DEQX Beginner seeking advice

Hi Mike,

Q1)I’m not aware of any such tutorial. But I think that if you read through the sections of the manual on room measurements and room corrections a couple of times you’ll find them to be a good deal less formidable than they may initially appear.

Q2)Yes, that’s true as far as I’ve been able to determine (for room corrections; speaker calibrations are of course done individually for each speaker). In my case, though, it didn’t seem to be a significant issue.

Q3)I don’t use subwoofers, and I haven’t taken the time to familiarize myself with the sub integration process, so I can’t help on this question.

Keep in mind that in contrast to speaker calibrations, room corrections are done instantaneously, in real time, when you make the adjustments in the cal software running on a connected computer. But while the resulting adjustments are then immediately stored in the DEQX, they are not stored in the computer until and unless you download them from the DEQX into a configuration profile you have previously created, and then perform a "save."

Also, as a starting point, at least, it may be helpful to use the auto-EQ feature for the room corrections. Although I would suggest some changes to the default settings for the auto-EQ function that are in the latest version of the software. If I recall correctly it defaults to 3 parametric "control points," which I would suggest changing to 7 (that being the maximum number that can be used while retaining the ability to subsequently introduce equalizations with the remote control). And if I recall correctly it defaults to zero maximum boost (i.e., to only reducing selected frequency ranges, rather than boosting any). Provided that you believe the power capability of your amplifier and the power handling capability of your speakers to have ample margin relative to your requirements, I would suggest raising that default limit from 0 to perhaps as much as +6 db (which would result in up to a four-fold increase in power delivery at the boosted frequencies).

As with any sophisticated software program, during the initial familiarization process it can seem daunting, but once you get the hang of it after some hands-on experience I don’t think you’ll find it to be nearly as complex as it may first seem.

Good luck. Regards,
-- Al

Al,

Thanks very much for the hints. They will be useful.

I have no doubt that I could master the DEQX software; however, I am less sure I can master it in two weeks -- two weeks of life filled with other activities as well. But I'll sure give it a try.

Again, I appreciate the tips and encouragement.

Regards,
--Mike

Hi Mike
In addition to Als' excellent advice, I can help you with point 3), it's actually quite easy if you are methodical...

A) Take a room measurement from the listening chair.

B) Then use the 'viewer' to display this & go full screen - it will default to the frequency response.

Now click on the 'step response' option (from the little row of buttons on the right edge of the second toolbar) which will show both the mains (spiky response) and the sub (longer wavy response). Normally the first peak of the sub will be further to the right than the mains, ie 'slower' because the wavelengths are longer and often the sub is further away from the listener as well.

Enlarge this view using the + view button (also on the second toolbar), so you can still see both the top of the sub plot and the first main speaker spike.

As you move the cursor over the tip of the sub response, make a note of the delay time which displays in real time in the bottom RH corner of your screen.

Now move to the first peak of the mains and again note the time.

Subtract the time of the mains from the sub and this then gives you the delay to add to the main speakers, ie 35.4-25.2 = 10.2 as an example.

C) Go to your speaker configuration setup view and select one of the main speakers. Double click & go to the time/level tab. Then add the delay from above into the appropriate box (it defaults dark blue ready for you to enter anyway)

Repeat for the other speaker.

D) Save to the DEQX and then repeat the process again, naming your next measurement something like 'verification xx.x' (xx.x being the time delay you added ie 10.2ms etc).

E) The verification window should now show the two peaks aligned together.

Your sub is time aligned!

Good Luck...

If you need any other help in the brief time you have available, drop me a PM - I can give my email address / you can mail me your .mzd file & I could do some of the basic setup for you. It will get you going

Thanks, drewan77, for the tips. Though I decided not to keep the DEQX (the relay clicks and dropouts when changing sample rate proved too distracting), the general principles you outlined are useful to know. I can use them for adjusting subs, whatever gear I wind up with.

BTW, I'm currently evaluating the Classé CP-800, which has much less DSP than the DEQX, but enough for my needs, and is delightfully simple to operate.

Mike

Drewan77, I would like to thank you !

