Philharmonic Audio - 3-way open back ML-TQWTs designed by Dennis Murphy

[Dennis Murphy]

Dennis, what is the primary advantage of using Ribbon tweeters vs. cone tweeters and Planar midrange vs. cone midrange?

Is it basically bigger soundstage?

In both cases, the theoretical advantage is a driver element with much lower mass. As for soundstaging, the planar dipole is free of any structural frame members that could restrict the rear wave, but I don't think that's a big deal.
None of this matters, of course. The only issue is whether users will like what they hear. And we'll have to wait a little before there are enough of these things out there to generate meaningful feedback.

 

[DenPureSound]

HI Any peak at 12 kHz is in the tweeter response, not the planar. The Neo8 is crossed to the tweet at a hair under 3 khz, 24 dB/octave. So the peak has gone bye-bye by 12 kHz. Plus, the peak is really only significant on-axis. The listening axis is above the midrange axis on the Phil. On the low end, the Neo is crossed to the woofer at 650 Hz. That means the planar is operating over a fairly narrow, and for it, comfortable zone. It really doesn't limit the Philharmonics' dynamic range.

My mistake, I stepped on my toes again. I was looking at the Neo8 Plots and noticed the 12kHz. Peak, but was not thinking that the Xover to the Tweeter was way down at around 2.8kHz. so the slight gain around 12kHz. is being produced by the RAAL Ribbon tweeter, which looks like it is a little more noticeable with a slight gain in db at 0 and 15deg off axis than at 20/30/45 degrees off-axis.

So the Neo8 Planar really only has to work from 640Hz. to 2800Hz. in the range that the LR 4th order filters put it in.

Dennis, thank you for clarifying this matter.

 

[DenPureSound]

In both cases, the theoretical advantage is a driver element with much lower mass. As for soundstaging, the planar dipole is free of any structural frame members that could restrict the rear wave, but I don't think that's a big deal.
None of this matters, of course. The only issue is whether users will like what they hear. And we'll have to wait a little before there are enough of these things out there to generate meaningful feedback.

So please explain this DM, are you saying that the sound the brain interprets is different in comparing a Cone Mid/Tweeter driver vs. the Planar and Ribbon Tweeter, even if the cones and ribbons where able to yield the same db gain or loss at those frequencies (hypothetically the same plots)?

Basically, the tonal qualities of the two for comparative reasons are different, even if they both were to produce the same FR plots? In other words a different sound color?

 

[Dennis Murphy]

So please explain this DM, are you saying that the sound the brain interprets is different in comparing a Cone Mid/Tweeter driver vs. the Planar and Ribbon Tweeter, even if the cones and ribbons where able to yield the same db gain or loss at those frequencies (hypothetically the same plots)?

Basically, the tonal qualities of the two for comparative reasons are different, even if they both were to produce the same FR plots? In other words a different sound color?

I really don't want to make any claims based on physics, since I lack a rich background and this isn't an area of consensus. The idea is that the lower the mass of the driving element, the quicker it responds to transients and the wider the ultimate frequency response (on top). It makes intuitive sense, but I've seen some technical minds dispute the "quickness" theory. I chose the Neo8 because it was a natural dipole and extended upward high enough on and off axis to cross easily to the RAAL 10 mm ribbon. Does the RAAL sound better because it's "quicker." I really don't know. But it does sound considerably more open in an A-B test. And to me the Neo8 sounds as good as the Accuton. But as I said, we'll have to wait and see how much agreement there is.

 

[GranteedEV]

I chose the Neo8 because it was a natural dipole and extended upward high enough on and off axis to cross easily to the RAAL 10 mm ribbon. Does the RAAL sound better because it's "quicker." I really don't know. But it does sound considerably more open in an A-B test. And to me the Neo8 sounds as good as the Accuton. But as I said, we'll have to wait and see how much agreement there is.

Do you find the Neo8 combo to be as 'coherent' as a smaller verti al combo? The CTC spacing of a tall planar and a ribbon near 3khz is definitely bigger than a small cone + ribbon near 2khz... or is this a case of 'on paper vs in execution'?

FWIW in the industry was saying he thinks the BG Radia which use the same Neo8, were the best speakers he's ever heard.

As for the RAAL, whatever it is, it has some of the sickest decay/distortion/impulse response that i've seen.

