Welcome, Guest. Please Login or Register
Decware Audio Forums
01/31/23 at 00:53:24 




Pages: 1
Send Topic Print
Who's a doper? (Read 6933 times)
Donnie
Global Moderator
*****


Why does it hurt
when I pee?

Posts: 2127
Who's a doper?
05/29/17 at 23:51:11
 
Has anyone ever doped a speaker driver?
I've never really known how or when to do it, or what to use.
Any ideas or comments are appreciated.
What did you think I was asking about?
Back to top
 
 

Owner of the infamous RED TORII and Dan the Redheaded Amp
  IP Logged
pursuitofnow
Seasoned Member
****




Posts: 412
Re: Who's a doper?
Reply #1 - 05/30/17 at 03:21:48
 
I've had it done on guitar speakers from weber. Personally I'm not a fan of it. Seemed to add a veil over the sound to my ears when compared to a speaker without it. I prefer without for a more transparent tone. It's claimed to smooth treble for distortion and I prefer clean undamped tones.

Sorry I can't add anything as to how doping my contribute to hifi audio other than dampening at higher volumes.
Back to top
 
 

VPI Classic Signature | ZP3 | ZSTAGE
DirectStream DAC | ZTPRE
ZBIT | ZROCK2 | SE84UFO3
Omega Super 3 HO XRS | Deep 8
Zenwave D4 | SCR-11 | PI Audio Uberbuss
  IP Logged
Lonely Raven
Seasoned Member
****


Jack of all Trades,
Master of None

Posts: 3563
Re: Who's a doper?
Reply #2 - 05/30/17 at 23:41:44
 
Oddly enough, that's my answer as well, even down to the same brand of speakers. Smiley  We dope guitar speakers (which is basically painting the cone with a thinned down medium of some sort) to lower their FS, smooth treble, help with cone twisting or some such.

Since you're basically coating a paper cone with watered down varnish (or whatever medium), it's not always predictable what you're going to get.

Not something I'd do to precision audio speakers that you would normally want light and fast.
Back to top
 
 
WWW Lonely Raven   IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 5858
Re: Who's a doper?
Reply #3 - 05/31/17 at 02:27:00
 
I've smoked several speakers in my day, does that count?

Steve
Back to top
 
 
WWW   IP Logged
maddog07
Seasoned Member
****


seeker of truth

Posts: 575
Re: Who's a doper?
Reply #4 - 05/31/17 at 22:52:48
 
smoking rope...!!!!
Back to top
 
 

Decware Torii MK3, Wyred4Sound DAC2, Theta Digital Miles, Emotiva XMC-1, Emotiva XPA-5, Aesthetix Calypso, Wyred STP-SE, Martin Logan Vista, Audio Nirvana 12" Alnico's, PS Audio PW P5, Goertz, Kimber, Nordost and DIY wires, PSA pwr cords, Cary SLI-80, DM945's.....
  IP Logged
maddog07
Seasoned Member
****


seeker of truth

Posts: 575
Re: Who's a doper?
Reply #5 - 05/31/17 at 22:56:05
 
I have known folks to use rope caulk on passive radiators to tune the bass response of a BR speaker.... but I don't think I'd mess around with adding mass to the cone of an active driver... unless you can figure out some way to do it that's "reversible".
Back to top
 
 

Decware Torii MK3, Wyred4Sound DAC2, Theta Digital Miles, Emotiva XMC-1, Emotiva XPA-5, Aesthetix Calypso, Wyred STP-SE, Martin Logan Vista, Audio Nirvana 12" Alnico's, PS Audio PW P5, Goertz, Kimber, Nordost and DIY wires, PSA pwr cords, Cary SLI-80, DM945's.....
  IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 5858
Re: Who's a doper?
Reply #6 - 06/01/17 at 03:44:20
 
After experimenting with varnishes and various coatings and painting little patterns on a variety of cones, I found poly-acrylic to have the best results when mixed with water to a milk like consistency.  This would be for paper cones.  Poly cones don't need or really benefit from it in my experience.  Fiberglass, Kevlar, Ceramic and Aluminum cones are about high SPL with low distortion not about timber so there is no point to ever coat one.