I have been playing with my DEQX Express II for a while and I thought I knew most of the nuts and bolts, but in your post above on subwoofer time alignment, you offered a major league trick I didn't know and even ever think of: measuring the actual delay between mains and subwoofers at the listening chair : really smart !

So far, I have only used the DEQX utility to calulate the required delay based on the distance between the subs and the mains, which provided what I thought, a good result. When I modified those values with the actual measured values using your process, wow, much better, without any doubt! The result is a convincing demonstration of the benefits of a well  "time aligned" speaker system and while I will not describe those benefits because you all know them (!), I can't resist to say that the improved "soundstage"/"imaging" was what striked me the most !  

So again, thanks Andrew for sharing your knowledge with us and if Alan (Langford) is reading this... Alan, this is something that should be added in the DEQX user manual !

Regards,
Denis 

Thanks Denis, you're welcome & glad you're enjoying your system.

(I guess I must be telepathetic (!) or something as I rarely look into this site but just glanced at it within 30 mins of you posting!

Hello Mike. I was the OP on a lengthy DEOX thread,perhaps the one you've seen. Countless gents graciously contributed to it. I would suggest you browse the thread and send questions to those who addressed your interests. Good luck. Pete

The result is a convincing demonstration of the benefits of a well "time aligned" speaker system and while

one correction (major, in fact. :-) ) - once you did what drewan77 suggested you’ve corrected your speaker system become more time-COHERENT (not just simply time-aligned). Time-aligning is aligning the acoustical centers of the drivers while time-coherent means making an effort to ensure that the sound waves from each driver arrive at your ear at the same time. While you might not have achieved full time-coherency (you probably need to tweak DEQX a bit more) you’ve certain made a step in that direction. In time-alignment there is little guarantee that the sound from each driver will arrive at the same time at your ear but the action of time-aligning is a requirement for time-coherency.

I'm still waiting for a more consumer friendlier version.

I’m new to this forum and this is my first time posting. I first became interested in DEQX (most likely the PreMate) as a way to properly integrate a subwoofer in my 2-channel system. The extra benefits of timing and frequency correction interest me as well. I’d greatly appreciate any advice or commentary on the following items, especially from those who have used DEQX products. If I could get a response to ANY one of these items on my list, I’d be happy.

SIDENOTE ABOUT MY SYSTEM

· Auralic Aries to stream local files and Tidal (Mostly 16bit/44.1khz)

· Cambridge Azur 851N. This is my streamer/DAC, but I recently picked up the Aries to handle the streaming part since it is Roon Ready and allows me to upgrade to a better DAC in the future (likely the PreMate).

· Audio Research DSi200 integrated amp. The current plan is to replace this with the PreMate and a new separate power amp. This unit has no lines out for separate preamp or subwoofer, which is my only disappointment with this component.

· REL T7 subwoofer. Again, the ARC has no line out for a sub so I connect the REL to the ARC via speaker terminals. Therefore, I’m running my speakers full range and blending the sub in at around 80Hz, which overlaps with the speakers…not ideal. I fully intend to upgrade to a JL Audio E-sub or Fathom; one sub to start with, and perhaps a second when funds allow.

· Revel F208 speakers

1. Many in this forum have mentioned how burdensome it is to haul your speakers and other necessary playback components outside for measurement. I agree this is a pretty significant barrier. I wonder if its possible for DEQX to adopt the same strategy that Devialet employs with their Speaker Active Matching (SAM) technology by taking the speaker measurements for you and publishing the results online for download. DEQX could do this by acquiring various speaker models in their own lab or simply giving speaker manufacturers the opportunity to do it themselves. Perhaps there are barriers to this approach, but it seems to me the best alternative to the current approach.

