[bdp24]

Danny---In all the pics of it, your 12" sub driver has the thick rubber surround/gasket you provide with the driver on the mounting flange. Do you put anything between the rubber and the baffle when mounting the 12 in a sealed box, or does the rubber alone provide an airtight seal?

[Danny Richie]

Danny---In all the pics of it, your 12" sub driver has the thick rubber surround/gasket you provide with the driver on the mounting flange. Do you put anything between the rubber and the baffle when mounting the 12 in a sealed box, or does the rubber alone provide an airtight seal?

The rubber gasket alone seals nicely.

[kenreau]

Seeing this thread pop up reminds me to ask, Danny, have you experimented with using brass mounting screws, in lieu of typical steel ones?  I've read a number of times of recommendations to replace all the standard steel (and magnetic) mounting screws with brass screws for everthing from tweeters to the main LF drivers.  Also, all torqued down to the same 20 to 30 inch pounds.

Thx
Kenreau

[Danny Richie]

Seeing this thread pop up reminds me to ask, Danny, have you experimented with using brass mounting screws, in lieu of typical steel ones?  I've read a number of times of recommendations to replace all the standard steel (and magnetic) mounting screws with brass screws for everthing from tweeters to the main LF drivers.  Also, all torqued down to the same 20 to 30 inch pounds.

Thx
Kenreau

I have heard of people doing things like that. Keep in mind this is also a really heavy cast frame on a 36 pound driver. So I don't really see the screws having a real effect.

[PDR]

Ok, since were asking PAudio questions......

What is the big rubber ring around the magnet of the PAudio on the Super V for....
The driver that came with my V1 didnt have it.....

[Danny Richie]

Ok, since were asking PAudio questions......

What is the big rubber ring around the magnet of the PAudio on the Super V for....
The driver that came with my V1 didnt have it.....

I don't know.

[minisq]

Ok, since were asking PAudio questions......

What is the big rubber ring around the magnet of the PAudio on the Super V for....
The driver that came with my V1 didnt have it.....

I think in general  they are designed to protect the magnet...and possibly improve cosmetics if the magnet is rusty or unpolished. I always remove them before installation.

[kenreau]

This video illustrates using the brass screws and torquing process I was referring to.  Seems to make sense.

Oddiophile Ep 5 Brass Screws Part 2

http://www.youtube.com/watch?v=qhlDrLKBmXA
 

[bdp24]

So THAT'S what Ric looks like. I've spoken with him on the phone many times, back when I was having him modify my Audible Illusions pre-amp. Tweakus Supremus!

[Danny Richie]

Funny how he talks about baffle resonances. If there is a difference is how much a brass screw will transmit a resonance to a baffle compared to a steel screw, imagine the difference between a steel frame verses the polymer frame used with all of our small woofers. 

I am not dismissing the effect of the screws, but the gasket will have a much greater effect.

As far as being ferous who knows. In most cases the screws are too far enough away to have any effect on the driver.

I got a kick out of seeing the speaker that he was demonstrating it on. The lower limit of the frequency range of that tweeter is about 2.5kHz. So it is important that the acoustic centers of the drivers be as close as possible for the drivers to blend well, but the loudspeaker designer decided to space them very far apart. You'd think that with drivers that expensive the designer wouldn't want to make such obvious engineering errors that will have a detrimental effect like that.    I'd be much more concerned with that than the screws.

[kenreau]

...I am not dismissing the effect of the screws, but the gasket will have a much greater effect.

As far as being ferous who knows. In most cases the screws are too far enough away to have any effect on the driver.

Yeah, I was wondering about the same issues.  For the mounting gaskets, do you preferer to use something with vibration dampening?  or acoustically dead, like a putty?  Just a rubber washer ring doesn't seem ideal.  And, should a gasket material differ for a tweeter vs a subwoofer?

I got a kick out of seeing the speaker that he was demonstrating it on. The lower limit of the frequency range of that tweeter is about 2.5kHz. So it is important that the acoustic centers of the drivers be as close as possible for the drivers to blend well, but the loudspeaker designer decided to space them very far apart. You'd think that with drivers that expensive the designer wouldn't want to make such obvious engineering errors that will have a detrimental effect like that.    I'd be much more concerned with that than the screws.

Good point.  I do like the Verity box designs of mostly non-parallel walls, but they are sure expensive speakers for what appears to be off the shelf drivers, etc.

For torquing consistency, I remember Bobby P. at Merlin say he used a Mikata portable drill with the clutch chuck set to a minium value (can't remember the inch pounds).   Those precision small value torgue wrenches can get spendy.

Thx
Kenreau

[bdp24]

Funny how he talks about baffle resonances. If there is a difference is how much a brass screw will transmit a resonance to a baffle compared to a steel screw, imagine the difference between a steel frame verses the polymer frame used with all of our small woofers.  :green:

I am not dismissing the effect of the screws, but the gasket will have a much greater effect.

As far as being ferous who knows. In most cases the screws are too far enough away to have any effect on the driver.

I got a kick out of seeing the speaker that he was demonstrating it on. The lower limit of the frequency range of that tweeter is about 2.5kHz. So it is important that the acoustic centers of the drivers be as close as possible for the drivers to blend well, but the loudspeaker designer decided to space them very far apart. You'd think that with drivers that expensive the designer wouldn't want to make such obvious engineering errors that will have a detrimental effect like that.  :scratch:  I'd be much more concerned with that than the screws.

