New stuff coming soon?

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Peter J

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New stuff coming soon?
« on: 27 Jun 2013, 08:59 pm »
Danny, I remember reading you had some new open baffle designs in the works, and possibly a replacement driver that would take the place of the no-longer-available driver in Super V. Any news on either front?

Danny Richie

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Re: New stuff coming soon?
« Reply #1 on: 28 Jun 2013, 01:30 pm »
I am still working on new stuff, and getting closer.

I really did not have to much interest in a Super-V replacement, and going to an off the shelf driver has its drawbacks.

nickd

Re: New stuff coming soon?
« Reply #2 on: 28 Jun 2013, 03:07 pm »
Hey Danny,

Any thoughts on an update to the OB 7 with a open back Neo 3.

I kind of thought you might use all those copper plug woofers you displayed at RMAF to take the OB-7 to the next level?

Do you have to move all the "old stock" first?

Danny Richie

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Re: New stuff coming soon?
« Reply #3 on: 28 Jun 2013, 03:24 pm »
Hey Danny,

Any thoughts on an update to the OB 7 with a open back Neo 3.

I kind of thought you might use all those copper plug woofers you displayed at RMAF to take the OB-7 to the next level?

Do you have to move all the "old stock" first?

I actually have tried the open back Neo 3 with the M-130/16 woofers. I got some really good sound from it, but the one thing that I didn't like was the phase issues when you went to the back side. See the tweeters playing surface is actually ahead of the voice coil of the woofers. No bid deal really as the crossover allows for the delay so the output is in phase. However, as you move around to the back side the tweeter is delayed in time (physically) compared to the woofers and the crossover is shifting a delay in the wrong direction. So the rear output is not so smooth since the drivers are not in phase.

Now in a design like the Serenity Acoustics Super-7 when on open back Neo 3 is used, it is perfectly aligned with Neo 10's. So the phase is the same in both directions.

I have several designs in the works for those new woofers. They will be really good.  Hang in there.

Ric Schultz

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Re: New stuff coming soon?
« Reply #4 on: 28 Jun 2013, 04:19 pm »
Danny,
Do you have any idea when the servo amps for the 8s will actually be here?  Seems like over a year now they have been delayed.  Other than boost and roll off rates, is there any other reason why the big amp couldn't be used with the eights?  Have you tried the big amps with the 8s?

Danny Richie

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Re: New stuff coming soon?
« Reply #5 on: 28 Jun 2013, 04:55 pm »
Danny,
Do you have any idea when the servo amps for the 8s will actually be here?  Seems like over a year now they have been delayed.  Other than boost and roll off rates, is there any other reason why the big amp couldn't be used with the eights?  Have you tried the big amps with the 8s?

From Brian Ding a few days ago...

"I will be in China between from June 30 to July 9.  There are minor change to the HX300 amp. So there is a delay."

I know these amps have taken longer than we hoped, but Brian is very serious about these being just right for the job and very reliable.  As you know there are very few failures of Rythmik amps compared to other available amps.

The bigger A370 will work with the new 8's, but will overdrive them, especially on the 14Hz setting, if one is not careful. The new amps are designed to drive the woofers to the max but not over.

Hang in there. No one wants them to be ready more than I do.

nickd

Re: New stuff coming soon?
« Reply #6 on: 28 Jun 2013, 06:45 pm »
Quote
the one thing that I didn't like was the phase issues when you went to the back side. See the tweeters playing surface is actually ahead of the voice coil of the woofers. No bid deal really as the crossover allows for the delay so the output is in phase. However, as you move around to the back side the tweeter is delayed in time (physically) compared to the woofers and the crossover is shifting a delay in the wrong direction. So the rear output is not so smooth since the drivers are not in phase.


Thanks Danny,

I had not really thought of that. I guess that explains Linkwitz using 2 Seas tweeters back to back in his design. Tricky animal these OB designs. "Back soundstage smear" who knew that was possible?

Chops

Re: New stuff coming soon?
« Reply #7 on: 28 Jun 2013, 07:40 pm »
Danny, maybe it's in another thread somewhere that I haven't found yet, but why did the V-2 and V-1 (Super V) live such short lives? Was it because of off the shelf drivers?

