[Tyson]

I think I am growing tired of boxed speaker sound, I might try my hand at building a V2.  I do have a few questions, if you don't mind.

1) Is the tweeter front-firing only?  If so, how hard would it be for someone (say, me) to open it up in the back?

2)  Any specific reason for choosing the P-Audio BM8CXA unit over similar 8 inch coax units from Beyma, B&C, Radian, etc...?

3)  I have a DEQX unit for my preamp/DAC/Crossover/EQ needs, plus I have two stereo tube amps (one for mids, one for highs), and a huge SS amp for bass, plus a very good mic from Earthworks.  Could this be used in place of the passive parts and just let me run the speaker in tri-amp mode?  I can use pretty much any crossover point and any slope, plus I have unlimited flexibility in the EQ area as well.

[Danny Richie]

Okay, but you'll be ruined for ever and ever and you won't be able to go back.

The tweeter on this model is front facing only. One reason is that I am trying to keep the cost down on this model. Making that modification to all the drivers really takes a lot of time, and it would require the network to be completely changed.

I looked at all the available drivers and by build quality and performance the P-Audio looked top notch. It also offered the best value.

The big limitation to the DEQX is that you are then stuck with a mid-fi level DAC for each channel. It is too much of a bottleneck. Get yourself a Tranquility DAC and go with the design as designed and you'll never look back. Plus you just need one amp.

[Tyson]

What makes the DAC's in the DEQX mid-fi?

[Danny Richie]

What makes the DAC's in the DEQX mid-fi?

There is WAY to much processing and components in the signal path. No I2S direct input or any USB input at all either. So they are completely missing the boat on all computer based audio formats that are leading the way in high resolution playback. Once you get away from those spinning disc then having to go back is a big backwards step.

[Tyson]

I actually use my PC for my source, and a USB-SPDIF converter from Empirical Audio.  Best sound, ever

In fact, the DEQX is the primary reason I'm interested in open baffle speakers at all.  Basically, my speakers measure perfectly (using several different measurement programs), and they sound better than anything else I've ever had in my system.  But, there are still some issues that I can hear, and I'm pretty certain that those are related to box colorations.  Hence my desire to hear OB speakers like the V2's.

One other question - why choose an 8 inch model instead of a 10 or 12 inch for the "little brother" to the V1?

[Danny Richie]

In fact, the DEQX is the primary reason I'm interested in open baffle speakers at all.  Basically, my speakers measure perfectly (using several different measurement programs), and they sound better than anything else I've ever had in my system.  But, there are still some issues that I can hear, and I'm pretty certain that those are related to box colorations.  Hence my desire to hear OB speakers like the V2's.

Build one out and try it both ways, passive with a good DAC and with DEQX.

One other question - why choose an 8 inch model instead of a 10 or 12 inch for the "little brother" to the V1?

That 8 measured great compared to many others. It sounded REALLY good, and it was not expensive. I was trying to keep cost really low to get more people to try one of my open baffle designs. I already have a couple of models above it, but they are quite a bit more expensive.

The sale price on the V-2 makes it really attractive.

[PaulFolbrecht]

This is of interest to me since I also have a DEQX.  (I'm not sure if the V2 is the "Super V" improved but if so I am considering building it as well, for fun, though I love my front horns.)

There is nothing at all wrong with running an external DAC with the DEQX.  There are better DACs than its internal DAC.  I plan to use my excellent Audio Note Kits DAC.

Now, of course, the objection is that you are then doing "unnecessary" AD and DA conversions.  Here are my counters to that:

- Very high quality AD and DA can be very close to transparent, at 24/96.  One thing I have learned from digitizing vinyl is that most digital nastiness comes from the recording & mastering.  My digitized vinyl sounds extremely analog and close to the original at 24/96 even done on a rather humble Masterlink machine.

- The advantages the DEQX gives - linear-phase xovers, very steep slopes, time & phase correction (even correcting a single driver's phase errors), and room correction can well far exceed the slight disadvantage of the extra conversions.

At the 2006 RMAF the Cogent/Welborne room used a DEQX crossover with their vinyl source.  I did not find out they used this digital crossover until years later and I was rather stunned, because that was the most realistic and amazing audio system I had ever heard.  The palpability, nuance, detail, and emotion that came through, in a completely natural way, was actually literally jaw-dropping for me at the time.  (Again, thinking it was pure analog.)  This experience eliminated my theoretical rejection of digitization in an analog chain.

Furthermore, the DEQX actually has an advantage when used with an external DAC: with the analog inputs, all digital processing is done at 24/94, but using a digital in it is done at the input bitstream's rate - so, if you are playing redbook, the unit is doing everything at 44.1 Khz.  It's easy to see how an external DAC could be superior at least for redbook.

For high-res files, I would counter that it is NOT true that less is always better.  For example, I, like many others, discovered through much trial-and-error that a good active tube preamp almost always makes a system sound better, even when the gain is not necessary (the key word here is "good").  Same situation with a DAC: while less might be "closer to what was recorded" it might not be closer to what the original event actually sounded like or better-sounding.

[Tyson]

Danny,
2 more questions - what drivers do you use for the bass section, and would you pick a different driver with a larger budget?

Also, I listen off-axis quite a bit and am hoping that the combo of coax point source combined with open baffle will make this a better experience than listening to monopoles.  Is that a correct assumption?

