Hi Chromenuts,
Your slob may just be lacking baffle width, adding the U wings may just be the ticket. Give it a try - temp ones just to do a sound check. There’s no reason they can’t be as good as a 15in in an OB H baffle(?).
Your slob may just be lacking baffle width, adding the U wings may just be the ticket. Give it a try - temp ones just to do a sound check. There’s no reason they can’t be as good as a 15in in an OB H baffle(?).
Hi XRK
I’m definitely not ruling it out.
My first thought concerning the lack of bass was that it had to be partly due to the limited baffle size and that increasing it with wings would hopefully produce better extension.
My idea was to try and keep the shape of my design by installing wings that would be under the screens I built for the sides angling back to a point where a rear slot on both sides would be maintained with dimensions that were at least 1/3 Sd. (Image)
Of course things got sidetracked when someone knocked over one of my Oris horns that I was using on top of these bass panels. I still haven’t repaired it.
The panels are quite heavy…probably similar to my KEF 104/2 which weight in at about 75 pounds. Moving them back up from the garage will be a task.
I’m currently trying to expand my signal management capabilities to try a variety of coaxial solutions up top after wrapping up a pair of stereo BJ2 amps to drive them.
I’m definitely not ruling it out.
My first thought concerning the lack of bass was that it had to be partly due to the limited baffle size and that increasing it with wings would hopefully produce better extension.
My idea was to try and keep the shape of my design by installing wings that would be under the screens I built for the sides angling back to a point where a rear slot on both sides would be maintained with dimensions that were at least 1/3 Sd. (Image)
Of course things got sidetracked when someone knocked over one of my Oris horns that I was using on top of these bass panels. I still haven’t repaired it.
The panels are quite heavy…probably similar to my KEF 104/2 which weight in at about 75 pounds. Moving them back up from the garage will be a task.
I’m currently trying to expand my signal management capabilities to try a variety of coaxial solutions up top after wrapping up a pair of stereo BJ2 amps to drive them.
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Your suggestion is essentially a Y baffle . It's been a long time since I played with Y baffles but if I recall, the resultant pattern was even more cardoid in shape. One thing you could try is lightly to moderately stuff the rear Y cavity . At that point , your SLOB will behave as a quasi- aperiodic - cardoid hybrid... and the bass should pick up .
It's worth a shot to prototype .. all you need are a few old pillows to tear up, some wood scraps and a couple of clamps
Just a small update, top and bottom panels glued on an routed flush. Now the front panel needs to be glued. Actually, the beech plywood "veneer" looks pretty good.
Nice to see you’re still working towards your goal.
I was actually thrown a curve ball in the form of relocation to a new house recently.
The move has been insane and is on going.
In the process my SLOB project has recaptured my attention.
I’ve resolved to go back into it once things settle enough and try to integrate some horns that were gifted to me last year. (Pic)
I’ll be experimenting with some less sensitive Fostex 108ez in them at first…so the output demands on the SLOB panels won’t be as high as they were with my 8” widebands in the Oris horns.
I’ll be adding some wings to the SLOBs, as discussed previously, and taking some more measurements to see if the low frequency extension improves.
From there I’ll see what happens.
I was actually thrown a curve ball in the form of relocation to a new house recently.
The move has been insane and is on going.
In the process my SLOB project has recaptured my attention.
I’ve resolved to go back into it once things settle enough and try to integrate some horns that were gifted to me last year. (Pic)
I’ll be experimenting with some less sensitive Fostex 108ez in them at first…so the output demands on the SLOB panels won’t be as high as they were with my 8” widebands in the Oris horns.
I’ll be adding some wings to the SLOBs, as discussed previously, and taking some more measurements to see if the low frequency extension improves.
From there I’ll see what happens.
Attachments
No…I wish I had the smarts and resources.
They were gifted to me by someone who does.
I was told they were prototypes. They didn’t perform as expected and they moved on to evolve the horn profile.
They appear to be a simple conical horn with an embellished round over at the mouth. 3” throat, 21.5” mouth and about 16.5” long.
They look similar to the AH! (OMA) horns in concept. A throat adapter wasn’t available for the BMS coaxials I purchased from the owner at the time.
I didn’t look a gift horse in the mouth.
Only had a convertible that day…and my wife was with me. We drove all the way home (1.5hrs) with her holding them on her lap. Yes, she is a keeper! 😉
Since I haven’t had the opportunity to build a throat adapter for CDs yet, I tried modeling them in hornresp based on the dimensions as a simple conical horn with the factory TS parameters of the 108ez.
It looks like they should boost the response starting at around 200Hz and then immediately rolloff as frequency increases.
No idea how that will work out in the end.
I’m a complete hornresp amateur. I still have questions about what to do regarding a back chamber, so I just didn’t enter any of that data.
