Scan-Speek 4" for 49 cents?

[Wolf]

Re: Scan-Speek 4" for 49 cents?

Don't break out the Elmer's just yet...



Blue is raw cone, Red is wood glue

There is a bit of peak suppression, but the bad news is that the only distortion that improved is 2nd order. All other distortions were slightly worse than stock at all frequencies. Sound quality is unpleasant.

FS dropped from 115 to 114 and Qes stayed the same. Interesting that Qms increased from 4.59 to 6.18. This Qms increase was not seen in any other damping method.

I would think that you would want a more brittle glue to stiffen the cone. I was actually hoping for a more pronounced break-up, knowing I could get rid of it later with slits. Maybe a superglue-coated cone?

The old methods that came out of the NSB threads were a 1/4" hole in the cone, and coating the cone in a lacquer-clear- for the SIMPLE ones anyway.
Some people slit the spider too....
Later,
Wolf

[caleb]

Re: Scan-Speek 4" for 49 cents?

Put that driver in the sun to bake. If you want to stiffen use lacquer or shellac but it will take some time to fully cure. You could always use an ultra hold hairspray and a blow dryer for quick results.

[jbruner]

Re: Scan-Speek 4" for 49 cents?

I would expect that Sample 3 will be in the "pretty nice midrange" territory now. Tweeter mandatory.

Don't break out the Elmer's just yet...



Blue is raw cone, Red is wood glue

There is a bit of peak suppression, but the bad news is that the only distortion that improved is 2nd order. All other distortions were slightly worse than stock at all frequencies. Sound quality is unpleasant.

FS dropped from 115 to 114 and Qes stayed the same. Interesting that Qms increased from 4.59 to 6.18. This Qms increase was not seen in any other damping method.

I would think that you would want a more brittle glue to stiffen the cone. I was actually hoping for a more pronounced break-up, knowing I could get rid of it later with slits. Maybe a superglue-coated cone?

[J Fallows]

Re: Scan-Speek 4" for 49 cents?

I would expect that Sample 3 will be in the "pretty nice midrange" territory now. Tweeter mandatory.

[caleb]

Re: Scan-Speek 4" for 49 cents?

Well you already said the edge treatment didn't change things much. As for the wood glue treated, I would guess the the first signs of breakup maybe pushed down to 5k and spread out 3 db lower as well as to top end rolling off quicker. I doubt the thick stripes of flexible glue will be nearly as effective as the slits.

[jbruner]

Re: Scan-Speek 4" for 49 cents?

How thick did you apply the wood glue did you thin it with water?

Full strength, went on pretty thick in one coat.

[caleb]

Re: Scan-Speek 4" for 49 cents?

How thick did you apply the wood glue did you thin it with water?

[jbruner]

Re: Scan-Speek 4" for 49 cents?

I'll post the test results for samples 3 and 4 tomorrow.

First, I'd like to see some predictions from the audience.(SQ, breakup changes?)

Sample 3- (no dust cap) unblemished cone coated with wood glue.



Sample 4- Flexible glue at surround/cone edge only.
Sample 4- Uncut cone with thick stripes of flexible glue in the same positions as the slit cone, along with the cone edge treatment.

Pic shows glue still wet-it dried clear.

[ernperkins]

Re: Scan-Speek 4" for 49 cents?

All of this reminds me of the EnABL process that has been kicking around diyaudio for a long time. Here's a link to a diyaudio thread that explains the process:

http://www.diyaudio.com/forums/full-...-speakers.html

[dlr]

Re: Scan-Speek 4" for 49 cents?

I think these could be worth a try:

[ATTACH=CONFIG]46628[/ATTACH]

They might work. My thought back then was that for the dots, it was more a case of added mass than any damping effects. This would alter the resonances in the cone. It took surprisingly few.

dlr

[thekorvers]

Re: Scan-Speek 4" for 49 cents?

[ATTACH=CONFIG]46626[/ATTACH]


dlr

Cool, a speaker with freckles! I would be more likely to try something like this without destroying the cone. At least it is modifiable and reversible.

[killa]

Re: Scan-Speek 4" for 49 cents?

Why? The response of the ER18RNX is already quite smooth whereas the NSB was anything but.

Why. Because I can. I am willing to bet the revelators would still be smooth without the slits. Perhaps in the case of the revalators it is a marketing tactic to drive up the price :eek: While they are great drivers the slit cone may not be the reason. If it is these slits might also improve the seas driver.

[Tin_Ears]

Re: Scan-Speek 4" for 49 cents?

I think these could be worth a try:

[ATTACH=CONFIG]46628[/ATTACH]

I was thinking the same thing only with various round foam stickies and foam tape.

[fatmarley]

Re: Scan-Speek 4" for 49 cents?

Try this as a test. These are small bits of a non-drying putty of some kind.

[ATTACH=CONFIG]46626[/ATTACH]
This is a KEF (Celestion) F15 driver in a 2-way. I tried a lot of variations, but never slit the cone. I didn't want to risk destroying it, though I was very interested in the SS technique. I tried it and a couple of variations of added damping material. The result was actually fairly good, but the arrangement above was the best result in what I tested.

[ATTACH=CONFIG]46627[/ATTACH]

The best single improvement was with the application of the damping at the inner edge of the surround, in the case it is "The Wet Look" purchased from PE. Took several applications (same thing when I modded other drivers). This is the same thing that a lot manufacturers do, SS included. They had (still have?) a small bottle now that is something like $5. Well worth it for experimenting and I suspect far better for damping than silicon caulk or similar. The full set of tests (SPL, no distortion) are described at the link.

KEF driver tests

dlr

I think these could be worth a try:

[Pete Schumacher]

Re: Scan-Speek 4" for 49 cents?

hmm. I have a couple er18rnx that have been sitting around for a while. If I could find a way to accurately cut the slits I would try it.

Why? The response of the ER18RNX is already quite smooth whereas the NSB was anything but.