Is DEQX a game changer?

Hi all,

I recently became interested in DEQX and discovered this epic thread.  I read through most of it and it has been very helpful.  I am seriously considering an HDP-5.  The weak links in my system are my Oppo BDP105 which I use as my DAC and a dbx 223 crossover that I use with my JL f113 sub.  I've been considering upgrading both the DAC and crossover and in a discussion about DIY speakers, a knowledgeable friend mentioned DEQX.  

I am a pretty knowledgeable audiophile, but I had not heard of DEQX.  It is a revelation!  I immediately realized that not only is the HDP-5 an upgrade on my Oppo as a DAC and a vastly superior crossover, but it can also replace my preamp (offsetting about half the cost of the HDP-5) and adds amazing time and room correction -both of which should be highly beneficial to the challenging sub integration process.  What an incredible machine.  

Then there is the icing on the cake.  I just discovered that the HDP-5 supports the incredible Roon server on board, without a PC and USB!  This is a terrific feature.

My one concern remains putting my signal though digital processing, although most everything I've read indicates this is a non issue.   My only other concern is the lack of home theater prepro passthru.   I run a hybrid system and frequently switch between 2 channel and surround.  Any suggestions on how I can best create a passthru set up with the HDP-5?   Thanks!

Ah good, the volume settings could solve the problem.  May seriously consider just sticking with 2 channel for TV if the voices can be tuned correctly.  

Definitely going to measure outside.  Big grass lawn next to my house and easily moved Raidho D1 monitors.  My old ML CLXes would not have been contenders for outside measurements!

Thanks Andrew.  That's extremely helpful on the bypass question.  My other concern though is having to max the volume on the prepro source and the risk of switching sources forgetting to turn the volume back down.  One solution I thought of is putting my current preamp between the HDP5 amp outputs and the amps.  I would run all of my two channel from the HDP5 to a passthru input on the preamp and the prepro directly to another passthru input.  The preamp would essentially just act as a line level switch between 2 channel and surround.  The problem is that I HATE to put an additional piece in the chain and I was hoping to sell off the preamp to mitigate the price of the HDP5.

Another option is simply to add another pair of main speakers and a dedicated amp (I have a set up in another room that I never use) and literally run two separate systems in the same room only sharing sources.  This is kind of cool, but a bit cluttered and I'm not sure if the additional speakers in the room will cause unwanted resonances when I'm listening to just 2 channel.

My third option is to just go all 2 channel.  I read somewhere (maybe here) that the fully corrected system sounds so good and the center is so optimized that surround is not critical.  I watch regular TV and am not critical of theater sound at all while being fanatical about my 2 channel music.  I know that I could also work a profile to optimize the voices as well, that is key.  So this may be a good option and would let me sell off even more gear...maybe get a nice 'table! 

Thanks also for the validation regarding sound quality.  this is what I am hearing pretty much everywhere, but best when it comes from a long term user.  I will definitely post my journey when I decide to move forward.

Thanks!

Jeff

I just stumbled upon this story in TAS form 2008:

http://www.theabsolutesound.com/articles/magico-ultimate-loudspeaker-1/

Alon Wolf of Magico used a DEQX crossover in his own Ultimate speakers.  That certainly is a big validation of the transparency of these units!

Thanks blang.  That's a terrific article, I had not scene it.  I am currently attempting to learn everything I can about speakers and acoustics prior to pulling the trigger on a DEQX (now more "when" than "if").  I'm slowly working my way through the dense but brilliant, Master Handbook of Acoustics.

How would you add a better DAC to a DEQX preamp?  If it comes before the DEQX and goes into the analogue input, isn't the superior DAC's signal then reduced to the limits of the DEQX's DAC?  I read that you can use a superior DAC after the DEQX on the output side, but if you are using the crossover function (I would be) then you have the better DAC between the DEQX and the high frequency amp, but the DEQX DAC direct to the low frequency amp.  This does not seem right to me.  

This consideration is even greater if MQA rises to ubiquity.  Do you decode the MQA file in a DAC before the DEQX, then what happens to the decoded MQA signal when it goes through the new A/D and D/A processing in the DEQX?  Is the higher resolution preserved?  

Yes, that's what I was wondering too.  Wouldn't the signal be limited to the weakest link in the chain?  Would the analogue output of the superior DAC not be limited to the same quality as if the original digital signal was just sent through the DEQX directly?

I too have followed MQA very closely.  Very promising, crazy enthusiasm, but so far...nothing.  

I wrote to DEQX a few weeks ago with some questions, one of which regarded MQA integration.  Their response was that the jury is still out on MQA, they place significant burdens on the DAC manufacturer, and the availability of media remains far too limited.  So it does not sound like they are getting on board anytime soon.  

MQA integration was one of my few hesitations regarding the HDP5.  I assumed that something would be lost in the additional AD/DA required using a separate DAC.  The comments above more than confirmed my suspicions.  So I recognize that if I go forward with the HDP5, MQA is likely not happening for me for quite a while and I think that's okay.  The real benefits of the DEQX seem to outweigh the promises of MQA.  

Roon running directly on the HDP5 is awesome.  

This may have been touched on earlier, but the potential power of the DEQX has inspired me to seriously consider attempting to build my own speakers.  I've been researching this quite a bit and it appears that the real challenge of speaker building is the cross over and time alignment -both issues that are addressed by the DEQX with near infinite flexibility.  So putting really good drivers in really rigid cabinets and then bi or tri amping with the DEQX crossover could yield some pretty amazing results.

I've gotten a lot of feedback on a terrific DIY forum.  I am leaning towards building a translam two way sealed cabinet made from laminated layers of Baltic birch with approximately 2" thick walls.  I'm still working out the details, but the design resembles a Magico Mini.  I will likely use ScanSpeak drivers with either a berillium or ring radiator tweeter.  If this comes out nicely, I plan to add a bass cabinet with 2 10" woofers.  Ultimately, the stack will be tri-amped and all controlled by an HDP5.  I've identified a number of very fine and very expensive speakers that use similar drivers and architecture but of course use passive crossovers.  It seems like I could build something pretty extrodinary for a fraction of the cost and far superior dedicated amps, electronic crossover, and time alignment.  

Does anyone here have experience with DEQX units and DIY speakers?  I would love to hear your feedback.

Thanks Andrew!  That is exactly what I'm hoping to do.  I cannot wait until I can get an HDP5!

Congrats!  Please let us know your experience once you get set up.