[andyr]

What your saying might be true for you in a practical sense, but does not hold water as a logical argument.  Even if some modern LP was digitally mastered, there is greater potential for degradation with additional AD/DA conversions on playback.  This is beside the fact that the vast majority of records out there, were never digitally converted. 

Not knowing what's available in electronic X-overs, I'm not condemning your choice, just don't make it seem more than it is. 
neo

I was like you, neo - for many years I said that a digital (active) XO couldn't possibly be as 'clean' as my analogue active XO ... so going to a digital XO would be detrimental to my vinyl listening.  Then I decided I wanted to add a pair of subs to my Maggies - and this (due to the subs being about 5' further away from my ears than the Maggie bass panels) required the Maggie bass panels to be 'delayed', relative to the subs.

This required a digital XO between subs and Maggies ... and so I decided to replace the 3-way analogue active XO I was using on my Maggies with a digital equivalent - which gives room correction, as well as HP/LP filters.     As I said in my original post, I am happy (but amazed) to be able to report that I cannot pick up any degradation in my vinyl listening from having a miniDSP unit as my XO, instead of the analogue unit.


Andy

[abernardi]

   There's no question that careful use of a digital crossover to correct for timing problems and room issues will result in a VERY dramatic improvement in most listening rooms.  And I'd even bet that in most cases, the improvement might very well be worth going the digital route.  BUT (and it's a big but), by definition, you're losing the advantages, or if you prefer, the characteristics of analogue by doing this.
   We can have an endless debate on digital vs analogue, but at the least, why continue to spin vinyl if you're only going to convert it to digital?  Go with a hi-rez digital source and all the advantages that brings... lack of surface noise, pops, clicks, resonances, etc.  It seems to me that by using a digital crossover with vinyl, aside from some mastering differences, you're only adding the shortcomings of vinyl to the shortcomings of digital.  However, as i stated above, that still may be outweighed by the improvement in room and timing correction.

[abernardi]

I do like PEQ on the low low end. GR-Research Servo subs do a great job. But, I'm not interested in AD>DA for anything above 80Hz.

I've often felt that I can live with a "digital" low end, that it's the mids and highs that suffer most in the digital domain.  Right now I'm using a Marchand analogue electronic 2-way crossover for my 2-way speakers.  I may be uninformed, but I wonder if there's a crossover that would keep things in the analogue domain above, let's say 120Hz and then could go digital below that and do some room/time correction for the low end.

[andyr]

Please see my comments inside your post, in blue.

Regards,
Andy

   There's no question that careful use of a digital crossover to correct for timing problems and room issues will result in a VERY dramatic improvement in most listening rooms.  And I'd even bet that in most cases, the improvement might very well be worth going the digital route.  BUT (and it's a big but), by definition, you're losing the advantages, or if you prefer, the characteristics of analogue by doing this.

But as I've said, I cannot hear any degradation of my vinyl listening experience, with the digital XO.

   We can have an endless debate on digital vs analogue, but at the least, why continue to spin vinyl if you're only going to convert it to digital?  Go with a hi-rez digital source and all the advantages that brings... lack of surface noise, pops, clicks, resonances, etc.

I continue to spin vinyl because I have well over 1,500 LPs and $20K's worth of vinyl equipment.  To replace my LPs with hi-rez music would cost more than I can spare - plus I suspect I have a lot of music that isn't available in hi-rez downloads.  But, sure, if I was starting off I would go hi-rez downloads.

It seems to me that by using a digital crossover with vinyl, aside from some mastering differences, you're only adding the shortcomings of vinyl to the shortcomings of digital.  However, as i stated above, that still may be outweighed by the improvement in room and timing correction.

Looking at the before-PEQ and after-PEQ sweeps, I am very glad to have room correction facilities.  All those with analogue XOs (passive or active) will never know the improvements from this.

[andyr]

I've often felt that I can live with a "digital" low end, that it's the mids and highs that suffer most in the digital domain.  Right now I'm using a Marchand analogue electronic 2-way crossover for my 2-way speakers.  I may be uninformed, but I wonder if there's a crossover that would keep things in the analogue domain above, let's say 120Hz and then could go digital below that and do some room/time correction for the low end.

AFAIK, that is not possible.  The best you can do is split your 2-way XO into 2 sections:
* feed the output from your preamp into the Marchand but only use the HP feed (to your tweeters).
* have a parallel feed into a miniDSP 2x4Hd and set up only a LP filter in the miniDSP.  Obviously, this will be somewhere between 500Hz and 2Khz - so your mids will still be subject to "digital degradation" (as you call it - which I can't pick up).     However, this will give you room-mode equalisation for those frequencies.  Just FYI, I have PEQ set up at 6Khz / 2480hz and 1Khz.

Andy

[SteveRB]

But as I've said, I cannot hear any degradation of my vinyl listening experience, with the digital XO.

I think the sticking point for most of us in this thread relates to the analog v digital. It's not about sound quality. The word you used 'degradation' is interesting. We are not necessarily talking about degridation of sound quality: measurable his, lows, clearity... The difference is a continuous analog wave form from source to speakers versus the digital sampling of the wave from the miniDSP.  Personally, I use analog to avoid that sampling stage altogether.

