 | | From: | Robin Bowes | | Subject: | Crossover in digital domain? | | Date: | Tue, 18 Jan 2005 23:00:57 GMT |
|
|
 | [Also posted to music-dsp mailing list]
Hi,
I'm playing around with my bi-amping audio system [1] and an idea popped
into my head: instead of feeding the same signal to both HF and LF
drivers and relying on the crossovers built into the speakers, why not
have a crossover in the digital domain and use two DACs each feeding a
separate amplifier?
[1] Squeezebox -> Art DI/O DAC -> Rotel RA820A (modified)(HF) + Rotel
RB850 (LF)
I had a quick google around and found several devices that have analogue
inputs and analogue outputs, but I couldn't find anything that simply
takes a digital input signal and filters it digitally, producing a LF
and HF digital output.
Does anyone know of such a device? How easy would this sort of thing be
to build?
Thanks,
R.
--
http://robinbowes.com
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| | From: | Jon Harris | | Subject: | Re: Crossover in digital domain? | | Date: | Tue, 18 Jan 2005 17:57:32 -0800 |
|
|
| It is pretty common to use digital crossovers in the installed sound market
(think stadiums, sports arenas, etc.) and even in high-end home audio. The
filtering requirements are quite simple, but finding something with the right
form-factor and price may be a challenge.
For a commercial product, check this out:
http://www.bss.co.uk/includes/product_list_include.aspx?header_id=6&archived_flag=0
but it may not be geared exactly to your market.
A DSP evaluation board with digital audio I/O may be the best bet if you like to
program. Or you may be able to find PC software that allows real-time
filtering.
"Robin Bowes" wrote in message
news:JygHd.11$Jo6.0@newsfe2-gui.ntli.net...
> [Also posted to music-dsp mailing list]
>
> Hi,
>
> I'm playing around with my bi-amping audio system [1] and an idea popped into
> my head: instead of feeding the same signal to both HF and LF drivers and
> relying on the crossovers built into the speakers, why not have a crossover in
> the digital domain and use two DACs each feeding a separate amplifier?
>
> [1] Squeezebox -> Art DI/O DAC -> Rotel RA820A (modified)(HF) + Rotel RB850
> (LF)
>
> I had a quick google around and found several devices that have analogue
> inputs and analogue outputs, but I couldn't find anything that simply takes a
> digital input signal and filters it digitally, producing a LF and HF digital
> output.
>
> Does anyone know of such a device? How easy would this sort of thing be to
> build?
>
> Thanks,
>
> R.
> --
> http://robinbowes.com
|
|
| | From: | Al Clark | | Subject: | Re: Crossover in digital domain? | | Date: | Wed, 19 Jan 2005 01:50:29 GMT |
|
|
| Robin Bowes wrote in news:JygHd.11$Jo6.0
@newsfe2-gui.ntli.net:
> [Also posted to music-dsp mailing list]
>
> Hi,
>
> I'm playing around with my bi-amping audio system [1] and an idea
popped
> into my head: instead of feeding the same signal to both HF and LF
> drivers and relying on the crossovers built into the speakers, why not
> have a crossover in the digital domain and use two DACs each feeding a
> separate amplifier?
>
> [1] Squeezebox -> Art DI/O DAC -> Rotel RA820A (modified)(HF) + Rotel
> RB850 (LF)
>
> I had a quick google around and found several devices that have
analogue
> inputs and analogue outputs, but I couldn't find anything that simply
> takes a digital input signal and filters it digitally, producing a LF
> and HF digital output.
>
> Does anyone know of such a device? How easy would this sort of thing be
> to build?
>
> Thanks,
>
> R.
You can do this with our dspstak family of boards. We have an S/PDIF
board as well as analog ADCs & DACs. We are working with the Visual Audio
group at Analog Devices that will allow you to create these kind of
systems graphicalkly as well.
--
Al Clark
Danville Signal Processing, Inc.
--------------------------------------------------------------------
Purveyors of Fine DSP Hardware and other Cool Stuff
Available at http://www.danvillesignal.com
|
|
| | From: | glen herrmannsfeldt | | Subject: | Re: Crossover in digital domain? | | Date: | Tue, 18 Jan 2005 15:17:22 -0800 |
|
|
| Robin Bowes wrote:
(snip)
> I had a quick google around and found several devices that have analogue
> inputs and analogue outputs, but I couldn't find anything that simply
> takes a digital input signal and filters it digitally, producing a LF
> and HF digital output.
Motorola has an application note for the 56001 for a graphic
equalizer. I don't remember if the I/O was analog with
appropriate A/D and D/A converters or digital. It seems that
the 56001 is fast enough for a stereo equalizer with a
reasonably number of bands, so should easily be enough for a
crossover.
-- glen
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| | From: | Uli | | Subject: | Re: Crossover in digital domain? | | Date: | 19 Jan 2005 03:03:20 -0800 |
|
|
| Google for BruteFIR as a PC software that enables you to build a
digital crossover by yourself. BruteFIR is Open Source and free.
Uli Br=FCggemann
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|