We still treat our modified Fostex cones in this manner, but mostly for longevity and consistency. It does add a moisture barrier to the cone which protects it from direct contact moisture and adds to it's strength, but the effect is subtle.

The real attraction to varnishes and doping the cone was to reduce cone breakup caused by modal resonances across the surface of the cone causing peaky / distorted / itchy response.

Sadly not one time did I find any of the varnishes to help the sound.  They pushed back the breakup a dB or two at the expense of a plastic aftertaste over the sound.

I found somewhat by accident during the development of our DFR8 full range modified Fostex driver, that when placing a convex polyether foam surround glued over a concave breathable cloth surround that model resonances were pushed back almost 6 dB.  Turns out the air space between the surrounds combined with the breathable membrane of the inside surround creates a pretty nice diaphragmatic absorber turning the model resonance into heat.

That is the problem with model resonance / cone breakup.  Once the energy reaches the point of modality it has nowhere to go except back into the cone as it tries to rip the fibers apart to expend itself... unless you have a broadband absorber around it's circumference such as the case with our DFR8.

The beauty of this approach is obvious, but less obvious is that the added foam surround is supported by the frame so the mass of the cone is untouched and the overall moving mass is barely changed.  Efficiency of the driver does not change.

That's about all I know about it, except to say that no coating or doping will work like this does.

Interestingly, the first FRX drivers I made this way and later found out it did almost nothing because the FRX drivers use a slick trick of absorbing the excess energy while it is still forming in the voice coil and turns it into heat electromagnetically.

So that's the two completely different but equally effective ways I have found best to deal with cone distortions.

Steve
Back to top
 
 
WWW   IP Logged
Lonely Raven
Seasoned Member
****


Jack of all Trades,
Master of None

Posts: 3563
Re: Who's a doper?
Reply #7 - 06/01/17 at 17:27:51
 
Quote:
The real attraction to varnishes and doping the cone was to reduce cone breakup caused by modal resonances across the surface of the cone causing peaky / distorted / itchy response.


That's what I was trying to remember. I knew it had something to do with the cone itself resonating or twisting.
Back to top
 
 
WWW Lonely Raven   IP Logged
Donnie
Global Moderator
*****


Why does it hurt
when I pee?

Posts: 2127
Re: Who's a doper?
Reply #8 - 06/01/17 at 22:46:08
 
Thanks Steve, I seemed to remember reading in some of your white papers about doing this.
Speaking of the white papers, I think that I have read most if not all of them over the last 5 or so years. They are always thought provoking.
But back to the doping, I know that I have seen various drivers with patterns doped on them and I just wondered it it was just advanced "salesmanship" or if it truly worked.
What started me really thinking about it lately was reading a review of Ed Schilling's Horns and it said that he doped his drivers. While I know that Ed is a mad dog(not saying that is a bad thing), I do understand that his speakers are pretty good in the bang for your buck arena.
So I just thought that I would ask around about it.
Back to top
 
 

Owner of the infamous RED TORII and Dan the Redheaded Amp
  IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 5858
Re: Who's a doper?
Reply #9 - 06/02/17 at 06:10:48
 
I think in the late 90's early 2000's there was a consciousness shift among those who can hear... towards the unrestrained raw sound of a single voice coil with no crossover combined with low mass aka high speed.  Despite it's limitations, it clearly delivers twice or three times the information.  

The first time you hear this, it's a wow moment.  The wow can overpower the ragged edges and tipped response for almost anyone the first several times you cross paths with it.  That in and of itself can create a real enthusiasm for any speaker that attempts reasonably successfully to hit that goal.  

The true test is the same as with amplifiers or anything else in the chain... time.  How long is it fully intoxicating, mind bendingly distracting and euphorically inclined...  Weeks?  Years?  Decades.