Danny Richie

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Re: New stuff coming soon?
« Reply #8 on: 28 Jun 2013, 07:57 pm »
Danny, maybe it's in another thread somewhere that I haven't found yet, but why did the V-2 and V-1 (Super V) live such short lives? Was it because of off the shelf drivers?

P-Audio quit making the drivers. They were available for a while though. I released those kits in 2009. Both the V-2 and Super-V were both showed at RMAF in 2009 as well.

Danny Richie

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Re: New stuff coming soon?
« Reply #9 on: 28 Jun 2013, 08:00 pm »
Thanks Danny,

I had not really thought of that. I guess that explains Linkwitz using 2 Seas tweeters back to back in his design. Tricky animal these OB designs. "Back soundstage smear" who knew that was possible?

It doesn't real smear the back sound stage. They are just out of phase. So it causes about a 15db suck out in the output around the crossover area.

And yes, that is why Linkwitz uses two of them back to back.

These things are trickier than you'd think sometimes.

Jonathon Janusz

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Re: New stuff coming soon?
« Reply #10 on: 29 Jun 2013, 12:36 am »
. . . which would also add a piece to the puzzle explaining why the open back tweeters on the V coaxes worked too?  The tweeter being physically offset to the rear of the driver addressed this issue?

. . . and I thought the extra tweeter was JUST to get a bi/dipole radiation pattern out of the tweeter section to match the open woofers.  Learned something new today!

Danny Richie

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Re: New stuff coming soon?
« Reply #11 on: 29 Jun 2013, 12:49 am »
Quote
. . . which would also add a piece to the puzzle explaining why the open back tweeters on the V coaxes worked too?  The tweeter being physically offset to the rear of the driver addressed this issue?

It wasn't perfect but it wasn't bad. Keep in mind that these crossed at 1kHz. That is a pretty low crossover point for a tweeter to a woofer, and the wavelengths are much longer than if it were crossed at 2.5kHz or so. So while there is an offset it is less phase rotation at the lower frequency crossover point than if it were higher. Instead of the wavelength being 5 to 6 inches it was more like 13.5 inches. Make sense?

Jonathon Janusz

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Re: New stuff coming soon?
« Reply #12 on: 29 Jun 2013, 01:23 am »
I think I got most of it. 

Summary: The offset improved the situation of a dip in the output near the crossover vs. having the tweeter flush to the front of the baffle, but the lower crossover point made the phase difference itself - regardless of magnitude - less of an issue due to the difference in wavelengths involved compared to crossing higher.  In this case, physical driver positioning reduces the magnitude of the basic problem, crossover point selection adjusts the range of the problem area attempting to make the problem itself a non-issue.

Hope I got that close. :D

Danny Richie

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Re: New stuff coming soon?
« Reply #13 on: 29 Jun 2013, 02:03 am »
I think you got the just of it.  :thumb:

AKLegal

Re: New stuff coming soon?
« Reply #14 on: 18 Aug 2013, 12:26 am »

The bigger A370 will work with the new 8's, but will overdrive them, especially on the 14Hz setting, if one is not careful. The new amps are designed to drive the woofers to the max but not over.


Danny, is there a setting configuration on the bigger amps that would make more difficult to overdrive the 8s?  Would 28 hz with high damping with the rumble filter on be too much?

Any issues with using a standard class d amp on the 8s and just not using the servo coils until the new amps arrive?


Danny Richie

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Re: New stuff coming soon?
« Reply #15 on: 18 Aug 2013, 12:40 am »
Danny, is there a setting configuration on the bigger amps that would make more difficult to overdrive the 8s?  Would 28 hz with high damping with the rumble filter on be too much?

Any issues with using a standard class d amp on the 8s and just not using the servo coils until the new amps arrive?

You can use the standard A370PEQ amps if you want. And the 28Hz setting would be ideal. You just have to be wise with the gain setting.

Hoping for new amps soon, but no new news yet. I know Brian Ding went back to China to iron some things out again. I hope he has them available soon. I have new designs waiting on them.