Beyond the Ariel

[phase_accurate]

What's your opinion about using linearisation FIR filters for music playback?

If you belong to the camp that dislikes stored-energy then you'd rather not use FIR filters.
If you are afraid of the post-ringing caused by stored energy the use of FIR filters would introduce something that is even worse: PRE-RINGING.

Regarding the Manger transducer: Yes the decay shows effects of stored energy mostly around the two infamous holes at 0.8 and 1.6 kHz.
Above that it is very good and its initial rise-time is very good at just 13 us.


Regards

Charles

[jzagaja]

The problem with ringing is that it is created everywhere in recording productions now - when antialiasing digital filters are used. What can we do? Back to the analog sources or use AD/DA without AA filter (NOS-ADC).

If Manger is so good then we can easily evaluate the codecs artefact and this ringing. If the ringing is there then why measured CSD after DSP applied is so clean (much better than Manger MSW, and 4 times less price)? Is it out of band ringing?

Jordans after linearisation have impulse response very close to the Dirac pulse. My ears aren't trained maybe that's why I don't hear the cone breakups (but I'm attending to jazz clubs few times per month).

Do you have Manger's square wave response? Mine looks like this:

http://audiostereo.lukarnet.com/gfx/700000/708561_3.gif
(1kHz)

And step:
http://audiostereo.lukarnet.com/gfx/700000/708561_1.gif
http://audiostereo.lukarnet.com/gfx/700000/708561_2.gif

[phase_accurate]

You can see the step response of the bare Manger driver on their website and it is for sure better than the one from your link.
I bet it would even improve significantly if the response errors are EQed out.
It wouldn't be difficult to guess the square-wave response from this.

The step response of a Manger + Woofer combination using a prototype active minimum-phase crossover of mine can be found here:

http://www.diyaudio.com/forums/showt...11#post1139711

Regards

Charles

[jzagaja]

Step response of Zerobox in Gelsenkirchen is smoother than from metal cone - see appended picture. Does it explain the subjective impression that Jordan JXR6 and Manger MSW are completely different drivers? Jordan is electrostatic archetype with breathing clarity and MSW is extremely smooth but without this electrostatic clarity.

Or maybe we should look in the time domain in other way - mentioned power cepstrum used by Holland and Newell for direct radiators and horns comparisons.

[chrismercurio]

I had Mangers in a diy system for about 3 years. It was extremely difficult to mate them to anything else and have the sonic picture sound complete. On their own, despite the limited dynamic range and top octave extension, they are quite special. It was a little like having a JX-92 that sounds MUCH better for a LOT more money.

After reading the whole thread this morning I think it is worth mentioning that Hemp Acoustics has an 8", 12" and 15" coaxial drivers available. The concentric tweeter is a compression driver, and the cones are obviously hemp. They also have a 15" designed specifically for open baffle use. Lynn mentioned a desire for hemp, they industrial type of course, earlier in the thread.

C

[Lynn Olson]

Originally posted by chrismercurio
I had Mangers in a diy system for about 3 years. It was extremely difficult to mate them to anything else and have the sonic picture sound complete. On their own, despite the limited dynamic range and top octave extension, they are quite special. It was a little like having a JX-92 that sounds MUCH better for a LOT more money.

After reading the whole thread this morning I think it is worth mentioning that Hemp Acoustics has an 8", 12" and 15" coaxial drivers available. The concentric tweeter is a compression driver, and the cones are obviously hemp. They also have a 15" designed specifically for open baffle use. Lynn mentioned a desire for hemp, they industrial type of course, earlier in the thread.

C

The Hemp Acoustics 12 and 15 drivers are in fact my first choices for the new project - I am awaiting specs for the horn and bass unit to evaluate their suitability. Hemp-composite cones have much less breakup and "cone cry" coloration than anything else I've heard so far - I surmise the hemp is tougher, more elastic, and more resistant to failure modes than paper, carbon-fiber, or other synthetics. I've always been impressed that ropes strong enough to hold ocean liners were made of hemp. That isn't a light-duty application!

The G load forces where the voice-coil former meets the cone are extremely high, and many materials audibly fail at higher SPLs. In addition, when the speed of sound in the VC former and cone are different, that creates a reflection that propagates up and down the cone, and sets it up for bending modes. This is why the choice of glues joining the VC former to the cone are absolutely critical to the sound of the speaker - it's both a mechanical weak point and a region where two materials have different speeds of sound.

