[jdbrian]

Hi

   After years of fighting to get decent sound in my rectangular room 19Lx12.5wx8h I am considering going to a OB speaker. My current speakers are Newform 645's and I am not happy with them. I am looking at the Nao2 kit from Music and Design, the OB 7 kit from GR research and maybe the Superv from GR.
    I have some concerns with each of them. The Nao looks interesting but there is not much info. about it. I like the ability to use cardoid or sealed box woofers with the system. I also have 4 8545 mids in my 645's that could be used in the Nao.
   The OB 7 looks nice and Danny Ritchie is a talented and inovative designer but the design uses cheap drivers and I am leary of the overall sound quality compared to a design using higher quality parts.
   The Super V is interesting and the most costly alternative. What worries me about it is the 12" pro coaxial driver and if it is refined enough for critical listening. Most 12" Pro drivers have some serious resonances in the midrange and these can be seen as peaks in the impedance. I don't know how audible it would be.
   Any help you can offer would be appreciated as I live far away from any large centers where I could hear any of these designs in person.

Thanks
Brian
r

[Bear]

Hi

   After years of fighting to get decent sound in my rectangular room 19Lx12.5wx8h I am considering going to a OB speaker. My current speakers are Newform 645's and I am not happy with them. I am looking at the Nao2 kit from Music and Design, the OB 7 kit from GR research and maybe the Superv from GR.
    I have some concerns with each of them. The Nao looks interesting but there is not much info. about it. I like the ability to use cardoid or sealed box woofers with the system. I also have 4 8545 mids in my 645's that could be used in the Nao.
   The OB 7 looks nice and Danny Ritchie is a talented and inovative designer but the design uses cheap drivers and I am leary of the overall sound quality compared to a design using higher quality parts.
   The Super V is interesting and the most costly alternative. What worries me about it is the 12" pro coaxial driver and if it is refined enough for critical listening. Most 12" Pro drivers have some serious resonances in the midrange and these can be seen as peaks in the impedance. I don't know how audible it would be.
   Any help you can offer would be appreciated as I live far away from any large centers where I could hear any of these designs in person.

Thanks
Brian
r

[2bigears]

   call Danny,he is easy to talk to and will help you out.....i went with the Super V   

[Danny Richie]

The OB 7 looks nice and Danny Ritchie is a talented and inovative designer but the design uses cheap drivers and I am leary of the overall sound quality compared to a design using higher quality parts.

Just because they are not expensive does, not by any means, mean that they are of lesser quality in any way. For instance, the midrange of the M-130 is cleaner than that of the Scan Speak 8545, and the resolution is much better in the upper range near the crossover point.

And there are very good reasons why they are not as expensive and have no problem sharing that info with you. Just shoot me an e-mail regarding it.

The Neo tweeter is also better sounding than any dome on the market at any price point as well. At least that's what I think based on all of my experience. It fact it has many advantages over most domes.

The Super V is interesting and the most costly alternative. What worries me about it is the 12" pro coaxial driver and if it is refined enough for critical listening.

You'd be surprised. I'd be willing to bet it to be as good as, or better than, anything that you have ever heard.

Most 12" Pro drivers have some serious resonances in the midrange and these can be seen as peaks in the impedance. I don't know how audible it would be.

These have no such issues.

Maybe you'll get some good feedback from others that have heard them as well.

There were a LOT of people, including some reviewers, that felt that the Super-V's were one of the best sounding speakers at RMAF this year.

[Bear]

  call Danny,he is easy to talk to and will help you out.....i went with the Super V   

Any impressions on the super v?  What is your associated equipment?  What speakers and equipment(if any) did you replace and how do they compare/differ?

Thanks

[mcgsxr]

I have heard the OB7's (or were they OB5's at Daygloworange's shop I wonder?), and was impressed with the overall sound balance top to bottom.

I wish I could hear Danny's OB coax based speakers, I have read many positive things about them.

[2bigears]

  Bear... i have yet to build them.Danny is waiting on parts.i was going to buy Vandersteen 5A's or Aerial 20T's on the cheap---used they go for ten grand.i want to hear O/B sound and see what the fuss is about.the Super V's look very interesting to me.can't wait to hear them.

