Amp question

[Ian C]

Here is a question for you car audio experts - yer average head unit cheerfully amps the output across four channels with an internal amplifier.  Not good enough for the connisseur, but good enough for me.  Now, if I came into possesion of a nice head unit that plays mp3's (hurrah!) but doesn't have a built in amp (boo!), can I get a small module that sits behind the dash, between the speakers and the head unit, and does the same job that a built in amplifier does?

I am not going to arse around with 2- or 4-way amps the size of a playstation, and cabling that looks like it's off electricity pylons.  If it can't be done with a small black box, bye bye mp3 player, hello easy-to-install-and-does-the-job CD player...

-Ian

[matt]

What exactly is this head unit?? If it needs a slave amp I would've thought they came with it.....

Otherwise you could get a CD player that has a line-in facility and hook the mp3 player thro this ....... best of both worlds?

[Matt Harwood]

A lot of top end head units will not have an internal amp because even when not connected to the speakers it can internally distort and have an adverse effect on the output from the preout.

Yes you can get smallish 4 channel amps but, in my experience, they usually aren't that great. I think Phoenix Gold did a little 4 channel amp a while ago, 4 x 20 rms. I'll see if it's still available.

Personally, I'd get a smallish, (playstation sized), decent amp. It would only need 8 awg cable and could still go under the passeger seat easily. It'd take about 1 to 1.5 hours to install and sound far far better.

What head unit do you have?

[Ian C]

I've got a Rio MPEG unit - the 10gb hard drive Linux jobbie.  I really, really don't want an under-the-seat amp.  As I'll only be playing mp3's, quality isn't an issue :)

Currently I'm perfectly happy listening to MP3's converted to WAVs, recorded to a cd, and played via a single disc slot head unit, running the stock speakers off the cd head unit's internal amp.  That gives you an idea of the level of quality I'm after :biggrin:

As I have a CD player that will work at no cost to me, I'm not spending £100+ and hours (as I've never plumbed in an amp before so I would need to research it and trail & error it) installing an amp.

So I don't know what an 8 awg cable is, and 20rms doesn't mean anything either  :)  If a £100 cd head unit can have four channels amped to my requirements built into it, I don't see why I shouldn't be able to get something similar as a seperate unit for not much money - or am I being naive?

-Ian

[Matt Harwood]

Sorry Ian, Phoenix gold don't do their small amp anymore. However I have just remembered that Sony were doing one recently... I'll look this up for you.

I can understand, (sort of), about not wanting to put an amp in although, having read some of your previous posts, installing an amp would be a walk in the park for you. I can tell you all you would want/need to know. - Still we'll cross that bridge if/when it comes to it. I'll try the Sony thing first.

I know what your saying about built in amps but the problem is, theres not a market for it to make it worthwhile for the manufacturers. Bear in mind that a "small" 4 x 80 watt amp can retail for £120 inc vat deduct vat £102, deduct dealers margin £68, and that'll give them a margin of around £30. See what I mean.

[Mycroft]

Sony do a little 'hide it bhind the dash' amp 4×55w not flash very cheap and will do the job perfectly.

[Matt Harwood]

Yeah, looks like a little silver chunk of metal. That's the one I had in mind. I think it's around £79 but I'll see what I can get it for... If it's still available..

[Ian C]

Thanks, Matt, but due to financial pressures I've decided to can the whole thing and sell the MP3 player (if yer interested :) )

-Ian

[Matt Harwood]

Sorry, already got a Alpine mp3 autochanger.

Not 10 gb admittedly, but id does mean that I dont need extra bits floating around the car... Got enough bits already. RLTC, DSBC, Car phone cradle, Alpine time alignment unit...

Ash, don't s'pose you fancy doing another headliner install? Justins looks bloody nice.

[DArby]

Ok Matt, whats an Alpine Time alignment unit ???

and do i want one :)


Dean..

[Adam W]

How much are you after for the MP3 player, and how would I hook it up to my existing Sony Minidisc head unit which is powering the speakers - I really don't want to buy an amp as well for it!

[Matt Harwood]

A time alignment unit takes away most of the need for trying to get the ideal speaker positioning. If you have a sub in the car, that will usually be mounted in the boot, about 1.5 meters from your ears, then you'll have the off side rear speakers about 0.5 m away the front about 0.3m, the n/s front about 1m and the n/s rear about 1.2 or something like that.

