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Thread: Ok here it is... [DEQX]

  1. #1
    RIP 2014 Ken Pachkowsky's Avatar
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    Ok here it is... [DEQX]

    Hi All,

    I have had a couple of inquiries re the dual Deqx setup and my impressions of it.

    There is very little published info re setting up a dual Deqx system. I had a great deal of help from engineer, Ionwyn Buckland at Deqx. Needless to say there are several options for configuring the Deqx for 4-way operation.

    Widget has been a strong supporter of the Deqx solution for some time. As some of you know I spent several months upgrading my Westlake HRX cards to the latest revision with very positive results. Widget had suggested (on more than one occasion) I should forgo the old technology, save the $1000+ for new parts and get a Deqx. At the time 3000+ seemed like a heck of a gamble and I rejected the temptation to buy one, not to mention I needed 2 to do it properly.

    A couple of months ago I managed to pick up a Deqx with the digital output option from a fellow forum member at a reasonable price. This allowed trying it out with little financial risk if I did not like it. Low and behold a couple of weeks later I was in the right place at the right time to pick up a brand new custom dual chassis Deqx with all possible options for another good price. By the way, thanks to all the members who grabbed goodies from my hastily put together yard sale to come up with the cash for the second Deqx.

    My initial impressions of the Deqx were mixed at best. The built in automated measuring system is simply put “confusing and difficult”. The software interface is not intuitive or user friendly. I am running the system using the latest firmware and software.

    The engineers at Deqx have published a simple 2 page document on daisy chaining 2 units together for 4 and 5-way systems. The article describes a couple of different ways to configure the filters to accomplish the goal. Unfortunately they have not updated these instructions to reflect the changes in the software and firmware. In fact there are several other combinations that can be used to setup a 4-way system including a dual mono option utilizing the RS232 ports. This option has only become available with the latest firmware upgrade.

    My current setup is as follows:

    The dual chassis model is the Master PDC configured as tri-amp with L1/R1 (woofer outputs) crossed over at 250hz with 24db Linkwitz filters. This unit is set to control volume for both PDC’s.

    L2/R2 (mid bass outputs) crossed over at 1000hz with 96db Linear Phase filters.

    L3/R3 set to digital output above 1000hz going to the digital input on the second Deqx.

    The regular Deqx unit with optional digital outs is configured as follows.

    The Slave PDC is configured as single amp with optional stereo subwoofers.

    Input is the digital output from L3 and R3 of the Master PDC.

    L1/R1 set to bypass.

    L2/R2 are configured as filter’s only (deqx owners will understand) from 1000hz to 4500hz with 96db Linear Phase filters.

    L3/R3 are configured filters only from 4500hz up using 96db Linear Phase filters.

    After setting the gains on each pair of outputs I used my RTA to average frequency response throughout the room and used the built in Parametric EQ’s to correct for room anomalies. I have heard once you try parametric yada yada…..it’s true.

    In short this is the first setup I have heard that surpasses the old pre-amp, hrx and bss eq configuration. Hard to believe but the difference is quite dramatic. I hate to use over used terms but sometimes they say it all. Here goes……it’s like a veil was lifted. Yes, I really said that……now I will go and wash my mouth out with soap. Overall it just sounds cleaner and more dynamic . I can’t help but think it would be hard to get these sounding any better without building a room around them (coming soon).

    In closing let me say, the tweak freaks would love the Deqx. The analog section is a bit noisy when changing inputs and volume levels (annoying little click sound) but is as good as any mid to high quality stand alone SS preamp. Where these shine is first and foremost the crossover capabilities combined with fantastic parametric eq’s and very good dac’s. To bad the Eq’s can’t be set seperately left and right. They say that’s coming in a future software and firmware upgrade.

    I hope a couple of you found this useful.

    Widget, you were right

    Be well guys.
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  2. #2
    Senior Member Valentin's Avatar
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    I am glad it work out for you
    after treating my room i still have some ishus and i don't want more acoustic material in my room
    i thick it is time for some EQ

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    RIP 2010 scott fitlin's Avatar
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    Good reveiw, Ken, glad to hear its working out for you.

    You know, my first impressions of my BSS-366t were also mixed at best. However, with much time tweaking, and learning, yes, I had to learn how to use the newer technology, I also am having great results with DSP.

