technical questions about stock radio

[MrTube]

Ok I know i'm pushing my luck on this one but I wont know unless I ask

Does anyone know what chipamp the factory radios use "non-monsoon"? I assume any 2000+ is most likely the same chip.



If anyone has a factory deck laying around open, Theres most likely a somewhat large chipamp near the back bolted to a heatsink, I need the number off of it.

I may have a cheap mod in mind. Ive got a gut feeling its going to end up completely not worth my time or effort tho.

[matt5112]

you'd need to look at the entire amp design first before you mod, you need to look at the class, the power supply and the rails.

Some amps might benefit from larger chips, some benefit from a beefier power supply or more caps.

All comes down to amp design for which you'd need the schematics for it.

I've got a radio out of a 2002 I'll open and take a look for you if you'd like.

[MrTube]

matt : i am assuming the radios use a chipamp. The chipamp data sheet will tell me 98% of what I need to know.

If you could have a look when you have time i'd appreciate it greatly.

my assumption is it may be capable of driving a 2 ohm load under certain conditions, such as if cooling needs are met. But I won't know anything until seeing a data sheet. National semiconductor an ST have some nice chips out there. The house amps I built use national LM3886's in bridge-parallel with integrators that keep dc offset near 0. those are used for my woofer amps, while a single LM3886 is used to drive tweeters directly.

Chances are the GM radio uses a simple chipamp for all 4 channels, which is driven directly from 12-14 volts. very simple design, has very few parts and works pretty darn well., most of the time they even have EQ\tone built in as well.

Reason I thought of this is I noticed infinity kappas are now 2 ohm. if i could do a simple mod to the factory deck and throw in some kappa 6x9's and 5 1/4's or 6 1/2's and be done for a bit, i'd be happy for now.

[matt5112]

This may have to wait till monday since it looks like its full of odd bolts and such.

[MrTube]

matt : thats fine, I really appreciate your help dude. I've got a feeling 4 ohm is as low as its capable of. But i'm hoping i'm wrong

At one point i'd like to get my a/d/s amps installed in the car with a really good head unit, but until i have the time and the money for the headunit.

[matt5112]

know this... the factory front speakers are a 4 ohm woofer wired in parallel to a 6 ohm tweeter.

[MrTube]

Matt : getting depressed. Been almost a month without the setup I had in my truck, At work I run a pair of 1990s A/D/S house speakers, I think model L-300E or something. they have the same 5 1/4" woofer and 1" dome tweeter they used automotive apps, were around $450 for the pair. I'm driving them with a 1978 pioneer receiver and it sounds SO much better then the stock GP system the GP system sounds way too bassy\boom at low levels and then looses all of it at higher levels due to the loudness curve they have programmed. Its a shame a pair of 5 1/4" woofers in tiny cabinets outperform a pair of 6x9s AND 5 1/4's in a car....... BY A LOT.

[matt5112]

Its a cheap car.

A lot of things on it are cheap.

[MrTube]

matt : your really not helping

The stock GP system is far far nicer then older factory systems. Like the 1970s and 80s systems with the 4x10's and the 3" in the dash...

my 92 pickup came stock with 4 4x6's which is why i had a new system in it within a week.

[matt5112]

The monsoon system isn't that bad, neither is the bose system.