[abernardi]

AFAIK, that is not possible.  The best you can do is split your 2-way XO into 2 sections

Right, that's what I was thinking, but it seems like a lot of cabling and electronics to push the signal through...

...will still be subject to "digital degradation" (as you call it - which I can't pick up).   

Did I write "digital degradation"?  I can't find that, if I wrote that, it was a mistake.  I don't look at it as degradation necessarily.  I used to think of it as SteveRB described it, the analogue continuous wave form, but I'm not so sure about that anymore.  To my ear, sound reproduction is still a far cry from accurate or natural, whether analogue or digital.  We settle for these fair approximations, some better than others in various aspects, but none really coming close to the real thing.  I like many things about a digital source, it's free from the drawbacks of mechanical analogue reproduction (surface noise, pops, clicks, clogged heads, rumble, wow, flutter, tape hiss, etc) but poses its own problems (ringing, digital glare, etc).  At this point I do prefer analogue for one reason I can't really quantify and can only describe as "more alive".  It fools my brain just a little more into believing I'm really listening to the music.  And once I noticed that, digital became harder and harder to listen to on a regular basis.  Anyway, just my 2cents....

[G Georgopoulos]

guys dsp introduces JITTER very BAD to the ear

[woodsyi]

I've often felt that I can live with a "digital" low end, that it's the mids and highs that suffer most in the digital domain.  Right now I'm using a Marchand analogue electronic 2-way crossover for my 2-way speakers.  I may be uninformed, but I wonder if there's a crossover that would keep things in the analogue domain above, let's say 120Hz and then could go digital below that and do some room/time correction for the low end.

I went digital below 80Hz with room eq and time delays to optimize 4 subs in push/pull configuration.  Time delay was needed as the back subs were closer than the front subs from my listening position.

I use two outputs on my preamp.  One goes to HAL's 6 channel digital crossover that sends all signals under 80Hz all 6 woofers.  The other goes to Marchand to send signals above 80Hz to my digital amps  that drive the low mid woofers and tube amps that handles my ribbons.  There is a passive filter between my mids and tweets.  I could go active there but it will in analog domain.  Small caps there don't seem to sap much from my big monoblocks.  It's Brian Cheney's series first order crossover.  It think the ribbons and phase coherent but the crossover region is not perfectly flat .  I have all the binding posts and what not to go full active but I sold my 300b amps for the tweets.  I am keeping my eyes open for a good flea power amp.  It's good to have something to work on, you know.    As it is,  there are 7 amps.     I am a little slow to getting 2 more amps.

I tried full DSP and I felt like I lost some je ne sais quoi in tonal texture from AD DA loop.  I didn't like it.  I like it the way I have it now.  Certainly the bass is tighter.

[Russell Dawkins]

guys dsp introduces JITTER very BAD to the ear

Where do you get this information from? Reference?

[JDUBS]

I went digital below 80Hz with room eq and time delays to optimize 4 subs in push/pull configuration.  Time delay was needed as the back subs were closer than the front subs from my listening position.

I use two outputs on my preamp.  One goes to HAL's 6 channel digital crossover that sends all signals under 80Hz all 6 woofers.  The other goes to Marchand to send signals above 80Hz to my digital amps  that drive the low mid woofers and tube amps that handles my ribbons.  There is a passive filter between my mids and tweets.  I could go active there but it will in analog domain.  Small caps there don't seem to sap much from my big monoblocks.  It's Brian Cheney's series first order crossover.  It think the ribbons and phase coherent but the crossover region is not perfectly flat .  I have all the binding posts and what not to go full active but I sold my 300b amps for the tweets.  I am keeping my eyes open for a good flea power amp.  It's good to have something to work on, you know.    As it is,  there are 7 amps.     I am a little slow to getting 2 more amps.

I tried full DSP and I felt like I lost some je ne sais quoi in tonal texture from AD DA loop.  I didn't like it.  I like it the way I have it now.  Certainly the bass is tighter.

woodsyi, I think what you're doing sound pretty optimal.  My question is, is there a delay issue on the <80hz material since it has to go through A->D + processing + D->A vs. the >80hz material which has no conversion / processing associated with it?

-Jim

[JDUBS]

Bump for Woodsyi's input!

-Jim

[THROWBACK]

Great discussion on a dilemma that many of us are wrestling with these days having to do with digital (DX) versus analog (AX) crossovers. On the one hand, the DX gives the promise of better control throughout the frequency spectrum, flatter response (in the room!), and the avoidance of passive components (inductors, caps) between the amp and speakers that rob power and muck up the sound. AndyR, HAL and Roger Sanders (among others) are articulate champions of this approach.

OTOH, the non-theoretical observations of woodsyi ("lost some je ne sais quoi in tonal texture") cannot be ignored. Early CD and transistors penalized the early adopters for reasons that were difficult to explain in engineering terms. Some of us have painful memories in that regard.

The DX experimenters deserve our support and our applause. DX is almost undoubtedly the real wave of the future. Is it ready now or should we wait for more refinement in jitter, digital filters, bit rate, slew rate, etc., before trusting our precious analog front ends to it?  I don't know, but I believe I am ready to try it out on my own system. Perhaps I will after RMAF.