Eminence Beta. I have samples of a GRS which is very similar.
https://www.diyaudio.com/community/threads/grs-15-on-open-baffle.184606/
GRS 15PF?
One guys sez the measurements differ from specs.
Excited to see the test results. VERY price competitive
that's are similar to alpha not what Nelson like ....around 0,5Qtshttps://www.diyaudio.com/community/threads/grs-15-on-open-baffle.184606/
GRS 15PF?
One guys sez the measurements differ from specs.
Excited to see the test results. VERY price competitive
like https://www.soundimports.eu/en/grs-15pt-8.html copper ring
15PT as I recall. It's in storage or I would go look.
I hesitate to ask, but what is the SMALLEST SLOB people have made?
I'm contemplating two competing designs for a VERY PORTABLE "sub" to go with something called TDK I'M A SPEAKER CD-case (planar sound down to ~200hz). The 5" bass drivers I have are pancake-thin (well, a stack) and featherweight, with big coils, and (I was told) came from something very, very expensive (they sound like it). So a foldable SLOB? The alternative is to copy tiny Bose M3 which uses a pair of facing passive radiators slot-loaded. The (double-size) zip-open-flat CD cases would carry the "subs" and possibly Class D amps instead of CD pouches. 😏
Are there "physics" lower limits on SLOB size?
TDK I'm A Speaker https://www.amazon.com/TDK-Speaker-Blue-Speakers-PSCDSB24AX/dp/B0000A2XTM
5" pancakes
And for reference, Bose M3:
I'm contemplating two competing designs for a VERY PORTABLE "sub" to go with something called TDK I'M A SPEAKER CD-case (planar sound down to ~200hz). The 5" bass drivers I have are pancake-thin (well, a stack) and featherweight, with big coils, and (I was told) came from something very, very expensive (they sound like it). So a foldable SLOB? The alternative is to copy tiny Bose M3 which uses a pair of facing passive radiators slot-loaded. The (double-size) zip-open-flat CD cases would carry the "subs" and possibly Class D amps instead of CD pouches. 😏
Are there "physics" lower limits on SLOB size?
TDK I'm A Speaker https://www.amazon.com/TDK-Speaker-Blue-Speakers-PSCDSB24AX/dp/B0000A2XTM
5" pancakes
And for reference, Bose M3:
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The size of the SLOB , or any “open baffle” speaker is the most important thing that determines how low the low notes in music will go, and to make it better, the SLOB has a huge bass driver mounted in the bottom…
A panel the size you are suggesting isn’t going to do much. However the panel doesn’t have to be exceptionally strong to function somewhat. You can mount your speakers in (folding?) panel made of corrugated cardboard or foam core to see how it works.
A panel the size you are suggesting isn’t going to do much. However the panel doesn’t have to be exceptionally strong to function somewhat. You can mount your speakers in (folding?) panel made of corrugated cardboard or foam core to see how it works.
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More work on my SLOB project over the weekend and the bass section is almost ready for finishing, just a little trim to add.
I've also cut the baffles but that has generated a question; the piece of 18mm birch ply I had available wasn't quite long enough so my baffles are the specified width (20ins) but a little shorter than specified at 37ins (instead of 40ins) - is this likely to be an issue?
The 18mm birch ply was a 74in x 26in offcut, purchased from a local ebay seller for the princely sum of about $12 - too good a bargain to pass on - pun intended.😊
Apologies for the mixed units...
I've also cut the baffles but that has generated a question; the piece of 18mm birch ply I had available wasn't quite long enough so my baffles are the specified width (20ins) but a little shorter than specified at 37ins (instead of 40ins) - is this likely to be an issue?
The 18mm birch ply was a 74in x 26in offcut, purchased from a local ebay seller for the princely sum of about $12 - too good a bargain to pass on - pun intended.😊
Apologies for the mixed units...
I have a SLOB with 8x 6.5in woofers. Really cost effective GRS 6PR. The cone area is same as two 12in woofers. The decreased slot depth allows upper bandwidth of 475Hz which makes for a nice crossover with a midrange. The opposed drivers with one inverted with basket in the slot cancels suspension induced distortion. This upper bandwidth reach also allows the SLOB to deliver the critical chest punch 120Hz to 300Hz region. It’s one of the most impressive low distortion dipole bass speakers I have ever heard. More info here.
Listen to it here.
Assembly of both base (bass) sections complete and first coat of finish (wiped on satin polyurathane) applied.
Jumping into this thread awfully late, but hoping to get some direction from the collective experience.
I’m considering a (2) 15” build. I have (2) Eminence Delta 15LFA woofers and (2) Alpha 15A woofers, as well as a pair of TB W8-1808 FR drivers available for the build. I’m thinking the Alpha 15A’s (Qts=1.26) would be baffle mounted and the Delta 15LFA’s (Qts=.48) would be downward firing. Does that make any sense? I’d like to try to use the drivers I have, if at all possible.
I also do not have an electronic crossover, B5, etc.. My amp is a KT88 PP (NOS Valves VRD), which I’d plan to use to drive the TBs. I’d likely pick up a couple plate amps to drive the LF section. Has anyone done a passive crossover for this configuration? Or is the B5 a necessity? Building the speakers is a piece of cake. Same with building a passive crossover (if I know the values/configuration - I’ve never designed one from scratch). But I know zippo about electronic crossovers.
Any help/advice is appreciated. I currently run a pair of Econowaves that I built, with a 15” woofer in a large “folded OB” cabinet (the back is about 50% open) with a SEOS 15 waveguide and Radian 475Pb CD. It’s all run from my VRD amp (the speakers are about 100 dB. I have the itch to do another build and the SLOB intrigues me.
Thanks!
I’m considering a (2) 15” build. I have (2) Eminence Delta 15LFA woofers and (2) Alpha 15A woofers, as well as a pair of TB W8-1808 FR drivers available for the build. I’m thinking the Alpha 15A’s (Qts=1.26) would be baffle mounted and the Delta 15LFA’s (Qts=.48) would be downward firing. Does that make any sense? I’d like to try to use the drivers I have, if at all possible.
I also do not have an electronic crossover, B5, etc.. My amp is a KT88 PP (NOS Valves VRD), which I’d plan to use to drive the TBs. I’d likely pick up a couple plate amps to drive the LF section. Has anyone done a passive crossover for this configuration? Or is the B5 a necessity? Building the speakers is a piece of cake. Same with building a passive crossover (if I know the values/configuration - I’ve never designed one from scratch). But I know zippo about electronic crossovers.
Any help/advice is appreciated. I currently run a pair of Econowaves that I built, with a 15” woofer in a large “folded OB” cabinet (the back is about 50% open) with a SEOS 15 waveguide and Radian 475Pb CD. It’s all run from my VRD amp (the speakers are about 100 dB. I have the itch to do another build and the SLOB intrigues me.
Thanks!
Attachments
I followed Nelson’s recipe and went with the W8-1808 and the Definimax 15” 4015LF in his SLOB configuration. I used a B5 with a DIY F5 feeding the full rangers. I used a mini DSP to play around with settings before moving over to the B5. There was a very noticeable difference between the mini DSP and B5. The end result is awesome. Thanks Nelson!!!
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