As for the Manger, eh, not my cup of tea. Not a fan of PHY either - it's a popular type of "hifi" sound I don't care for. The audiophile "exotics" have a rather artificial and unnatural sound to my ear, and the waterfall typically has a chaotic character in the critical 1 to 5 kHz region.

This is the frequency band where hemp excels - even the Tone Tubby 12" guitar speaker has smoother characteristics than the fancy exotics. See the measurements I've made of drivers used in very expensive and well-reviewed audiophile speakers, and compare the smoothness of the rolloff region (a figure of merit that I consider very important).

[IslandPink]

Hi Lynn,
Nice to see you thinking about a very timely and relevant subject ( for me ! ) .

It would be really good, as Scottmoose has said , to get JamesD onto this thread, because he has done some serious modelling and practical work with OB design, driver choice and series crossovers . His 'Quasar' I design which is buried somewhere in Bert Doppenberg's BD-Design forum, is a very capable design . The ( 20mm Acrylic ) baffle transitions from Open at the top to shallow U-baffle at the bottom and the bass radiation I believe goes to Cardoid at the lower end as a result . I can vouch for the performance , and the quality of the drivers ( AER and Supravox ). Bass tone and speed is glorious .

James has been very tied up with work projects and family stuff in recent weeks . He may be back in audio circulation in the next week or two , so I'll alert him to this discussion .

Good luck with the recovery, Lynn . I'm sure Thom will have you on the treadmill soon !

Mark

[BudP]

Indeed. just what is needed, folks with working experience who have solved some of the mounting plate / driver / room problems successfully and also not successfully. Those errors will teach us as much, or more, than their successes.

We need to get Gary Pimm to discuss his system, choices, and a few pictures too. He has solved the low frequency issues and has gone a long way towards solving some of the other issues.

Bud

[Lynn Olson]

Originally posted by IslandPink
Hi Lynn,
Nice to see you thinking about a very timely and relevant subject ( for me ! ) .

It would be really good, as Scottmoose has said , to get JamesD onto this thread, because he has done some serious modelling and practical work with OB design, driver choice and series crossovers . His 'Quasar' I design which is buried somewhere in Bert Doppenberg's BD-Design forum, is a very capable design . The ( 20mm Acrylic ) baffle transitions from Open at the top to shallow U-baffle at the bottom and the bass radiation I believe goes to Cardoid at the lower end as a result . I can vouch for the performance , and the quality of the drivers ( AER and Supravox ). Bass tone and speed is glorious .

James has been very tied up with work projects and family stuff in recent weeks . He may be back in audio circulation in the next week or two , so I'll alert him to this discussion .

Mark

Well, that's along the lines of what I've been thinking of since last summer - a baffle that is flat for the upper driver, and has (one) side panel that extends maybe 12" deep at floor level. This extends the path-length for the bass driver to maybe 24" or so, yet leaves the diffraction-sensitive wideband driver alone.

One difference between using an AER/Lowther and a potent 12 or 15-inch coax is not needing to use a highpass electrical filter for the mid/hi driver - I can run the 400-watt prosound driver full-range, with no cabinet loading, and not fear the driver will be destroyed. I'd never dare try that with an AER/Lowther with its 1mm of linear excursion and very soft suspension.

But - if you can just find a big cap of high quality (not easy) - an AER/Lowther would most certainly be a candidate for the mid/hi driver, since the efficiency from 500 Hz on up is pretty high, and the big boy down below can handle the bass power. After listening to the Ariel for 12 years, though, I kind of hunger for the stupendous 120dB peaks of horns and prosound gear, and that would be certain death for the AER/Lowther, at least as a direct radiator.

The real challenge is going to be domesticating the prosound stuff - this is the part where I'm jumping into the wild blue yonder. (Well, once I get walking again. First things first. The next X-ray on May 1st will show whether I can start putting any weight on the left leg - so far, it's toe-touch only, and walkers, crutches, and wheelchairs to get around. If the X-ray and the surgeon give the green light, then I can start up physical therapy again.)

[jzagaja]

As for the Manger, eh, not my cup of tea. Not a fan of PHY either - it's a popular type of "hifi" sound I don't care for. The audiophile "exotics" have a rather artificial and unnatural sound to my ear, and the waterfall typically has a chaotic character in the critical 1 to 5 kHz region.

Don't understand. "Exotic" drivers have clean and robust either CSD and impulse response. Don't you like ESL57 now? For example Bandor 50mm unit is popular among musicians in UK (Doreen Bance words) - are they stone deaf?

I understand that dynamic range is important for either speakers and photographic cameras but do you really need a rock concert in your house?

I understand also that we cannot describe the driver subjectively just looking on the graphs.