Open Baffle - Bass On Wall (OB-BOW) for ESL bass and lower-mids reinforcement
Here's an idea to kick around for dealing with the perennial ESL bass augmentation dilemma. I havent seen this done so it needs input from the brains trust about feasibility please. If you are anti-OB bass please kindly ignore. This is about OB.
ESL's can be extraordinary in the midrange but struggle with bass. Some ESL can even struggle with lower mids giving a thin sound lacking body and warmth. A friend with Acoustat 2+2 wants more bass but not from a box subwoofer. He listens to rock, jazz and classical and only wants bass to 40Hz. He wants bass that can integrate with the ESL's and also fill in the lower mids.
With a large room the ESLs can be positioned in from the side walls. This gives a great site for an open baffle for woofers to be sited against the wall like in the red below:
Design ethos:
- Plain baffles avoid the resonance issues of H-frames etc. and so allow a higher frequency reach to fill in the lower mids for body and warmth.
- The ESL and OB both being large dipoles, should blend well with similar impulses.
- The open baffle when placed against the wall will have improved efficiency.
- The OB and ESL are in the same plane with a good gap. This places the ESL membrane in the OB null and is decoupled from being driven by the bass output.
Driver:
For OB bass drivers there is a 12" GRS 12SW-4 at just $32 each which allows six per side x2, for only $380.
Hornresp:
The lowest bass instrument he listens to is the bass guitar at 41Hz so with a 40Hz cut off, hornresp indicates one side can do 124dB:
Impulse looks good too:
This all seems to good to be true. I assume Ive made multiple mistakes in Hornresp so I exported the file and attached it below. Its just a txt file of 2kb file so its tiny and safe. Ive attached it just in case anyone wants to download and save it in the "import" Hornresp folder to check it out.
I have used two 15" GRS per side on OB with great results. The baffle was not small. The crossover was simply achieved with an 18mH inductor in series.
GS also now make an 18" woofer that will work well on OB.
GS also now make an 18" woofer that will work well on OB.
Thats great to know. So only two x GRS 15" a side were enough. I might need to rethink the idea of six a side but they are so cheap 🙂
Did you ever try your OB bass against the wall for the 1 x Pi boost?
I don't know if that question was for me - but certainly the 2x15 panels had to be away from the wall to have proper bass. I gave them to a friend and he put them up against the wall in his living-room. He wouldn't believe me that they needed to be pulled away from the wall until he did it. "Wow! These things have bass!" Having been an audio engineer for several A-list rap and rock artists, he does like bass. 🙂
WoW !!! 😱
This is exactly the type of setup I have been contemplating for my narrow room of 11.5' x 18' .......
In fact I have chosen the very same driver to work with !!!
The GRS 12SW-4 is an incredible driver for what it costs, they work fantastic in my over stuff and untuned 2.75 cu.ft. (highly dampened) cabinets from my old stack that I started rebuilding last summer.
That update is found here,
https://www.diyaudio.com/community/...lated-foam-speaker-grills.375333/post-6861635
I too have six of them to work with for now but plan on getting another case or two to use in OB for my ESL's and the four I have going Now is plenty enough for this room already !!! ;O 😀
I am actually gonna get the 10" versions, the 10sw-4's as well for a pair of smaller 2x10's I use with the stack, I am thinking a pair of 8x10"s per side with 6" wide segmented ESL's 6-8 foot tall would be nice in my bigger Living room area, and is actually my dream system been in design all these years. 🙂
Below are pic's the the original stack that I kept blowing the midranges and started the Desktop ESL project to adapt to it for mid's and the way I had each stack stacked in the corner of the room and it's now current condition.
The two graphs are of the woofer it self in my setup as it is and a FR with the match to the mid's I am currently using, eventually will new replaced with new ESL's. 😉
When properly tuned they are flat down to 20-25hz or so, and that is just 4 drivers so far.
I have included them to show that the THD of this driver is very good for what it cost (me $23), WaY better than the old stock crap I blew up !! 😀
However they are actually better than what REW depicts as I was having a noise issue with the mixer I was using to interface to my computer, It uses JRC junk and the floor is not any lower than -68-72db and the room was rattling a bit as well !! 😠
But anyhow I am following your project closely to see what kind of results you get, meanwhile my project is at rest until the summer meanwhile I will play with HornRes as well, thanks for the File !! 🙂
I was thinking about using the side of the wall as part of a simple TL with the stack next to it or something, with 11.5 feet my space is tight as you can see in the pic's.
Cheers !!!
jer 🙂
This is exactly the type of setup I have been contemplating for my narrow room of 11.5' x 18' .......
In fact I have chosen the very same driver to work with !!!
The GRS 12SW-4 is an incredible driver for what it costs, they work fantastic in my over stuff and untuned 2.75 cu.ft. (highly dampened) cabinets from my old stack that I started rebuilding last summer.
That update is found here,
https://www.diyaudio.com/community/...lated-foam-speaker-grills.375333/post-6861635
I too have six of them to work with for now but plan on getting another case or two to use in OB for my ESL's and the four I have going Now is plenty enough for this room already !!! ;O 😀
I am actually gonna get the 10" versions, the 10sw-4's as well for a pair of smaller 2x10's I use with the stack, I am thinking a pair of 8x10"s per side with 6" wide segmented ESL's 6-8 foot tall would be nice in my bigger Living room area, and is actually my dream system been in design all these years. 🙂
Below are pic's the the original stack that I kept blowing the midranges and started the Desktop ESL project to adapt to it for mid's and the way I had each stack stacked in the corner of the room and it's now current condition.
The two graphs are of the woofer it self in my setup as it is and a FR with the match to the mid's I am currently using, eventually will new replaced with new ESL's. 😉
When properly tuned they are flat down to 20-25hz or so, and that is just 4 drivers so far.
I have included them to show that the THD of this driver is very good for what it cost (me $23), WaY better than the old stock crap I blew up !! 😀
However they are actually better than what REW depicts as I was having a noise issue with the mixer I was using to interface to my computer, It uses JRC junk and the floor is not any lower than -68-72db and the room was rattling a bit as well !! 😠
But anyhow I am following your project closely to see what kind of results you get, meanwhile my project is at rest until the summer meanwhile I will play with HornRes as well, thanks for the File !! 🙂
I was thinking about using the side of the wall as part of a simple TL with the stack next to it or something, with 11.5 feet my space is tight as you can see in the pic's.
Cheers !!!
jer 🙂
