I think the build and listen in a good call. The 10f was tested for power handling by Zaph and even at 400hz LR2, it can handle gobs of power……thermal power compression is the only enemy. I’d play around a bit and see where it takes you…..you can always add a tweeter later
You don't even need to mod it for this. Has worked just fine in the Protones https://github.com/Ponkala/audiopoli-protone/wiki
OH, haha! I used the B&G Neo3 with the NEW123 in a 2 way. I tried the GR planar as well and some samples were good, others not very (bumpy response or high distortion). I had to buy 4-6 to get a well matched pair with expected response. It's obvious why the B&G originals were becoming expensive - much like the original Quad ESLs they probably fail over 50% and send them back for re-skinning the film.
Too easily, I dropped a butterfly accidentally while dismounting the front plate. Take care.
If I planned to use DSP crossover, I wouldn't sweat 1.5 khz either, but I need to go passive. End users want to use the new Wiim Amp, ordered at my recommendation. That + Qobuz + these speakers + 65" LG OLED + streaming video will be their AV entertainment system. To replace a lousy soundbar & various google speakers. Neighbor friends who ventured into my studio to see/hear my audio projects a while ago.
Agreed. The 4 screws thread in only a few turns, and there's very little friction to hold the dome/coil in place when the faceplate comes off. I used a tiny drop of crazy glue to hold it more firmly -- still pulls off easily but stays put otherwise.
I tried putting a small piece of foam in the cavity. FS dropped from 590 Hz to 570, impedance peak from 6 to 5 ohms. Didn't measure FR -- want rebated baffle for that.
It's tricky to experiment with damping w/o opening up the back. Removing the front & dome assembly multiple times invites an accident. If the back was open, it'd be a lot easier, though I'd then need to devise a new easily opened/closed bigger cover.
Need to invite @Patrick Bateman to post pics & details of the metamaterial & how he applied it to his sb26. He said it transformed the sound of the sb26.
OK, so here's where @Patrick Bateman posted STL files of the metamaterial block he made for the SB26ADC -- probably usable with any SB26:
I took that over to my local FabLab & they had a close look at the file. The device looks maybe 2" tall, like a cylindrical extension of the magnet. It has 2 layers or "floors" of a circular maze-like pattern of channels with different lengths. The anticipated weight is ~85 grams. They will have one for me next week. If that one turns out ok -- and gives me the desired results -- I'll get a second one printed.
A good xmas surprise gift. 🙂 Thanks PB!
I took that over to my local FabLab & they had a close look at the file. The device looks maybe 2" tall, like a cylindrical extension of the magnet. It has 2 layers or "floors" of a circular maze-like pattern of channels with different lengths. The anticipated weight is ~85 grams. They will have one for me next week. If that one turns out ok -- and gives me the desired results -- I'll get a second one printed.
A good xmas surprise gift. 🙂 Thanks PB!
So the @Patrick Bateman meta-block for the sb26adc got finished yesterday. From the backside, it looks a lot like an ice hockey puck.
From the other side...
There are 4 rectangular holes in the cylindrical hollow, a pair lower, a pair higher, that lead into the maze-like channels within. At the bottom of the cylindrical hollow, PB has replicated the conical deflector of the original back cover.
Overall inside diameter (inside the perimeter lip) seems a touch bigger than that of the magnet. I think all of the original plastic end cap has to be removed. Based on PB's comments and my initial poking, this is likely to be a PITA.
Pic above shows the tweeter, the @Patrick Bateman meta-puck, and the 6" @augerpro waveguide I had made a while ago. Neither of these mods would be possible without the efforts of these outstanding DIY audio members: thank you both!
I'm hoping the combo will give me a tweeter that can be crossed as low as 1500 Hz 2nd order while maintaining excellent dispersion to 10khz & extension to 20khz. Ie, a tweeter that's near-unobtainium. 🤞🤞
I will try to accurately record & report my findings.
From the other side...
There are 4 rectangular holes in the cylindrical hollow, a pair lower, a pair higher, that lead into the maze-like channels within. At the bottom of the cylindrical hollow, PB has replicated the conical deflector of the original back cover.
Overall inside diameter (inside the perimeter lip) seems a touch bigger than that of the magnet. I think all of the original plastic end cap has to be removed. Based on PB's comments and my initial poking, this is likely to be a PITA.
Pic above shows the tweeter, the @Patrick Bateman meta-puck, and the 6" @augerpro waveguide I had made a while ago. Neither of these mods would be possible without the efforts of these outstanding DIY audio members: thank you both!
