps in the rear and 5x8s in the front. That amp rocks. I have all the settings on the low side and have went through several pairs of Alpines speakers with it. It wasn't until I went with the infinites that I was happy. They have great highs and mids. Although I don't know about their bass, I also have two infi 12s for that pushed by the RF p5002 2ch amp. And that one is great also.

 

[Kid Red]

I'm looking into the Alpine 250 (4x40w) and was going to use LOCs because I heard the sound is better. Is it worth it for the cost and extra install work sound wise to install the LOCs?

Also, I have the 5, and I'm thinking of putting in a JL Audio 6w0 in a rear compartment. I guess it would need to be made with a fiberglass front or something. Anyone have suggestions on rear compartments and using them to house a sub?

 

[Poseur]

Im looking for a 4 channel amp to power 2 sets of infinity kappa 6x8s that put out 100 rms at 2 ohms.

Just a quick note, speakers don't MAKE watts, they take them. Therefor you're looking for an amp that will put out around 100wrms@2ohms for speakers that'll handle about thatmuch.

As Chuyler said, amp the fronts, rears off the deck, and get a sub in it.

 

[Kid Red]

Just a quick note, speakers don't MAKE watts, they take them. Therefor you're looking for an amp that will put out around 100wrms@2ohms for speakers that'll handle about thatmuch.

As Chuyler said, amp the fronts, rears off the deck, and get a sub in it.

Why only amp the fronts? I have 4 6x8s in my Mazda 5, and if I amped just the fronts then I would not hear the rears. Or does that only apply to cars?

 

[Hughes412]

Why only amp the fronts? I have 4 6x8s in my Mazda 5, and if I amped just the fronts then I would not hear the rears. Or does that only apply to cars?

For the most part that is how people set up their systems now days. I personally like to hear all my speakers and have it centered. One thing on a sedan it that the rears are mounted higher so you would hear them more then the fronts that are typically buy your feet. But if you do like I did and adjust the amp so you can get it play evenlly through all 4. I would say in a 5 I would amp all 4 and not do a sub. The whole thing in getting a 5 was for space, so why take away the space for a sub? You most likely wont be bassing it with the kiddos in it anyways. No that I have mine I wish I wouldn't have got the subs and amp and saved that cash. I think I grew out of the bass craze.

 

[Kid Red]

For the most part that is how people set up their systems now days. I personally like to hear all my speakers and have it centered. One thing on a sedan it that the rears are mounted higher so you would hear them more then the fronts that are typically buy your feet. But if you do like I did and adjust the amp so you can get it play evenlly through all 4. I would say in a 5 I would amp all 4 and not do a sub. The whole thing in getting a 5 was for space, so why take away the space for a sub? You most likely wont be bassing it with the kiddos in it anyways. No that I have mine I wish I wouldn't have got the subs and amp and saved that cash. I think I grew out of the bass craze.

Word for word my thoughts. However, you think 4 6x8s will produce enough bass to curve those bass cravings? I have two Polk MMC 570s in the front, haven't bought the second set yet and was thinking of the Alpine 250 or the eclipse EA3422 to run the 4 6x8s. There aren't many 4 channel amps that will fit under the passenger seat, so I'm limited with size.

Also, for the sub, the 5 has a compartment in the back, 5" deep, 8" wide and 12" down. I think the JL Audio 6.5" sub would fit in there nicely allowing for a little bass.

What are your thoughts on the best, cleanest 4 channel amp around 10x10x2 dimensions?

What other pair of 6x8s would you pair with the Polks, or should I just get a second set of Polks?

Should I get a LOC? A 4 channel one I guess? And if I get the Eclipse, I need to match the voltage or something with a Line Driver. Do you know of an option that's maybe a line driver and line converter or does one do both?

I've always had thump, but like you said, kids means more pure sound then boom and there is little space for anything.

 

[theDRIZZLE]

I know the speakers dont make watts. i was just in a hurry, had to go to class. This is going to be for a 2005 mazda3 hatchback. Found one I like and the folks said i can get it in a week. I got a clarion head unit but buying a new eclipse headunit and i already got 2 12's in the back but changing to 1 12 in. eclipse titanium so im not really concerned with the bass up front.

 

[chuyler1]

I can't argue with you if that's your personal taste...but once you hear a properly configured car stereo that only uses front speakers and a subwoofer you'll never go back. Eventually you'll simply chuckle like me when you hear someone say "I like to hear all my speakers centered".

Ok, so you don't want a subwoofer that takes up your entire trunk. That's fine. We can work with that. There are plenty of other options that don't involve running multiple sets of full-range speakers in your car (unless you intend to install a video system and are looking for surround sound).

For a sedan, a few companies make 6x9" midbass drivers that could be used as subwoofers. For example, CDT Audio makes the CL-69 midwoofer that would be a great candidate. Kicker also used to make a 5x7 and 6x9 subwoofer but they have since discontinued them.

