Is DEQX a game changer?

DEQX claim that their algorythm time aligns all frequencies within a given measured speaker, even if this is a 2 or 3 way, regardless of the crossover order or even physical placement of drivers on a flat or stepped baffle (measured at once - not so if a sub is then manually added for instance. That requires the manual 'best compromise' time alignment I have previously mentioned)

Therefore it is my understanding that Bruces' speakers have been time and phase aligned during measurement and calibration - within the limits of the microphone and the accuracy of the measuring environment but including the inbuilt passive crossovers

My reply relates to DEQX digital time alignment and not speakers that are physically aligned via the baffle and containing passive crossovers. Of course Bombaywalla is correct about that and the impact of the crossover order

Al/Andrew/Bombaywalla ... any thoughts about the impact (if any) DEQX has on driver distortion? My guess is that driver distortion is more a function of crossover and driver design and build quality itself. And that it is outside the realm of the DEQX to correct such deficiencies.

Just an fyi: Here's some bench test measurements of my Paradigm S8s (an earlier version #2): http://www.hometheaterhifi.com/surround-sound-speaker-systems/surround-sound-speaker-systems-reviews/a-secrets-speaker-system-review/page-4-the-paradigm-reference-signatures-on-the-bench.html

Not bad ... at least in the opinion of the reviewer.

My S8s (v3) use the same tweeter and mid drivers. The woofers and x-over were upgraded. Nevertheless, I assume the distortion specs would be about the same as those reported for the V2.

Even still ... compare the Magico S5s in my post above. Almost vanishingly low distortion specs. I suppose the real Q is whether we can hear the difference. Stated differently, assuming the Magico S5 and Paradigm S8 were DEQX corrected, how differently would they actually sound?

I gotta' believe that a 500 Hz test signal produced by the Magico sounds exactly like a 500 Hz test signal produced by the Paradigm S8. The real Q is how do the two speakers make music after being DEQX corrected???

Thank you for the kind works Bifwynne.

Yes, correct - for those who cannot & will not buy time-coherent speakers DEQX is one answer to the problem. And, I believe the DEQX people were smart when they realized that the room acoustics play an imp part & they incl room correction as well. I think we can safely say that 99% of the people live in homes where the room sucks! Does that mean these people cannot have good sounding playback systems? No, they surely can with room correction - either passive (tube traps) or active (PARC, DEQX, Lingdorf, etc).

Re. DEQX taking into account driver distortion - I think DEQX does that already. You put a mic in front of the speaker & measure. DEQX sees distortion. It does not itemize the distortion - X% from x-over, Y% from drivers, Z% from cabinet, A% from room. How does it know where the distortion is coming from? To it distortion is distortion. When it does a correction for the speaker is lumps all the distortion into one number & tries its best to fully correct it. Then, I believe, you go to the next step & do room correction with the mic at your listening position. And, this 2nd part takes out the other big contributor.

So, as you are playing music, the driver is still distortion (as it always did) but the DEQX correction curve has an inverse function to straighten this out. So, I believe that driver distortion is included to whatever extent the measuring mic can pick-up & whatever is the correction capacity of DEQX.
I'd be interested in others' comments too. Thanks.

Hi Bruce,

Here are the benefits of DEQX as summarized in the calibration software manual:

Correcting full range ‘passive’ (traditional Hi-Fi) speakers plus room correction:

Anechoic Frequency-response calibration.
Anechoic Phase-response/Timing-coherence calibration.
Integrate subwoofer/s with time-domain and/or Parametric EQ room correction.
Multiband Parametric EQ for real-time preference and room EQ adjustment.
Improved imaging and sound-staging.
Improved frequency-response accuracy.
Improved timing coherence.
Three band ‘tone’ control including a fully parametric-EQ band with 99-memory (remote control).

Additional features if using DEQX-Active crossover option (available on some models):

Stereo 3-way active crossovers: 6dB/octave to 300dB/octave.
Steep linear-phase filter option.
Automatic timing/phase alignment between up to 3-way speakers (or 2-way plus subs).
Increased loudness.
High dynamic resolution (reduced distortion) due to drivers operating in linear operating zone.
Reduced crossover distortion - reduced ‘comb filtering’.
Improved natural dispersion - reduced unwanted on-axis driver ‘beaming’ of high frequencies.

I'd imagine that the main benefit DEQX can provide with respect to driver distortion would be in cases where subs are being used (as in your case), or in biamped or triamped setups. In those situations DEQX could introduce very sharp filter slopes that would keep some of the drivers from having to deal with frequencies that are out of their comfort zone. And it could do that without the adverse timing and phase effects that would result if that were done in speaker crossovers or elsewhere in the analog domain.

With a single-amped speaker that is being driven full-range, such as in my case, I'd imagine that any benefits to driver distortion would be incidental, due to relatively minor "second order" effects. An example perhaps being taming a frequency response peak in the bass region that is contributed to at that frequency by harmonic distortion of a lower frequency.

Regarding Magico, as you've no doubt seen in various threads here and elsewhere, they tend to be controversial. While they seem to do pretty much everything right on paper, and a lot of folks love them, some find them to be unmusical. Also, the impedance characteristics of the S5 shown in the SoundStage measurements you linked to do not inspire confidence in their tube-friendliness. While their impedance magnitude is relatively flat across most of the spectrum, as you've mentioned in the past, it is around 3 ohms in a good part of the bass region, and that low magnitude is combined with a fairly severe -45 degree capacitive phase angle around 50 Hz. That said, though, I suspect that your amp could handle them better than most tube amps, due in part to their relatively low output impedance and their very substantial power supply.

Best regards,
-- Al

Thanks again Al and Bombaywalla. More great responses from Al and Bombaywalla.

Al, I think your quote about using the DEQX with active x-over function (and I assume this entails multi-amping) answers my driver distortion question:

"High dynamic resolution (reduced distortion) due to drivers operating in linear operating zone.

"Reduced crossover distortion - reduced ‘comb filtering’."

But I think your following comment may say it all:

"I'd imagine that the main benefit DEQX can provide with respect to driver distortion would be in cases where subs are being used (as in your case), or in biamped or triamped setups. In those situations DEQX could introduce very sharp filter slopes that would keep some of the drivers from having to deal with frequencies that are out of their comfort zone. And it could do that without the adverse timing and phase effects that would result if that were done in speaker crossovers or elsewhere in the analog domain."

Al/Andrew/Bombaywalla: There is only one speaker that I know of that uses super high-order internal/passive x-overs; namely: Joseph Audio. I think Mr. Joseph describes his crossovers as an "infinite baffle" types or something to that effect. I'd call them brick wall filters. I bet the DEQX would do a great job with Joseph Audio speakers.

As an fyi: PJ, the DEQX National Sales Manager chap I spoke about before is also the local rep for Joseph speakers. He speaks well of them.

Next to last point ... as Al and Andrew both know, I use a self powered sub (1700 watts; 3400 watts peak) that Larry, the DEQXPert, folded into my system. I think Al makes a good point that using the sub diverts low frequency signal away from my main amp, thereby reducing the power demands placed on the amp.

Last point ... I wonder out loud if I should even ponder upgrading my speakers at any time in the future. Perhaps, the best next big step, which would entail taking a whole different path, is to do what Andrew has done.

Namely, DIY speakers with excellent drivers ... and no internal crossover. Instead, I would use the DEQX as the cross over and I would multi-amp each speaker.

Very expensive path. I wonder if Duke LeJuene (sp?) from AudioKinesis could custom build the speakers.