Ron’s New System

[pjwd]

Given the main tower is a dipole, this means a figure 8 radiation pattern. As such there is not a significant issue with first reflection as with a conventional non-dipole speaker. I never put any sidewall treatment for an of my big Stat or Ribbon dipoles, Absorption or diffusion. At the very least it should be much further away from the speaker because the first wall interaction will be much further into the room.

That's just not correct .. the figure 8 pattern has a lot of energy at side angles as it reduces to a low level on the baffle plane .. depending on baffle shape and driver ... they are not narrow baffles on the pendragon and I would expect a low db drop at say 45 degrees for some frequencies

 

[morricab]

That's just not correct .. the figure 8 pattern has a lot of energy at side angles as it reduces to a low level on the baffle plane .. depending on baffle shape and driver ... they are not narrow baffles on the pendragon and I would expect a low db drop at say 45 degrees for some frequencies

My own extensive experience with line source dipoles disagrees with your assertion. Genesis also disagrees with you:

Dipole Radiation Pattern | Genesis Advanced Technologies | United States

Genesis loudspeakers are designed with an innovative dipole radiation pattern for more natural, spacious sound reproduction - no matter what the room's configuration or challenges.

www.genesisloudspeakers.com

 

[DasguteOhr]

Therefore, if possible, you should allow dipoles to be at least 1m away from the wall in all directions. then the problem corrects itself.

 

[pjwd]

My own extensive experience with line source dipoles disagrees with your assertion. Genesis also disagrees with you:

Dipole Radiation Pattern | Genesis Advanced Technologies | United States

Genesis loudspeakers are designed with an innovative dipole radiation pattern for more natural, spacious sound reproduction - no matter what the room's configuration or challenges.

www.genesisloudspeakers.com

here are some measurements for a tweeter and mid in a baffle approximately 600 wide - with no crossovers - they are on axis , 22.5 and 45 degrees, as you can see there is a hardly any drop off in the fr until you get to beaming in the tweeter. I don't know what the pendragon of axis response is but I am just suggesting an experiment to Ron.. after all he does have absorbers to deal with the supposedly non existent reflections already

 

[morricab]

here are some measurements for a tweeter and mid in a baffle approximately 600 wide - with no crossovers - they are on axis , 22.5 and 45 degrees, as you can see there is a hardly any drop off in the fr until you get to beaming in the tweeter. I don't know what the pendragon of axis response is but I am just suggesting an experiment to Ron.. after all he does have absorbers to deal with the supposedly non existent reflections alreadyView attachment 121047

I am guessing the teeeter in the above plots is not a dipole?

 

[pjwd]

I am guessing the teeeter in the above plots is not a dipole?

It is 2 seas diamond tweeters back to back

 

[Salectric]

Why can’t you guys agree that a dipole has less side radiation but there is still some; therefore there is still some effect with side wall absorbers even if it may not be as much as with forward-radiating speakers.

 

[pjwd]

Why can’t you guys agree that a dipole has less side radiation but there is still some; therefore there is still some effect with side wall absorbers even if it may not be as much as with forward-radiating speakers.

I agree with the plots above
Even the generic directivity graph by DasguteOhr shows only 3db down at 45 degrees ..its a pretty wide room that would have less than 45 at first reflection
Dipoles excite the room less because of this cancelation but not necessarily at the first reflection point .. different baffle profiles will have different results

Phil

 

[Carlos269]

Ron, please post an updated “Fields of Gold” video. I like to hear what all these latest room treatments, Cardas cables, active bass traps, Jadis JA-100 amps with new KT90 tubes, tower repositioning, and all your latest hijinks have done for the sound of your system. I recorded “Fields of Gold” during my listening session with my reference horn system and although I don’t use any acoustic room treatments, it sounds great! Looking forward to hearing the latest evolution of your system.

 

[BruceD]

Thank you for the kind words!

Does this experience include TubeTraps diffuser side out in the middle of the front wall between planar dipoles?

Yes on the front wall middle sections--I'd only prefer the Diffusing turned INWARDS to the wall on the first reflection points( side walls forward of each speaker).

I think that solo bass trap centre in you pic is serving little or no purpose there.

i'm asking because I don't know about diffusing the back wave of a planar dipoles. I'm concerned that that could confuse the imaging arising from an otherwise clean, adulterated back wave.

Yes that could be a slightIy different can of worms to fixed Box Speaker positioning ( my pref's noted above)--although the only open back wave 's I've owned ( Soundlabs A1's) I found absorption preferable-YVMV--purely subjective on your listening circumstances and sonic preference upon evaluating.