2. Has anyone experienced problems with taking speaker measurements outdoors due to noise from birds, cars, etc.?

3. Some of you have commented on the sound quality of the DEQX as preamp, which is helpful, but I’m curious about its basic functionality. Do DEQX owners find the volume control offers fine enough adjustments? This is an important factor for me in choosing a preamp. Before I acquired my ARC integrated amp (103 attenuation steps), I used my Cambridge DAC’s volume control (30 steps) and found the volume adjustments too large. I found it difficult to get just the right volume and it drove me mad. Interestingly, the DEQX manual says the volume adjustments range from 1db steps at louder levels, to as much as 6db steps at lower levels. I have heard of any other digital volume controls operating this way. How do you feel about it?

4. Also on the topic of volume controls, I personally feel DEQX could make their products more attractive as preamps if the front panel included a numerical volume display. Seeing a number helps me quickly find a known volume level that works in certain situations. I’m aware that the LED light turns various colors to signify certain ranges of volume, but I feel this isn’t optimal. I’m curious how others feel.

5. I haven’t seen anyone mention considerations around speaker ports when integrating a subwoofer. I know “Soundoctor” (JL Audio expert) insists that output from the port should be considered as part of the equation and that sub integration is better when dealing with sealed box speakers and sealed box subs. Are there any decision points in the DEQX calibration process related to speaker ports? I’m wondering if I should use the foam plugs provided with my Revel F208s, thereby blocking their output, diminishing the lowest frequency response of the speakers, and blending in the sub at a higher frequency to compensate.

6. JL Audio Fathom subwoofers come equipped with an on-board, automated DSP EQ function called Digital Automatic Room Optimization (DARO). If I used a Fathom sub, how should I handle this DARO functionality? Perhaps I could tell DEQX not to adjust frequencies below the sub crossover point? Or perhaps I could handle all low frequency EQ with DEQX and turn DARO off? I assume it would be a mess to have both technologies employed at the same time.

7. Perhaps this will make audiophiles cringe, but when I’m not doing critical listening in my sweet spot chair, I sometimes listen casually to the side on my couch or at the dinner table (we have an open living room/kitchen/dining area). In light of that, I’m curious how DEQX might affect off-axis listening. I don’t see the speaker correction doing any harm, but the room correction is another story. Since room correction is based on measurements taken from the listening position, has anyone noticed anything highly irregular when listening outside of the sweet spot? This isn’t a huge deal. I’m just curious. I suppose if I find I don’t like what I hear off-axis, I could just create a profile with no room correction and use that when needed.

8. Here’s the obligatory MQA rant…I hate to be that guy prattling on about a technology that has hardly even arrived yet, but it would be great if DEQX could offer MQA playback. My understanding is that MQA is integral to the DAC chip so this can’t be implemented to existing units in the field…not without sending the unit back for upgrading. Even then, perhaps it is not feasible. If it is, I’m sure there would be some willing customers. If anybody has heard anything about DEQX incorporating MQA, please share.

9. To enable full MQA playback, one could always add a separate MQA-capable DAC downstream from the DEQX, but I don’t think that would work in a system using the DEQX’s analog sub out because you are no longer using the DEQX to control volume of sub and mains at once. Right?

10. Having read through this forum and assessing my own skills, I’m fairly certain I would need to rely on DEQXpert service to get my system calibrated. According to the website, online DEQXpert installation service is now USD$399 and “manages all of these processes on-line, where you help set up the measurements, play music when all is done, adjudicate results and set any preferences. DEQXpert can also provide you with one on one software tutoring.” Can anyone describe his or her experience with this service? I’m wondering how much time the service tech spends with you and if it met your needs. I mean…you don’t get unlimited time so the handholding must stop at some point!

11. Does anyone know if DEQXpert service is available to those who buy used DEQX products? Buying used would be easier on my bank account, but of course it is probably wise to buy from an authorized dealer and rest easy knowing I have warranty coverage and additional support. I’m in Portland, OR so the closest dealer would be Acoustic Frontiers in CA. I’m quite impressed with Nyal Mellor there.

make sure you guys read this long thread "Is DEQX a game changer" 

https://forum.audiogon.com/discussions/is-deqx-a-game-changer

we've discussed many of the questions you are asking in this thread.....
thanks.

