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Hi-def DSP


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Well you need to start with your requirements. Are you willing to use a pro amplifier that has DSP internally on the front end? Do you require a digital input for DSP? Are you putting the (analog) attenuation after the DAC from the DSP box (this means the not only the signal but any residual hiss / noise is also being attenuated)? How sensitive are you to a low price? Do you have any desire to use FIR filters and not just IIR filters? This is just a start. 

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What features are you looking for ?

 

Front ending your pre amp with an EQ and time and phase adjustments, room correction ?

 

There are at least 10 players in this space

 

 

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This isn't really as difficult as it appears--in my experience.  If you look for 96/24 (internal bit rate and bit depth), you'll see that this will cut way down on the number of available units.  In particular, those DSP units that were designed before ca. 2008-2010 will not pass this bar. 

 

In my experience, there are at least two good choices based on value-for-money:  Xilica XP series and miniDSP HD series.  Other companies make 96/24 units, but for various reasons, they are usually screened out of the decision process.  And there are many 48 kHz units available, but are not advertised as such unless you dig into the specification sheets a bit.

 

For instance, the Behringer DCX2496 (its name gives away the internal bit depth and rate per channel), the issue is fidelity--but not the digital side, but the analog sides (front end and back end).  The dbx DriveRack PA2 doesn't make the 96 kHz cut, nor does the Ashly Protea series, as well as the EV Dx38 or DC-One.  This also applies to the Dayton Audio DSP-408 (a.k.a., very inexpensive automotive-focused DSP units).  The Yamaha SP2060 passes the 96 kHz bar, but is more noisy than the Xilica XP series.  It can work (just like the miniDSP HD series), but the issue is usually cost/performance.  The Yamaha SP2060 is usually expensive--even used.

 

The Lake processors and even the DEQX (I suspect since they don't list the internal sampling rate) also do not come into solution due to either their internal sampling rates or their prices. 

 

So the question is: if you are focused on internal sampling rate, is this because you're worried about fidelity?  In my experience, there is a very, very slight difference with the 96 kHz units that fall well into the "subjective" category.  I believe that I hear that higher fidelity with the Xilica and to a similar degree, with the miniDSP 2x4 HD, although all the miniDSPs are slightly more noisy than the Xilica XP series in practice--usually due to the quality of the connectors (XLR or Euro/Phoenix balanced connections vs. RCA unbalanced).  The miniDSP 2x4 HD uses only unbalanced RCA connections--the reason for its higher noise, I believe--but the miniDSP 4x10 HD can use both XLR or RCA, which is a way to avoid having to use in-line filters like the Jensen ISO-MAX series, which are fairly expensive and will usually push the overall price up to Xilica levels if they are needed to control noise. 

 

So if you're dealing with loudspeaker sensitivities and overall fidelity at the Klipsch Jubilee (i.e., K-402 and a good 2" compression driver) level, I recommend the Xilica.  Anything else with slightly lower sensitivity and fidelity, the miniDSP HD series will typically be able to be integrated, albeit at a slightly higher noise level. 

 

Chris

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Thanks, Chris.

Future system is a bit of a blank sheet at this point:  ??? --> DSP (biamp) --> 6channel power amp --> CF2's.
Likely this would be fed with some sort of home theater pre-amp.  1080p is fine by me (then I can scoop up all the leftovers of the goobs that rush off into 4K :D)  
Long hours in the recording studio showed with no doubt remaining that 24/96 is the minimum to avoid all that digital 'brickwall filter' phase hash that lives in the top octave of a digital signal chain.  24bit was a definite improvement over 16 bit, but the bitrate was the biggest thing.

 

 

Now, I gotta finish feeding all my other hobbies for a little while.

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19 hours ago, DirtyErnie said:

Thanks, Chris.

Future system is a bit of a blank sheet at this point:  ??? --> DSP (biamp) --> 6channel power amp --> CF2's.
Likely this would be fed with some sort of home theater pre-amp.  1080p is fine by me (then I can scoop up all the leftovers of the goobs that rush off into 4K :D)  
Long hours in the recording studio showed with no doubt remaining that 24/96 is the minimum to avoid all that digital 'brickwall filter' phase hash that lives in the top octave of a digital signal chain.  24bit was a definite improvement over 16 bit, but the bitrate was the biggest thing.

 

 

Now, I gotta finish feeding all my other hobbies for a little while.

When you're ready, PM me and you can come out and see a Xilica 8040 in action.

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Here's a page of processors that Fulcrum Acoustic provides setting for their speakers. I've found it a good place to check what's out there in pro land.

https://www.fulcrum-acoustic.com/support/processor-configurations/

 

The BSS BLU series might be of particular interest, like this BLU-160  https://bssaudio.com/en/product_documents/blu160datasheet-pdf

I believe it runs 48/96k...but not sure if FIR can run at 96k. (it's open architecture like discussed below)

 

I use a Q-Sys Core 110f, but it's 48k only. 

I put channel counts, input types and connections, output types and connections, processor functions, FIR capability, AD/ DA of sufficient quality, ease of use, design flexibility, and so on above 96k. 

96k would be the tie breaker for me, all else equal....otherwise not than important (for me)

 

One additional biggie...and a must for me since moving to Q-Sys...is an Open Architecture processor. 

Their incredible flexibility....the configurations that can be easily put together, tuning experiments, etc, not to mention their network capability ....are all simply mind boggling imho.