Exciting times especially when it all clicks into place for you--Kudos!

Trust you are enjoying your JA100's --I've owned those-lovely smooth Amps-hope yours aren't fudging the 150Ohm resistor across the tubes at all--mine did all rather too frequently--I'm told the latest Amps have that sorted Good One!.

Good listening,
BruceD

 

[Audiohertz2]

It is 2 seas diamond tweeters back to back

Bipolar wired in phase Or out of phase .. ?

 

[Audiohertz2]

I don't know what you mean by a "single-ended system."

Both Gryphon and VTL are true-balanced. But Jadis is single-ended. So it is a "mixed" system.

Yes your signal source is SE your VTL is not true Balanced so SE with balanced inputs . I’m not sure about Gryphon but i think they maybe fully differential , only full differential is true balance.

In a fully differential true balanced system a fully balanced cable is necessary , its why quasi Balanced systems really don't see much going between SE or balanced cables ..

Regards

 

[pjwd]

Bipolar wired in phase Or out of phase .. ?

Out of phase .. so dipole

 

[morricab]

I agree with the plots above
Even the generic directivity graph by DasguteOhr shows only 3db down at 45 degrees ..its a pretty wide room that would have less than 45 at first reflection
Dipoles excite the room less because of this cancelation but not necessarily at the first reflection point .. different baffle profiles will have different results

Phil

No one is saying the wave never hits the side wall…it’s all about where the first reflection points are. 45 degrees is not so wide dispersion. The later that reflection the less it detrimentally impacts imaging and tonality. You are basically arguing against what speaker designers have known for decades.

 

[Ron Resnick]

your VTL is not true Balanced

Where are you getting this from?

 

[Ron Resnick]

I spend some time today with Jim White at the Los Angeles Orange County Audio Society 30th anniversary luncheon. Jim is very familiar with Cardas cables, and he uses Cardas wire in some Aesthetix components.

Jim said that the Clear Reflection will open up over time.

 

[pjwd]

No one is saying the wave never hits the side wall…it’s all about where the first reflection points are. 45 degrees is not so wide dispersion. The later that reflection the less it detrimentally impacts imaging and tonality. You are basically arguing against what speaker designers have known for decades.

Acousticians broadly agree that you need about 10ms between direct and reflected to minimize smear . The math on reflected energy is irrefutable .. attached is a sketch of a largish room showing energy at angles less than 45 degree off axis do reflect to the listener.
Speaker designers who are knowledgeable about room acoustics know this
I dont want to clog up Ron's thread any further and there is nothing further to prove anyway

 

[DasguteOhr]

Acousticians broadly agree that you need about 10ms between direct and reflected to minimize smear . The math on reflected energy is irrefutable .. attached is a sketch of a largish room showing energy at angles less than 45 degree off axis do reflect to the listener.
Speaker designers who are knowledgeable about room acoustics know this
I dont want to clog up Ron's thread any further and there is nothing further to prove anyway View attachment 121087

It depends on where the 30-45° wave first hits the wall (speaker placement) and whether the sound waves actually hit the ear or mix with the main signal. A large mirror sometimes helps more. So to speak, mirror, mirror the wall and say where the reflections are. Entry angle corresponds to exit angle, that's all I'll say about it. I would hang a nice acoustic painting there that would do the same as these panels above 200hz.

Akustikbild – HOFA-Akustik

HOFA Akustikbildab 399,00 €inkl. 19 % MwSt.kostenloser Versand innerhalb DeutschlandsAkustik-Absorber mit wählbarem Motivin 3 Größen erhältlich (50 x 100 cm, 100 x 100 cm, 150 x 100 cm)hoher Wirkungsgrad, vor allem in Frequenzbereichen von Spracheschwer entflammbar nach DIN 4102-B1mit...

hofa-akustik.de

 

[Ron Resnick]

My old Pass amps rang like crazy when I shouted or clapped my hands anywhere near them.

What was happening there, exactly? Was the metal case reflecting back to your ears the sound of your clap?

 

[Audiohertz2]

Thanks Ron. I just wanted to get a sense of how much treatment you have in the room.

My old Pass amps rang like crazy when I shouted or clapped my hands anywhere near them. I was happy to get that ringing out of the room. I never listened with the Lamm SETs in place with the Pass still in the room, so I do not know the actual effect on the sound.

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