Although these distances aren't huge, obviously there not even. with a time alignment unit you can alter the speaker outputs by 0.1 millisecond steps. - The difference is amazing. true stereo, with no delay from the sub. (anyone that says they're sub has no delay has either spent ages setting and positioning their speakers or has never heard a good quality system before.)

It also has an added advantage of a parametric eq on each speaker inc. sub

Do you want one.... - I wouldn't be without one.

[GavinL]

Quote: from Ian C on 8:51 pm on April 2, 2002[br]Thanks, Matt, but due to financial pressures I've decided to can the whole thing and sell the MP3 player (if yer interested :) )

-Ian


Ian ...I have a stock UK spec amp if you want it.

[Matt Harwood]

A-ha!

Does the unit have RCA outputs? - Not that really matters if it's jack plug style you can still get converters..

Once we can get to the stage where the audio will come out of RCA's you can get an FM modulator that'll work with any radio by putting the audio signal in via the FM radio. - JVC make a good one that I can get for about £50ish

Why I didn't think of that in the first place I don't know! :)

[Alex]

Quote: from GavinL on 12:38 pm on April 3, 2002[br]Quote: from Ian C on 8:51 pm on April 2, 2002[br]Thanks, Matt, but due to financial pressures I've decided to can the whole thing and sell the MP3 player (if yer interested :) )

-Ian


Ian ...I have a stock UK spec amp if you want it.


I have no AMP...it was ripped out by one of the previous owner...

Cost please?

Private Mail me if necessary...

Will this make any difference to my Clarion 4x40W Double Din Head Unit (ADX5555) (ADX5655 is the current version...I think)

[Matt Harwood]

Sorry Alex, a Toyota amp won't easily work and certainly wont be of any benefit to your Clarion unit.
You'd need an aftermarket amp for that.

[Barry]

Having listened to the time alignment in Matt's car today at pod (thanks for the Demo Matt), I can honestly say I was amazed at the difference it made to the sound quality, an absolute must if you have the money for it, I have one on my shopping list already, just gotta get the turbo's sorted and my holiday out the way! :)

[HedgehogSandwich adi]

Timing issues are the biggest problem with car stereos, and seeing as a car is THE worst place to put any kind of sound system then id advise any kind of' time alignment' as they put it (id just call it a glorified delay unit). shame it only works for the driver though :)

How much of a difference does it actually make? Even with standard car systems the delay is probably only 3 milliseconds or so (more for the sub obviously), which under normal circumstances is indifferent, yet in a car i suppose it's more noticeable.

Parametric EQ? Got to learn how to recognise your frequencies first :) Doesn't anyone make a full range graphic EQ for a car? And if not (slamming fist on table)...why not?

adi



(Edited by HedgehogSandwich adi at 10:40 pm on April 10, 2002)

[Matt Harwood]

You can get the best of ALL worlds with Alpine's F#1 status processor. It has 30, (that's pretty much all of them), bands of equalisation 1/3 ocatve for EVERY channel! (6 channels, designed for Dolby Digital and DTS as well) It also has phase alignment to compensate for sound reflections and full crossover facilities 12,18 and 24 db per octave - Downside is, it costs £3500!!!

Phoenix Gold do a PC based system with 30 bands of eq with adjustable Q on every band, again, full crossover facilities. This system is only for front L & R + Sub. - This goes out at £999

Pioneer do a crappy one for £429 but don't bother with it. it's dated, difficult to use and pants.

I'd go for, and I have, the Alpine PXA-H600. It does enough to tidy up the sound anomolies and cost £499. (Theres a better one coming out in August that is DIN sized and does more for the same price.)

It does make a big difference. You have to hear it to apreciate it. I'm happy to demo it to anyone that's even remotely interested. Just ask next time we meet.

ps. sorry if some of the above sounds like technobabble. I'm happy to explain if you want. And yes, I do have an audio anorak! :)

[HedgehogSandwich adi]

Quote: from Matt Harwood on 6:45 pm on April 11, 2002[br]

ps. sorry if some of the above sounds like technobabble. I'm happy to explain if you want. And yes, I do have an audio anorak! :)

Nope thats okay, i worked as a live FOH sound engineer for several years :)

adi

(Edited by HedgehogSandwich adi at 7:49 pm on April 12, 2002)