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May 22, 2019, 10:04:29 pm

Author Topic: bi-amp or custom crossover?  (Read 136 times)

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Offline Jay

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bi-amp or custom crossover?
« on: May 13, 2019, 09:03:14 am »
I have been thinking of replacing my stereomourII with Beepre/Kaiju.  This would leave me with an extra amp of course.  My present system is turntable->SUT->Eros->StereomourII->Great Plains Audio 604 8hIII speakers with the available N604 8A crossover.  The system has brought me a lot of pleasure, but alas, I grow restless.

Now, I'm trying to learn about bi-amping and designing my own crossover.  I have Room EQ Wizard and a calibrated mic.

Would it be feasible to bi-amp using the Kaiju for the low frequency and the SII for the high?  There seems to be a dizzying array of active crossovers/DSPs etc. out there, but I wouldn't want to "de-analog" my system with all those extra chips.  :)

Then I think, well, if I'm going to go to all that trouble, aI could try to design my own crossover for the GPAs and stick with a single amp system.

Any comments on which approach might yield more palpable results, or be easier to achieve?
Jay L.

Offline Paul Birkeland

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Re: bi-amp or custom crossover?
« Reply #1 on: May 13, 2019, 01:02:14 pm »
Do you have a schematic for the N604 8A crossover?  If it has separate inputs for HF/LF, then you can biamp with the Kaiju and the Stereomour.  You can use your cell phone as a signal generator and a DVM set to AC volts to set the gain of the S2 and the Kaiju to be identical.

The active crossover may just not be necessary for what you're interested in doing, and depending on what's in the crossover, it may not even work properly.
Paul "PB" Birkeland

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Offline Jay

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Re: bi-amp or custom crossover?
« Reply #2 on: May 13, 2019, 05:29:11 pm »
I don't have a schematic, but I know there is only one set of inputs.  My thought was that if I biamp, I would have to add a second set of inputs to the back panel of the speaker and bypass the crossover altogether.  Then use something like these active crossovers between the Beepre and the amps.

https://www.xkitz.com/collections/active-crossovers-and-bi-amplifiers-1/products/linkwitz-riley-2-way-active-crossover-fully-assembled-xover-2

a picture of the GPA crossover.  I have the N604-8b, not 8a
https://www.picclickimg.com/d/w1600/pict/332062446199_/Altec-Lansing-GPA-N604-8B-Crossover-NEW.jpg

Jay L.

Offline Paul Birkeland

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Re: bi-amp or custom crossover?
« Reply #3 on: May 13, 2019, 07:29:04 pm »
Without a crossover schematic, it's still rather impossible to know.  Crossovers are sometimes a lot more than just book value filters, and without understanding all of what's going on with that PC board, it's very difficult to determine what you would actually need in an active crossover.  It may be that a fair amount of what's on that board has to stay even if you do end up with an active XO.

You could certainly contact GPA and ask them about biamping with that crossover.  They may even be able to make you a custom one that allows this.
Paul "PB" Birkeland

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Offline Paul Joppa

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Re: bi-amp or custom crossover?
« Reply #4 on: May 13, 2019, 08:46:57 pm »
The crossover (and various alternatives) circuits are widely available, along with forum threads (diyaudio for instance) on this very subject. People have been messing with the 604 crossovers for many decades.

I googled a bit last night and looked at several crossover circuits. They looked separable with a little rewiring. Both had equalizers for the tweeter/horn rolloff, and one or two adjustable controls - not simple or obvious.
Paul Joppa