I'm hoping the combo will give me a tweeter that can be crossed as low as 1500 Hz 2nd order while maintaining excellent dispersion to 10khz & extension to 20khz. Ie, a tweeter that's near-unobtainium. 🤞🤞
I will try to accurately record & report my findings.
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Oh the back chamber comes off in about twenty seconds. I used a hand saw and it went through it like butter.
I used a Japanese hand saw that I bought from Home Depot, it's one of my favorite tools.
I think that a conventional hand saw is probably too blunt/inaccurate, and a hack saw might use a blade that has teeth that are too small to really cut through it quickly. Japanese hand saw is just about perfect.
I used a Japanese hand saw that I bought from Home Depot, it's one of my favorite tools.
I think that a conventional hand saw is probably too blunt/inaccurate, and a hack saw might use a blade that has teeth that are too small to really cut through it quickly. Japanese hand saw is just about perfect.
Since I was in the hacking mode with the Yamaha 3" BE dome from the NS1000 and had the @Patrick Bateman meta-puck in hand, I kept going.
I have one of those Jap saws from Lee Valley that I've never used before. Used it. Cut the back away. Stuffed a bit of sponge to approximate what KEF said they do with their meta coax. Used double-side tape to stick the puck to the opened back of the SB26.
No time for FR or other acoustic measurements but the DATS results are significant.
Stock SB26ADC:
With Patrick's meta-puck absorber:
Fs dropped from 590 to 405 Hz. No significant change in amplitude.
This SHOULD allow safe, low distortion operation to a lower frequency.
I'd love to get FR tests done quickly, esp the with @augerpro 6" waveguide I have on hand... but busy couple days and a little trip away. Might not get a chance for a week.
I have one of those Jap saws from Lee Valley that I've never used before. Used it. Cut the back away. Stuffed a bit of sponge to approximate what KEF said they do with their meta coax. Used double-side tape to stick the puck to the opened back of the SB26.
No time for FR or other acoustic measurements but the DATS results are significant.
Stock SB26ADC:
With Patrick's meta-puck absorber:
Fs dropped from 590 to 405 Hz. No significant change in amplitude.
This SHOULD allow safe, low distortion operation to a lower frequency.
I'd love to get FR tests done quickly, esp the with @augerpro 6" waveguide I have on hand... but busy couple days and a little trip away. Might not get a chance for a week.
Loving the thread.
I wonder what that graph would look like if the chamber was stuffed more like how scan-speak does it with (what appears to be) wool felt:
https://www.diymobileaudio.com/threads/scan-speak-d3004-grill-removal.82182/
https://www.diymobileaudio.com/thre...-speak-illuminator-d2004-60200-tweeter.62171/
I wonder what that graph would look like if the chamber was stuffed more like how scan-speak does it with (what appears to be) wool felt:
https://www.diymobileaudio.com/threads/scan-speak-d3004-grill-removal.82182/
https://www.diymobileaudio.com/thre...-speak-illuminator-d2004-60200-tweeter.62171/
Glad you're enjoying. 😉
I tried teased long lamb hair in the cylindrical chamber of a Yamaha JA0801 3" BE dome here and it made no appreciable difference vs poly fiber. But this was with the relatively huge volume of a 12" tall traffic cone for a back. I doubt thick felt would be useful -- too much reflection & absorption before the meta-chamber, imho. Might try a little ball of lamb hair later.
This meta-puck did not do anything good on the JA0801, btw. Too small, methinks, or maybe wrong resonant frequencies. Need to get @Patrick Bateman to tell the specs of the puck.
Got it, I agree it would take away from the impact of the chambers. I'm thinking about seeing what Scanspeak-style stuffing does to one of my SB26CDC's I have on hand.
I see a lot of secondary resonances in the measurement with the ‘meta-absorber’. What would imply that some strange things are happening, maybe noticeable, maybe not.
@GreatLaBroski -- forgot to mention, the stock back was filled with that type of felt already. My Japanese saw split it in half when I cut the back cap.
@markbakk -- I realize the seal between the meta-absorber & the tweeter might not have been complete because the double sided tape was partly on the felt. This might be responsible for those secondary resonances. Will try sealing it tighter with tape & run DATS again. For permanent installation, will scrape the remaining felt off the magnet before using adhesive.
@markbakk -- I realize the seal between the meta-absorber & the tweeter might not have been complete because the double sided tape was partly on the felt. This might be responsible for those secondary resonances. Will try sealing it tighter with tape & run DATS again. For permanent installation, will scrape the remaining felt off the magnet before using adhesive.
I would use blue tack putty to seal it, then wrap electric tape around the outside to fasten everything together.
Can you post that absorber here?
Can you post that absorber here?