mige0 said:
four 18" !
Yes - within its limitations - the bass quality of OB is second to nothing IMO
Michael
I've listened to my OB prototype for a while now, so it was time to turn back to my reference - the big Gjallarhorn 418 towers with its four 18" in sealed boxes. Its was quite interesting.... and disappoiting! Especially the bass is nothing like the OB speaker at all. Yes, there is more LF extension, but the bass quality is far from what I achieved with the OB experiment. The OB also presented a larger stereo image with more depth.
I guess the next project will be to redesign my 4-way towers to become OB speakers. Maybe four 21" per side will do?
StigErik said:
I guess the next project will be to redesign my 4-way towers to become OB speakers. Maybe four 21" per side will do?
There was a guy who did *a lot* of 15" in OB - basically from side wall to side wall and to maximise count he did fold 'em slightly.
I was searching for his page but couldn't find any more.
I guess he found what he was looking for in bass...
I's been Beymas as well IIRC !
Michael
Well, it does sound like its Doppenbergs own last big basshorn, converted into this multi woofer arrangement
But though its not OB as mentioned, it very well could be
When I first saw it some time ago I actually thought of doing a similar multi woofer setup, but in a dipole design with AEs cheap IB15
But I dont have the space fore it yet, but I may have in a few years
But I reckon I will consider it a bit too crazy
I dont know, but with better woofers, less than half the woofers might do just the same, if spread out a bit more
But though its not OB as mentioned, it very well could be
When I first saw it some time ago I actually thought of doing a similar multi woofer setup, but in a dipole design with AEs cheap IB15
But I dont have the space fore it yet, but I may have in a few years
But I reckon I will consider it a bit too crazy
I dont know, but with better woofers, less than half the woofers might do just the same, if spread out a bit more
Time is the main problem now... and the 21" Beyma woofers have not yet arrived. I've redesigned it a little bit to avoid too many weird angles, making it easier to assemble. The MDF boards are sitting in my garage right now!! Hopefully my and my buddy Lars will have time to work in the project again next week.
Below is the latest design, I call it Prototype MKII.
We will make the cutouts behind the mid and tweeter a bit wider than shown here to avoid cavity resonances.
Below is the latest design, I call it Prototype MKII.
We will make the cutouts behind the mid and tweeter a bit wider than shown here to avoid cavity resonances.
Attachments
An interesting lesson learned from my OB project is that internal damping in closed boxes affect the sound a lot more than I though. My big Gjallarhorn towers are closed box, and I stuffed the entire volume, right up to the rear of the drivers. Bad idea! After removing most of the damping (leaving some to avoid resonance), it sounded more like the OB... especially the bass quality and stereo imaging.
Almost every time I do new project, there is something to be learned....
Almost every time I do new project, there is something to be learned....
Interesting observatrion..
I usually don't - well - didn't - stuff too much but its mainly been 2 way.
So from that I'm light at experience - despite I got mad by the "bong bong" sound creeping in after a while with anything I tried to get rid of it.
*But* there was a very early DIY closed speaker from my brother - guess it must have been 3 decades or more ago - that I remember having had outstanding bass.
When I disassembled I found it
- not really tight (no seal / not much screws - most pretty loose in the chipboard)
- stuffed by fibreglass completely (the stiff one used for bottom insulating) with hardly any room between the boards or towards the speakers basket
very interesting - no explanation - not measured anything - unknown el cheapo speakers
Depending on frequency range of interest with respect to box size you might get away with no stuffing at all - as done in many sub's
Good luck to both of you!
Michael
I usually don't - well - didn't - stuff too much but its mainly been 2 way.
So from that I'm light at experience - despite I got mad by the "bong bong" sound creeping in after a while with anything I tried to get rid of it.
*But* there was a very early DIY closed speaker from my brother - guess it must have been 3 decades or more ago - that I remember having had outstanding bass.
When I disassembled I found it
- not really tight (no seal / not much screws - most pretty loose in the chipboard)
- stuffed by fibreglass completely (the stiff one used for bottom insulating) with hardly any room between the boards or towards the speakers basket
very interesting - no explanation - not measured anything - unknown el cheapo speakers
Depending on frequency range of interest with respect to box size you might get away with no stuffing at all - as done in many sub's
Good luck to both of you!
Michael
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