Thanks for chiming in bombaywalla. I actually read almost the entire ""Is DEQX a game changer" thread before posting. It took me a few days to get through it! I didn't see any of my specific questions/comments addressed. Of course, it's possible that I missed something, but I really tried seeking out the info I was looking for prior to posting. 

Blang11, welcome to Audiogon! As you can see in my system description thread I am using an HDP-5 in my system, which serves as my line stage preamp in addition to providing its signal processing functions. However my system does not include subwoofers or any form of biamping, so I can’t comment knowledgeably on some of your questions. But I’ll give them a shot:

1)I’m not familiar with what Devialet has done in that regard, but I’d imagine it would probably be impractical for DEQX to either do that sort of thing themselves, or to provide enough different speaker manufacturers with their equipment for the measurements to be comprehensive enough to be worthwhile.

2)As you may have seen in the thread Bombaywalla referenced I performed my measurements with the speakers moved to the center of my living room, with large acoustically absorbent panels placed against nearby walls and other reflective surfaces. But the one or two or three second tone bursts that are used for each speaker measurement are typically set to automatically repeat numerous times, which under most circumstances apparently allows the software to pretty much filter out and ignore extraneous outdoor noises.

3 & 4)Many analog volume controls operate similarly, of course, with respect to the resolution of the adjustment becoming coarser at low settings. The gain structure of my system is such that for my critical sources (LP and CD) I use the control in the upper half of its range, where I find the resolution to be satisfactory.

Ideally I too would certainly prefer a numeric readout of the setting, that would facilitate precisely returning to a given setting, but I can live without it. And although it is less convenient, it is still possible to do that using the up/down buttons on the remote, by going a given number of steps above or below a setting at which the light changes color.

Also, as you have most likely seen, the HDP-5 and also the Premate+ provide a volume slider on the touchscreen in addition to the indicator light that is provided on the earlier models. That is of course still less than ideal compared to a numeric readout, but I find it to be a marginally useful feature.

5 & 6)Can’t comment knowledgeably.

7)I don’t do any critical listening off-axis. But many users including me leave profile 0 (the others being numbered 1, 2, and 3) in its as-delivered bypass configuration, so that the speaker and room corrections can be disabled with one press of a button on the remote.

8&9)Can’t comment knowledgeably.

10)I didn’t use the DEQXpert service, but I am somewhat familiar with the experience of one of the members here who posted extensively in the "game-changer" thread and did use the service, and who has a room that is particularly challenging from an acoustic standpoint. The session involved a few hours, with results that he found to be satisfactory at the time. A few months later he purchased another session, which also lasted a few hours, and resulted in some further improvement.

11)I’m not 100% certain, but I believe the answer is "yes," especially given that one pays for the service. Also, I believe that Nyal Mellor can provide a comparable service. I purchased my HDP-5 from him, and yes, he was wonderful to deal with.

Good luck. Regards,
-- Al

Re: #7

In my previous apartment, my most comfortable seating was also off to the side a bit in what could hardly be described as a sweet spot. I never got around to it (and have now moved into a much better situation: most comfy seating in sweet spot and room for my speakers to get away from the walls), but I'd thought about making one of the profiles specific to that less than ideal seating spot. On that profile, you could just place the mic at that location in the room. If you'd be moving around in the room, do multiple mic measurements (from spots in areas you'd likely find yourself) and get the best possible room correction from those measurements. 

Roscoe, congratulations on the new digs, and on the improved acoustical situation!  And thanks for posting the links to the John Darko reviews in the "game changer" thread.

Best regards,
-- Al
 

Thanks Al. Looking forward to getting the speakers, DEQX and everything else sorted out in the new room.  Will be reporting on that in the other thread. 

Thanks for welcoming me and offering some guidance! Also, apologies if I should have posted in the “game changer” thread instead of here. If I could cut and paste my post, I would.