    Although the dsp, at least to me, is still not quite as full sounding in the LF, I also find that it is VERY clear, and VERY dynamic sounding.

    I find myself not running to fast to pull it out and replace it with my older analog processing like I keep saying I will do. I have had freinds, and others here for demoing of what I have going on in here at the moment, I get comments ranging from OMG, thats SOOOO clear, you can hear the sticks hitting the cymbals, and its so real, so live sounding, to, If you didnt tell me this was digital, I would swear its analog, even one of my good freinds, who has good ears, and is a devout analog freak like me, told me, Scott, leave it in, you got it doing something great, just leave it!

    Simply put, DSP works, and Digital has been, and is, improving, to the point where it is in fact, very very good!

    scottyj

  4. #4
    RIP 2014 Ken Pachkowsky's Avatar
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    Scott

    Thanks Scott.

    I will pass on something else that I did this weekend that made a huge overall difference in the sound at the sweet spot.

    My rta has always showed an extremely sharp and narrow dip at 50hz. Over the weekend I was alone for a few hours and thought "What the hell" lets see what happens if I try using the Parametric DSP EQ in the Deqx to eliminate the dip. I created a narrow (5hz) filter from 48hz to 53hz and boosted it 14db. Yes, you read that right, 14db cause thats what the rta said.

    The improvement in that tight punchy smack of a kick drum was amazing as well as bass riffs. It did not cause muddy sounding bass due to the narrow width of the filter. This would have been impossible with a graphic eq.

    In the end, it has me thinking more about room design and treatments. Now, if I could only get my friggin house in California sold, so I can build my new house here!!!!

    Ken

  5. #5
    Senior Señor boputnam's Avatar
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    Quote Originally Posted by Ken Pachkowsky
    ...I created a narrow (5hz) filter from 48hz to 53hz and boosted it 14db. Yes, you read that right, 14db cause thats what the rta said.
    Well, this thread will suffice to my query on the other parallel thread...

    Anyway, do you have any way to measure coherence of the frequency response? My experience with Smaart has been that the low frequency range is notoriously of low coherence - that is, measurements below ~100Hz are not as concise as above which manifests as a signal coherence typically well below 35%. Low coherence response is nearly impossible to "treat" with EQ - that is, one ends-up with large magnitude filter inputs (i.e. ±14dB) which impart far greater phase disequilibrium than doing any actual "tuning", per se. 50Hz would seem to be an "awkward" frequency to be boosting so aggressively.

    But, I guess the hearing is believing!!
    bo

    "Indeed, not!!"

  6. #6
    RIP 2014 Ken Pachkowsky's Avatar
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    Quote Originally Posted by boputnam
    Well, this thread will suffice to my query on the other parallel thread...

    But, I guess the hearing is believing!!
    Bo, please feel free to move this to the other thread if you see fit.

    I understand what your saying and agree re the inconsitency of low frequency anomolies. However the overall bass performance in the sweet spot is much better to my ear's.

    Then again, perhaps I don't know my ass from a hole in the ground

    PS: Did you get my message re the ID rings?

    Ken

  7. #7
    Senior Señor boputnam's Avatar
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    Quote Originally Posted by Ken Pachkowsky
    ...the overall bass performance in the sweet spot is much better to my ear's.
    That is all that matters! Thanks for posting the treatment. (I'll consider merging these threads, but that action always elicits the strangest or reactions... Let me check the chronologies for overlap.)

    Quote Originally Posted by Ken Pachkowsky
    ...Then again, perhaps I don't know my ass from a hole in the ground
    Dammit, Ken!!

    Quote Originally Posted by Ken Pachkowsky
    ...PS: Did you get my message re the ID rings?
    :dont-know - you mean that they are hopelessly backordered? If that, I'm going ahead with some colored Gaffer's tape - the hellwith'em.
    bo

    "Indeed, not!!"

  8. #8
    RIP 2010 scott fitlin's Avatar
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    Quote Originally Posted by Ken Pachkowsky
    Thanks Scott.

    I will pass on something else that I did this weekend that made a huge overall difference in the sound at the sweet spot.

    My rta has always showed an extremely sharp and narrow dip at 50hz. Over the weekend I was alone for a few hours and thought "What the hell" lets see what happens if I try using the Parametric DSP EQ in the Deqx to eliminate the dip. I created a narrow (5hz) filter from 48hz to 53hz and boosted it 14db. Yes, you read that right, 14db cause thats what the rta said.

