Newb idiot trying to save money

[qtoche]

I am a newb audiophile, I have a pair of K701 headphones and a good headphone amp and I have to say that I am completely addicted to good music and I would like to expand that to my car and to my home. One thing that I have noticed is that there is a huge selection of used 12v automobile equipment. Mostly amps and subwoofers, but the used market for this stuff is huge and cheap...... Did I mention that I was cheap? Ok, I am and I want to find the best and least expensive to get my home system up and running. So, automotive amplification seems to be much less expensive much more availiable. Is there a way to use this equipment for my home? I don't know too much about electronics. I would guess that home amplifiers are dc and have quality inverters. I was thinking that I could get a really good inverter and run several inexpensive automotive amplifiers to build a home system. Or maybe use a battery and charger set up if the charger doesn't create too much noise. Maybe I could make it so that if the charger senses that there is a draw on the battery that it will wait to charge until after I turn off the amplifiers..... Here is what I have. 1 Onkyo reciever and a basic 5 speaker surround system with a powered Polk SW. I also have a PC with a couple of choices for DAC from my headphone equipment. CL or Wolfson(?) dac, either one of them sound very good to me and are very well implemented DAC units probably around 115 db snr. I see a very large swing in the automotive amplifiers from under 80 db snr to around 100 for the good ones.

Well, I guess I just need to ask if this wil work or not. I can run a well powered 2 ch 4 ohm amp with 4 8 ohm speakers for a 4 ohm load right? Will these automotive amps sound as good as home amps? I just can't get over the cost of home amps. I bought an older Sony home amp about a month ago but had to return it after I noticed the output transistors were blown. I would be interested in home amps if I can find some that cost about 100-200 bucks and put out 400 w rms like the decent automotive amps that I see.

Thanks for any information.

[aptquark]

There is a gentleman on here that has a web site dedicated to car audio information. It is VERY informative to say the least. I will try to find the link for you. What you want to do is possible. You can get very good sound from car components...you just have to get the power supply issue right. I'm not an expert in that area so I cannot make any suggestions.

Cheers.

[r0b]

My gut feeling says me a decent power supply for 12V will be expensive. I wouldn't like the idea of transforming down to 12v and the amping it up again.

I would suggest you look at used PA-amps maybe. Or maybe something with a Tripath class-d and smps would be your thing too.

If you like the car route, go for it.

[N4CR]

A good computer power supply can be had cheaply for 500w+ (in desktop pcs up to 1.5kw or so), often 30A+ for 12v or more on older single rail designs. You can confirm weather single rail or many small ones as it will be listed as smaller amperage per 12v circuit e.g. 12v1 10a 12v2 10a etc etc. Enermax is probably the rolls royce of computer powersupply, which would be nice and stable, clean power = clean sound. A good old single rail design one of which I use is the enermax EG465-VE with a 25A continuous 'even when mercury is in retrograde and the sparrows fly over the earthing pole' conservative rating - should be enough for anything under 500w.

Remember to be very careful with current even 12v if you start doing whacky things with psus. I've had a 9v battery short a thin piece of copper which cut through my middle fingerprint like butter (pretty unusual lol), so almost no current or voltage is safe really.

[AndrewT]

most CAR Audio is of very low quality. Most of Car Audio have grossly exaggerated specifications.
Any one selling off second owner gear must have a reason (unless it's to buy even more exaggerated powerful amplifiers). Could it be they were disappointed with the performance?

I seriously doubt that CAR Audio in the home can compete with a well designed and assembled home amplifier.

By The Way (BTW),
using higher impedance speakers helps CAR Audio power amplifiers to reproduce better.
If the Power Amp is specified for 4ohm duty, it will almost certainly perform better with 8ohm speaker. Just not quite as loud.
Similarly with 1ohm and 2ohm specified amplifiers. Using 8ohm speakers will be better.

[Jay]

Yes, car audio is of very low quality. Probably because of the "street noise" they don't need a high resolution requirement. Typical sound of the very best car amps can be compared with paralleled TO-220 IRF devices. You can build the Quasi Amp to beat them.

Commercial home amps are indeed too expensive for its sound quality, but a DIY amp can be built with 200 buck budget. The most expensive part is the transformer.

Gainclone LM3886 has different character. It is very cheap but the sound quality can be very high if you don't mind the harshness in the high frequency and not so well defined bass performance (But this is in comparison with very good discrete designs). If you prefer cleaner sound but less sonic then LM3875/LM3876 will do.

But the real performer is the speaker, and it is not cheap. Your speaker is unfortunately not suitable for audiophile quality sound system. May be you can invest on the speaker first, and use a cheap DIY chip amp (while investing on the 28V-0-28V transformer for better future amp)

[EBM_dude]

Indeed Jay. BTW I found out the hard way that MOST car speakers are utter junk and should be avoided at all costs.

Low power car amps are most of the time powered by chipamps. Those can be powered with a computer PSU and generally sound acceptable. Don't invest money here or else you will be disappointed. Go garbage picking for old car stereos as most of those contain such chipamps (i.e. TDA7376). Avoid units equipped with TDA2003/2004/2005. Also, don't get bothered too much with the claimed output power...

In the end, it is a much wiser idea to save your money and time to get a pair of TDA2030 or 2050 and create a chipamp yourself (been there, done that).

[jcx]

"pro" PA amps new cost less than you can buy the parts for individually

also powered monitors can give very good performance for the price if you listen nearfield


if you have any employment prospects or panhandling oppopurtunity you will spend less time earning and buying inexpensive finished products than getting into DIY

[Bigun]

Originally Posted by Jay

But the real performer is the speaker, [...] May be you can invest on the speaker first, and use a cheap DIY chip amp

FWIW, I agree entirely with this suggestion.

[sakis]

as a conclusion or a guide line

----all class AB car amplifiers are based more or less on the same circuit
---- quality of sound is average from topology aspect
---- but noise figures / cross talks / size issues /switching /powersuplly/qualityof material or built and so on makes it even worst
---- Typical designs with limmiters that are not acceptable when you think from HIFI till HI END
---- TRully are designed to operate in 4OHM or less and they will happily work better at 8 with a bit less boom boom

that was a brief sescription of normal car audio amps ...you will of course find many variation of the above depenting on the manufacturer

if you can live with that then your problem lays in energy power conversion to convert mains to 13.8 and not 12 volt ( computer power supply sugestion is simply out of the question unless is heavilly modified to proper voltage 13.8 and proper amperage )

totally the ammount of money you are going to pay for a system like that devided by quality of sound versus any comercial amp will be at least double and result by far terrible

so get our shelf a real amp ... and go ahead from there ...

happy regards sakis