I think he is talking about the 299-114 drivers? And either two boxes or one with all four... I could be wrong though...
Sorry, I think I must be a long way behind here. I meant isobaric drivers in general, 2 per channel. And mounting front and rear drivers with the rear firing down at 45 degrees to the front driver. Clamshell or not, can do either. The 4 separate amp channels mean each one sees 8ish ohms, plus relative levels could be changed if it would benefit. That's why I was curious about the need for all (both) drivers needing the same signal; or did that only apply to the 4 driver design? Xover is active, BTW.
This thread overlapped with another; with a lot of the drawings etc. Just for posterity:
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
http://www.diyaudio.com/forums/subwoofers/205896-6th-order-bandpass-design-dual-6-5-a-7.html
I think you would want go with 4 ohm connection (two channel).
Need a lot more detail though.
What woofers?
Btw, why 45 degrees?
Need a lot more detail though.
What woofers?
Btw, why 45 degrees?
Thanks for taking the time to reply.
KEF B139 (racetrack shape) bass drivers; I am quite poor (I already have them), they have a low Fs, and I liked them when I used them before. 🙂
45 degrees; firing the rear output at an angle to the rear cabinet wall which should make absorption easier. Reflections would also be angled. If I want to try aperiodic, positioning the vent would be easier for me. If the drivers are mounted both facing forward, I can get them closer together without hitting the front magnet. Clamshell mounting would not work so well, I guess.
And I like to try something different sometimes!
The B139s would be fitted to an inner box which would slide into the main box, and be multi-screwed to the outer box, perhaps with a felt sleeve between. This would mean I could change orientation or even the drivers.
Separate amp channels; possibility to experiment with different levels to front and rear drivers. Amps seeing ~8 ohms. Using different drivers for front and rear, level matching.
If there are no MAJOR problems with these ideas, then I can experiment without starting over (I have less energy these days).
Hope this doesn't sound TOO foolish, but a litle bit foolish is fine.😀
I am, or was, a joiner, shopfitter, kitchen cabinet maker, kitchen and bedroom fitter, etc. I have a small metal lathe, drill press, arc welder (oxy acetylene has gone, sadly), spray paint equipment, various routers, planer, drills and power saws.
TLs? Built quite a few in the last 35-40 years, Bailey design, PRO 9TL, cardboard tube types, ceramic or plastic wastepipes, various 1/4 waves, etc.
I actually prefer isobarics, not just for size, also the punch in a smaller room.
I may be a little crazy (ok, I am), but it's probably all the lead from making leaded lights, and the hydrofluoric acid fumes. At least that's my excuse; what's everyone else's?
It looks good in WinISD. It has a huge VAS, I can see where you would want go Iso.
I'd be afraid of the flat cone though, you can run into problems with speakers facing each other one speaker is stronger (or something) and pushes (pegs) the opposing driver into basket.
btw this was a 35L box with 31hz tuning - I'd use a slot port, easy to tune.
You have 4 of these?
I'd be afraid of the flat cone though, you can run into problems with speakers facing each other one speaker is stronger (or something) and pushes (pegs) the opposing driver into basket.
btw this was a 35L box with 31hz tuning - I'd use a slot port, easy to tune.
You have 4 of these?
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Actually I have 5, they are old after all, so I may need spares!
I am shy of using a port; I would rather sacrifice bass extension for transient response and a slower roll off. If I wanted low I would TL them.
If aperiodic loading would make it sound cleaner to my ears, that is probably as far as I would go. My room is 5.4m x 4.5m , but only 2.2m high, with as much bass trapping as I can get away with. WAF.
I love bass, cello and double bass, I once went to a concert with 10 double basses! So clean is what I am hoping for.
I have no computer skills, I never even turned one on until I was over 50, and still can't post pics, unless I have help! So running sims, and using CAD is tricky.😕 and
As for the flat cones (?) pushing, I hadn't thought of that. I can easily mount them further apart, but wouldn't they both reach Xmax together? I hope they are symmetrical! That's another vote for separate amp channels then. 😀
I am shy of using a port; I would rather sacrifice bass extension for transient response and a slower roll off. If I wanted low I would TL them.
If aperiodic loading would make it sound cleaner to my ears, that is probably as far as I would go. My room is 5.4m x 4.5m , but only 2.2m high, with as much bass trapping as I can get away with. WAF.
I love bass, cello and double bass, I once went to a concert with 10 double basses! So clean is what I am hoping for.
I have no computer skills, I never even turned one on until I was over 50, and still can't post pics, unless I have help! So running sims, and using CAD is tricky.😕 and
As for the flat cones (?) pushing, I hadn't thought of that. I can easily mount them further apart, but wouldn't they both reach Xmax together? I hope they are symmetrical! That's another vote for separate amp channels then. 😀
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If you have a camera, you could post a pic. only a couple of easy steps.
I don't know one driver can pound the opposite driver into submission, it can though.
Back to the easy ported build for a second - if you go back to post 434, that's a 30Liter box and you need 37liters (Iso I forgot to mention).
That's a fun little box to build; a friend measured it the other day and said if was pretty darn flat.