 

Oh, processors like the Core110f and the BLU-160 tend to trade used on ebay for around $1250. They are pretty robust, I don't worry about used.

 

 

 

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1 hour ago, babadono said:

And the answer is:......Xilica:)

 

Xilica rocks !   The Solaro series looks super duper !!

i would love to try it, but the used market for it doesn't exist, and even for the lower spec Q-Sys stuff that i use, the new price of Q-Sys is prohibitive for me.

 

Open architecture processors like the Solaro are where it's at, imo. Heck, even Xilica says so !

 

They offer so much; i would gladly chose a lower spec open architecture processor  than the highest spec conventional fixed I/O processor (in terms of the usual audiophool specs).

Big world, getter bigger 😀

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Mark, could you describe your software/hardware DSP architecture in a diagram, including sources for FIR and IIR algorithms, and what kind of either development environment you use or how you load third-party software/firmware and supporting software/firmare modules?

 

Chris

 

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1 hour ago, Thaddeus Smith said:

I have the Yamaha SP2060, but as Chris mentioned above they can be hard to find and somewhat expensive when you do. I tripped and fell into a good deal on mine.

Yes, I also got a deal on mine. They simply don't come up on the used market all that often 

 

 

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1 hour ago, Chris A said:

Mark, could you describe your software/hardware DSP architecture in a diagram, including sources for FIR and IIR algorithms, and what kind of either development environment you use or how you load third-party software/firmware and supporting software/firmare modules?

 

Chris

 

 

I'll try Chris, and please let me know if i'm providing the info requested, or not.

 

Q-Sys is a processor design program, that compiles the process design onto Q-Sys Cores. 

Cores are the term for various  hardware processors, all running Linux. They range from small Core 110f's, to giant enterprise Cores.

 

FIR is implemented by either choosing FIR HP and LP filters options, at chosen dB/oct slopes, or by loading into Q-sys custom filters made with other software (ala rePhase, or any of the commercially available programs)

 

The stock IIR xover can go to up 6-way, but that can be expanded.  Stock parametric EQs can be be 32 bands per channel, and again expandable (if ever needed )

1022964536_qsysxovers.thumb.JPG.bd0403c5f4d0ebbbd7eaa5f8ce19f81a.JPG

2095195865_qsyspara.thumb.JPG.e86874c4bf0a4edb65e497e0695b6970.JPG

 

 

Assortment of band pass, all pass, shelving filters...all kinds of functions ....

1582469122_qsysfilter.JPG.ace0b6dc8ed847995a2195ef17492f1e.JPG

 

 

Anyway, just begins to scratch the surface in terms of design flexibility.

here is a screen shot of the schematic design I'm current running on a a pair of syn7's

 

547760627_qsysexamplesyn7.thumb.JPG.8360db1dd98cf08e5cff5340103641a5.JPG

 

Every block or control in the schematic is available for real time adjustment, and live monitoring.

here is a few of the blocks blown up ( from a different design it think)

1548658973_qsyslayoutblocks.thumb.JPG.c75d1ff97476347443a5f7e5205997b0.JPG

 

Point is....everything is available to adjust or monitor in real time.

A PC connect to a Core and all is available realtime. The Cores can also run standalone, without any PC/Mac connection.

 

There really isn't any third party software involved, other than our usual measurement software, for figuring out what to do.

If you are into FIR, a FIR generator program is needed. I like FirDesigner for automated work, and rePhase for manual.

Q-sys accepts wav or csv FIR files.

 

It has been amazing to me how much my general understanding of audio processing has grown because of this type processor.

many times, i simply run electrical level transfer functions, learning how xovers and EQ's work, etc.

You can even imbed dual channel FFT analyzers into the schematic to test block components, as well as putting simple RMS or peak meters anywhere.

 

Sorry if i sound oversold....but i am 😀

 

I'd kill to see/hear  how the Xilica Solaro works  😀

 

 

 

 

 

 

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Thanks, Mark.  That's what I was asking to see. 

 

Chris

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Thanks for replying Chris, Glad to hear that was the type info you were looking for....

 

A big capability i forgot to mention is Presets (or what Q-Sys terms "Snapshots').

The Snapshot capability  allows  changes to however many selected & altered settings you choose in the schematic.

A Snapshot Bank can hold 24 presets, and each bank can do something entirely different. I think 6 banks are allowed if sky's the limit.

 

For instance, banks could be used simply to vary para EQs, or shelving filters for house curves, etc.

Or for switching xover orders, and types.

Or even from switching between FIR and IIR xovers and IIR processing.

 

The reason I'm bring this Snapshot capability up, is unlike other processors I've owned, where changing Presets is essentially a global operation that causes a reload and a service interruption,

the Q-Sys Snapshot implementation has all the various 'presets' loaded into the one design, and ready to simply switch between.

It allows instantaneous switching without glitch or tick, even accommodating multiple FIR file changes instantly and silently.

 

 

I've found it to allow A/B testing for things like  quick comparisons / polar measurements  of Xover frequencies and slopes.  And comparing whatever order linear phase xovers to the same order IIR xover, all other things the same.

 

I've seen in the Xililca XP/XD Manuals, they speak of 'Presets within the Device Only'. 

I'm hoping/curious  this is along the same lines as Q-Sys Snapshots, with similar broad capabilities in what can be altered on the fly.

Do you use them much?

 

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