Greg Timbers Interview

[Ian Mackenzie]

Hello Ian

I have a couple of questions:

Is he using he 045Be or just running the 476Be all the way out. Could he be using a 476Mg??

What is the horn/waveguide based on?? Is it similar to the M2 where there is a constantly changing flare rate to reduce reflections?? Can't tell from the photo but it doesn't look that deep also like the M2/some PT waveguides. Is it symmetrical or asymmetrical vertical diffraction slot??

Any chance of better look at them say a picture??

Thanks Rob

I have passed on your request

[rusty jefferson]

...I really enjoyed Greg's discussing a number of points:

1. The "shopping mall live piano" demonstration of the importance of dynamics.
2. How power compression in testing will affect measurements.
3. His mention of the difference of opinion between the "Sean and Floyd guys" and his personal take on the importance of dynamics versus directivity.
Widget

4. Linear Phase digital crossover filters and time alignment.

Let's not bury the lead. Greg built (essentially) a diy Everest system with components he personally designed and chose to use DEQX crossovers not just for the Everest but also the K2 in his system. That seems like high praise indeed.

I remember reading this thread (http://www.audioheritage.org/vbullet...highlight=Deqx) started by Ken Pachkowsky about his experience with the DEQX and at the time thinking "this is unlikely". But recently I met this fellow Ken mentions and got to watch him tune a custom 3 way. My friend who built the system is an experienced audio engineer who designs and builds good equipment, is very competent in all things audio, and regularly writes for an audio magazine. He worked a long time with the DEQX software and barely got the system to the point of being listenable. In just a few hours, this DEQX tech had that system sounding amazing. It was something to see/hear. Perhaps Greg is as good using the software or maybe even uses the fellow to help tune the system? I'd be curious to know.

...I and others on this forum have invested countless hours into tweaking a Deqx setup. I would bet most Deqx owners have never heard their system with the Deqx properly tuned? It's only in the last year that I met someone who has an intimate working knowledge of the Deqx Architecture and Software well enough to set it up properly. We setup an internet client so he could take over my pc remotely. I simply setup the microphone where I was told. In a few hours he had it sounding better than it ever had. I wish you could all be here to hear the difference.

I was so impressed with what he had done I arranged an audition of the HD3 system at Westlake Audio. Both of us met in LA and spent 2 days at Westlake Audio. To say the techs at Westlake were impressed is an understatement. For the demo a miss-matched pair of LC8.1’s combined with a Westlake custom subwoofer system were placed in the sound room. A series of measurements were taken and custom correction filters were created with the Deqx software. The correction filters had illiminated the miss-match problem. We then created a set of three room correction filters, each using slightly different crossover points. These were merged with the correction filters and stored in three different profiles. During the listening tests we could switch between the profiles by selecting each one with one click of the remote. The Westlake techs were astonished, stating the system was sounding as good as or better than anyone heard before. This is no small feat. Tuning a Westlake system normally takes several weeks with constant hardware tweaks being done to the passive internal networks. Dozens of man hours go into this process.

The fellow who did the setup understands the nuances of the Deqx software and interprets the resulting data “differently” than anyone else I have seen. The subsequent filters he builds are truly amazing and certainly show what this tool is capable of when used properly.
For those of you that have owned and already have disposed of a Deqx (I know there are many) it’s unfortunate.

For those that have not tried one....go for it....but only if you’re prepared to spend a few hundred bucks setting it up right. I promise you will not regret it.

I would be happy to share the gentleman's contact info on a person to person basis. I don't think I should be posting his name here. ...

[Mr. Widget]

4. Linear Phase digital crossover filters and time alignment.

Let's not bury the lead. Greg built (essentially) a diy Everest system with components he personally designed and chose to use DEQX crossovers not just for the Everest but also the K2 in his system. That seems like high praise indeed.

I remember reading this thread (http://www.audioheritage.org/vbullet...highlight=Deqx) started by Ken Pachkowsky about his experience with the DEQX and at the time thinking "this is unlikely". But recently I met this fellow Ken mentions and got to watch him tune a custom 3 way. My friend who built the system is an experienced audio engineer who designs and builds good equipment, is very competent in all things audio, and regularly writes for an audio magazine. He worked a long time with the DEQX software and barely got the system to the point of being listenable. In just a few hours, this DEQX tech had that system sounding amazing. It was something to see/hear. Perhaps Greg is as good using the software or maybe even uses the fellow to help tune the system? I'd be curious to know.

I also loved his referring to the "rock on the end of a stick"

I have no doubt that his custom E3 Everests are outstanding. There is no getting around it, the man has years of experience, great ears (or at least ears that hear in a way the I tend to agree with), access to drivers, test, and playback equipment that not everyone of us does... what is not to love!

Regarding DEQX, his mentioning the next generation DEQX which is apparently just now becoming available definitely has me interested it giving them another try.


Widget

[Ian Mackenzie]

Good point.

Greg has been using DEQX a long time and has considerable depth of expertise in crossover network design.

It wasn’t straight forward though. None of this is about clicking your fingers no matter what anyone says.

Greg originally used two Pass Labs XVR1’s. Then modified them to improve the transparency bypassing circuit coupling capacitors and hard wiring some of the switches. That’s a long and at times frustrating problem working with Nelson Pass. Pass is purely focused on experimenting with power amp active devices.

Greg then started using DEQX and found the DA converters and output op amp buffers the weak link and installed high end Meitner outboard DA converters. I understand DEQX has upgraded the software which Greg says is an improvement. Greg’s system is really complicated now. When we tested a prototype analogue active crossover we were developing it was a long procedure changing the cabling. It took half an hour. Luckily it worked really well.

For someone like Greg with his expertise DEQX is a great loudspeaker developer tool.