Really good points Danny. Getting the speaker 99% of the way to it's best sound with good engineering before worrying about the last 1% with tweaks. By the way Danny, you probably are already aware of this, but Ric Schultz is offering your new speaker design using the Neo midrange and tweeter drivers with the OB ServoSubs, in custom cabinetry he has done in his area. What surprised me when seeing it on his website, was that in the product description there was no disclosure of intellectual property of the speaker. No, Ric didn't claim credit for designing it, but he didn't credit you for having done so either, giving the impression that it was proprietary. Intellectual honesty? No offense intended Ric! I have a lot of respect for you, and you deserve credit for what you have done. I'm just sayin'!

[Danny Richie]

Really good points Danny. Getting the speaker 99% of the way to it's best sound with good engineering before worrying about the last 1% with tweaks. By the way Danny, you probably are already aware of this, but Ric Schultz is offering your new speaker design using the Neo midrange and tweeter drivers with the OB ServoSubs, in custom cabinetry he has done in his area. What surprised me when seeing it on his website, was that in the product description there was no disclosure of intellectual property of the speaker. No, Ric didn't claim credit for designing it, but he didn't credit you for having done so either, giving the impression that it was proprietary. Intellectual honesty? No offense intended Ric! I have a lot of respect for you, and you deserve credit for what you have done. I'm just sayin'!

That's not a design of mine. That's his design. He is just purchasing the drivers from me. And I hope he sells a lot of them.

[Danny Richie]

For the mounting gaskets, do you preferer to use something with vibration dampening?  or acoustically dead, like a putty?  Just a rubber washer ring doesn't seem ideal.  And, should a gasket material differ for a tweeter vs a subwoofer?

I like softer foam gaskets on lighter weight and high frequency drivers.

I like a harder gaskets for lower frequency or heavy drivers. Anything that is compressed between the drivers will break up or minimize any resonance being transmitted to the baffle. Most really low frequency drivers or subs don't play up into the resonance frequency range of the baffle (the resonance of the baffle is higher than the woofer play) so good stability and a strong rigid structure is important. 

Our polymer framed woofers use a fairly thin foam gasket for sealing. There is no frame ringing or resonance to begin with from them.

For torquing consistency, I remember Bobby P. at Merlin say he used a Mikata portable drill with the clutch chuck set to a minium value (can't remember the inch pounds).   Those precision small value torgue wrenches can get spendy.

I do the same as well. A cordless with an adjustable clutch setting.

[bdp24]

That's not a design of mine. That's his design. He is just purchasing the drivers from me. And I hope he sells a lot of them.

I stand corrected  !

[Jonathon Janusz]

Danny, not getting into a better/worse debate about another designer's product, but considering I'm sure you've tried the arrangement of servo subs in Ric's design before, I think you could answer this question better than most.

Arranging the servo subs on a flat baffle (like Ric has done), in comparison to the h-frame of the S7/V1/SV, I'm guessing the difference in performance between the two is that the flat baffle of appropriate size would allow the woofers to play flat down to around 20Hz (as Ric quotes on his website), while the h-frame reenforces them to get down into the teens, with the flat baffle maybe playing a little cleaner due to the complete lack of any possible (minimal? unobservable? hypothetical?) coloration from the sides of the h-frame?

Another semi-related question - using the drivers on a shared baffle as Ric has, in comparison to the S7, would supporting the upper drivers on the edges of the baffle/woofer frame (S7) theoretically reduce vibrations transmitted from the woofers to the upper drivers more effectively than the drivers all sharing a common baffle (Ric's design)?  I know that in any case one is most likely spitting hairs in debate, and I know that folks around here have talked before about the common baffle design being more "aesthetically marketable" regardless of sonic performance differences, but I'm curious to know if I've got the ideas about right?

. . . I'm sure Ric's design is a fine speaker and looks to be at a nice price point. . .  How about some of the follow up models to the S7 from Serenity Acoustics to stir up some friendly competition?  

[Danny Richie]

Obviously the flat baffle arrangement of the subs gives up a lot of low end reinforcement and SPL in the lower region. And if the H frame is of sufficient thickness then panels resonances are not much of an issue.

There is a ton of detail I could go into about the baffle and I have learned a lot about the baffle design for the Neo drivers. They are very sensitivity to baffle design in many ways. I'd rather not discuss it too much though as I am designing products for a company that is using what I have designed.

[Ric Schultz]

Will the real Ric(K) Schultz please stand up!  he he.  There are two Ric Schultz's in high end audio.  The one on the video is Rick Schultz, formerly of Virtual Dynamics.  He now has a new interconnect ($1600) that uses patented magnetic goodies on it.  The other Ric Schultz (me) is the tweakaudio guy.  We both love brass screws and torque wrenches.  Comes with the name.

About the baffle vibration thing: I have always known that it is absolutely best to decouple the mids/highs from the vibrating woofs.  But, as you say....not always good WAF or HAF.  The speaker on my site now has its head cut off.  I am building baffles to test the various amounts of drivers (1 neo 10 and 1 neo 3; 2 10s and 6 3s; 4 10s and 12 3s; and 6 10s and 16 3s).  These baffles will have their own bottom and rest on a shelf on top of the woofs.  I will be experimenting with isolating these baffles as well as moving the baffles backwards to see if time aligning with the woofs is audible or you can just compensate for the time difference with the phase control on the servo woofs.  My all out speakers use separate baffles for the woofs so then there is no issue about bass vibrations smearing the mids/highs.

I am sure that an H-frame will give slightly more and slightly lower distortion lower bass.  Its simply a bigger baffle.  A bigger baffle means the driver does not have to move as much to make lower frequencies.  But is this small difference really that important.....and to whom? 

[persisting1]

Is there a link to the speakers using Danny's drivers?

[stevenkelby]

Is there a link to the speakers using Danny's drivers?

http://www.tweakaudio.com/EVS-2/OPEN_BAFFLE_SPEAKERS.html