 

[Dennis Murphy]

Do you find the Neo8 combo to be as 'coherent' as a smaller verti al combo? The CTC spacing of a tall planar and a ribbon near 3khz is definitely bigger than a small cone + ribbon near 2khz... or is this a case of 'on paper vs in execution'?

FWIW in the industry was saying he thinks the BG Radia which use the same Neo8, were the best speakers he's ever heard.

As for the RAAL, whatever it is, it has some of the sickest decay/distortion/impulse response that i've seen.

Is sick good or bad? I was sick last Saturday--bad. The rules for center-to-center spacing don't work too well for planars and ribbons--they behave more like line sources than point sources. I didn't run into any integration or phase issues at 3k--you can see that from the reverse-null plots on my site.

 

[AcuDefTechGuy]

Is sick good or bad?

Sick, sick, sick and tight, tight, tight is really good.

 

[DenPureSound]

Do you find the Neo8 combo to be as 'coherent' as a smaller verti al combo? The CTC spacing of a tall planar and a ribbon near 3khz is definitely bigger than a small cone + ribbon near 2khz... or is this a case of 'on paper vs in execution'?

FWIW in the industry was saying he thinks the BG Radia which use the same Neo8, were the best speakers he's ever heard.

As for the RAAL, whatever it is, it has some of the sickest decay/distortion/impulse response that i've seen.

Grant -- as for the RAAL 70-10D Ribbon Tweeter in the Phil 3's, to me the specs. do NOT look like the sickest decay with more than 13,000 G's of Acceleration in less than 200 microseconds, and after that the Air is Stopped! Now, that is SUPER FAST. What are you looking for 200 NanoSeconds before it comes to a dead stop?

Sick is OK then you can go horizontal and listen to Music all day long, just don't set the Sleep Timer on.

 

[GranteedEV]

To clarify for everyone:

Sick == Sickeningly Good

 

[DenPureSound]

To clarify for everyone:

Sick == Sickeningly Good

Boy, that changed quickly, thank goodness, LOL. Your good Grant!!

Ok, GRANT now let's assume we have a 20kHz. input sinusoidal waveform at it's Maximum Voltage (RMS) input imposed upon the RAAL Ribbon Tweeter, how fast (in Micro or Nano Seconds) do we need the driver to be in so that it is back at a Neutral NULL Position before the next forcing cycle comes at it to displace it again?

Isn't 200 MicroSeconds quick enough, at standard room temp. and pressure of course?

 

[DenPureSound]

Is sick good or bad? I was sick last Saturday--bad. The rules for center-to-center spacing don't work too well for planars and ribbons--they behave more like line sources than point sources. I didn't run into any integration or phase issues at 3k--you can see that from the reverse-null plots on my site.

I think DENNIS MURPHY is not a JUNIOR Audioholic... far above that one, and certainly way beyond me !!

DM, are the "Line Sources" you speak about in what axis, Vertical or Horizontal, or ?? I am guessing, Horizontal Plane left to right of us listening?

BTW -- looking at the Reverse Null Plot on the PH3's, which by the way looks Excellent, just curious from my stupidity why at around 2.8kHz. and 650Hz. why don't they cross over a little down at 45db, dumb question by me, but just trying to understand this stuff. They never even touch each other, and there is a gap a Xover's. Not critical, just wanting to be more technical in this stuff.

Thank you, DM.

 

[AcuDefTechGuy]

To clarify for everyone:

Sick == Sickeningly Good

Boy, that changed quickly, thank goodness, LOL. Your good Grant!!

SICK, WICKED, & TIGHT are GOOD, GOOD, GOOD.

Now if you are Michael Jackson (pre-propofol), then BAD is also GOOD.

 

[GranteedEV]

DM, are the "Line Sources" you speak about in what axis, Vertical or Horizontal, or ?? I am guessing, Horizontal Plane left to right of us listening?

I think;

line source refers to the way it radiates sound. ribbons and planars are very flat and tall - a line. its acoustic phase stays pretty consistent over the frequency range and over the vertical area directly in front of it.

a cone or dome on the other hand undergoes a bunch of phase shift as frequency changes, because of its shape. as it gets larger the inner radiation and outer radiation are no longer in time or phase with each other. Combine that with a crossover to another point source and things get a bit difficult.