 

2. Great answer. That solves that!

 

3.,4. That’s nice that you’re using the upper end of your volume control for the most part. This is not the case in my current system, but because the ARC volume control has 103 steps, I find the adjustments are fine enough for my taste even though I never listen to anything louder than volume setting “75” (typical volume is around 20-40). I’ve been reading up on gain staging so that if and when I upgrade to a DEQX, I won’t have more gain than I need for proper volume range. I’ve seen that Bryston and Bel Canto amps have adjustment gain settings, the lower of which (around 23 db) might be more suitable for my needs. My speakers are rated 88db sensitivity and my room is on the small side of medium. After thinking about gain staging recently, I find it odd how little I see this mentioned in audio websites/magazines. I suppose it doesn’t matter much if you have a fantastic preamp, but not everyone does. I’m currently trying to learn more about the interplay between voltage gain, power output (watts per channel) and current delivery.

 

5. I think it’s telling that multiple posters to the DEQX threads have gone through the DEQX setup process, including with customer support and no one has mentioned speaker ports. I’ll take that as a sign that it doesn’t come into play very much in the company’s opinion.

 

10. Great answer. That solves that!

 

Lastly, I too had read John Darko’s recent review series on DEQX and am looking forward to part III. I hope he gives the crossover functionality a spin. It would be nice to get his take on integrating a subwoofer, but who knows if that’s his bag.  

Re #5: I'd still ask around about the ports issue. If you buy a DEQX then you can ask the dealer for a recommendation or to go over the pros and cons and whether the general pros and cons for ported vs sealed apply to speakers paired with DEQX. Would be interesting to know what you find out. Lack of comment may reflect that not a ton of speakers come with plugs for their bass ports. 

I haven't spoken to DEQX or a DEQX dealer about the port question yet, but I did get a helpful response from Harman Luxury Audio Group (Revel). A Field Support Engineer emailed me a number of frequency response measurements of the F208 showing the effect of using the tweeter level switch, LF compensation switch, port plug and port plug+ LF compensation switch. The gentlemen said there is no detrimental effect of using the port plug besides the reduced low frequency output, and that I should play around with it to determine the best setup for my space. So it seems to me that Revel doesn't share the same opinion as JL Audio about the importance of managing the port output when integrating a subwoofer in with the mains. I'll just take it all with a grain of salt, but I appreciate the timely and helpful support from Revel. I'll surely take this up with DEQX at some point. I'm guessing their advice one way or the other will come with the caveat that the ports are not the biggest deal in the grand scheme of things.

Hi Blang.  Per Barry the Soundoctor's strong recommendation, I plugged the ports on my Raidho's and never looked back.  Barry's explaination of the impact of the secondary output from the ports and their detrimental effect on phase optimization was pretty convincing.  I gather this is an important, if not under appreciated, consideration with the DEQX.  If/when I pull the trigger on the HDP5, I do not expect to unplug the ports.  Of course, the ports are far less critical when electronically crossing over.  I'm crossing over at about 90hz so the low bass in the mains is irrelevant and I think sealing the box tightens the upper bass and definitely improves the timing considerations.  

Per your question regarding the room optimization on the JL sub, I plan on bypassing it and letting the DEQX handle it all.  

I was at a very similar place as you are now -running the mains full range.  Per Barry's superb instructions, I plugged the ports, added an inexpensive yet adequate dbx electronic crossover (a critical piece), carefully aligned the placement of mains and subs, and painstakingly set the phase on the sub.  The results were stellar.  I have not tweaked the system in months and had no desire to until I discovered DEQX.  The HDP5 has everything to take every one of these settings to the next level, while providing a major DAC and crossover upgrade over my Oppo and dbx respectively.  There are some compromises such as not having a critical home theater passthru and the same concern about MQA.  On the other hand, the new support for on-board Roon is the icing on the cake.  

Actually, plugging ports is a good thing to do when using active EQ. :)

It reduces the acoustic order from 4th to 2nd, and increases dynamic range. 

The end result is a 4th order electro+acoustic high pass instead of 6th order, not to mention the group delay effects caused by the port.  This is why THX specifies sealed satellites.

It's not absolutely mandatory, but if you want the absolute highest dynamic range and easiest integration it's good practice.

Best,

Erik

Erik, can you elaborate on the acoustic order principals?  I get the group delay and dynamic range concepts, but I would like to understand more about what you refer to as acoustic order.