[Cacophonix]

I owned OB-5, and was very impressed with them. Don't disregard GR just because they are not expensive. Read the lexicon thread here or elsewhere if you don't know what i mean ..

[grubyhalo]

I owned OB-5, and was very impressed with them. Don't disregard GR just because they are not expensive. Read the lexicon thread here or elsewhere if you don't know what i mean ..

I did search, but couldn't find the thread you referenced here. You wouldn't have a link to the thread, would you?


Cheers!

[Danny Richie]

There is a ton of feedback and reviews of all of our open baffle speakers in the GR Research circle.

[Wind Chaser]

The OB-7 and the OB-5 will positively crush the 645's in every way, I've heard them both.

BTW, those cheap inexpensive drivers are far better than you might dare to imagine.  Combined with the genius of Danny's crossover, they are simply outstanding and untouchable in their price class... and then some

I was initially very skeptical for similar reasons, but upon hearing them my immediate impression was WOW!  That translated into buying a similar speaker using essentially the same drivers and a crossover designed by Danny in a smaller version that would fit better into my small digs.

[Rocket_Ronny]

Shoot for the Venues. They are the speaker I had wanted for 15 years. You have to factor in the fact you can use flea amps on it. Like 1-2 watt wonders.

I own the OB5s and the drivers are amazing, esp, the Neo tweet. I have owned the 645s and enjoyed them as well. The OBs are a good step ahead and I believe the Venues would make another step, esp. in bass and dynamic range.

I had a pair of Acoustats in a room about your size. While it is on the smaller side, open baffles could work. I would just make sure you can have at least 3' behind them, as with any speaker, the more the better, like 6-10 feet, and you may want to dampen that wall as well.

Do a search for "Black Beauty Rides Again" in the GR forum for my gushing review of the 0B5s. After having them for about 2 years I would say the review still holds true. Maybe a bit over enthusiastic, but not by much. The things make great music. You need a good 70 watts if you play loud.

Rocket_Ronny

[jdbrian]

Hi Folks


   I had given up on any feedback after 2 weeks or so! Thanks everyone for your input.
Obviosly I am looking for a change and am trying to deal with my room problems by changing the radiation pattern of my speakers ie. dipole or partial dipole. My remarks about the drivers being cheap were not meant to disparage the designs mentioned, which are of course much more than the sum of the parts. Speaker design is an art for sure.
  I am used to the Scan Speak 8545 as a mid bass. They have incredible output for a 7" driver. When you look at the distortion plots for the SS drivers on Zaph they generally have very low distortion and high quality. Not being able to audition any GR research speakers I am trying to get some ideas of the trade offs that are involved.
   My room is not that large but is pretty much dedicated to music listening so I have freedom to have lots of space behind the speakers. My 645's are generally 4 to 6 ft. from the front wall.
  I have a background in electronics and woodworking and have built some equipment / speaker cabinets for the 645s, sub and preamps and power amps-SS and tube. I enjoy building equipment but would like a design that is going to give me a predictable result as I cannot afford to waste money on experimenting with my own speaker designs. The GR designs are attractive and there seem to be some that are not published so I will probably drop an email to Danny to see what he can offer for my specific situation.
   I am curently using the 645's with a Rotel 990 power amp, 995 pre and a Behringer DEQ2496 used as a DAC with a cd player or soon a USB pc setup. I just ordered a USB converter from Hagerman and am shopping for a laptop. I have a homemade sub using 2 Dayton 15" series 2 drivers in a 6cuft. sealed box. It is driven by a Hafler 220 and a crossover with an EQ circuit of my own design that functions like the Linkwitz Transform. I am also looking to replace the sub with 2 smaller ones and have been looking at the GR servo subs as well.

Thanks again for your input
Brian

[Danny Richie]

A word of caution and something to think about regarding this statement below:

They have incredible output for a 7" driver. When you look at the distortion plots for the SS drivers on Zaph they generally have very low distortion and high quality.

Distortion measurements made below 2kHz or so and done outside of an anechoic chamber will give you little to no useful data. Even the manuals that come with most measurement software packages will tell you that in room measurements of distortion can not be done with any level of accuracy. It is about like trying to take a measurement of a speaker in a gymnasium while a basketball game is going on.