The next Gen DEQX is looking upward of AUD $7500.00. With a lot of hand holding it would be okay and l think DEQX did that at one stage. But what you don’t know you don’t know and it’s a hard lessen finding that out.

[rusty jefferson]

...For someone like Greg with his expertise DEQX is a great loudspeaker developer tool...

I think the point Ken was making, and I witnessed is you don't need to know Jack about the software. The DEQX comes with one of these "tuning" sessions included in the cost. A user, except maybe someone like Greg, isn't going to get it sounding any better than this fellow who sets it up. Just leave it alone and listen to music.

[Ian Mackenzie]

I think the point Ken was making, and I witnessed is you don't need to know Jack about the software. The DEQX comes with one of these "tuning" sessions included in the cost. A user, except maybe someone like Greg, isn't going to get it sounding any better than this fellow who sets it up. Just leave it alone and listen to music.

I do remember those fun times. Ken was very, very passionate about his Westlake system and his 4345's before that. Like many of us that passionate leads to excessive exadgeration which is all part of this hobby.....Lol. That's the other thing. What's better to you may or may not be liked by the next guy or the next guy after that. That's what makes audio sound reproduction so unique.

"What comes out of any loudspeaker is never going to match a live performance". Greg makes that point. But it can become a life long obsession.

There’s are no absolutes in this business. Some stuff focuses on one element of sound reproduction at the expensive of all else and people still pay a lot of money for it. The Klipschorn is an example of that and they are still being made. Klipsch is a big company these days. Vandersteen is at the other end of the spectrum.

You get used to what you have!

[sebackman]

Interesting interview and I like the form that Erin provide the time to actually explore different topics. In a world where everything is 2-minute sound bites this is refreshing.

He has also done interviews with Sean Olive and Floyd Toole that I find very interesting. Well worth a listening.

It would be very interesting to find out what settings Mr. Timbers uses in the DSP for both the home brewed Everests and his S9900. I understand that he uses FIR filters but XO points and corrections would be very interesting to see.

[hjames]

Here ya go... take a look at the wave guide. It is a mini original Everest/S3100 type wave guide.

https://www.jblsynthesis.com/product...d=loudspeakers

Widget

Thank you!
Looks like it may be related to the JBL HDI-1600, which is available in a walnut finish
https://www.jbl.com/bookshelf/HDI-1600.html

and also uses that 2410H-2 1" compression driver. (Greg said it had mylar-like but not mylar diaphragms)
At $990 a pop, price is approaching the $1,100 InWall Synthesis SCL-7s ...

[BMWCCA]

Looks like it may be related to the JBL HDI-1600, which is available in a walnut finish
https://www.jbl.com/bookshelf/HDI-1600.html

Wow! Those little suckers are nearly a thousand-dollars each.

[rusty jefferson]

...I love it, in the context of the old penchant for Bose-bashing in these forums, that GT seemed intrigued by the basic idea of the BOSE 901 and said that if the shortcomings had been addressed, it could have become quite an interesting speaker. That is: 1) use higher quality drivers; 2) provide some decent-sounding electronics in the EQ box; 3) change the front single driver into a two-way with a tweeter because there is no way to get any decent treble by EQ'ing a five-inch full range....

So, since there's interest in this I'll share an article written by a fellow I met last winter who said he'd been inspired by the Bose 901 many years ago and has been on the path to improve the concept ever since. He'd had many conversations with Dr Bose about it over the years as well as other audio engineering friends.

After reading the article and discussing it with my audio gurus, I thought his system would be just as smeared (or worse) as the 901s but would probably have better dynamics. Our biases poison us. His system fixed exactly the problems discussed about the 901s and created the most natural full range 3 dimensional soundstage accurately placing the musicians across the stage I've ever heard, barring one other system. Any recording of a live acoustic event spanned the entire width of the room (24 feet) and has as much depth and most important, as much imagine specificity as the microphones captured. And the dynamics were through the roof. Like a cinema experience. High sound pressure, low distortion, and absolutely transparent sound. You cannot tell there's even speakers in the room. I was stunned. No smear. Clean and clear, with excellent transients. Not a perfect system, but shockingly good. Most interesting, is that there is no change to the image or soundstage when the center speaker is turned off/on. Just more dynamic headroom when on.

I reached out to him this morning to see if it's okay to share the article. For anyone seriously interested, he's always happy to discuss the design. Let me know and I'll put you in touch. If you're in the area (Tampa) he'll probably invite you to listen to it.

https://drive.google.com/file/d/1YXx...ew?usp=sharing

[Mr. Widget]

Thanks Rusty!

I quickly read through bits of the article and then downloaded it.
I'd like to spend more time with it when I am not on the clock... solving and creating other audio problems.


Widget

[DS-21]

Here ya go... take a look at the wave guide. It is a mini original Everest/S3100 type wave guide.

https://www.jblsynthesis.com/product...d=loudspeakers


Widget
.

Are you sure? He said they were from Pro and used the same compression driver as his 5-series.

[Mr. Widget]

Are you sure? He said they were from Pro and used the same compression driver as his 5-series.

Nope, not sure… but I am fairly certain it is the correct model.


Widget

[Ian Mackenzie]

From the spec sheet

High Frequency Driver
1" (25 mm) 2410H-2 Teonex annular ring-diaphragm compression driver- mini compression driver

Not Mylar but used for the same reasons

[DS-21]

Nope, not sure… but I am fairly certain it is the correct model.


Widget

I'm pretty sure that's not the model.

Going back to the video the speakers are under square grilles, not rectangular grilles. See at 4:58 in Erin's video.



Maybe they're SCL-3's, and he's simply mistaken about the horn pattern.