Amp under seat?

[pbarcher]

I would like to mount a four or five channel amp under the driver's or passenger seat in my 73, perhaps a Sony XM4S Slim Line 4/3 or Alpine PDX-5. These are the smallest high quality amps that I can find, but with wires may still be too big.

Have any of you mounted the amp under the seat? If so, can you give a model number or any other tips?

Thanks.

Peter

[fiveleaf]

I didn't have stock seats in the first place, but bolted the EQ to the back of the passenger's seat, and the main amp to the back of the driver's seat.

The second amp mounted under the drivers seat. There was about 2" under there to play with; I used the "PowerClass 4400" for this. 4 Channel @ 50 WRMS at 4 ohms, I believe. I bridged the four outputs, and ran two front speakers.

I recently ripped out the heater core and blower motor and relocated the amp and EQ to under(ish) the dash.

It is important that you (1) have in inline fuse by the battery, and (2) run the positive power wire to the amp from the battery, and on the opposite side of the car as you run your speakers.

My re-modeled setup is not ideal, as there is a short length where power wire runs parallel to speaker wire. One 90* junction would be ideal. Here's something to give you an idea of what I mean (just note that the rainbow speaker wires are on the opposite side as the red power wire):

I also found these tech articles useful:

http://www.caraudiohelp.com/newsletter/index.htm

Edited February 26, 2010 by fiveleaf

[fiveleaf]

I can't get the uploader to work. Here's what I ment with the wires (drew it when thinking of where everything could go)

Edit: Re-learning how to resize in HTML. I'll be back.

Edited February 26, 2010 by fiveleaf

[Jetaway]

Yeah, I've mounted an amp under my seat. In quite a few cars, as it is generally a good place for an amp.

I have a 20 year old Harmon-Kardon CA-215 (Rated at 12W X 2, but it doesn't give anything to most 50W amps) under my seat. Fits with plenty of room to spare. Which probably ain't gonna help you much.

Far be it for me to discourage someone from buying a nice piece of equipment (I checked the specs on the Alpine), but let me ask you this:

Do you really need 4 X 70 watts?

You don't have a lot of space to fill in a Z. Off a strong signal, I hit 110db (average, not peak) in my 240Z using the H-K and a nothing special 4-channel Phase Linear head unit rated at 13W X 4 (came with car). OK, the H-K plays much larger than its rated 12W, but 2 of the Phase Linear's channels aren't contributing much, if anything, to the dbs as they are only driving a pair of tweeters to add some imaging. And I don't have a sub kicking it up either. As a bonus, though some may find it a shortcoming, it isn't that loud 10 feet away from the car.

Depending on what kind of speakers you are planning on getting and where you are mounting them, you might be quite happy with a 15W -- 30W head unit and a 50W stereo amp. Or maybe a lower power, and presumably smaller, version of one of the amps you are considering.

Or if you still want the power, can't fit the Alpine or Sony, consider a pair of 2-channel amps, one under each seat.

Home audio has gone absolutely bat-$^!# crazy over connectors, nonetheless, in the electronically noisy automobile environment it makes sense to pop for quality interconnects. Monster, of course, is one, I'm sure there are others just as good and less expensive. Be aware that while you can bend them shorter, you shouldn't, and should allow 3 1/2 to 4 inches, minimum for the plug into the amp. Technically, with the short runs and relatively low power, 18 gauge speaker wire would work just fine. Personally, because of the physical hazards in an automobile, I prefer a heavier wire, say a 14 gauge. Your audio dealer will be more than happy to sell you 12, 10, or 8 gauge wire, all of which you pay through the nose for and none of which will make the slightest difference in sound.

Do use a heavy gauge wire for the amp power supply and run it directly to the battery. Make sure your ground connection is solid. I assume the amp grounds through the case, it wouldn't hurt to sandpaper the floorpan where the amp makes contact. Don't buy a noise suppression / conditioner at this point. I've put decent systems in my cars for thirty years and if there is one thing I've learned it is the absolute impossibility of predicting whether a noise problem will exist or not. If it sounds like total crap, you have a bigger problem than a noise suppressor can cure and you'll need to figure out and fix the cause of the problem first. If there is just a little noise then you can splice a suppressor into the circuit. If it's clean, you've saved yourself a few bucks.

And finally -- its the speakers that ultimately make the sound. Good quality speakers driven by a middling power plant sound make a better sounding setup than middling speakers driven by a quality amp.

Chris

[Walter Moore]

So, any advice on the best quality and sound available in speakers today?

That is meant to be a serious question by the way. The speakers in my car right now are old used parts that I bought cheap in the 80's, pulled out of my Volvo after my better half drove it through a stone wall, and were stored sitting on a steel shelf for 20 years. You could say they have seen better days.When I have to crank the stereo up on the interstate they sound really bad.

(By the way, my wife walked away from the crash without a scratch. By golly those cars are safe!)

[JonnyRock]

So, any advice on the best quality and sound available in speakers today?

I've always been impressed with Polk Audio, so that's what I put in my Z. Worked @ a car stereo place at the time so got 'em at cost which didn't hurt. They're not the most expensive, but not cheap either. No complaints so far.