The easiest path to success when dealing with a single 4 inch driver is a 15 inch driver near by for moral support.


I may as well expound a little bit since this is a thread about damping the cone which is to say make it sound less offensive...  

A. The Lowther Shout, a somewhat unfair label, is not from the whizzer cone.  
B. The Shout from Fostex or any other driver of similar low mass and efficiency is mostly from the cabinet.
C. Loudspeakers have to be designed completely differently for low mass cones.  
D. Open Baffle , ie. box less speakers let you hear what the driver actually sounds like from 80Hz on up on average in small baffles and 40 Hz in larger baffles.

It is the simple fact that because the cone is so thin, you hear EVERYTHING inside the box as if you had a microphone hanging inside the enclosure.  (Which I have done BTW)

If you don't go with open baffle, you will have to create an exquisite design to handle the back wave so that it does not reflect back through the cone anywhere in the harmonic decay which can be seconds.

Of course with open baffle you have no low bass and no box bloat from overly simple reflex enclosures.  

The more I watch the popularity of open baffles here around Decware and elsewhere, my spider senses are telling me that the dual 15 support for a single 8 inch full range driver as demonstrated by Pure Audio Project is the ultimate balance of tradeoffs and frankly if Decware were producing an Open Baffle Speaker other than the ZOB, this would probably be the approach we would pursue.

I can only imagine how good an FRX2 driver might sound in a similar open baffle design in place of the lowther.

And that brings me to a sudden reality check.  Randy's Open Baffle Speakes using that magical 8 inch drivers of his for $500.00 is still the champion of diminishing returns.  What I'm talking about would be easily twice as good in many but not all ways, yet cost 10 to 20 times as much.





Back to top
 
 
WWW   IP Logged
maddog07
Seasoned Member
****


seeker of truth

Posts: 575
Re: Who's a doper?
Reply #10 - 06/02/17 at 22:12:55
 
OB Betsy's paired with 1 to 4 fifteen inch Augie's, Torii on the Betsy's, pick your favorite sand amp for the Augie's, has taken me to a place that I'd never been to before in my home listening room.  Maybe never heard anywhere before, at any price.  
The amount of "churn" in my system is the lowest it's every been in over 40 years... which is a sure sign of sonic satisfaction and contentment.  
Now my audio stress is all about computer audio, streaming and what DAC should I get.  I think Steve is currently answering this question - at least for awhile - the Teac NT-503/ZBIT combo.
What the Zen Master has described about passing the signal through three transformers and the sound getting subjectively better with each transformer... also makes sense to me from a scientific and logical perspective - as long as the transformers are good.  The transformers are filtering off high frequency hash and "smoothing" the sound.....
Back to top
 
 

Decware Torii MK3, Wyred4Sound DAC2, Theta Digital Miles, Emotiva XMC-1, Emotiva XPA-5, Aesthetix Calypso, Wyred STP-SE, Martin Logan Vista, Audio Nirvana 12" Alnico's, PS Audio PW P5, Goertz, Kimber, Nordost and DIY wires, PSA pwr cords, Cary SLI-80, DM945's.....
  IP Logged
Donnie
Global Moderator
*****


Why does it hurt
when I pee?

Posts: 2127
Re: Who's a doper?
Reply #11 - 06/03/17 at 00:41:16
 
Thanks again Steve, your insights are always enlightening.
Now you have me wondering if I should pony up the cash for a pair of FRX2 drivers for my OB design.
The Tang-Bands that I'm currently using aren't too dog gone bad, but if there could be a improvement....
My design is kind of out of left field compared to everyone else's, and seems to have turned out pretty good without me really knowing what I was doing. But now I'm wondering what would happen with different drivers, that is true salesmanship, hitting me with pure logic, lol.
Back to top
 
 

Owner of the infamous RED TORII and Dan the Redheaded Amp
  IP Logged
Pages: 1
Send Topic Print