[bprice2]

miniDSP takes the analog signal at some point after the initial digital to analog conversion from your DAC and then coverts the analog signal back to digital, then performs whatever processing needs to be performed to the digital signal, and then converts the signal back to analog.  The conversion that miniDSP does to the analog signal involves converting it to a 24/48or96 digital signal.

Is this a reason to be concerned when playing PCM (176.2 or 192) or DSD files?  My guess is that it is probably not, but I am unsure.

[ted_b]

Certainly a concern for DSD files.  There is significant damage done when downrez'ing from DSD to PCM.  Don't do it if you don't have to.

Personally, I'd much rather involve analog EQ if needed, or simple room treatments, rather than the deliterious digital-to-analog-to-digtal-to-analog.  Think about it, the music you are likley listening to has already ahd that done to it before you even get it in the system..

[Tyson]

I use the miniDSP, and going from pure DSD to PCM is lossy, no doubt about it.  The real question is whether the losses from the conversion are outweighed by the advantage of being able to get rid of your passive crossovers.  IMO, it is.  If you are going fully active, the miniDSP is a great (and inexpensive) solution. 

On the other hand, if you are just using it for EQ functions and not for going active (ie, you are keeping your passive crossovers in place), then ted is absolutely right - analog EQ and/or room treatments all the way!

[bprice2]

Certainly a concern for DSD files.  There is significant damage done when downrez'ing from DSD to PCM.  Don't do it if you don't have to.

I hear what you're saying, but I'm still not sure.  I definitely see where degradation would be an issue if the conversion happened at the digital level between the computer and outboard DAC.  But, at the analog level after the outboard DAC has done its thing...I don't know.  Can't seem to wrap my head around it.

[bprice2]

I use the miniDSP, and going from pure DSD to PCM is lossy, no doubt about it.  The real question is whether the losses from the conversion are outweighed by the advantage of being able to get rid of your passive crossovers.  IMO, it is.  If you are going fully active, the miniDSP is a great (and inexpensive) solution. 

On the other hand, if you are just using it for EQ functions and not for going active (ie, you are keeping your passive crossovers in place), then ted is absolutely right - analog EQ and/or room treatments all the way!

I just put the miniDSP in the system a few days ago and am still in the learning mode.  However, what I am ultimately trying to do is institute an active crossover to seam the gap between a pair of full rangers and a pair of OB subs.  The way I have it figured, I can go about accomplishing this at least a couple of ways.  One of those ways is to simply let my full rangers do their thing and just apply high and low passes to the subs, leaving the signal to the full rangers pristine.  But, I'm not sure this is the best way to go in regards to best implementing the miniDSP's ability to give me those steep filters that going active can achieve.

Anyway, I don't mean for this to be a discussion on implementing active crossovers.  Just curious about signal degradation.

[TJHUB]

I just put the miniDSP in the system a few days ago and am still in the learning mode.  However, what I am ultimately trying to do is institute an active crossover to seam the gap between a pair of full rangers and a pair of OB subs.  The way I have it figured, I can go about accomplishing this at least a couple of ways.  One of those ways is to simply let my full rangers do their thing and just apply high and low passes to the subs, leaving the signal to the full rangers pristine.  But, I'm not sure this is the best way to go in regards to best implementing the miniDSP's ability to give me those steep filters that going active can achieve.

Anyway, I don't mean for this to be a discussion on implementing active crossovers.  Just curious about signal degradation.

Having messed around with DSPs over the years, you absolutely want to keep them out of the signal path of your mains.  I haven't heard a MiniDSP yet, but I can't imagine it's any different sound quality wise from other similar devices.  However, using one to low-pass and EQ your subs is more than ok.  I've been using various DSPs over the years to do just that with great results.  But my mains are too bass capable and excite a room mode at 36Hz.  I needed something to pull some of that bass out so I could use my EQ'd subs to correct the issue.  I use the little FMOD in-line RCA filters from Parts Express.  They are low cost, and while they don't measure as effective as stated, they pull enough bass out of my mains to function quite well.  I've been using them for years, and I find them to be very transparent.  The best thing of all is that they don't require an additional pair of ICs to use them.  HUGE plus in my book.  If you decide to try FMODs, be sure to size it properly based on the input impedance of your amp. 