    The improvement in that tight punchy smack of a kick drum was amazing as well as bass riffs. It did not cause muddy sounding bass due to the narrow width of the filter. This would have been impossible with a graphic eq.

    In the end, it has me thinking more about room design and treatments. Now, if I could only get my friggin house in California sold, so I can build my new house here!!!!

    Ken
    I agree, once you learn how to use it, it does work, and you can do things you just cant with a graphic!

    scottyj

  9. #9
    Senior Member UreiCollector's Avatar
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    Parametric EQ alternative

    Everyone,

    I wanted to suggest another piece of hardware for Parametric EQ. The Behringer DEQ2496 Ultracurve. I'm using one in my theater for the JBL2242H's to fix room induced response issues.

    http://www.behringer.com/DEQ2496/index.cfm?lang=ENG

    This unit can be had for $250 if you do a little digging, sampling is 24bit 96khz, and distortion is nice and low. There is incredible flexibility with this unit, and the built in 61 band analyzer is a great plus!

    I considered the DEQX, but couldn't justify the price...
    Frederick "The Urei Collector"

  10. #10
    RIP 2014 Ken Pachkowsky's Avatar
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    Quote Originally Posted by boputnam
    50Hz would seem to be an "awkward" frequency to be boosting so aggressively.
    Quote Originally Posted by boputnam

    But, I guess the hearing is believing!!


    Bo

    Based on further research I see your point. This is part of a white paper published by Floyd Toole at Harman.

    ------------------------------------
    Dips are caused by acoustical cancellations

    • The problem is very position sensitive – it will be different at different positions in the room. In fact that leads us to the solution: move the speaker, the listener, or both. A few inches may be sufficient.

    • Trying to fill the dip is foolish! A 10 dB boost uses 10x more power! A 20 dB boost uses 100x more power! You have just added a 10 or 20 dB resonance that will be clearly audible at most locations other than the one at issue.
    -------------------------------

    Ken

    I can confirm the later part of bullet 2. The sweet spot sounds great but toward the rear of the room or in the corners its very muddy.


  11. #11
    Senior Señor boputnam's Avatar
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    Yea, that's been my experience. The "coherence" function in Smaart (in Transfer mode) is damned useful for this - it plainly shows (as %) how coherent the particular frequency is. Low coherency (below 65%) is basically impossible to remedy, without moving walls / ceilings / bodies.

    In your situation, low coherence was evidenced by the extreme correction you imposed...
    bo

    "Indeed, not!!"

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    RIP 2010 scott fitlin's Avatar
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    Question

    Ken, I read you are using the 96db Linear brick Wall filters. have you tried any of the lower order filters? Like third order? Im using 12db bessel, and having tremndously amazing results.

    I tried higher order filters, my unit can go up to 56db neville-thiel but, above 18db per octave slopes, I dont like what I hear.

    Just wondering if you have tried anything else?
    scottyj

  13. #13
    RIP 2014 Ken Pachkowsky's Avatar
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    Quote Originally Posted by scott fitlin
    Ken, I read you are using the 96db Linear brick Wall filters.
    Just wondering if you have tried anything else?
    I am using the 96db slopes on the mid horn and high horn only. When I used them on the low side I did not like the results. I am using 24db LinkW's there. I have not tried any others at this time because it is quite time consuming......but I will down the road.

    Ken

  14. #14
    RIP 2010 scott fitlin's Avatar
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    I see. I think, and I know programming is a PITA, but I think you might be surprised at the results with 12db bessel, or 18db butterworth.

    I was using third order filters, and I just decided to try some others, now that I have got things really going well, at first, I went higher, 24db LR, then even higher.

    When I went to 12db bessel, I was blown away. Very natural sounding, very seamless and coherent. I am running 12db bessel on 15,s compression drivers, and even 2404 tweeters. And my mids and highs are really SMOOTH! Bass is natural, and believe it or not, tighter sounding. I have been through all the filters in my unit, I tried second order LR and Butterworth, but Bessel wins.

    It even has me wondering if my piece is really digital! The transparency and openess are really something to marvel at.

    Even I must admit, none of the things I can do with my BSS could be done with conventional analog crossovers.

    scottyj

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