I never thought of it as "punchy" sub, more of a Orchestra kettle drum (amazing) sound , I was considering lining the walls with some 1" fiberglass.
I don't know....If I were you, I'd start cutting some race track rings.
I don't know one driver can pound the opposite driver into submission, it can though.
Back to the easy ported build for a second - if you go back to post 434, that's a 30Liter box and you need 37liters (Iso I forgot to mention).
That's a fun little box to build; a friend measured it the other day and said if was pretty darn flat.
I never thought of it as "punchy" sub, more of a Orchestra kettle drum (amazing) sound , I was considering lining the walls with some 1" fiberglass.
I don't know....If I were you, I'd start cutting some race track rings.
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Maybe this is what you are looking for.
Same 38L box with a 12" Pr. I only spent a few minutes on this but looks good. (red line)
12" Pr with 30 grams.
Dayton Audio SD315-PR 12" Passive Radiator 295-496
Same 38L box with a 12" Pr. I only spent a few minutes on this but looks good. (red line)
12" Pr with 30 grams.
Dayton Audio SD315-PR 12" Passive Radiator 295-496
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Why do I need to do anything but sealed box? Extra work, uncertain (for me) performance, reduced speed, etc. I have made 'barics before, and they go low enough for me without any extra help.
Any PRs I've heard in the past, I didn't like, and the same with most ported designs.
I have the drivers for the 'barics, and cut the ply (2 years ago!!!), so I just want avoid mistakes before I start.
My back wall has a Persian rug, covering 5-8", curved, of rockwool, front wall 90mm of 200gm rockwool behind curtain fabric, top corners similar. Made big subjective improvements.
I've tried posting pics, always have problems. Computer illiterate!
Any PRs I've heard in the past, I didn't like, and the same with most ported designs.
I have the drivers for the 'barics, and cut the ply (2 years ago!!!), so I just want avoid mistakes before I start.
My back wall has a Persian rug, covering 5-8", curved, of rockwool, front wall 90mm of 200gm rockwool behind curtain fabric, top corners similar. Made big subjective improvements.
I've tried posting pics, always have problems. Computer illiterate!
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The best I can manage is links, and this took me half a dozen tries!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/ListeningArea002.jpg http://i1134.photobucket.com/albums/m604/awkwardbydesign/ListeningArea001.jpg
These pics were taken before the upper edges of the walls were filled and covered. The bead curtains on front of the hifi are to improve the WAF, and I can reach through to the controls, plus they allow airflow, as I use computer fans to cool the amps.]#
Speakers on Seismic Sink style stands, inner tube type. Cat position variable.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/ListeningArea002.jpg http://i1134.photobucket.com/albums/m604/awkwardbydesign/ListeningArea001.jpg
These pics were taken before the upper edges of the walls were filled and covered. The bead curtains on front of the hifi are to improve the WAF, and I can reach through to the controls, plus they allow airflow, as I use computer fans to cool the amps.]#
Speakers on Seismic Sink style stands, inner tube type. Cat position variable.
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Posting images is
Just copy the IMG code from the photobucket or use the links you have above by clicking the insert image button
at the top of the message box...
Nice stuff...
Just copy the IMG code from the photobucket or use the links you have above by clicking the insert image button
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Nice stuff...
Ok, I'll try that now.
Whoa! Wonder if I can do it again? THAT is the test.
Oops, one too many! Lol.
Well, thanks for that, I just hope I can remember next time.
Whoa! Wonder if I can do it again? THAT is the test.
Oops, one too many! Lol.
Well, thanks for that, I just hope I can remember next time.
Nice Kitty.... That looks a nice place (now I feel poor)
Pic on this site: Click "Go Advanced", then click on the paper clip icon, load photo. (this takes 5 - 10 seconds)
Why a vented box.....I don't know much about the woofer, but every photo/link I've seen it is in a vented box of some type. WinISD defaulted the sims - vented/PR.
Pic on this site: Click "Go Advanced", then click on the paper clip icon, load photo. (this takes 5 - 10 seconds)
Why a vented box.....I don't know much about the woofer, but every photo/link I've seen it is in a vented box of some type. WinISD defaulted the sims - vented/PR.
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How much storage does this site have...
I don't know awkward....sounds like you are trying to
a square peg in a round hole.
I don't know awkward....sounds like you are trying to
a square peg in a round hole.
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Ok, now I have to learn to use thumbnails!
Linn Isobariks used a sealed box, I think, and that's where I was first impressed with the quality of the 'baric bass. I've used sealed box in the past, and it worked fine for me.
I must confess, I have been described as a square peg, myself.
And the last pic is at Lake Como, we used to go on the 'bike, but now we fly. Italian police shout at you if you skate on the road; philistines. 🙁
Oh, it is a thumbnail! I think?
Linn Isobariks used a sealed box, I think, and that's where I was first impressed with the quality of the 'baric bass. I've used sealed box in the past, and it worked fine for me.
I must confess, I have been described as a square peg, myself.
And the last pic is at Lake Como, we used to go on the 'bike, but now we fly. Italian police shout at you if you skate on the road; philistines. 🙁
Oh, it is a thumbnail! I think?
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