DEQX Owners Thread

[Paul Spencer]

True if you use their IIR only base model 2x4's, 2x8's etc. Their SHARC based stuff runs FIR, is reasonably powerful and is almost at the stage of being stable

 

Indeed, it's impressive what they are offering.

 

That's all I need to know.

I was under the false belief that it's room correction tech would eliminate the need for treatment.

Thanks for clearing it up.

 

A few examples might help.

 

Firstly with bass. You can use bass traps and they will give you a global improvement in bass tightness. When you seriously trap a room, the improvement is obvious in measurement and subjectively also. Most people use traps too small or too few to get that improvement, but it can be dramatic. Even done seriously, you will still get peaks and dips remaining because it's simply not practical to use enough bass traps to tame them all. So the traps help improve the bass globally (every seat) but they still don't get the entire job done. Along comes EQ - now we can tame the worst peaks - we can do it really well for one seat, pretty well for a row of seats, definitely not for a home cinema room with multiple rows.

 

Along comes DEQX with some very powerful processing that can correct group delay below 200 Hz. The result of this, even without any EQ being used, is tighter bass. One DEQX owner set up a blind test demo of this and it was obvious to all. The group delay correction sounded like a loudness control being turned on and off, even though the frequency response was closely matched.

 

So with bass traps vs DSP you get different kinds of improvement. If you want the best possible result, use both.

 

Above 200 Hz things change. Now this is where DEQX when used well, will correct issues related to the speaker without the room. In other words, you don't want to stick the mic in the listening position and EQ everything flat. Subjectively DEQX can also dramatically improve the sound stage, making it much bigger and more three dimensional without giving up any image tightness. However, most rooms also could benefit from a mix of diffusion and absorption, especially if your room is adding a detrimental colour to the music. Treatment can even improve a room when music isn't playing ie talking in the room can sound nicer, especially with diffusers.

 

Again there is some overlap because DEQX and treatment can have a huge impact on the sound stage and imaging and the sense of the music being closer to the original, more natural. At the same time, they don't do the same job. You always want to fix a problem close to its source where you can. If the room is adding problems with reflections and reverberation in the midrange, this is where you really need treatment and DSP doesn't really help. If the problems are more related to the speaker itself, then a tool like DEQX is a better solution. Again, most systems will benefit ideally from both.

[sir sanders zingmore]

Paul, what is "group delay" ?

[Paul Spencer]

Group delay is the time delay with respect to frequency. It usually comes up in the context of things like sealed vs ported subs or various crossover filters.

[Darren69]

I was wondering that myself SSZ, thanks Paul.

I like thisn thread because it sounds (pardon the pun) like I am doing the right thing, with the room treatment then the DEQX (pending power amp change). I assume I would need to fit and tune the DEQX as a final move and changing the power amp after tuning the DEQX could throw some measurements out with the amps new characteristics, if any.

[frankn]

@ "Darren69" i doubt that changing a power amp would totally change the speaker profile that would necessitate re calibrating the room correction, however it is reasonably simple to check since all you need to do is re-measure the Speaker response and compare the new profile to the old one - no or minimal change would tell you no-need to re-calibrate

Also, DEQX will set-up your system remotely for you if requested. You & DEQX share your laptop via internet with the DEQX box and microphone connected to your system. You move the microphone according to their instructions, they do the measurements and then show you how to build the filters, calibrate and construct corrections etc. Then off you go. Apparently takes about an hour. You can then of course go for more detail, experiment etc while keeping the original measurements and profiles intact

Sent from my iPad using Tapatalk

[Darren69]

I am paying for a man to physically come and do it, I got that quoted, haha!!

I am not confident enough for that electronic stuff and am also paying for peace of mind. I have a noisy mind. The f^&ker.

Thanks for your thoughts Frankie, it makes sense and I am assuming what you say will be true once I get familiarised with the product.

[frankn]

You are lucky man, are you in Vic? SA has no DEQX ppl. The manual is all over the place.

Sent from my iPad using Tapatalk

[Darren69]

No, NE NSW. Am simply happy to fork out the extra $$ to get a competent person to come with the Premate.

[almikel]

I use my Deqx as the heart of my setup.

About to go 4 way and can't justify the cost of daisy chaining 2 Deqx together so I'll use my old 3 way Linwitz Riley 24db on the high output of the Deqx

What have others been using slope wise on their filters?

I've been using 96db linear, but I'll experiment with lower slopes & linkwitz Riley alignments for my new speakers.

I think 48db is a good balance between steep without too much ringing,

Mike

[Satanica]

72db here.

[Malcolm]

I think 48db is a good balance between steep without too much ringing,

Mike

What does ringing sound like ?

[Peta]

it sounds like the echoes you get when you clap your hands or tap spoons in a hall or room. The longer and louder the echoes the more the 'ringing'.

[Malcolm]

So guys and girls who's heard ringing on high order slopes on a DEQX , myself I haven't .

Cheers

[almikel]

Hi Malcolm,

I haven't done much listening testing to compare, but it's the pre-ringing that's inherent in linear FIR filters that is audible based on a video I watched/listened to on linear EQ vs minimum phase EQ (I'll try to find it and post a link).

 

On transients such as drum hits you could hear the drum hit build before the main peak of the transient on the linear EQ due to the pre-ringing.

 

In Peta's example above, imagine hearing the build up of the tap of spoons before the tap, then the main transient of the tap of spoons, and then the normal ringing after.

