Is DEQX a game changer?

Good to read your comments Denis and you have reminded me of an important aspect that Almarg may want to consider

A full range speaker such as the Ulysses that he describes will benefit from DEQX (automated) phase and time alignment, however the larger drivers will still need to handle all lower frequencies up to the passive crossover point

If you can reduce the number of frequencies a driver has to cope with and use a steep crossover, each cone has less work to do to reproduce the remaining range cleanly

Adding a sub to such a speaker gives the facility to remove deep bass frequencies via DEQX (in 'our' case below 100hz) which means the larger drivers will only concentrate on mid-bass upwards and this makes a significant difference to transient attack and overall cleanness of the sound. It is exactly what I originally did with my old Obelisks ad still do with the OBs

Your points about voicing are very valid and yes crossover frequencies and slopes can be tested via the presets as part of the configuration process until you arrive at your optimal voicing. For all the uninitated reading this - it means your system can sound exactly how you want it, in my case clean fast, dynamic & punchy right down to a measured -2dB at 16hz

Tim, Andrew, Denis, thanks for the excellent inputs. Points taken.

11-19-14: Timlub
When building speakers, we time drivers [that] are not time aligned on the frontal plane by adding padding/baffle step compensation to change the delivery of the tweeter and mid hitting your ear at the same time. This is built into the crossover. An External device cannot change that as far as true timing speed is concerned.

Hi Tim,

You may already be aware of this, but just to be sure the DEQX processing divides the spectrum into thousands of segments, adjusting the delays of each of them such that time coherence is attained even in the presence of a passive crossover within the speaker that is higher than first order, which would normally make time coherence impossible. See the graph and the references in the text to group delay in this writeup at the DEQX site, as well as the HDP-4 brochure and their FAQ writeups.

Best regards,
-- Al

Hi Al, yep, Oh, absolutely. You can increase delay, but you cannot decrease the delay. If any designer ever over compensated with Baffle step compensation or match pad, you cannot remove that resistance or speed up the passive parts inside. On the other hand, you can add delay electronically. What I have loved reading about the DEQX is that once mic'd, it will automatically adjust time delay and help eq... This is a tremendous benefit. I would also suggest that you take your current crossover points and try taking a listen at very steep slopes, say 48db per octave. On some speakers that alone can make things more coherent and easy enough to reverse if it doesn't work out. Good Luck with it, Let us know how you like it, Tim

The comment to use steep crossover slopes is for those that can bi amp that still have their crossovers in place.... sorry for any confusion.

Andrew (Drewan77) --- been following the last several posts. As you know, I just bought the PreMATE. Larry, the DEQXpert, set it up. Interestingly, he cut the self powered sub woofer off at 120 Hz and let the speakers' passive woofers take it from there until they crossed over to mid-driver at 200 or so Hz.

Based on Larry's measurements, my sub woofer is pretty flat down to about 13 Hz, which is pretty low. Kinda weird, but the speaker's woofers are covering about 80 to 100 Hz of bandwidth. So, the bottom line here is that the heavy bass lifting is being handled by the sub woofer.

There is an added plus ... namely that it takes "pressure" to delivery power off my amp and shifts it to the subwoofer, which has a built-in amp rated at 3400 watts max-Q. I've tripped my circuit breakers plenty of times.

All-in-all, I think my speakers sound better than before. When I cut the PreMATE out of the circuit (P0 button), the sound presentation is muddy and imaging is smeared. When engaged, sharper imaging, better transients, nicer sounding musical presentation.

I would like to explore and play with the PreMATE's considerable functionalities. Problem is that the owner's manual is not very user-friendly and is accessible only on-line or off a disc. Plus, I am not very tech or computer wise.

Sure wish I could spend some more time with Larry the DEQXpert.

Bruce