I’m winging it. I’ll just mount them up once I figure a way to support the horns and run some sweeps with REW and my Mic.
Maybe I’ll get lucky and be able to cross them to the OB panels where they rolloff around 300Hz.
They were gifted to me by someone who does.
I was told they were prototypes. They didn’t perform as expected and they moved on to evolve the horn profile.
They appear to be a simple conical horn with an embellished round over at the mouth. 3” throat, 21.5” mouth and about 16.5” long.
They look similar to the AH! (OMA) horns in concept. A throat adapter wasn’t available for the BMS coaxials I purchased from the owner at the time.
I didn’t look a gift horse in the mouth.
Only had a convertible that day…and my wife was with me. We drove all the way home (1.5hrs) with her holding them on her lap. Yes, she is a keeper! 😉
Since I haven’t had the opportunity to build a throat adapter for CDs yet, I tried modeling them in hornresp based on the dimensions as a simple conical horn with the factory TS parameters of the 108ez.
It looks like they should boost the response starting at around 200Hz and then immediately rolloff as frequency increases.
No idea how that will work out in the end.
I’m a complete hornresp amateur. I still have questions about what to do regarding a back chamber, so I just didn’t enter any of that data.
I’m winging it. I’ll just mount them up once I figure a way to support the horns and run some sweeps with REW and my Mic.
Maybe I’ll get lucky and be able to cross them to the OB panels where they rolloff around 300Hz.
Chromenuts, do you know if these prototype horns are going to be made into a production run? they are just so pretty!
I also wish I was able to create a 9 petal horn with curved inner surface and turn it into a MEH. So far, I can only do flat petals.
Hmm, to the 1st approximation, pure conical in free/4pi space:
sqrt(3*21.5) = ~8" mean diameter
~13543.8/pi/~536.8 Hz BW mean/4 = ~134 Hz Fc
Use directivity = 0 deg for on axis response Vs sim
sqrt(3*21.5) = ~8" mean diameter
~13543.8/pi/~536.8 Hz BW mean/4 = ~134 Hz Fc
Use directivity = 0 deg for on axis response Vs sim
I didn’t want to just repost the same information here, but thought that since this thread was specifically concerned with the use of horns with dipole bass I’d link a post with some measurements I took while trying to integrate the wooden conical horns with my SLOB panels.
I extended my panels with “wings” of about 8” length on the back in a manner that would still allow me to cover them with the screens I built.
After taking measurements and making adjustments with my B5 as best I could I was still left with a lack of mid-bass impact…hence the post in the linked thread.
The feedback I got from CowanAudio makes sense.
It seems I need to move more air and need a driver with higher xmax or some sort of sub to integrate properly.
https://www.diyaudio.com/community/threads/open-baffle-midbass.413684/page-2
I extended my panels with “wings” of about 8” length on the back in a manner that would still allow me to cover them with the screens I built.
After taking measurements and making adjustments with my B5 as best I could I was still left with a lack of mid-bass impact…hence the post in the linked thread.
The feedback I got from CowanAudio makes sense.
It seems I need to move more air and need a driver with higher xmax or some sort of sub to integrate properly.
https://www.diyaudio.com/community/threads/open-baffle-midbass.413684/page-2
I need to finish this one finally. Now when the large bass horns are gone, I have some space for it.
That’s funny…I picked up some LaScala commercial bass bins cheap that are a little rough aesthetically and I have been debating on whether it would be worth my effort to reinforce and spruce them up for use under my various mid/high horns.
They would still come up short on the bottom end and require that I either try the bass reflex modification or build some tapped horns for the bottom end.
My dipole panels would require modification to the chambers to even try one of the GRS drivers I was looking at with higher xmax. There’s no way I could maintain the design and add the high excursion driver since its too deep.
Either way, there truelly is NO free lunch.
They would still come up short on the bottom end and require that I either try the bass reflex modification or build some tapped horns for the bottom end.
My dipole panels would require modification to the chambers to even try one of the GRS drivers I was looking at with higher xmax. There’s no way I could maintain the design and add the high excursion driver since its too deep.
Either way, there truelly is NO free lunch.
I've got 24 ScanSpeak 18Ws waiting for a purpose. They have about 0.45 Qts and Fs of 40 hz and would probably be suitable this type of build. Thats about a total surface area of 2 x15" woofers per side. I've sometimes brain stormed of the best way to array a larger amount of smaller woofers for the best efficiency and response. A line isn't always the best choice depending on frequency range.
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The bass horns I had were great but huge, if this does not work to my liking, I will need to come up with something else. First, I had Peavey FH-1 clones (LaScala like) and missed the low end. 40 Hz bass horns were fine, but not enough space to fit in all four.