 

This type of non-causal effect does not happen in nature - we're much more used to "something happening" and the effects that come after.

 

Even Alan Langford from DEQX recommended to me soon after I had my DEQX not to use the 300dB linear filters (I of course had dialled in the maximum I could - steeper MUST be better right?), due to the "potential" audibility of pre-ringing.

 

On normal music can you hear it? don't know....BUT

 

My theory is - given the magic of Group Delay correction in the DEQX, the ultimate should be to use "reasonably" steep Linkwitz Riley filters say 48dB/octave - LR8 (which are IIR, not FIR, hence no pre-ringing and "reasonable" post ringing because 48dB is not ridiculously steep) and both drivers are in phase all the time due to the Linkwitz filter (2 x 360 degrees for LR8) assuming time alignment, which the DEQX conveniently does.

 

I think I'll set up one of the profiles on my DEQX tonight to do just that.

 

I reckon I'll be able hear a "difference", but I won't be able to determine which is "better".

 

It would be fabulous to have Alan from DEQX contribute to some of these discussions - for a guy in sales he knows an amazing amount of stuff regarding the technical side of the DEQX product!

 

Mike 

[ArthurDent]

Hi Malcolm,

I haven't done much listening testing to compare, but it's the pre-ringing that's inherent in linear FIR filters that is audible based on a video I watched/listened to on linear EQ vs minimum phase EQ (I'll try to find it and post a link).

 

This one perhaps...

 

http://logic-pro-expert.com/logic-pro-blog/2013/04/20/linear-phase-eq-vs-minimum-phase-eq.html

[almikel]

well done Ken - yes that's it

 

Mike

[robin-hobart]

Hi-fi is getting so complicated these days.  Remember when it was just hooking up an amp to some passive speakers?

I had the privelege of listening (briefly) to Rod Crawford's (Legend Acoustics) evolving Tikandi / Aketha active DEQX system a few months back - here in rural Tassie!

It was like opening a door into a recording studio.  Stunning. Sooooo dynamic. IMO, Rod has absolutely nailed this segment of stereo magic.

Fully active speakers, with room equalisation DSP systems make absolute and complete sense to me.

For the genuine audiophile.

Having made that observation......

I've decided to regress - to the simplest I can live with.  I'm 63 years old - ears on the way out, & more interested these days in sampling the vast variety of the internet stations (Space Dreams?  Zen Attitude?) as well as using my Dell/Vortex Box for music streaming.

Recently purchased an Arcam Solo Neo all-in-one unit (can't justify the considerably more expensive Naim kit) - and as more time passes, the more I'm enjoying it; does just about all that I require.  One-remote user-friendliness.

Is the Arcam as good as the Naim?  Frankly no. The naim has more toe-tapping rhythm and life.

But, in short, there's not enough sound difference in it, and the sheer simplicty / convenience wins out for my needs.  I want to listen to the music rather than the system.

Edited June 7, 2014 by robin-hobart

[Darren69]

Pure poetry Robin, keep the faith mate.

[almikel]

Learned something about the DEQX.

If implementing a crossover within a speaker using the "calibrate" feature - you only have a linear filter or "no crossover" to choose from.

 

You have the option of FIR (linear phase) or IIR (traditional Butterworth or Linkwitz Riley) filters for the "limit" filters, and crossover filters built outside the Speaker Correction/Speaker Calibration process.

 

 

Mike

edited for clarity as I found a typo

 

further edit:

ps: the reason I was trying to use IIR filters was to see if I could hear a difference between LR8 (no pre-ringing) and the same slope FIR (with pre-ringing) crossovers, as per post #42

Edited June 12, 2014 by almikel

[Darren69]

Interesting and good to know, thanks Mike.

[sleach]

How would the DAC in a deqx compare with, for example, a crossover and DSP in something like a minidisp nanodigi paired with a good DAC like, say, pS audio or equivalent?

Sent from my iphone

[Paul Spencer]

How would the DAC in a deqx compare with, for example, a crossover and DSP in something like a minidisp nanodigi paired with a good DAC like, say, pS audio or equivalent?

 

That is an interesting question. I've been involved in some blind testing that involved DEQX, MiniDSP and Behringer DCX. They were all very transparent and in fact indistinguishable from a short run of interconnect cable. On the other hand, I have experienced much more expensive DACs that I could identify blind due to an obvious sonic signature. Price tells us much less than we expect sometimes.

[Darren69]

I have e mailed DEQX to check if the DAC is the same type throughout their range.

[sleach]

"On the other hand, I have experienced much more expensive DACs that I could identify blind due to an obvious sonic signature. "

That has been my experience too. I was also surprised by the difference usb cables can make. I was quite skeptical about that sort of thing until I heard it in AB testing and the difference was very clear.

I tested my current set up with a deqx during audition and it was very

Impressive. However I am now using minidsp from the speaker makers recommendation. I feel like something is a little bit lacking in certain passages of music.

It will be interesting to hear if there is any differences in the dacs within the deqx range

Edited June 11, 2014 by sleach

[frankn]

Quick couple of question about the digital inputs;

My lowly Meridian 506.20 CD player has s/pdif output (looks like an RCA connector) and Optical EIAJ. The DEQX has s/pdif in and AES/BU inputs. It seems simple but is there any difference in performance bt the DEQX input paths? Is S/PDIF also Toslink? Is there a recommended s/pdif cable or do I just go to the local store and by whatever is available?

Thank you in advance

Sent from my iPad using Tapatalk