As some of you know, I ditched my sub and large amplifier from the boot of my Z. I have never been a fan of having ICE on show and I wanted my boot back! So, my next process is to beef up the sound coming from the 4 speakers in the car.

 

Now the head unit is an Alpine IVA-W200RI - getting a little old now, but still a good system. It is 4x50w peak and 18w RMS - it also has a 6 channel pre-out.

 

 

I am a complete novice with car audio. I am not interested in a competition system as I can't think of anything more boring than taking part in a 'Sound-off' or ruining the car's performance and handling with half a tone of speakers etc. I want a basic system that sounds like the sort of thing you get in modern cars.

 

I want to do this by fitting an amplifier as I am not sure that my head unit does a good enough job. There's little mid-range and when you increase the volume, clarity is lost until eventually you get distortion. Now it's not terrible, but it isn't that great. I am not interested in fitting fitting larger (by diameter) speakers, so no 'get some 6x9s in the door' comments. I am considering fitting better door speakers with a tweeter component and a cross-over (fully hidden) based on the standard size of 16.5cm or pushing out a little to 17cm. The rears I'll leave as they're 2 way Alpine 13cm fitted in gutted out Bose speaker boxes.

 

The front speakers I am after are these : http://www.caraudio4less.co.uk/alpine-spr17s-2-way-component-speaker-system-p-162.html which are slightly bigger.

 

 

My doors have sound deadening in them and I am using the tin speaker carriers, also sound deadened and I have new cabling throughout.

 

What I want to do is fit a small hidden amplifier to power all 4 speakers that'll give me the sound quality you'd find in a new car. I want it all hidden away up under the dash (aware of airflow restrictions). Any advice gratefully received. I have spoken with Mark Derby about it, but can't remember what he said!

 

Small 4 channel amps are what I am really looking for - so any pointers would be great!

Edited January 3, 201411 yr by Funkysi
Shitty grammar.

i can get a alpine mini amp thats around 200w over 4ch .. RMS but u be looking around £230

Got any pics of it? Wouldn't kill the speakers I have? I never know how much they can take? 200 over 4 is still effectively 4 x 50? Excuse my ignorance, I know 50 is peak power.

yeah its 200w RMS over 4ch ... So u gonna get a true 50w per speaker .. Unlike your 18w now

Will that help with mid-range too? I don't know too much about how it will affect everything. I have 2 way Alpine 16.5cm in the doors. Not sure on their spec without taking them out again.

Ever seen one of these?

 

MRX F30 4-Channel

 

£175 quid m8 .. typo on last price

 

4-channel car amplifier

50 watts RMS x 4 at 4 ohms (75 watts RMS x 4 at 2 ohms)

150 watts RMS x 2 in bridged mode (4-ohm stable in bridged mode)

CEA-2006 compliant

Variable high- and low-pass filters (50-400 Hz, 12 dB/octave)

Variable bass boost (0-12 dB at 50 Hz) on rear channels

Preamp and speaker-level inputs

Class-D amplifier design

MOSFET power and output stages

Fuse rating: 25A x 2

8-gauge power and ground leads recommended - wiring and hardware not included with amplifier

9-15/16"W x 2-5/16"H x 9-1/16"D

 

wow thats quit an old way of boosting low output stereos

it uses the Hi speaker output .. Kinda crapy really

I guess you wouldn't recommend it. Looks like a neat design in terms of package-size and ease of fitment.

no m8 i wouldnt .. Not that i would say your head unit is to powerfull on the input .. they was only designed for outputs of 10>25w peak

Oh right, I see. Thanks for the heads up! I need to do some investigative work as to where to fit the amp and will report back. Would it totally transform the sound with that little amp you posted up?

If you run any of these high-power amps, be sure your alternator / battery / wiring are up to the job. W = V x A so 75W x 4 ch = 300W (assuming at full chat and your ears would be bleeding). 300W from a 12v source = 25A

I have fused power lead that I used for my previous sub/amp set up still in the car and a nice big beefy battery Mike. Alternator is stock TT....I won't be using it on full volume or all that much.

