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#185751 - 21/10/2003 07:37 Thought regarding EQ
jbrinkerhoff
member

Registered: 02/04/2002
Posts: 148
OK, after spending about 9 hours working with a networking guy and a over-zealous consultant to install a load balancer on our new WIn2K server farm, I too a long ride and started thinking Empeg thoughts...

One thought was this - I finally found a bad MP3 that killed V3a... Oh well. It was a piece of crap I downloaded. Went to allofmp3 and paid for the album in lame 256kbs, and all is good now.

The real thought I had was this - ya know how the DSP in the empeg can split the EQ, but it winds up being left/right? And how that is pretty much useless for most of us, as front/rear would be a LOT more useful. I remember that it was "just the way the chip works" from the early discussions.

But, help me here, what if you were to wire your empeg in 90degrees off, for instance the front channels were the right side, and the rears the left. Now all you would need is the software to swap the channels (and fader/balance functions) and you'd be able to EQ the rear and front.

Follow me? Picture rotating your actuial speakers in a "musical chairs" fashion, one position clockwise. RF goes to RR, RR to LR, LR to LF, LF to RF. Now you have front rear eq, but the music is the "wrong way". Well, to the empeg its all just bits, so tell it to "move" the RF signal to LF, LF to LR, LR to RR, RR to RF. Boom all done with a software change and a simple RCA cable swap.

Thoughts? My brain hurts, so poke some holes in this.

Jeff


Edited by jbrinkerhoff (21/10/2003 07:38)
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#185752 - 21/10/2003 10:02 Re: Thought regarding EQ [Re: jbrinkerhoff]
sundayjumper
journeyman

Registered: 19/06/2002
Posts: 72
Loc: West Berkshire
Nah, that doesn't work, as you'd need four discrete combinations while currently you have two (i.e. left & right).

You have the four corners - FL, FR, RL, RR. At the moment, FL = RL, save for the overall level from the fader. So you have left & right EQ. In your idea, none of the pairs have the same signal to them. FL != RL because of your front/rear EQing and FL != FR because of the whole stereo concept.

I think you're stuck with the five band, four channel combination if you want separate front/rear EQ.

Steve.
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#185753 - 21/10/2003 11:01 Re: Thought regarding EQ [Re: jbrinkerhoff]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31600
Loc: Seattle, WA
As SundayJumper said, it will not work.

The music is encoded left/right, and it can only send it to the DSP as left/right. The DSP has only the left and right inputs, so there is no way for the software to send anything other than left and right to the DSP.

So if you were to wire the outputs rotated 90 degrees, you would be getting the left channel out of your front speakers, and the right channel out of your rear speakers. It would sound genuinely bad, with no stereo image, and any instruments that were panned left or right would get EQ'd strangely.
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#185754 - 21/10/2003 17:23 Re: Thought regarding EQ [Re: jbrinkerhoff]
PaulWay
addict

Registered: 03/08/1999
Posts: 451
Loc: Canberra, Australia
Isn't what you want to do to have four channels, and just change the rear EQs (RL and RR) to suit the rear speakers, and likewise for the front? OK, you're limited to five band parametric on each of the four channels, but each of those can be set separately and a five band parametric is easily equivalent to a ten band graphic if you spend the time to tune it.

To me it sounds like what you're trying to do is to get better EQ for the front and rear pairs by a clever combination of software and hardware changes. You're not asking for the left channel to physically come from the rear or whatever, yeah? Because the reality of the DSP is that it's delivered only two channels, left and right, and it then has two independent outputs (FL and RL, FR and RR) for each of those inputs. No amount of software mangling can change that.

Does that make sense?

Paul

P.S. I've got a couple of tracks on one CD that have a third '.1' channel encoded as the difference between the left and right signals - you wire a third speaker up to sit behind you with 'signal' coming off the left signal and 'ground' coming off the right signal from your ordinary CD player. I don't know if this changes the sound much, and I don't know if the theory behind it is OK or not, but there was definitely a signal there when I tried it a long time ago. It just didn't sound like much more than what was already on the left and right speakers...
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#185755 - 21/10/2003 17:42 Re: Thought regarding EQ [Re: PaulWay]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31600
Loc: Seattle, WA
Absolutely right, Paul. 5 parametric bands per speaker is actually a HUGE amount of control, if you're interested in tweaking parameters.

And by the way, anyone who's thinking of using the front/rear EQs as a poor-man's crossover... Don't. It doesn't work. An EQ is not a crossover. Use a real crossover or F-mods and then EQ normally.
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