[ted_b]

Doug,
You can do that!  The DEQX is a digital box, though.  You're just digitizing (needless a/d d/a steps) your analog signal.  Why have an analog pre if you're gonna do that?  That was my issue.  My analog (tubed) redbook/SACD sources didn't like the extra a/d d/a stage at all.  Going in from their digital outs was ok, but not nearly as good as all-analog.....for me.  That is, until John lines me up with an NHT xD demo and I see God.

Ted

[mac]

and, i agree w/josh - 4-way is better than 3-way.

doug s.

And, I can understand you you'd think that to be true.

"One really needs to experience this device in their system (in multi-amped mode) to fully appreciate what it's capable of doing."

[John Ashman]

ok, what am i missing here?  why cannot you yust run the standard analog outs of your analog preamp into the analog inputs of the deqx?  

You can, but here's the thing - a secondary preamp would just add another analog circuit and lower the resolution needlessly.   If you add a DAC, you would be going CD out to a DAC then to an ADC, then through a DAC again.  But if you go digital into the PDC-P, you get only one DAC, with two steps removed.  You could have a $20,000 DAC and/or preamp, but as soon as you put it in line, you are lowering the fidelity of the system as opposed to running straight into the PDC.  

The ONLY way to improve upon it without hurting the sound is to use bypass the AD/DA processes of the of PDC as well as its preamp function, keep it entirely digital and that requires 3 DACs, a switcher/AD coverter (a la Meridian) and a 6-channel analog preamp.  So, I hate to say it, but your preamp and DAC would be obsolete in all reality.

[John Ashman]

That is, until John lines me up with an NHT xD demo and I see God.

[Bingenito]

I fully support R&D and making the world a better place.

John and Mac- You guys love DEQX "GREAT" I am sure that when used in the correct application just like anything else it works wonders.

The right application may not be what some consider ideal for there analog gear. That is fine too.

No one is wrong here. Except for the guy that likes single driver systems. Kidding..... Oh hell no I am not

What more really needs to be said on this topic?

Unless there is a shootout of 2 speakers that use the same drivers, gear, room, etc. With and w/o DEQX and someone that knows how to use it we can go back a forth all week.

Prove it's worth. BTW I do not doubt the benefits but there are always compromises. You have got to decide which compromise is acceptable to you.

[doug s.]

Doug,
You can do that!  The DEQX is a digital box, though.  You're just digitizing (needless a/d d/a steps) your analog signal.  Why have an analog pre if you're gonna do that?  That was my issue.  My analog (tubed) redbook/SACD sources didn't like the extra a/d d/a stage at all.  Going in from their digital outs was ok, but not nearly as good as all-analog.....for me.  That is, until John lines me up with an NHT xD demo and I see God.

Ted

so, ted, yure telling me that you tried the unit as a x-over only, & were actively bi/tri-amping?  as i said before, i have no problem whatsoever using a/d-d/a if it's at the active line-level crossover point between loudspeaker drivers.  

if used yust as an active x-over, it's awfully hard for me to imagine that it wouldn't *still* be far more transparent than any passive speaker-level x-over, and that yer analog preamp & analog sources will still be presented in all their glory!  

and mac, not sure what yure getting at, but yes, since my ideal speaker (presently in my head!    )  consists of a three-way, plus subwoofers, a 4-way x-over would be required.  but, it *is* posssible that i may end up w/a two-way plus subs, so a 3-way x-over may end up being ok...

doug s.

[mac]

I fully support R&D and making the world a better place.

John and Mac- You guys love DEQX "GREAT" I am sure that when used in the correct application just like anything else it works wonders.

The right application may not be what some consider ideal for there analog gear. That is fine too.

No one is wrong here. Except for the guy that likes single driver systems. Kidding..... Oh hell no I am not  

What more really needs to be said on this topic?

Unless there is a shootout of 2 speakers that use the same drivers, gear, room, etc. With and w/o DEQX and someone that knows how to use it we can go back a forth all week.

Prove it's worth. BTW I do not doubt the benefits but there are always compromises. You have got to decide which compromise is acceptable to you.

John started this "thread" as a review of the DEQX PDC.  He shared his impressions of what this unit is capable of doing with his modest $300 JBL speakers.  I've echoed his praise.  Did I mention that I also use some decent quality analog gear with my DEQX? (probably).

WRT the "shootout" using two speakers with the same drivers, gear, room. etc...  That's an extremely easy thing to do with the PDC.  You can program it for different crossover topologies.  Simply setup two configurations - one with conventional LR4 filters and no speaker correction and the other with linear phase high-order filters and driver correction.  With the simple click of a button it'll be as clear as day what the benefits are.  

One really needs to experience this device in their system (in multi-amped mode) to fully appreciate what it's capable of doing.  Until you've done that you can only theorize.

[JohnnyLightOn]

Does the DEQX use a separate amp for each speaker driver?  So in a 3-way pair of speakers, do you use 6 separate amps?  

I have a pair of B&W speakers, each with 2 8" bass/mid drivers and one tweeter.  My transport is a Squeezebox streaming lossless files from my PC.  I use an Ack dAck as my source, and a JVC digital amp as my power.  Can anyone give me an example of how I would integrate the DEQX into my system?  Which components could I keep, and which would I need to add?

Also, if my room is oddly shaped and untreated, with sub-optimal speakers positioning, will the DEQX make it seem like I'm in a well-treated room with well-positioned speakers?

[Bingenito]

The shootout I mentioned was with and without DEQX not with and without room correction.

In terms of deciding what compromise you prefer that is the way to do it IMO.

All analog/ passive crossover vs. a bi or tri-amped active system. You may say why bother DEQX will blow the analog system away. All I am saying is prove it. Again I do not doubt it but hearing is believing.

