Digital Sound Processing

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Ray P
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#1 Digital Sound Processing

Post by Ray P »

Over the last few weeks I've been thinking on a new speaker project and, as a result, on speaker crossovers. One of the options available is to achieve crossover in the digital domain so I've had a cursory look around the internet on that topic and found this interesting;

http://www.minidsp.com/

I know its not purist hifi, but this little module offers digital sound processing that could be used for room correction, crossovers, etc. It is, apparently, capable of handling 192K 24bit data. To me it appears possible to plug one of these in front of a dac; in my case of looking at a two-way digital crossover I assume the outputs would interface to two RAKK dacs (I already have one, and it looks as though the interface could be via I2S), one for bass and one for mid/treble.

Not necessarily looking to implement but thought it might be of interest?

Ray
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andrew Ivimey
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#2

Post by andrew Ivimey »

It looks v.interesting but I can feel a luddite phase coming on. I haven't even got valves sorted yet!
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Nick
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#3

Post by Nick »

Looks like fun, I have avoided DSP programming so far, I should have a play some time, though this board claims to avoid all that messy coding stuff.
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Ali Tait
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#4

Post by Ali Tait »

Could be just the thing for the OB's.
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andrew Ivimey
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#5

Post by andrew Ivimey »

its just sticking paster - botching up a poor job in the first place ;-)
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Ray P
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#6

Post by Ray P »

Nick wrote:Looks like fun, I have avoided DSP programming so far, I should have a play some time, though this board claims to avoid all that messy coding stuff.
To most of us not having the messy coding stuff seems like a positive but you make it sound disapointing!

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Ray P
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#7

Post by Ray P »

Oh, and I've posted about it on the K&K forum (K&K sell the RAKK dac) to see what they think of the technical aspects of interfacing va I2S to my dac. I'll feedback if I find anything out.

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#8

Post by richardcooper2k »

on the web a lot of people seem to be of the opinion that if using a behringer 2496 you get much better results processing in the digital domain than analogue

on the other hand the analogue circuitry can be modified to improve results
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#9

Post by Ray P »

richardcooper2k wrote:on the other hand the analogue circuitry can be modified to improve results
but isn't the point that in the digital domain you simply change the filter profile, via the software, to optimise the result.

I have read a little more of the miniDSP documentation and, for example, you appear to be able to change a crossover filter profile almost on the fly; I think that means you can sit with a computer connected to the device, listen to some music, adjust the filter profile, listen again, adjust, listen, and so on....

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#10

Post by Ray P »

I've been thinking further around the possibilities of the MiniDSP module and I think it does have some potential. I'm thinking that with a full range mid/top unit that is underpinned by a bass driver, such as in some of the OB designs and Mark's Azurahorn, that you could use it just for the bass filter.

My main question is what does DSP do to the data resolution; digital volume controls discard data as you attenuate the volume and it concerns me that DSP might do the same if you use it to adjust gain, delay, whatever. But, if you were only using DSP on a bass filter would it matter too much? I feel the need to frame some questions for the MiniDSP forum.

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Nick
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#11

Post by Nick »

To most of us not having the messy coding stuff seems like a positive but you make it sound disapointing!
Its just my masochistic tendencies coming out :-)
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#12

Post by richardcooper2k »

Ray P wrote:
richardcooper2k wrote:on the other hand the analogue circuitry can be modified to improve results
but isn't the point that in the digital domain you simply change the filter profile, via the software, to optimise the result.


Ray
depends if your main source is vinyl.......

i assume yours isn't so that simplifies things :D
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#13

Post by Ali Tait »

Ray P wrote:
richardcooper2k wrote:on the other hand the analogue circuitry can be modified to improve results
but isn't the point that in the digital domain you simply change the filter profile, via the software, to optimise the result.

I have read a little more of the miniDSP documentation and, for example, you appear to be able to change a crossover filter profile almost on the fly; I think that means you can sit with a computer connected to the device, listen to some music, adjust the filter profile, listen again, adjust, listen, and so on....

Ray
Just got a Behringer DCX2496 and you can do the same with canging the filters.Just waiting for the xlr adaptors to come so I can try it. Scott suggested this would be better than a passive crossover.
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#14

Post by Ray P »

richardcooper2k wrote:depends if your main source is vinyl.......

i assume yours isn't so that simplifies things :D
No, gave up liquorice pizza years ago!

Mind you, the MiniDSP is equipped with an ADC for legacy sources! :lol:

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#15

Post by Ray P »

Ray P wrote:
richardcooper2k wrote:depends if your main source is vinyl.......

i assume yours isn't so that simplifies things :D
No, gave up liquorice pizza years ago!

Mind you, the MiniDSP is equipped with an ADC for legacy sources! :lol:

Ray
However, having said that, I do have a similar problem in that I have a reasonable collection of SACDs and, of course, I can only get an analogue output from my SACD player unless I play the CD layer of the disks.

Ray
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