Paul,
Cool, another DEQX owner!  I also find that the errors inherent in speakers are quite a bit more audible than those in sources.

[Danny Richie]

I appreciate your input.

I also have some recordings that were played back on vinyl that was digitized at a high bit rate and it blows away the same original CD.

Even without the AD then DA double conversion, I am just not sold on those DAC's in the DEQX. I feel it was more built to hit a price point. Plus having hosted some DAC comparisons I have a good feel for what it take and what it cost to get there.

I heard a speaker system at RMAF last year that featured some open baffle speakers using some type of DEQX or similar system with room correction. It was still a long way from the performance that we were getting in our room with a Tranquility DAC and passive crossover design on our open baffle speaker. Even people that I know of that bought those speakers wound up feeling like it was good for the money but still not a high end speaker.

The time and phase correction is a great feature if you have a design with delay errors to correct, but I am pretty good about not having those issues with a passive design. My experience has shown me that it is great to work towards perfection in those areas, but once the speaker gets placed into a room, the room response dominates (hugely) and over shadows any perfection one might attain in that direction.

The bigger fundamental drawback that I heard at RMAF with one of those systems was the implementation of room correction feature in place of room treatment. The speaker itself might have been corrected for phase errors, but the side wall reflections in the room cause a MUCH greater disruption in the response. The room correction does not change the fact that there is a reflection. It just turns the on axis level down so that the two combined sum back to a level balance (same SPL). It still comes from multiple directions though. The imaging and sound staging is still disrupted. Also, the room correction is only effective at the point it was measured from. Move locations and you have to start all over.

I still greatly favor a passive design with good electronics and a well treated room.

[Danny Richie]

what drivers do you use for the bass section, and would you pick a different driver with a larger budget?

They are a 12" woofer made by Eminence. They are prefect for that application and price point.

And sure, for more money my open baffle servo subs are in a different league. That is why I use them in my V-1's and Super-V's. But a Super-V kit is $2,495 and not $1,095 that the V-2's are on sale for.

Also, I listen off-axis quite a bit and am hoping that the combo of coax point source combined with open baffle will make this a better experience than listening to monopoles.  Is that a correct assumption?

They are great off axis. You can move allover the place and the driver alignment never changes. 
Plus the OB bass does not load the room and you don't have bass hot spots like you get with a boxed speaker.

[ctviggen]

Plus the OB bass does not load the room and you don't have bass hot spots like you get with a boxed speaker.

Technically, that's not correct.  You still have the same bass hot spots, but perhaps the open baffle bass might not excite them to the same degree.  For instance, see here:

"2 - Its [an open baffle, dipole speaker's] total radiated power is 4.8 dB less than that of a monopole for the same on-axis SPL. Thus the strength of the excited modes is less.
3 - A 4.8 dB difference in SPL at low frequencies is quite significant, due to the bunching of the equal loudness contours at low frequencies, and corresponds to a 10 dB difference in loudness at 1 kHz.
Thus, bass reproduced by a dipole would be less masked by the room, since a dipole excites fewer modes, and to a lesser degree, and since the perceived difference between direct sound and room contribution is magnified by a psychoacoustic effect."

http://www.linkwitzlab.com/rooms.htm

[Danny Richie]

I won't load the room like a boxed speaker does (how about that).

It cancels the output at 90 degrees off axis, and it is pushing air from one side of the room to the other verses creating a pressure differential in the room verses the box.

[Tyson]

I think I'll order the kit and build the passive crossovers in a separate box.  That way I can switch between it and the DEQX and see which one I like better.  How do I place an order and get the sale price?

[Danny Richie]

I think I'll order the kit and build the passive crossovers in a separate box.  That way I can switch between it and the DEQX and see which one I like better.  How do I place an order and get the sale price?

That sounds like a good idea. I look forward to hearing your results.

Call GR Research to get the sale price. 940-592-3400

If you want, you can e-mail me your complete shipping info then call with CC info.

[jtwrace]

Where's the sale info?  With me not spending as much time on A.C. as I have in the past...I'm in the dark. 

[Danny Richie]

Where's the sale info?  With me not spending as much time on A.C. as I have in the past...I'm in the dark. 

I just bumped it to the top for you. 

http://www.audiocircle.com/index.php?topic=84439.msg819136#msg819136

[Tyson]

Order placed!  Hopefully this speaker will address some of the issues that I now know I'm very sensitive to - my room is an L shape (combo living/dining room area), and the bass loads the room much more on one side than the other.  Depending on where you sit, there's always too much or too little.  Second, I often sit pretty close to the speakers, and off-axis.  Having the tweeter separate from the midrange just sounds "off" to me, I always hear a discontinuity between the units.  Last, since I do sit off axis a lot, I'm hoping the open baffle will give me more of that "big, room filling" sound I'm after.

[PaulFolbrecht]

Danny, how does this speaker compare to the Super V?  Thanks!

[Danny Richie]

Danny, how does this speaker compare to the Super V?  Thanks!

Super-V's are in a different league.

In short, the servo controlled bass it flat to 20Hz and stops on a dime. Resolution levels are better across the board, sensitivity is higher, dynamics are greater... It's a V-2 on steroids. But it isn't on sale for $1,095 either.

[jtwrace]

But it isn't on sale for $1,095 either.

I think I'm looking forward to when it's on sale for $2,095 though.