Ron’s New System

[Audiohertz2]

Argonaut‘s link to GIK page above shows mostly different variations on BAD panels, with more stylistic diffusion grids than the grid beneath the original RPG BAD panels. (https://www.rpgeurope.com/products/product/bad.html) I am surprised with all the comments I have read in so many places (and my own experience) you'd have opted for strictly absorbing panels at the reflection points (and elsewhere). Friends who’ve used GIK absorbers and then instead have used some of the BAD type panels have always kept the latter and had better results.

Of course, my own room would be more damped than yours given built-in custom BAD panels throughout per Bonnie’s spec, but I’ve not had comments from anyone it is over-damped. The closest to that might have been Daniele of Alsyvox who, when he visited, preferred the curtains in the back of the room to be more opened, which allowed more of the ambient (and reverberant) energy of the stairways and hallways to become part of the acoustic. (That all behind the listening position, similar to your space opening to the side of your room.)

Yes Dipoles are best with front wall behind speakers without treatment or diffusion only ..!

 

[Audiohertz2]

a very special device, you can like it,but you don't have to. the input and output transformers determine the sound not the tubes. I'm not a big fan of it. An interstage transformer is ok as a replacement for a coupling capacitor between the stages.
But tastes are different and that's a good thing.
P.S
I drive with one tube 6h30 parallel linestage three power amps 10feet cable works good

Thats interesting as i find Tooby pre amps very sensitive to the drop in load impedance when driving multiple amps , timbre suffers ..!


Regards

 

[DasguteOhr]

Wow ! thats crazy , if you play them on a dummy load you can actually hear music thru the chassis , they all do that ..!

Pass amps do not have a Boucherot element in front of the speaker output as far as I know. This protects against excessively high frequencies and a tendency to oscillate. either good sound or security in all positions. Many other manufacturers do this too, but if the electronics tend to stop working correctly, I prefer security.
The tweeter dies first

What is Tooby?

 

[Ron Resnick]

I am surprised with all the comments I have read in so many places (and my own experience) you'd have opted for strictly absorbing panels at the reflection points

Actually for the sidewall reflection points I didn't opt per se for absorption panels; I simply had them in inventory and so figured I would start with them.

As a general principle I think diffusion is the correct place to start for sidewall first reflections.

(and elsewhere).

As a general principle I don't believe in diffusing the backwave of a planar dipole. I like preserve a clean backwave off of the front wall, either with no treatment, or with absorption to attenuate the back wave.

 

[Ron Resnick]

These are interesting candidates for diffusion of sidewall first reflections:

 

[Lagonda]

View attachment 120913

Ron, this snakes nest supplies signal and power to the best system I’ve ever heard. 115 DB speakers and I heard resolution and lack of noise and distortion like nowhere else. You’ve heard this system and it’s a good example opposed to the conventional wisdom of cable lengths, cable type, and cable dressing.

David obviously has a "Tripoint Troy" hidden inside his wall !

 

[Lagonda]

We seem to agree. Shorter cabling of all types is ultimately preferable although I guess I would add not always practical.

Good point on the room modes! When I position an amplifier somewhere between my speakers I very unscientifically listen to the sound between the speakers, fore and aft, and select a spot where I hear the least bass. There are also a few room mode calculators on the internet that can also be helpful in giving you a rough idea of where the trouble spots are likely to be.

I will take long cables over piling up equipment in the middle of the soundstage any day of the week !

 

[PeterA]

Actually for the sidewall reflection points I didn't opt per se for absorption panels; I simply had them in inventory and so figured I would start with them.

As a general principle I think diffusion is the correct place to start for sidewall first reflections.

As a general principle I don't believe in diffusing the backwave of a planar dipole. I like preserve a clean backwave off of the front wall, either with no treatment, or with absorption to attenuate the back wave.

Your photos seem to show a different approach than the one you advocate here. Why is that? You are using what seems like a very large number of absorption panels in your listening room, both behind the speakers and to their sides and in front.

 

[Ron Resnick]

Your photos seem to show a different approach than the one you advocate here. Why is that?

For the sidewall reflection points I didn't opt per se for absorption panels; I simply had them in inventory and so figured I would start with them. This is the only difference in approach.

If the listening chair is close to the rear wall, it is worth experimenting with diffusion and absorption. I wanted to start with an ASC MatrixPanel behind the listening chair, but with shipping that panel is $3,000. So I figured I would start with an absorption panel behind the Listening chair as well.

 

[pjwd]

For the sidewall reflection points I didn't opt per se for absorption panels; I simply had them in inventory and so figured I would start with them. This is the only difference in approach.

If the listening chair is close to the rear wall, it is worth experimenting with diffusion and absorption. I wanted to start with an ASC MatrixPanel behind the listening chair, but with shipping that panel is $3,000. So I figured I would start with an absorption panel behind the Listening chair as well.

How far is your chair from wall

 

[bonzo75]

I will take long cables over piling up equipment in the middle of the soundstage any day of the week !

or get small SETs that take very little room at the back on the floor and don’t interfere with the stage. But then you need to change speakers..

 

[Lagonda]

or get small SETs that take very little room at the back on the floor and don’t interfere with the stage. But then you need to change speakers..