[bprice2]

Heeded the collective wisdom here and am simply using miniDSP as active crossover and EQing lower frequencies to the OB subs, which require it in my book.  No DSP is being added to the mains.  Result... .  Thanks for the input, guys...much appreciated.

[wisnon]

Certainly a concern for DSD files.  There is significant damage done when downrez'ing from DSD to PCM.  Don't do it if you don't have to.

Personally, I'd much rather involve analog EQ if needed, or simple room treatments, rather than the deliterious digital-to-analog-to-digtal-to-analog.  Think about it, the music you are likley listening to has already ahd that done to it before you even get it in the system..

With the DSPeaker AM 2.0 you can do the processing in the digital domain and pass it out without conversion via toslink to the Dac and then to the amp. The only limitation is a max of 24/96.

DRC to 500hz and 16 band full parametric EQ 20 to 20khz.

[Russtafarian]

I played around with a MiniDSP module a while back.  The functionality for the price and the size is very impressive.  Digital latency is pretty low, and sound quality is pretty good.  But on my system I still got the same filet mignon in, hamburger out results that I've experienced with other DSPs. 

My subs aren't OB, but I have six of them "swarmed" around the room, and I need electronic XO and EQ to get them blended correctly.  I've tried digital EQs from Behringer, DBX, and the above-mentioned MiniDSP, but could never get the subs to sound right or integrate properly.   I'm now using two analog Behringer units on my subs, an electronic XO and a parametric EQ and I've got the integration nailed.

One issue with DSP units is input/output gain structure.  You have to drive the input to a certain level to get the signal encoded properly by the ADC.  Too low and the signal gets encoded at less than 16 bits of resolution, too high and the input overloads.  Not a big deal with a pre-volume control line level signal.  But putting a DSP unit on the output of a preamp means at low volume levels the DSP is encoding/decoding at low bit resolution and at high volume levels the input is clipping.  An analog processor with low noise and lots of headroom sidesteps these issues.  I think this, along with latency issues, is why DSP on my subs has not worked as well as the analog processors.

Russ

[bprice2]

I played around with a MiniDSP module a while back.  The functionality for the price and the size is very impressive.  Digital latency is pretty low, and sound quality is pretty good.  But on my system I still got the same filet mignon in, hamburger out results that I've experienced with other DSPs. 

My subs aren't OB, but I have six of them "swarmed" around the room, and I need electronic XO and EQ to get them blended correctly.  I've tried digital EQs from Behringer, DBX, and the above-mentioned MiniDSP, but could never get the subs to sound right or integrate properly.   I'm now using two analog Behringer units on my subs, an electronic XO and a parametric EQ and I've got the integration nailed.

One issue with DSP units is input/output gain structure.  You have to drive the input to a certain level to get the signal encoded properly by the ADC.  Too low and the signal gets encoded at less than 16 bits of resolution, too high and the input overloads.  Not a big deal with a pre-volume control line level signal.  But putting a DSP unit on the output of a preamp means at low volume levels the DSP is encoding/decoding at low bit resolution and at high volume levels the input is clipping.  An analog processor with low noise and lots of headroom sidesteps these issues.  I think this, along with latency issues, is why DSP on my subs has not worked as well as the analog processors.

Russ

Thanks.  That explains some things I was experiencing last night regarding clipping at higher volumes, which I rectified.  However, at lower volumes I believe I experienced the low bit resolution you speak of.  I'm not sure how to fix the problem with my current gear, other than find a volume level I like and just leave it there. 

[Tyson]

I agree with Russ - analog in is not the best way to use a digital DSP unit.  But if you send it a digital signal, it sounds quite good.

[Hank]

Russ stated: 

An analog processor with low noise and lots of headroom sidesteps these issues.

  so this is your ultimate solution?: 

I'm now using two analog Behringer units on my subs, an electronic XO and a parametric EQ and I've got the integration nailed.

  Model numbers?

[rw@cn]

Rives

[Russtafarian]

so this is your ultimate solution?:

Model numbers?

Not an "ultimate" solution, more like a cheap-ass works well without spending a ton of money solution.  I use a Behringer CX2310 crossover and PEQ 2200 parametric EQ for sub xo and eq.  Unfortunately the PEQ 2200 is no longer in production.  Not a lot of analog parametrics out there these days.  I think Rolls might make one.

Rives would be an ultimate solution.  That's a nice unit.

Russ