green mountain.

[Shakeydeal]

3db

PSB does not make a speaker that can compete with the C3. Sorry to let you down.....


Shakey

 

[TLS Guy]

What does it matter if the sound is worse off axis? Where do you do most of you listening?

And no, the GMA speakers do NOT have a smaller sweet spot than a maggie 1.6. Not many speakers do.

Shakey

A speaker with first order filters can have a reasonable off axis response. For obvious reasons the vertical rather than the horizontal axis is skewed.

If you think about it the area where the speaker is perfectly phased and time aligned is very small. The other issue is change in frequency response, especially with change in vertical position due to driver overlap and therefore varying frequency nulls and cancellations. That is the reason it is very difficult to get an accurate idea of the speakers performance, especially in the near field.

What it really boils down to, is that you end up voicing the speaker by an awful lot of trial and error with extended listening tests.

I ended up with one series rather than parallel transition and they are very difficult because changes in just one component affects response in two drivers.

This type of crossover arrangement tends to sound better in the distant field on the whole.

It is a very difficult project and for many reasons authorities in reference texts on crossover design tend to advise against attempting it.

As far as planar loudspeakers are concerned they are totally different case with sound generated over a large area and so beaming results. However since they are dipoles there has to be a null at 180 degrees so that comment about Maggies and the 180 degree off axis response is a cheap shot.

 

[TLS Guy]

The purpose of the question was to encourage a more varied appraisal of the speaker, and to check if the claims being posted had the realistic possibility that the poster in question was being honest.

Someone being honest would have to agree that better 180-off-axis performance than a bipolar ribbon was impossible from a monopolar speaker. It's the nature of the design as the cabinet sits between the driver and the 180-degree position on a monopolar speaker (such as everything GMA makes). The exception would be in lower-frequencies where sound tends to radiate in spheres (though even then, there is a baffle effect at certain ranges).

Similarly, the "sweet spot" must necessarily be larger on large ribbon drivers like the Maggies because
1) There are actually two sweet spots 180-degrees apart.
2) The height of the emitting ribbon means an extremely large vertical dispersion.
3) The large size of the radiator means slower fall-off of volume (The inverse square rule applies to point-sources. The larger the driver, the farther your imaginary point-source).

Someone who was dishonest in their appraisal: who simply wished to assert that their product was all things to all people, even in the face of the impossibility of such, would assert that their product (the GMA) had better off-axis performance and a larger sweet spot out of an inability to admit real limitations.

What confuses me is that I even showed my hand when asking. I didn't just ask "is the 180-degree off-axis performance better than a Maggie".. I actually went ahead and explained why the answer is necessarily "no". Yet here we are with someone asserting "yes".

The off axis response can not be ignored. Even if you don't listen off axis, an off axis response significantly different from the axis response will sound poor, and be unduly affected by the room. A speaker with an off axis response that mirrors the axis response, will sound better and be much more tolerant of differing listening environments and even actually sound very good in quite ambient spaces.

As far as a tall ribbon tweeter is concerned it actually widens horizontal dispersion and narrows vertical dispersion over its operating range. That is a highly desirable characteristic for a loudspeaker.

The problem with large panels driven over their entire area is beaming.

In the Quad ESL 64 Peter Walker elegantly handled the problem by not driving the diaphragm uniformly, but letting the sound spread out like a ripple on a pond to keep the waveform as spherical in its radiation pattern as possible.

 

[JerryLove]

Certainly I was not attempting to assert that one technology (planars) was better or worse than another (monopole cones)... merely seeing if I could get an acknowledgment that one could accomplish something that the other could not.

Heck. I'm actually an advocate that "no off-axis sound" is better than "perfect off-axis sound" for many axis. It's a point of contention I have with Chris (and I believe others)... though I fully agree that off-axis sound which does exist needs to be as accurate as possible.

 

[TLS Guy]

Certainly I was not attempting to assert that one technology (planars) was better or worse than another (monopole cones)... merely seeing if I could get an acknowledgment that one could accomplish something that the other could not.

Heck. I'm actually an advocate that "no off-axis sound" is better than "perfect off-axis sound" for many axis. It's a point of contention I have with Chris (and I believe others)... though I fully agree that off-axis sound which does exist needs to be as accurate as possible.

How on Earth could you create a device that had no off axis sound?

 

[JerryLove]

How on Earth could you create a device that had no off axis sound?

Hypothetically? Not sure, can sound be lased?

Audiably? Sit in a truely anechoic space (the speaker may make off-axis noise, but you won't hear it). More functionally? Headphones.

I should revise my position from above. I don't believe that a lack of off-axis sound makes a "better" speaker. I merely assert that reflections from off-axis sounds are not in the original recording (the reflection is not in the recording) and therefore represent a reduction in fedility from the source material.

In practical use: the presence of off-axis sounds (and therefore reeom reflections) tends to improve the subjective experience.

