I just went to the Parts Express tent sale: was able to find 9 of the GRS woofers for 2 bucks a piece!
Hey XRK
I took an interest in making something similar to this after I read Pa’s SLOB article years ago.
Took it as far as I could without crossover design skills…instead opting to find one of his B5 units used.
I built the bass units separately and stacked them onto the back of a baffle I could “live with”…about 20”X32”.
I used some drivers Pa tipped us off about on “Buy Out” at parts express. Some Peerless 8” 91.5dB poly woofers 12 Ohm wired series parallel (6) per side in same push pull arrangement for 8 Ohms.
I never got the bass output I was hoping for.
Maybe because in comparison I had much more efficient Oris horns on top of them.
I was driving the bass panels with two 120 Watt bridged Rotel HT amps as opposed to 25W push/pull tubes on the horns.
I’m wondering if the missing 8” of additional U baffle width was all that was holding it back?
I didn’t notice if you were doing anything else or equalize or give the bass a boost in your design.
I still have the panels and I’ve often thought of setting them back up active with some hypex amps I now have.
Just wondering if its worth the time in regards to bass extension now that I’ve heard 15” AE dipoles on OB and was considering the pursuit of a larger version slob with multiple AE drivers?
I took an interest in making something similar to this after I read Pa’s SLOB article years ago.
Took it as far as I could without crossover design skills…instead opting to find one of his B5 units used.
I built the bass units separately and stacked them onto the back of a baffle I could “live with”…about 20”X32”.
I used some drivers Pa tipped us off about on “Buy Out” at parts express. Some Peerless 8” 91.5dB poly woofers 12 Ohm wired series parallel (6) per side in same push pull arrangement for 8 Ohms.
I never got the bass output I was hoping for.
Maybe because in comparison I had much more efficient Oris horns on top of them.
I was driving the bass panels with two 120 Watt bridged Rotel HT amps as opposed to 25W push/pull tubes on the horns.
I’m wondering if the missing 8” of additional U baffle width was all that was holding it back?
I didn’t notice if you were doing anything else or equalize or give the bass a boost in your design.
I still have the panels and I’ve often thought of setting them back up active with some hypex amps I now have.
Just wondering if its worth the time in regards to bass extension now that I’ve heard 15” AE dipoles on OB and was considering the pursuit of a larger version slob with multiple AE drivers?
Attachments
Not in a plain baffle. Only as part of the SLOB. The basket looks identical and similar Qts and rubber surround. However, mine are 8ohms and the Dayton $5 blowout drivers were 4ohms. Maybe GRS makes this in 4ohms?
Hi Cr-Nuts,
Nice build! Just add a U baffle (i.e., wings) and that extends the baffle width without making the front larger. The bass extension in OB is primarily a function of the baffle width. You are at 20in and that’s less than the 12+8+8in I have. Also, the U shape adds more virtual width to baffle I think. Add some wings and you should get deeper bass. I do not use any EQ. If running active DSP, certainly a Linkwitz transform or bass EQ can help a lot as there is a lot of room left given the low distortion. Can you wire the drivers for lower impedance? I am at 97dB at 2.83v before OB losses so about 91.5dB net. But that’s 4 ohms. If you have a 2ohm capable amp, wire them parallel / parallel and buy a lot more sensitivity. It may even be better to wire 2ohms nominal and add 3ohm power resistor in series to increase Q for more bass extension below Fs. There will be 2-3dB loss but you will have about 6dB more gain than before.
Hi XRK
I think I’m gonna give it a try…I like how the top of your “U” legs taper down towards the back of the speaker.
I was struggling to maintain aesthetics and a smaller footprint with my design.
I was thinking to put something with a little lower sensitivity on top like some 4” fullrange Fostex drivers in modified B52 horns I also got on “Buy Out”.
I think I’m gonna give it a try…I like how the top of your “U” legs taper down towards the back of the speaker.
I was struggling to maintain aesthetics and a smaller footprint with my design.
I was thinking to put something with a little lower sensitivity on top like some 4” fullrange Fostex drivers in modified B52 horns I also got on “Buy Out”.
The preorder listings for the XSD Crossover and Waveguides are now up.
https://www.etsy.com/listing/122418...128&click_sum=93614f40&ref=shop_home_active_2
https://www.etsy.com/listing/122420...902&click_sum=35fb7475&ref=shop_home_active_1
https://www.etsy.com/listing/122418...128&click_sum=93614f40&ref=shop_home_active_2
https://www.etsy.com/listing/122420...902&click_sum=35fb7475&ref=shop_home_active_1
Just to update - I added some butyl rubber based product to the woofer baskets of my XSD inspired build (as suggested by XRK). A significant difference to say the least...think I'll actually need to reconfigure crossover.
Improvement in clarity/imaging/separation - had no idea it would make such a change. Cheap too!
Improvement in clarity/imaging/separation - had no idea it would make such a change. Cheap too!
Nice result EarPlay, did you apply the butyl to the woofer or the full range?
Just to the woofer baskets, and also lined part of the inside of wings.Nice result EarPlay, did you apply the butyl to the woofer or the full range?
Hi X
as the tweeter is not available yet I need an alternative. I have a pair of the big Heil Amt 1 at hand. They are hevy! May I ask for your take on how the baffle cold look like with the Heils as a replacement? Just a simple scetch is OK. I belive the crossover should work but the Heil has to be padded down.
Thanks
as the tweeter is not available yet I need an alternative. I have a pair of the big Heil Amt 1 at hand. They are hevy! May I ask for your take on how the baffle cold look like with the Heils as a replacement? Just a simple scetch is OK. I belive the crossover should work but the Heil has to be padded down.
Thanks
It would work with the Heil AMT but the XO I developed would be different. Make a shelf to support the 12lb Heil. Locate it as close as you can to midrange.
You can get the one with a back cup and remove it carefully.
You can get the one with a back cup and remove it carefully.
News flash, boswald has proven that ordering the PTT2522C-4 with the back cup can be easily removed with xacto knife on glue fillet and a thicker knife blade to pry off. Those are in stock.
This is DIY. I can think of a lot more dangerous things like circular saws and routers. Radial arm saws have an unfortunately grisly name. 🙂
Yes, please be careful with hand tools.
Yes, please be careful with hand tools.