My head says that this rigid/soft thing is related to freq band.
A woofer making 30-300Hz with Mms of 150g must be rigidly attached to the frame and the floor!
A midrange or midwoofer playing up tio 2-3kHz and Mms of 5-15g is the real challenge and most prone to disturbances with resonances or IMD. I would attach it firmly to a heavy frame.,
Only a tweeter playing from 2kHz up and Mms of 0.2g would theoretically benefit from hanging freely in the air,.
A woofer making 30-300Hz with Mms of 150g must be rigidly attached to the frame and the floor!
A midrange or midwoofer playing up tio 2-3kHz and Mms of 5-15g is the real challenge and most prone to disturbances with resonances or IMD. I would attach it firmly to a heavy frame.,
Only a tweeter playing from 2kHz up and Mms of 0.2g would theoretically benefit from hanging freely in the air,.
Agreed. I’m not bothered with my bass, and it’s already rigid to floor etc.
Its the FR from 120 hz up I am keenly interested in improving.
The PAP frame I’ve got isn’t conducive to this type of change, but I will figure it out. There’s room to independently mount a ‘floating’ baffle...I need to figure out how to support the FR by its magnet. I can see my son in law’s 3D printer coming into the equation.
A Use PAP frame for woofer mounts.
B Independent front baffle assembly standing on floor, woofers fit (slide) into baffle holes with flexible seals
C FR independently mounted with its own floor frame, which can also slide into baffle hole with flexible seal.
That should work well, with C being the difficult bit to design.
Its the FR from 120 hz up I am keenly interested in improving.
The PAP frame I’ve got isn’t conducive to this type of change, but I will figure it out. There’s room to independently mount a ‘floating’ baffle...I need to figure out how to support the FR by its magnet. I can see my son in law’s 3D printer coming into the equation.
A Use PAP frame for woofer mounts.
B Independent front baffle assembly standing on floor, woofers fit (slide) into baffle holes with flexible seals
C FR independently mounted with its own floor frame, which can also slide into baffle hole with flexible seal.
That should work well, with C being the difficult bit to design.
You're welcome. I think there is a thread here somewhere about felt open baffle, it wouldn't be very effective at separating front from back at low frequencies.
There are a number of good tests, speech and piano can be difficult to reproduce convincingly. Complex music that you are familiar with, I use Zappa quite a lot because the recordings are also high quality. Girl and guitar is used a lot by people selling stuff because it's simple and easily reproduced, ie, tells you next to nothing
I can't find it now, but there was a DIY with what was called a lossy baffle.
They used a piece of thick wool carpet, iirc, as a non reflective baffle.
They described a more gradual roll off of bass, and better imaging.
Joe Satriani: Always With You, Always With Me
John Lee Hooker- and Santana: the Healer
Jewel: cover of You Make Loving Fun
Mickey Hart: Umayeyo
Rolling Stones: Can't You Hear Me Knocking
There are a number of good tests, speech and piano can be difficult to reproduce convincingly. Complex music that you are familiar with, I use Zappa quite a lot because the recordings are also high quality. Girl and guitar is used a lot by people selling stuff because it's simple and easily reproduced, ie, tells you next to nothing
Applause and piano are the best...you can’t fake those out!
If you look at pic 2-5 in post #2775 the FR is mounted on a separate floor stand, I could measure (spectrum not sweep looking for IMD and harmonic) or hear any difference between FR mounted on separate stand or on top of woofer cabinet. I attached an accelerometer to the FR baffle and also used my calibrated mic up against but not quite touching the baffle to look at baffle reflections and vibration.
I tried heavy sand filled baffles but found the current lightweight de-coupled had far less colouration. The heavier the baffle the lower its Fres, lower Fres will have more amplitude for a given energy. Measured with the acccelerometer baffle vibration energy was higher with the heavier baffle.
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That is basically the same as I used, carpet underfelt 10mm thick. It works. I got the idea from the BBC development of the LS3/5A.
Unfortunately I had a PC failure a month ago and lost ALL my REW plots. Yep it was backed up on a USB HDD but guess what it failed as I was restoring.
Yes I understand what you’ve done and agree entirely with it. I want to explore using some of those findings to improve the frame based OB I’ve got now, which doesn’t have a w frame to rest anything upon. (I’m quite happy with bass as is).
I don’t have much doubt I will eventually end at same place as you. When Spring arrives I will likely be building w frames.
Until then I am going to explore panel isolation, time alignment, baffle shapes and use of felt to see what I can achieve. You have given me new ideas to try out!
I don’t have much doubt I will eventually end at same place as you. When Spring arrives I will likely be building w frames.
Until then I am going to explore panel isolation, time alignment, baffle shapes and use of felt to see what I can achieve. You have given me new ideas to try out!
Its a second order between the 15A and Flat 8, and first order between the tweeter and Flat 8. Crossovers at 140 resp 2000 Hz.
I have had to make many changes to the filter as I have made changes the appearance of the baffle, especially concerning the crossover between the 15A and the Flat 8. Because of this i think that my crossover would be of no use for you unfortunately.
But the Flat 8 sounds really well in an open baffle, specially the mids are fantastic!
After a long hiatus ...
...I thought I'd comment (in general), regarding OB designs. I've had a pair that I cobbled together 15 years ago. Although I can't utilize them in current home they remain one of the few speakers that I always reference back to.
Tube Kingdom OBs, Oxford J10 instrument speakers (from a Leslie organ), Seas tweeters (Mission branded, mounted coaxially), and LS3/5A 11Ω (at least I think they are) crossovers. A full width "shelf" runs between 2 uprights, as well as a 6" "brace" between the uprights (about 1/2" above floor level).
One thing I've noticed, (looking on this thread and elsewhere) is how complicated many think they have to make OBs. Simplicity with as few (preferably zero) electronic band-aids as possible should be the goal for all. Baffle width is almost a dead issue as long as one gets creative getting whatever baffle geometry they use to approximate the 36" width of the Wharefdale SFB3 loudspeakers.
Al I have to say for now. Not looking to stir anything up, just trying to remind everyone that the real joy of OB designs are the simplicity of them.
...I thought I'd comment (in general), regarding OB designs. I've had a pair that I cobbled together 15 years ago. Although I can't utilize them in current home they remain one of the few speakers that I always reference back to.
Tube Kingdom OBs, Oxford J10 instrument speakers (from a Leslie organ), Seas tweeters (Mission branded, mounted coaxially), and LS3/5A 11Ω (at least I think they are) crossovers. A full width "shelf" runs between 2 uprights, as well as a 6" "brace" between the uprights (about 1/2" above floor level).
One thing I've noticed, (looking on this thread and elsewhere) is how complicated many think they have to make OBs. Simplicity with as few (preferably zero) electronic band-aids as possible should be the goal for all. Baffle width is almost a dead issue as long as one gets creative getting whatever baffle geometry they use to approximate the 36" width of the Wharefdale SFB3 loudspeakers.
Al I have to say for now. Not looking to stir anything up, just trying to remind everyone that the real joy of OB designs are the simplicity of them.