 

[RoyJ]

You know, I do appreciate all of the attitudes presented here. I don't mind at all defending my design thoughts, which are presented in depth for each speaker model, on our website.

So, if I may ask for your patience, I'll make every attempt to clarify my posts, read yours well and address your concerns, while I shorten my answers wherever possible.

You science-minded chaps should visit our website as time permits, since quite a lot is explained there about the science behind my speakers (and others). You'll find very little hyperbole. I describe to the best of my ability, and without giving trade secrets away, what I know about how sound evolves into and out of our particular transducers, over to your ears, about your room, and into the cabinet, and why I chose these drivers. I would expect someone to then just listen to determine if the claims that result are true.

And please note that on the website, I always say why such-and-such happens to the sound or to the speaker, by describing the insights that the (always incomplete) knowledge of physics, psychoacoustics, and the hearing of music bring to our table.

I wanted this to be a short goodbye for now, but it occurs to me now would be the best time to mention a couple of other things:

Those interested in speaker design would enjoy my PDF on the design goals behind the C-3 speaker, as it has the most-in depth writing I can make publicly on the evolution of sound as it travels. No math, I promise: C-3 design concepts.

Also, there is a lengthy article of mine on the causes and sonic consequences of phase shifts in speakers, one that Andrew Marshall asked to publish back in 1997, which I re-typed for our website at this link: Audio Ideas Guide article on Phase



We face choices in speaker design, not 'ultimate solutions', and that is all because the speed of sound is so slow. Therein lays all our issues, and it's why using the simplest math for light as the simplest math for sound does so by leaving out everything about that modest time of travel, hence, about any of the math behind time-coherence. I hope that makes sense!

Also, someone asked how many reviews we've had. I think at least twelve, and they are listed/reprinted on our site with each speaker model- new or retired. They should have more prominent access. Thanks for reminding me.

I'll be back, quite soon! Thank all of you again for your kind interest and questions, including the ones that felt like eating fiber. It's been awhile since I have done this on a forum and I thank you for the opportunity here.

Best regards,
Roy

 

[bocat57]

Now Just One Minute Jerry

I don't think it would be reasonable to say I questioned your integrity when I have no idea who you are. It might, however, be accurate to say I questioned your existence.

Could you please elaborate on your above quoted statement. I mean if you got something to say don't beat around the bush just come right out and say it.
By the way for the record I do EXIST !

Bob
New York

 

[bocat57]

And One More Thing "Field Marshall"

I would think one immediate disadvantage would be that they are mono-polar speakers. You won't get room reflections as complete as occurs with omni-polar and bi-polar rigs. Another obvious compromise vs. other speakers (planars and column arrays) would need to be the rate of sound drop-off. Volume on a GMA speaker will be more affected by distance than off a Maggie, or ML, or McIntosh XR2kt. Again: this is an inevitable trade-off with the choice to use individual direct-drive cones and domes.

Would you agree with those statements? Would you agree that the performance of your GMA speaker at 180-degrees off-axis is inferior to a Magipan 1.6? Would you similarly agree that the sweet-spot is smaller?

It is clear to me by the above quoted response that you did not read my post and if you did you did not understand it. I don't know what the hell your talking about in the above quoted statement. If you had read and understood my post I thought I made clear I am not about all that technical crap. I have critically listened to 3 high end speakers of which I Like the ones I have now.

I was wondering why it is so hard for you to accept the fact that I am completely satisfied with my speakers ( I am also completely satisfied with the rest of my gear ) My suspicion is that you are so obsessed with the equipment and the technical side. That you can not relate to people like me who just want to hear the music sound great.

I think you are the type thats so wrapped up in the equipment specifications and measurements that I doubt you can really sit down and enjoy the music and for that I feel sorry for you. I believe you suffer from audio nervosa.
You stated on an earlier post that you spend $20,000 a year on gear. It is my opinion you do this because your never really satisfied with your equipment. You have forgotten what this hobby should be about. But hey to each his own.

Bob
New York

 

[3db]

3db

PSB does not make a speaker that can compete with the C3. Sorry to let you down.....


Shakey

You're not letting anyone down. I rather have some freedom of movement without signifcantly altering the sound from the speakers instead of holding my head perfectly still to achieve perfect sound.

 

[TLS Guy]

Hypothetically? Not sure, can sound be lased?

Audiably? Sit in a truely anechoic space (the speaker may make off-axis noise, but you won't hear it). More functionally? Headphones.

I should revise my position from above. I don't believe that a lack of off-axis sound makes a "better" speaker. I merely assert that reflections from off-axis sounds are not in the original recording (the reflection is not in the recording) and therefore represent a reduction in fedility from the source material.

In practical use: the presence of off-axis sounds (and therefore reeom reflections) tends to improve the subjective experience.