Never ! But for a "above the garage" 4'th system, SET might do !

 

[bonzo75]

Never ! But for a "above the garage" 4'th system, SET might do !

look…Jacob Heilbrunn converted to horns, so microstrip will soon. There are not going to be many holdouts. You want to come quietly or…

 

[Ron Resnick]

How far is your chair from wall

about 36 inches

 

[Ron Resnick]

microstrip will soon.

Where did Francisco go?

 

[Elliot G.]

Actually for the sidewall reflection points I didn't opt per se for absorption panels; I simply had them in inventory and so figured I would start with them.

As a general principle I think diffusion is the correct place to start for sidewall first reflections.

As a general principle I don't believe in diffusing the backwave of a planar dipole. I like preserve a clean backwave off of the front wall, either with no treatment, or with absorption to attenuate the back wave.

dont agree with this , not what I was taught nor in my experience. Behind the listener diffusion is best and there are some cases for the front wall behind the speakers however it is not my first choice there or for the primary reflection on the side walls.

 

[PeterA]

As a general principle I don't believe in diffusing the backwave of a planar dipole. I like preserve a clean backwave off of the front wall, either with no treatment, or with absorption to attenuate the back wave.

I had discussions with former member Ack about his Martin Logans. He was happy with the fact that behind each of his speakers there was a huge distance to the front wall. He said in essence, there was no back wave or that it was so delayed that it did not matter or interfere with the direct sound.

You write that you prefer either no treatment, which is not the case in your present configuration, or with absorption. You have absorption. It attenuates some frequencies but not all of them. The back wave is attenuated with regard to only some frequencies. How is this better than with no treatment or with further speaker positioning experiments? What do you hope to improve with further panel movement experiments?

 

[Ron Resnick]

I had discussions with former member Ack about his Martin Logans. He was happy with the fact that behind each of his speakers there was a huge distance to the front wall. He said in essence, there was no back wave or that it was so delayed that it did not matter or interfere with the direct sound.

I have no substantive comment on why somebody I don't know chose to defeat in a system I've never heard
one of the main sound-staging advantages of a dipole loudspeaker.

You write that you prefer either no treatment, which is not the case in your present configuration, or with absorption. You have absorption. It attenuates some frequencies but not all of them. The back wave is attenuated with regard to only some frequencies.

I know this is a big bugaboo for you and David. It is not for me.

Keep in mind that human hearing does not maintain constant sensitivity across the frequency spectrum. These absorption panels absorb a little bit more in the frequency range at which human hearing is most sensitive. Instead of focusing on the non-linear absorption characteristics of the panel in isolation one should map it against the sensitivity of human hearing before concluding that it is adulterating the perceived frequency response of the system.

How is this better than with no treatment or with further speaker positioning experiments? What do you hope to improve with further panel movement experiments?

I've never said it is better in some objective sense. In my room, with these ribbon drivers, to my ears I think a little bit of attenuation of the energy of the backwave of the ribbon sounds right to me.

With other planar dipoles for over 25 years I never put any acoustic treatment of any kind on the front wall.

As the original edginess of the sound which troubled me from the beginning has evaporated with other changes, I may very well wind up removing all absorption panels from the front wall. Nothing on the front wall is my natural starting point.

 

[PeterA]

I have no substantive comment on why somebody I don't know chose to defeat in a system I've never heard
one of the main sound-staging advantages of a dipole loudspeaker.

Fair enough, I mention it only because I discussed the subject with him and he wanted to attenuate the back wave and it sounds like that is also one of your goals with the absorption panels on the front wall behind the speakers. You are also a big fan of Martin Logan speakers. From what he told me, it does not seem as though the two approaches are all that different. He has more space behind his speakers and you are absorbing some of the back wave.

I know this is a big bugaboo for you and David. It is not for me.

I see no reason for you to bring David Karmeli’s views into the discussion. I don’t know what exactly you think is a bugaboo for me.

Keep in mind that human hearing does not maintain constant sensitivity across the frequency spectrum. These absorption panels absorb a little bit more in the frequency range at which human hearing is most sensitive. Instead of focusing on the non-linear absorption characteristics of the panel in isolation one should map it against the sensitivity of human hearing before concluding that it is adulterating the perceived frequency response of the system.

I draw no conclusions. I have not heard the effect of the panels and I was hoping you would explain how their placement improves the sound of your dipole speakers with the non-linear absorption characteristics.

I've never said it is better in some objective sense. In my room, with these ribbon drivers, to my ears I think a little bit of attenuation of the energy of the backwave of the ribbon sounds right to me.

Thank you

With other planar dipoles for over 25 years I never put any acoustic treatment of any kind on the front wall.

As the original edginess of the sound which troubled me from the beginning has evaporated with other changes, I may very well wind up removing all absorption panels from the front wall. Nothing on the front wall is my natural starting point.

I look forward to reading your description of the differences you hear.

 

[pjwd]

about 36 inches

Thanks
Theoretically you should get a dip at 95hz .. assuming your back wall reflects that frequency
It's also about 5ms later than direct sound so within the "smear zone" so could warrant treatment but I think side wall reflections are shorter and more impactful