BTW -- looking at the Reverse Null Plot on the PH3's, which by the way looks Excellent, just curious from my stupidity why at around 2.8kHz. and 650Hz. why don't they cross over a little down at 45db, dumb question by me, but just trying to understand this stuff. They never even touch each other, and there is a gap a Xover's. Not critical, just wanting to be more technical in this stuff.

at crossover for an LR4, the upper and bottom driver are not only equally 6db down, but they are close to 100% in phase with each each other on axis. So if you make one driver 180deg out of electrical phase, the resulting acoustical phase relationship causes them to cancel aggressively. the point of the reverse null is to show just how 'in sync' the drivers were at crossover. the fact that the lines don't touch means they're extremely close to 0 degrees out of phase during normal operation.

 

[Dennis Murphy]

I think;

line source refers to the way it radiates sound. ribbons and planars are very flat and tall - a line. its acoustic phase stays pretty consistent over the frequency range and over the vertical area directly in front of it.

a cone or dome on the other hand undergoes a bunch of phase shift as frequency changes, because of its shape. as it gets larger the inner radiation and outer radiation are no longer in time or phase with each other. Combine that with a crossover to another point source and things get a bit difficult.



at crossover for an LR4, the upper and bottom driver are not only equally 6db down, but they are close to 100% in phase with each each other on axis. So if you make one driver 180deg out of electrical phase, the resulting acoustical phase relationship causes them to cancel aggressively. the point of the reverse null is to show just how 'in sync' the drivers were at crossover. the fact that the lines don't touch means they're extremely close to 0 degrees out of phase during normal operation.

I think you answered his questions, although I'm still not clear on what the question was about the reverse null. What you say is correct, however. And you're right about line-source vs point-source. I'm not saying one is really better than the other, just that the usual spacing rules apply to a point-source radiation pattern where the sound eminates from the center of the driver, rather than along the entire length.

 

[DenPureSound]

as the picture shows jim shared his room at the recent california audio show with dennis and there are several threads on the salk forum talking about the philharmonics, so i don't think that there is any real competition here. also about the name, dennis plays viola in the philadelphia philharmonic and is donating a portion of all sales to the orchestra. pretty cool!

Thanks, could you please ADD the URL's for the Phil's on the other forums.

 

[its phillip]

Den, the guy you are quoting is a spambot and what he said was copied from a post on the first page of the thread.

 

[DenPureSound]

RAAL 70-10D Ribbon in the Phil 3's !!

From RAAL:

"RAAL is a company based in Zajecar (Zayechar), eastern Serbia. It is 100% owned and managed by its founder and director, solely creating the company's policy, products, development and strategy.

In an effort to recreate a sound that happened in some other place, in some other time, audio engineers are constantly trying to find the best means to record and reproduce the sound as exactly as possible. If we could have absolutely accurate replica of recorded sound at the end of an audio equipment chain, than the sensation that we would have, would be the same as we actually participated in the recorded event.

Of course, absolute accuracy is not possible. Fortunately enough, it has been proven that it takes a certain level of reproduction accuracy to make the human or animal ears experience no difference to original. Impressive achievement, but with ridiculously expensive and impractical laboratory equipment and conditions.

Our goal is to bring the most of that experience to everyday life."

 

[DenPureSound]

Den, the guy you are quoting is a spambot and what he said was copied from a post on the first page of the thread.

Unreal, please BAN those SpamBots here, ... thanks for the update.

 

[DenPureSound]

Phil 3 Open Baffle Design

Dennis Murphy, can you explain why the Upper Enclosure on the PH3's has an Open Baffle design to it on the back and sloping, with the foam attached to the inner walls, but has no Dacron filling material w/in it -- I thought I read somewhere where the upper cabinet could be filled w/ different amounts of acoustical fill. But will wait for your reply.

 

[Dennis Murphy]

Dennis Murphy, can you explain why the Upper Enclosure on the PH3's has an Open Baffle design to it on the back and sloping, with the foam attached to the inner walls, but has no Dacron filling material w/in it -- I thought I read somewhere where the upper cabinet could be filled w/ different amounts of acoustical fill. But will wait for your reply.

I took the filling out when I snapped the pic, because I thought that would show more about the design. The speakers are supplied with fill--you use as much as you want, or none. It will all depend on the room, program material, and individual taste.