Any speaker in an anechoic space sounds dreadful! A microphone picks up ambient and direct sound. Distant microphone placement (generally a good thing) picks up largely the ambient field. In a concert hall your ears are picking up far more ambient then direct sound. In playback there must be an ambient field to even begin to create a believable sound stage.

Jerry I'm afraid your hypothesis is totally off bass. Highly directional speakers, such as those with sectoral horns like Klipsch, I think sound perfectly dreadful in most domestic spaces. Most speakers of the cone type need a better and wider off axis response.

By the same token excessive acoustic treatment in a room, (often done) is a bad thing.

 

[JerryLove]

In practical use: the presence of off-axis sounds (and therefore room reflections) tends to improve the subjective experience.

Jerry I'm afraid your hypothesis is totally off bass. Highly directional speakers, such as those with sectoral horns like Klipsch, I think sound perfectly dreadful in most domestic spaces. Most speakers of the cone type need a better and wider off axis response.

Please re-read what I said (I quoted the salient part above). I'm pretty sure you just agreed with me.

 

[JerryLove]

PSB does not make a speaker that can compete with the C3. Sorry to let you down.....

I have no experience with the C3, nor PSB's high-end gear; and I don't dispute your conclusion.

I am curious however how you personally came to this conclusion? Have you auditioned PSB's high-end gear? Is there something about PSB's high end gear that you are aware of that makes this a foregone conclusion?

 

[ski2xblack]

Highly directional speakers, such as those with sectoral horns like Klipsch, I think sound perfectly dreadful in most domestic spaces.

With all due respect, Dr. Mark, but I have to disagree with you on this. One of my systems is like you describe, and one of the most notable things about it is that you hear the speakers, and not so much the room response. They allow much closer proximity to room boundaries than a direct radiator, which is a placement restriction many of us face. Sure, there are many examples of crappy sounding horn loaded speakers, but there are also a few that perform quite well. Have you heard Earl Geddes system at all? It is quite impressive. And I'm no Klipsch fanboy, have auditioned many that I too disliked, but the Heritage line is for real.

Sorry for the OT post, I'll let y'alls get back to bashing the Green Mountain fan boy/sock puppet.

 

[JerryLove]

Jerry, are you already done with the B&W's? Just wondering how they are working out in your room?

Many of my complaints from my previous response are gone.... now that I've turned off the DSP on the P5000S (I feel stupid!).

Since fixing, I've yet to do good critical listening, but things look very promising... which will make parting with these (they still don't fit in the house) even more sad.

 

[Shakeydeal]

You're not letting anyone down. I rather have some freedom of movement without signifcantly altering the sound from the speakers instead of holding my head perfectly still to achieve perfect sound.

It's not that way at all. I have a two person wide sweet spot at my listening position in my room. How much more do you need?

Shakey

 

[jamie2112]

Many of my complaints from my previous response are gone.... now that I've turned off the DSP on the P5000S (I feel stupid!).

Since fixing, I've yet to do good critical listening, but things look very promising... which will make parting with these (they still don't fit in the house) even more sad.

I knew it had to be something wrong,as those baby's kick some serious A**.......You could always move to a bigger house
in all seriousness I hope you can break down a wall or something to get you some more space Jerry . I have always wanted a pair of those B&W's... I hope you sort it out.Good luck

 

[3db]

It's not that way at all. I have a two person wide sweet spot at my listening position in my room. How much more do you need?

Shakey

But according to the dealer, even a few microseconds in propogation can alter the sound so based on this, I can't see how you can have a 2 person sweet spot.

PSB may not be your cup of tea and thats ok. But all of their products have garnered nothing but rave reviews from all of the audio rags out there. PSB also provides the measurements to back up their products. Stereophile magazine concurs with their measurements. And where does this leave GM?

 

[Shakeydeal]

Don't know what to tell ya 3db. Once the speakers are dialed in, they sound good to great from multiple positions in the room. PSB makes good speakers, I am not denying that. So if YOU like your speakers, that's all that matters. For me, GMA speakers are superior.

Shakey

 

[TLS Guy]

With all due respect, Dr. Mark, but I have to disagree with you on this. One of my systems is like you describe, and one of the most notable things about it is that you hear the speakers, and not so much the room response. They allow much closer proximity to room boundaries than a direct radiator, which is a placement restriction many of us face. Sure, there are many examples of crappy sounding horn loaded speakers, but there are also a few that perform quite well. Have you heard Earl Geddes system at all? It is quite impressive. And I'm no Klipsch fanboy, have auditioned many that I too disliked, but the Heritage line is for real.

Sorry for the OT post, I'll let y'alls get back to bashing the Green Mountain fan boy/sock puppet.

What I'm talking about is compression drivers with narrow sectoral horns. That is not what Dr Geddes is working with at all.

Large sectoral horns need a very large space. I don't like narrow dispersion speakers in the home. They just do not present to me a believable sound stage or one I could enjoy.