For the Mazda5 I'm sure there's a place that you can shove a small 8" subwoofer. You can always just put it in a small MDF box and remove it when you need the cargo space.

 

[chuyler1]

Could you post a picture of this rear compartment in the 5?

 

[theDRIZZLE]

sorry its kinda far away.

 

[chuyler1]

Yeah that doesn't help. I found some better photos from google but they don't show much detail.

 

[Kid Red]

chuyler1- Yea, there's no room for a box in the 5. The compartment isn't big enough for an 8" but it should fit the JL Audio 6w0 6.5" sub. I don't know any other 6" subs and it would be to round out the sound. I'll take pics tonight.

I just want the best, cleanest sound I can get. I'm not interested in booming, but obviously need some bass, and it doesn't need to be too loud as evident in my 50w @ 4 channel amp choices. Also, the 5 has 5x7(6x8) all around, so a 5x7 sub would be nice but I couldn't find any.

 

[theDRIZZLE]

I have the kappas in my protege now and i have the headunit faded to the front so its kinda centered.

 

[Kid Red]

Could you post a picture of this rear compartment in the 5?

Here is the 5 (which may have a different compartment than the 3 or Protege) It's at night so may not be as visible but should give you an idea. It's about 8"-9" wide. I think the 6w0 would fit in there but I just don't know where to start about making the enclosure.

 

[chuyler1]

I could get an 8" in there and it would probably be the same amount of work as putting an 6" in. You would have to fiberglass the entire compartment to stiffen things up, and then fasten a baffle to the front made out of 1/2" or 3/4" MDF that would replace the current cover. If you mount the woofer from the outside it will give you an additional 3/4" mounting depth bringing the total to roughly 5.5-6". That is more than enough for something like an Image Dynamics ID8v3.

 

[Kid Red]

If I went with a 6, I could maybe get the cover to go back into place and keep the look clean. Granted it may or may not be a rattle issue, but as a family car I don't want an exposed 8" woofer in the rear where groceries, heavy items, bags, toys, etc may be flying around.

If I were to go with the JL audio 6.5" (depth is about 4"-5" and 6w0 only needs 3.5") and built this out of fiberglass, where do I start? Also, I assume the fiberglass would then be a permanent part of that compartment as I can't see how I'd get it out. If so, I'd want it to look at clean as possible. I've bookmarked a few fiberglass websites but if you can pass along any tips that would be cool. Great job on your box btw. I also need to know where to get all the supplies, fiberglass, bondo, fabric, baffles, etc.

My overall goal, while wanting full, clean rich sound is minimal or zero intrusiveness. I don't want a sub box taking up room and I can't have exposed amps or woofers. So, any way to have a sub in that compartment it would have to be hidden and protected. Ideally, I'd use the same cover.

 

[Kid Red]

Wow, just checked out the Image Dynamics, I'd need a much bigger amp to drive that bad boy. I'm thinking of going with an Eclipse EA3422 which is 11x11x2 or the soundstream picasso PCA4.400 at 9.5x11.5x2 is cool I just don't know where to pick it up at. This amp will drive my 4 6x8s and somehow the sub.

I know I need LOCs, so I'm thinking about-*NE-774V* or the PAC OEM-2. Any input on LOCs?

 

[1sty]

I'm looking into the Alpine 250 (4x40w) and was going to use LOCs because I heard the sound is better. Is it worth it for the cost and extra install work sound wise to install the LOCs?

Also, I have the 5, and I'm thinking of putting in a JL Audio 6w0 in a rear compartment. I guess it would need to be made with a fiberglass front or something. Anyone have suggestions on rear compartments and using them to house a sub?

LOCs "can" sound better then built in converters but they also "can" be a source of noise in a system. I typicly prefer to use the speaker level inputs in the amp as they tend to avoid problems. Not to mention they save you money.

If you are looking into the Alpine MRP-F240, then use the onboard LOCs. I have installed a few of these this way and it has been fine. Its a good amp but I would look for something better. If for nothing else, then becuase it has only an on/off crossover. It is not adjustable. The newer alpine MRP-F240 has MUCH better crossovers and is the same price as the 240 now that the 240 is discontinued. Eclipse, JL, and Apline have all made a great 4 channel amp in my experience. I have had several issues or atleast poor preceived results from rockford fosgate, Clarion, pioneer and sony 4 channel amps.

AS for the 6" sub...not unless you are gonna use 4 of them. THey will leave you wanting more. In short, you will barely even hear it. Not to mention, you will have to build a custom fiberglass enclosure to install it in that compartment and that kind of time and material cost is a big waste for a single 6" you won't even here. Do yourself a BIG favor and make a small test box out of just MDF for the 6" first and get it hooked up. This way you will know exactly what to expect for sound from it.

I would go with 2 8"s. or even a single 10" instead in a standard box that will fit up against your seats. They don't need to be in a large box and they only need 125 watts rms or so these days for the entry level stuff. Plus you just buy the box/sub as one peice and plop it in. No major time or money wasted.