[TriDawgn]

I have my professional installer certification and i've worked in a few shops and i've seen a good range of products. Kenwood is really tough to beat $ for $. Depending on how much you want to spend i like the Pioneer A series speakers. I have a pair in my civic at the moment and they sound great right off the cd player. They also make amps for tight spaces. Up from that is pioneers Premier line of speakers and amps. If you've got deep pockets and can find a dealer, Focal makes some truly beautiful products. And this is just me, but you wouldn't catch me dead with sony anything in my car. walmart brand IMO. Ive got nothing against alpine or clarion, just never caught my attention with anything.

[Zs-ondabrain]

Alpines new amps are small and powerful and will fit almost anywhere.

The MRP-F300

Per channel into 4 ohms: 50W x 4 (0.08% THD)

Foot Print (WxHxD) in: 10-15/16'' x 2-23/64'' x 9-27/32''

Amplifier Type: Class-A/B

Channel Design: 4/3/2 Channel

-OR-

The PDX-4.100

Per channel into 4 ohms: 100W x 4

Heat Sink (WxHxD) in: 10-1/8'' x 7-9/16'' x 2-7/16''

4/3/2 Channel Power Density Digital Amplifier

http://www.alpine-usa.com/product/category/amplifiers You'll find them NEW and much cheaper than the MSRP by over $100 less on Amazon.

[fixitman]

Perhaps the attached wiring schematic will be helpful for an under-seat amp installation. The layout was used for a stereo installation with separate tweeters mounted in the tail light covers.

Regards,

Fixitman

Datsun260Z-SoundSystemWiringSchematic.pdf

[fiveleaf]

I really don't believe the car is the place to go all out with top of the line equipment... but I do enjoy quality sound reproduction for the car. I'm going to leave out competition units. Though they are very nice... they usually have the best quality (say a 15% increase from a quaity brand), but cost twice, 3x, or 5x as much. For me, that's overboard in a car.

Everyone will have their opinion on brands. Brands like Alpine, Eclipse, Genesis, Focal, Earthquake, McIntosh, Precision Power, Fusion, and Precision Power make some very nice components (amps, head units, speakers) all around.

Head Units? Clarion and Pioneer are on par with the above list.

Amps? Phoenix Gold, Rockford Fosgate "Power Series", and Orion are on the above list.

More high mid>mid>"wallmart level"?

Clarion (Amps, Speakers), Kenwood, Polk Audio > Boss, Infinity > JVC, Jensen, Sony.

Stay away from SPL, Rockwood, Kenford, Legacy, Performance Teknique, Sheerwood.

This is not a complete list, and I have missed many. They are also subject to my personal bias.

I suggest joining an American online audio fourm. Usually there will be a car audio sub-section. And clasified adds that are of much better quality than kijiji or craigslist. Beware of bad advise -- some fourms are better than others. I don't know if

I have to disagree with the above comment on speaker wire; they are not all created equal. Just make sure not to run them parallel to your (+) power wire. Even the ammount that overlaps in my diagaram is usually unacceptable.

Here is a decent article on wires:

http://www.caraudiohelp.com/car_audio_wiring/car_audio_wiring.htm#car_audio_speaker_wire

Zs, don't tempt me with those small amps... I'm overbudget already.

Edited March 1, 2010 by fiveleaf

[Zs-ondabrain]

You want tempting? The MRP- F300 starts at only $132 on Amazon. Not bad for a small 4 channel amp, eh?

http://www.amazon.com/Alpine-MRP-F300-Amplifier-V-Power-4-channel/dp/B0013TVALU

And the mono sub amp (MRP-M500) is only $139 to start.

http://www.amazon.com/Alpine-M500-MRP-M500-Amplifier-1-channel/dp/B0013TQ6FK/ref=pd_cp_e_2_img

Sorry to put you thru this...

Dave

Edited March 1, 2010 by Zs-ondabrain

[fiveleaf]

So, any advice on the best quality and sound available in speakers today?

You really have to ask yourself what you want from a system. Do you want to reprodce the orginal music, and pick out the different insturments as you listen? Do you want to invision yourself at a live rock concert and hear it as it was played... or do you enjoy turning up the base every now and then..

Absoulote Sound Quality (SQ) systems very considerably from max Sound Pressure Level (SPL or "thumper") systems in everything from the size of the speakers, materials used for speakers, and especially enclosure size (and power required).

A subwoofer will sound quite differently depending on the enclosure (larger genreally = SPL, while smaller = better response time/less lag). Many people (even those looking to spend a lot on a stereo) are adverse about putting a sub in their car (especially a z!). I am not, and believe that they are necessary to produce the sound you would hear from say... the drums, or the tuba, or low resonating base guitar notes. A sub does not have to mean loud base.

There are many fourms availbiale; try google searching for them.

Look out for posters with little rep/post count. Even post count is misleading.

As far as car audio is concerned, I use www.CanadianCarAudio.com, but www.CarAudioFourm.com is popular as well. Different crowds, same idea.

Edited March 3, 2010 by fiveleaf
turn links into hyperlinks