G
Guest
·So, I got my '4-channel' stereo running. It's pretty good, and POWERFUL!
But, with the lack of a discrete 4 channel source, it's little better than
Stereo, unless you use one of the 'tricks' built into the amp. It has
Matrix SQ and Quatravox. Matrix SQ was a industry standard to take a 2 or
4 channel source and 'synthesize' 4 channel. It works OK. Quatravox was,
IIRC, developed by Radio Shack and is like "Stereo Wide", it takes a 2 or
4 channel signal and plays with phase relationships to synthesize and
expand a 4 channel 'image'. It works OK but you can hear the phase
shifting.
The real question is this: I used to take a stereo for my car and install
new speakers, esp. decent speakers for the rear deck. In the '80s Matt
Polk came out with his 'imaging' speakers, and they were GREAT. But, you
had to sit in an exact location to get the effect. If anyone remembers
these, they made the band appear to be positioned around the room. It was
100 times better than headphones.
He did this by feeding a 'component' from the opposite channel to the
other channel, at a lower volume. This cancelled out crosstalk and made
pure left and pure right from each speaker.
So, I would add a pair of 6x9 speakers to the rear deck of the car. Since
I almost always had hatchbacks, this would leave the original speakers in
their original locations. So, here's what I would do:
I would add an amp, sometimes two, one for the front and one for the rear.
By tapping the RCA outs from the preamp, this left the 4 original powered
outputs from the stereo intact. So, I would take the stronger channel,
usually the rear, and cross the speakers left as right and right as left.
Since I had 65-75 watt amps, and the outputs were typically 12-20 watts,
there was a 'deficiency' from the head unit's amp. Now for the trick: I
would put the car's original speakers out of phase. Then by playing with
levels and balancing, I would 'even' the system out. I never really
acheived the effect of the Polk speakers (I was trying to emulate $1400
speakers with $100 worth of components...) BUT, what it did do was to make
it appear as if the speakers were about 4 feet 'outside' the car. This
effect worked fairly well.
So, my question is, although I never appeared to do any damage to anything
(I ran this setup in my 'Hachiroku' for four years until the system (and,
indeed the whole car!) got ripped on Good Friday night. I got the car back
but never really built the stereo back up.) Since the RCA outs are picked
up at the preamp, and are a voltage with no 'load' associated, this left
the output stage virutally untouched.
Since the speakers were balanced amp-to-amp (ie, 4 ohms wired to the head
unit amp, and 4 or 8 ohms to the external amps), are there any ill efects
to putting speakers out of phase. In case you don't know what this does,
let's take the woofer: when the 'in-phase' side is pushing out, the 'out
of phase' side is pulling in. Since the load is balanced reactance-wise,
there SHOULD be no ill effect on the amp.
Right?
But, with the lack of a discrete 4 channel source, it's little better than
Stereo, unless you use one of the 'tricks' built into the amp. It has
Matrix SQ and Quatravox. Matrix SQ was a industry standard to take a 2 or
4 channel source and 'synthesize' 4 channel. It works OK. Quatravox was,
IIRC, developed by Radio Shack and is like "Stereo Wide", it takes a 2 or
4 channel signal and plays with phase relationships to synthesize and
expand a 4 channel 'image'. It works OK but you can hear the phase
shifting.
The real question is this: I used to take a stereo for my car and install
new speakers, esp. decent speakers for the rear deck. In the '80s Matt
Polk came out with his 'imaging' speakers, and they were GREAT. But, you
had to sit in an exact location to get the effect. If anyone remembers
these, they made the band appear to be positioned around the room. It was
100 times better than headphones.
He did this by feeding a 'component' from the opposite channel to the
other channel, at a lower volume. This cancelled out crosstalk and made
pure left and pure right from each speaker.
So, I would add a pair of 6x9 speakers to the rear deck of the car. Since
I almost always had hatchbacks, this would leave the original speakers in
their original locations. So, here's what I would do:
I would add an amp, sometimes two, one for the front and one for the rear.
By tapping the RCA outs from the preamp, this left the 4 original powered
outputs from the stereo intact. So, I would take the stronger channel,
usually the rear, and cross the speakers left as right and right as left.
Since I had 65-75 watt amps, and the outputs were typically 12-20 watts,
there was a 'deficiency' from the head unit's amp. Now for the trick: I
would put the car's original speakers out of phase. Then by playing with
levels and balancing, I would 'even' the system out. I never really
acheived the effect of the Polk speakers (I was trying to emulate $1400
speakers with $100 worth of components...) BUT, what it did do was to make
it appear as if the speakers were about 4 feet 'outside' the car. This
effect worked fairly well.
So, my question is, although I never appeared to do any damage to anything
(I ran this setup in my 'Hachiroku' for four years until the system (and,
indeed the whole car!) got ripped on Good Friday night. I got the car back
but never really built the stereo back up.) Since the RCA outs are picked
up at the preamp, and are a voltage with no 'load' associated, this left
the output stage virutally untouched.
Since the speakers were balanced amp-to-amp (ie, 4 ohms wired to the head
unit amp, and 4 or 8 ohms to the external amps), are there any ill efects
to putting speakers out of phase. In case you don't know what this does,
let's take the woofer: when the 'in-phase' side is pushing out, the 'out
of phase' side is pulling in. Since the load is balanced reactance-wise,
there SHOULD be no ill effect on the amp.
Right?
