A/M HU with factory speakers..problem?

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Phil08
Posts: 2
Joined: Sun Dec 09, 2007 10:18 am

A/M HU with factory speakers..problem?

Post by Phil08 »

I've got a JVC KD-G430 head unit which I just installed into my '03 Vibe with the M&T package. Didn't realize it had that 200w 2 ohm amp. Now, a friend of mine who's far more well-versed in the car audio department says there's a bit of an issue because the head unit ouptuts are rated for 4 ohm speakers, whilst the factory speakers are 2 ohm. I don't want to be going through the factory amp, I just want to bypass it and go straight from head unit to speakers, if possible, without burning anything up on the head unit or speakers. Can anyone elaborate and/or give me some advice on how to rectify the situation? I've heard of the Scosche FAI-3A. Is that the answer to my problem? Thanks in advance.
Phil08
Posts: 2
Joined: Sun Dec 09, 2007 10:18 am

Re: A/M HU with factory speakers..problem? (Phil08)

Post by Phil08 »

I should clarify, I'm most concerned about the HU, being rated for 4 ohm speakers, getting messed up because the factory amp/drivers are at 2 ohms.
dianebrat
Posts: 210
Joined: Wed Jan 17, 2007 11:48 am

Post by dianebrat »

If you didn't remove the M&T amp and are still running A/M unit into it, then it's a non-issue, you're not *supposed* to do it that way, but it works as long as you don't crank it up too high. (since the A/M HU isn't driving the speakers, it's only feeding the M&T amp)If you yanked the M&T Amp and the A/M HU is feeding the speakers direct, yes, you have a much bigger potential for issues.
last of the '06 AWDslava red monotone, preferred, sport, and side airbags
blue_can
Posts: 209
Joined: Fri Jul 13, 2007 4:21 am
Location: San Diego

Re: A/M HU with factory speakers..problem? (Phil08)

Post by blue_can »

Depends how much of an audiophile you are. Remember that the nominal impedance actually varies with frequency and is just not a resistance. The impedance is also inductive due to the voice coil.Many amps use a Zobel network to linearize the frequency response and this is normally designed to best fit the recommended speaker impedance. If you mismatch the speaker and amp you will get a worse freq response. Also it is possible that the amp may suffer instability.You should be able to get an off the shelf passive matching network.Here is a useful weblink I found where you can play around with the parameters on the Zobel network and see what happens.http://www.mhsoft.nl/spk_calc.asp
'07 Vibe
Sublimewind
Posts: 5140
Joined: Thu May 24, 2007 4:44 am

Post by Sublimewind »

I'm running my Sony with the stock speakers, no problems so far and it's been months... Link to my install.... http://forums.genvibe.com/zerothread?id=30794
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