I can tell you that room correction from a DBX DriveRack made my system sound like crap. Now I now a DriveRack and DEQX are not comparable just saying that I would need proof before making my system more complex.

[Rick Craig]

So, for the same driver/tweeter, will a line array have a truly wider dispersion or just a narrowed vertical dispersion.  If so, do you know why that is?

Jim Griffin's white paper can explain it better than I can. The output of the array has more narrow dispersion and a cylindrical out put pattern. That's why you can be sitting in front of one speaker at a normal listening distance and distinctly hear the other channel (much more than you would with a point source). Jim and I are currently discussing his next array project that will implement the DEQX.

[mac]

The shootout I mentioned was with and without DEQX not with and without room correction...

There is a big difference between "room correction" and "DEQX calibration" (driver frequency/phase correction).  What I proposed will allow you to hear the effects of just the calibration aspect of the product (which should be enough to convince you of its merits).

If one isn't already multi-amping there are other major sonic gains to be achieved by that aspect alone.

All analog/ passive crossover vs. a bi or tri-amped active system. You may say why bother DEQX will blow the analog system away. All I am saying is prove it. Again I do not doubt it but hearing is believing...

And what I've been saying is that one really needs to experience this device in their own system (in multi-amped mode) to fully appreciate what it's capable of doing.  I've already done that.  Have you?  You need to prove it to yourself.

I can tell you that room correction from a DBX DriveRack made my system sound like crap...

Yeah, I've had similar experiences with the Behringer gear in my system.

[mac]

Does the DEQX use a separate amp for each speaker driver?  So in a 3-way pair of speakers, do you use 6 separate amps?  

I have a pair of B&W speakers, each with 2 8" bass/mid drivers and one tweeter.  My transport is a Squeezebox streaming lossless files from my PC.  I use an Ack dAck as my source, and a JVC digital amp as my power.  Can anyone give me an example of how I would integrate the DEQX into my system?  Which components could I keep, and which would I need to add?

Also, if my room is oddly  ...

The DEQX PDC can be used in a variety of ways.  To use its full potential you should use a separate amplifier channel for each driver (or in your case one amp for both woofers and another for your tweeters).

I also use a Squeezebox in my system.  You can feed either the analog or S/PDIF output directly into the the DEQX.  The DEQX would act as a preamp which would connect directly to your amp(s).  Ideally, you'd need one additional stereo amp (in addition to the DEQX PDC).  PM me if you'd like more info.

[Rick Craig]

I fully support R&D and making the world a better place.

John and Mac- You guys love DEQX "GREAT" I am sure that when used in the correct application just like anything else it works wonders.

The right application may not be what some consider ideal for there analog gear. That is fine too.

No one is wrong here. Except for the guy that likes single driver systems. Kidding..... Oh hell no I am not

What more really needs to be said on this topic?

Unless there is a shootout of 2 speakers  ...

There are a few DEQX owners here; in fact, I'm going to be helping one of them implement it into his design. Maybe I can borrow one and we can do a shootout with my arrays.

[Bingenito]

Just let me know where I need to go to check it out.

To Mac's point the best comparison is in your own system. I am pretty damn happy right now so it will take allot of convincing to make me by another amp or two and a DEQX.

[mac]

There are a few DEQX owners here; in fact, I'm going to be helping one of them implement it into his design. Maybe I can borrow one and we can do a shootout with my arrays.

Yes there are.  Both Jim Salk and Jim Griffin are using them.

[mac]

Just let me know where I need to go to check it out.

To Mac's point the best comparison is in your own system. I am pretty damn happy right now so it will take allot of convincing to make me by another amp or two and a DEQX.

Sounds like you and your bud, Rick, need to chat.

[Rick Craig]

There are a few DEQX owners here; in fact, I'm going to be helping one of them implement it into his design. Maybe I can borrow one and we can do a shootout with my arrays.

Yes there are.  Both Jim Salk and Jim Griffin are using them.

Actually I meant here in the Raleigh area but I already was aware of Jim Salk and Jim Griffin using the DEQX.

[John Ashman]

Johhny, do you have Matrix 3s?

[Rick Craig]

The HT-3 is an ideal design for DEQX.  The NHT Xd which comes with DEQX is arguably even better for a few small, but possibly important reasons.  However, I've seen few other speakers that would respond as well to DEQX as the HT-3, based on my experiments.  

The most important criteria, IMO, are:

Rigid "pistonic" drivers with very linear motor structures.
Minimum, low diffraction baffles
Rigid cabintry
Acoustic suspension design
Proportional driver design (1"/4"/8" or 1"/5"/10" or thereabouts)
Ar ...

Don't sell the system short John. I think there are many types of systems that could benefit with possibly the exception of one (dipoles). I've had a chance to hear both the NaO dipole (basic active / passive combination crossover) and a dipole using the DEQX. The NaO was much better at depth retrieval and an overall sense of the acoustic space of the recording. I don't know what the problem was with the DEQX but I would be hesitant to use one with a dipole.

Rick

[John Ashman]

Well, I think all speakers would benefit if they're tri-amped, but I do believe some speakers will have a greater delta in performance from stock to DEQXed.  I think line arrays, for instance will benefit, but, for instance, DEQX lowers driver distortion and increases dynamic range, something most line arrays don't need to have fixed.  Or, for instance, the enhanced vertical dispersion wouldn't be noticeable or particularly beneficial.  It could, however, help a big speaker that moves a lot of air deal with the room modes, do time/phase alignment, and fix resonant peaks with parametric EQ rather than a passive notch filter.  And it always helps to ditch the passive crossover!  So, DEQX is almost 100% chance of being an improvement, but whether it is a 25% improvement or a 100% improvement depends just on how good the speaker is already and whether all of the processing functions can be fully and effectively utilized.