Indeed! A classic alignment [Vas/1.44, Fb = Fs] requires a 6" dia. x ~52-53" long vent to handle 400 W and even a T/S max flat at ~163.1 L/~19 Hz once 0.5 ohms for wiring increased Qts' = 0.472 requires a 6" dia. x 30-31" long vent, so right at the limit just to handle 300 W.
I think for that sub, around 2.5ft3 sealed yields qtc.707 F3=35hz, that's reaaaaallllllyyyyyy good for a sealed sub.
Not my rss390hf closer to 30hz F3, but not 4.4ft3 either.
Might be an option for isobarik (hate to toss the db away).
5ft3 sealed (for 2 drivers) could make a nice ppsl, or perhaps a m&k design....................
Not my rss390hf closer to 30hz F3, but not 4.4ft3 either.
Might be an option for isobarik (hate to toss the db away).
5ft3 sealed (for 2 drivers) could make a nice ppsl, or perhaps a m&k design....................
FWIW using the 0.472 Qts', I calc a ~0.727 Qtc, ~33.2 Hz, so yeah, my kind of sealed alignment. 😉
I’m SO SORRY for my absence. PLEASE forgive my senior citizen issues and allowing life to get in the way
I have had this page open on my phone since the last reply. I have the Dayton RSS315HF-8 12”. I failed to mention I picked this driver over many other 12” & 15” for its low F3 & bang for the $. I’m sure other bigger drivers could exceed its F3 performance w/bigger price tags & closure requirements - had to make a choice.
Still working on getting a windows platform computer to run WinISD. At Norman’s suggestion (thank you!) gonna work on modeling for a PR. Dayton make ‘em - several different series and sizes. Correct me if I’m wrong I recall reading somewhere WinISD does permit modeling PRs? Gonna try one of the reference PRs first. In the interest of maintaining closure integrity and keeping $s down. I hope a 15 incher will work.
So many thanks for your patience and ideas.
Tony.
I have had this page open on my phone since the last reply. I have the Dayton RSS315HF-8 12”. I failed to mention I picked this driver over many other 12” & 15” for its low F3 & bang for the $. I’m sure other bigger drivers could exceed its F3 performance w/bigger price tags & closure requirements - had to make a choice.
Still working on getting a windows platform computer to run WinISD. At Norman’s suggestion (thank you!) gonna work on modeling for a PR. Dayton make ‘em - several different series and sizes. Correct me if I’m wrong I recall reading somewhere WinISD does permit modeling PRs? Gonna try one of the reference PRs first. In the interest of maintaining closure integrity and keeping $s down. I hope a 15 incher will work.
So many thanks for your patience and ideas.
Tony.
??? It is what it is and we do what we can when we can in these trying times and there's enough of us senior citizens to 'feel your pain', so moving on......... 😉
No clue why you can't get it to work and yes, it does PRs, though don't know how accurately, but this Excel program is long since proven and does PRs and IIRC can be run online for free now: UniBox
No clue why you can't get it to work and yes, it does PRs, though don't know how accurately, but this Excel program is long since proven and does PRs and IIRC can be run online for free now: UniBox
well, PR is basically a port.
You tune the passive radiators resonance to what you want, same as if you had a ported subwoofer.
If you were to tune to 20hz, then that should be the frequency of the passive radiator.
Classic rule of thumb = a pr should move 4 times the air.
so a 12" pr should have 4 times the xmax of the driver.
People/industry often cheat this.
You tune the passive radiators resonance to what you want, same as if you had a ported subwoofer.
If you were to tune to 20hz, then that should be the frequency of the passive radiator.
Classic rule of thumb = a pr should move 4 times the air.
so a 12" pr should have 4 times the xmax of the driver.
People/industry often cheat this.
Don't recall that one, just Tom Danley's 1.5 - 2x Sd, but FWIW I designed all mine by finding the vent volume based on the woofer's next larger frame size effective diameter and calculating its total air mass @ 'x' Fb, which back then was usually in the published Vs measured Fs being 'close enough' since it was typically lower than any recordings I had, so basically a TT 'rumble' filter.