A much, MUCH more telling measurement that will tell you more about how a driver will really sound is a spectral decay. That's where the truth will be found.

[grubyhalo]

There is a ton of feedback and reviews of all of our open baffle speakers in the GR Research circle.

Absolutely. I am a regular lurker at the GR circle, it's just that I did not find this specific thread and was wondering if it was somewhere else... 

[ebag4]

Absolutely. I am a regular lurker at the GR circle, it's just that I did not find this specific thread and was wondering if it was somewhere else... 

The Lexicon thread that was mentioned is referring to the new Lexicon BD player ($3K+) that turns out to be an Oppo BDP-83 ($499.) with a Lexicon faceplate, here is the thread: http://www.audiocircle.com/index.php?topic=76445.0

The gist is that just because a speaker/driver is expensive doesn't necessarily mean that it performs better than a less costly unit.

Best,
Ed

[grubyhalo]

The Lexicon thread that was mentioned is referring to the new Lexicon BD player ($3K+) that turns out to be an Oppo BDP-83 ($499.) with a Lexicon faceplate, here is the thread: http://www.audiocircle.com/index.php?topic=76445.0

The gist is that just because a speaker/driver is expensive doesn't necessarily mean that it performs better than a less costly unit.

Best,
Ed

I see... Sorry for the side-tracking folks...

[jdbrian]

A much, MUCH more telling measurement that will tell you more about how a driver will really sound is a spectral decay. That's where the truth will be found.

  I agree that the measurements on the Zaph audio site may not be ideal but he does test a number of drivers with the same procedure so the results should have relative merit when looked at as a group. The Scan Speak SD1 motor does reduce distortion and also seems to keep the second order dominant while the higher order products are low in level.  Spectral decay tests are also on the Zaph site and they are harder to interpret    How these objective tests are reflected in the sound of a finished system is very difficult to predict as there are many variables at work. One thing that I look for in mid bass drivers is the breakup peak and how it shows up in the decay, distortion and impedance plots. 
   I recently heard a set of Gamut speakers with all Scan Speak revelator drivers- 2- 7" bass  7" for mid and the ring dome tweeter. Living in the boonies I don't get to hear many expensive speakers but these were incredible in terms of dynamics and lack of box coloration in the lower mids/ upper bass. The soundstage was huge. These are like 15k$ so there is no way that I can afford them but the lack of box coloration is something that can be a benefit of open baffle design and I would like to try to have that kind of sound for a more affordable price. I'm not sure that my room is large enough for the Super V - the OB 7 may be a better fit. 

Brian

[Danny Richie]

I agree that the measurements on the Zaph audio site may not be ideal but he does test a number of drivers with the same procedure so the results should have relative merit when looked at as a group. The Scan Speak SD1 motor does reduce distortion and also seems to keep the second order dominant while the higher order products are low in level.

Nope. It won't matter if they are all tested in the same way or not. There can be no consistency in measuring distortion levels outside a chamber. Average levels of distortion are below the noise floor level of the room.

For instance: If a woofer has a 90db sensitivity level and distortion levels fall into the 1 to 3% range at a given frequency range. That will put those distortions down in the 40 to 50db range in volume. The average noise floor of a dead quiet room is in the 45 to 55db range. Even a computer fan, refrigerator two rooms away, the air conditioner kicking on in the house, a car passing by outside.... can all kick the noise floor up into the 55db range or higher. So there is no way to pick any accurate distortion measurements out of that. You can't distinguish any of it from room noise. There can be no consistency from one measurement to the next, let alone one day to the next.

Spectral decay tests are also on the Zaph site and they are harder to interpret

Those are the easiest thing to get good data from, and easiest to take an accurate measurement of as it uses a gated time window use to measure the on axis response.

I'm not sure that my room is large enough for the Super V - the OB 7 may be a better fit. 

Actually the Super-V has much greater flexibility and can much more easily be used in a smaller room. The servo control system on the amp will allow you to adjust every aspect of the output levels over the whole span.

[jdbrian]

Hi Danny


   I am a novice at speaker design and have not studied the methodology used on the Zaph site. If the Superv is not too large for my room I will seriously consider it. Thank you for your responses
and I will contact you directly if I have more specific questions.

Regards
Brian