Yes indeed.
It doesn’t address the question of two woofers being at nearly 90d angles on their backwave to each other though.
I found very early in this thread this example built with both woofers. Measurements with each individual woofer and both look to all make sense, with no obvious cancellation issues. So I'm not really sure what to think from a cancellation point of view.
https://www.diyaudio.com/community/threads/pass-slob-build-discussion.300952/page-5#post-4945188
https://www.diyaudio.com/community/threads/pass-slob-build-discussion.300952/page-7#post-4947579
It doesn’t address the question of two woofers being at nearly 90d angles on their backwave to each other though.
I found very early in this thread this example built with both woofers. Measurements with each individual woofer and both look to all make sense, with no obvious cancellation issues. So I'm not really sure what to think from a cancellation point of view.
https://www.diyaudio.com/community/threads/pass-slob-build-discussion.300952/page-5#post-4945188
https://www.diyaudio.com/community/threads/pass-slob-build-discussion.300952/page-7#post-4947579
Slot:
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Front:
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Both
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Attachments
The wings make sure that some cancelation is eliminated. The slot have another purpose. Using both a front woofer and slot woofer could be done, but I don't think it's that easy. The cross over should be changed. It's the wavelength of the woofer output that that determines the cancelation, and not the angle of the two woofers.The point of having that slot is to make sure the front and rear waves don’t cancel out. How are you ensuring that for the front-facing woofer?
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Going for two woofers I think better options exist. W frame, Ripole, slot loading with woofers opposite etc
How about doubling the slot area, in a "V" configuration. and turning it vertically, mounting the two drivers on each side?
Nelson's idea of opposing slot loaded woofers was an upgrade to his AMT-3 prototype while working at ESS back in the 1970s. You can find the details in his 2011 article published at enjoythemusic.com. I believe this is the original inspiration for the SLOB project that the OP first inquired about.
Keep in mind, "When you build a slot loaded cavity like this, you will run into a cancellation frequency that occurs when the wavelength is twice the depth, where the pressure from the part of the woofer which is deepest in the slot is one half the wavelength and cancels out the pressure from the portion of the woofer near the slot opening. Here the cancellation occurs at 500 Hz."
I'm not sure what that would be for a 15" woofer. I have my 15" SLOB woofs crossed over at ~120Hz. They sound pretty good.
I'm not sure what that would be for a 15" woofer. I have my 15" SLOB woofs crossed over at ~120Hz. They sound pretty good.
Would you use a wing behind the woofer still or leave them open?How about doubling the slot area, in a "V" configuration. and turning it vertically, mounting the two drivers on each side?
If you were using an outer wing, you'd be getting closer to a ripole alignment?
You’d end up with 4 sides of a cube, rather than 3 as per the normal slob or a version without the outer wings.
Forgive my crude sketch:
Thanks. Right now, the plan is to use (as yet unpurchased) Dayton plate amps with 180 hz high max crossovers for the bass drivers. I have some Crowns I can use to experiment with beforehand. The design I'm working on will be a WAW with tweeter, all active setup. But I have to see how low the mid-bass units will go, they are still in smaller test baffles. Not really the design that is put forth in this thread, just a fun experiment.Keep in mind, "When you build a slot loaded cavity like this, you will run into a cancellation frequency that occurs when the wavelength is twice the depth, where the pressure from the part of the woofer which is deepest in the slot is one half the wavelength and cancels out the pressure from the portion of the woofer near the slot opening. Here the cancellation occurs at 500 Hz."
I'm not sure what that would be for a 15" woofer. I have my 15" SLOB woofs crossed over at ~120Hz. They sound pretty go
On my present design, I'm hoping to just use small 1x6 wings on the baffles on the sides, similar to the Manzanita OB speaker. Another thought would be "Besty" style baffles, on piano hinges, that can be pulled apart.Would you use a wing behind the woofer still or leave them open?
If you were using an outer wing, you'd be getting closer to a ripole alignment?
You’d end up with 4 sides of a cube, rather than 3 as per the normal slob or a version without the outer wings.
Forgive my crude sketch:
View attachment 1336944
work fine .no ones problem i can see , just put a little bit up ,you can use the 12 OB too...View attachment 1334158
I've perused this thread and haven't seen much/any discussion of this variation with dual 15". Is this a viable design or defunct? I was considering 2x SB 15OB350 on each side. Would this be a viable option?
Cheers!
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/post-7517593
To ZM's point from another thread, did a tweeter upgrade. SLOBs from bottom to top are Eminence Beta 15 in the bass slot, Altec 420a and the first iteration were cone tweeters that were pulls from the old school console that housed the Altecs. Upgraded the tweeters to ScanSpeak soft domes, with just a first order Solen cap, that's how it was done in that old console. 6-24 crossover and biamped. New domes add clarity and specificity; I can really hear the drummer's brushes on a Bill Evans track.
To ZM's point from another thread, did a tweeter upgrade. SLOBs from bottom to top are Eminence Beta 15 in the bass slot, Altec 420a and the first iteration were cone tweeters that were pulls from the old school console that housed the Altecs. Upgraded the tweeters to ScanSpeak soft domes, with just a first order Solen cap, that's how it was done in that old console. 6-24 crossover and biamped. New domes add clarity and specificity; I can really hear the drummer's brushes on a Bill Evans track.
Any advice on using the Eminence Delta 15-LFA with Lii Song Fast-8? I have a pair of Fast-8s sitting in the garage, but still have time to decide on the bass drivers for my SLOB build. Are the Deltas a good match or is there something better?
I have that identical setup & it works great. Give it a try. You can always change and that is how you’ll know what you like.


I used the lx mini….
At long last, I have completed the LX-mini Analog Crossover and posted
in in the Article section of FIRST WATT
It will serve as the documentation and assembly manual for the kit which
will soon be available in the diyAudio store.
Enjoy.

in in the Article section of FIRST WATT
It will serve as the documentation and assembly manual for the kit which
will soon be available in the diyAudio store.
Enjoy.

- Nelson Pass
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