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Recommended Posts

Posted

I have searched, I promise...

My 1999 MY has the 'improved' factory sound system - 6 ch amp in the trunk, components in the dash, components in the rear and woofers in the doors. Could anyone clarify the following for me....

1. Does the amp's three stereo pairs simply feed dash, doors and rears?

2. If so, is there a crossover (and where is it) that limits the signal to LF only for the door speakers?

Many thanks for any help.

Posted

The 6 channel AMP has three channels as you suggest. Front (dash), doors and rears. The crossover is in the AMP and you cannot only power the LF door speaker to my knowledge.

I have searched, I promise...

My 1999 MY has the 'improved' factory sound system - 6 ch amp in the trunk, components in the dash, components in the rear and woofers in the doors. Could anyone clarify the following for me....

1. Does the amp's three stereo pairs simply feed dash, doors and rears?

2. If so, is there a crossover (and where is it) that limits the signal to LF only for the door speakers?

Many thanks for any help.

Posted

Thanks. So as long as I keep the current channels-to-speaker location assignment I should be ok upgrading all my speakers? I was going to put 4" Alpine SPG (co-ax) in the dash and rear with Alpine SR woofer in the doors.....

Posted

The impedances will likely be wrong for the door speakers. The M490 Harman Sound Package uses 2 ohm impedance speakers in the doors, and 4 ohms in the dash and rear sides. I doubt it would do any damage, but the volume level will be lower if you fit 4 ohm speakers to the doors.

Posted

Thanks Richard. Speaker impedance is one subject I've never quite got my head around...

I found it hard enough finding any replacement 5.25" woofers, let alone 2 ohm models :-)

I guess ultimately I'll have to replace the amp as well (I kind of knew that was coming)...

I was confused initially by the fact that the head unit wiring only takes 'front' and 'rear' to the amp - I guess that makes sense with your helpful advice that the crossover is built into the amp.

I'm guessing that the the 'front' signal goes to the amp, is split by the crossover and then sent to two of the amp's three stereo pairs. The 'rear' signal is simply output by the amp's third stereo pair?

Posted (edited)

4 channels from the head unit to the amp, but it is still stereo output from the head unit (not 4 "distinct" channels). The amp then sends the left signal to front left and rear left. And right to right speakers/etc.

The crossover simply sends the higher frequency signals to the dash speakers and the lower frequency ones to the door speakers. If you have a subwoofer the crossover sends the lowest frequencies to the bass speaker.

I've read about plenty of people dropping in standard 4 ohm speakers on the stock amp and it works fine.

If you are after MUCH more sound though, you'll certainly need to do some upgrades (amp, speakers, etc.)

edited for accuracy

Edited by logray
Posted

Iogray - I'm confused. It doesn't take much :huh:

Are you saying that the head unit only sends one stereo pair to the six channel amp, and it's the amp itself that 'divides up' the signal into front, door (LF) and rear pairs?

If that's the case how does the 'fader' control on the head unit have any effect? Surely if it's only sending one pair then the 'fader' would 'move' the sound from min to max rather than rear to front?

Posted (edited)

This is correct, stereo output, but individual channels from the HU to the amp. Fading simply lessens the output (volume) to front/back/left/right from each amp channel, it doesn't move sound.

i used to run 5.1 true surround in my truck, which requies a 5.1 source and processor.

The output from your mp3 or cd is only 2 channel stereo.

edited for accuracy

Edited by logray
Posted (edited)

I'm sorry if I'm being thick, but I still don't understand how you can send only one (stereo) source to the amp and then have the fader control on the head unit affect the amp's output front / rear. Surely the the head unit would have to send two (stereo) sources, front and rear?

Unless of course you're talking about a digital output, which I don't think you are?

Edited by le bouch
Posted

On the Harman M490 amp there are inputs for signals from FL, FR, RL & RR from the head unit. Balance and fader controls are in the head unit. There are only 5 wires though, for the positive signal connections. The negatives are a common connection.

Drop me a PM with your email address, and I'll send you the wiring diagram.

Posted

Sorry for the confusion, for some reason I had the CD changer on my brain, which does have a stereo pair output. I'll edit my posts above for accuracy.

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