Simon, assuming you don't want to blow the doors off, then I have a Sony XM-2040 4 channel amp (true 20w x 4) you can have. It is old

school Sony - well built. It is also very compact (173x120x32mm). Got all the connectors. Specs in the attached file.

 

sony_xm-2040_sm.pdf

No need to upgrade your alternator ..

 

having an Amp thats a little more powerfull than u need is better than under driving a speaker .. Least u can fine tune the amp to remove all distortion

and tbh 200w amp dont need to mega cables or huge amps

It's going to be tight to fit an amp behind the dash. Will you not consider installing one in place of the open foam compartment under the false floor in the boot?

Simon, assuming you don't want to blow the doors off, then I have a Sony XM-2040 4 channel amp (true 20w x 4) you can have. It is old

school Sony - well built. It is also very compact (173x120x32mm). Got all the connectors. Specs in the attached file.

 

[ATTACH]76171[/ATTACH]

 

Thanks Andrew, that looks good. Spec sheet suggests it's 34 watts per channel RMS?

 

- - - Updated - - -

 

It's going to be tight to fit an amp behind the dash. Will you not consider installing one in place of the open foam compartment under the false floor in the boot?

 

That would involve running more loads more cable. I have considered it, but want to keep it as neat and compact as I can.

Thanks Andrew, that looks good. Spec sheet suggests it's 34 watts per channel RMS?

 

I tend to regard the "rated" output as more representative than the "max" figures. The amp was fitted in a 3 series and never

seemed (to me at least) to be underpowered for normal->louder listening levels. It was certainly better sounding than the built in

amps.

 

So with my '18w RMS', would that be 2w per channel more with this amplifier? Like I've previously said, I know very little about power ratings etc, so sorry if I come across a little ignorant.

If you check the spec sheet from Andrew it specifically says 35 watts per channel minimum RMS. So nearly twice as powerful as your existing.

 

From the depths of my audio geek past, RMS is higher figure than the actual continuous power (sine wave measurement vs DC equivalent) so I'm not surprised an amp rated at continuous 20W is also 35W RMS. And that's without going into Peak Music Power Output PMPO which is "think of the figure you'd like then double it" market-droid speak.

 

You also need to be sure that (like the Sony) the impedance is the same when comparing powers (both figures quoted into 4 ohms) and the distortion % is the same - which gives an indication of how "hard" the amp is working. So you'll get lower power figures if you test the amp at, say .05% THD compared to .5%. and let's not get into the definitions of "distortion".

 

http://uk.answers.yahoo.com/question/index?qid=20090108114331AALY08t is fairly sane as is http://en.wikipedia.org/wiki/Audio_power although my memory disagress with wiki on the equivalence of continuous with RMS.

Edited January 3, 201411 yr by Gio

I do like this automatic update feature, as Gio has just saved me a lot of typing!

I do like this automatic update feature, as Gio has just saved me a lot of typing!

 

But just interrupted my editing! Haha. Anyhoo all I had to say, this explains how easy it is for snake oil sellers to get into audio overclaims (says someone who used to work for Amstrad :) and even we were relatively technically accurate).

Ok, well if it's going to be twice the power of that which my HU currently produces, then it will certainly help. Thanks for the info - how did you want for it Andrew?

I think the main problem you will have with locating a separate power amp up front is adequate cooling. The obvious space to tuck a

small amp is behind the existing ICE unit on top of the transmission tunnel. However, it gets pretty warm in there (particularly on hot

days) and there is no airflow. So the footwell areas might be a better starting point in my view to look for a mounting location. Another

possible location is under the seats. That would also keep your wiring a reasonable distance from the existing wiring.

how did you want for it Andrew?

 

Me want nothing for it! If you don't end up using it, then let me have it back sometime.

As long as you're sure! Would be great to trial it!