Folks,
I have two things - and I want to get them to work together if I can. I have a pair of Bozak 302 “Urbans”, in very nice shape, though the tweeters are gone. I ALSO have a pair of Stephen’s 15” trusonic coaxial drivers. These are the 206 AXA models with crossovers. It seems to me I can remove the baffle from the bozaks and shoehorn in a new one, with the driver placed closer to the top of the baffle and some ports at the bottom.
My worry is that I am told that’s just not enough volume for 15” drivers. The bozak’s are 24 x 24 x 22 = 12,672 cubic inches. HOWEVER, the Tannoy Ardens (which also use 15” drivers) are just 36 x 24 x 14 = 12,096 cubic inches. Ie, 12,000 cubic inches would seem to support a 15” driver in a bass reflex enclosure. Where have I gone wrong?
I have two things - and I want to get them to work together if I can. I have a pair of Bozak 302 “Urbans”, in very nice shape, though the tweeters are gone. I ALSO have a pair of Stephen’s 15” trusonic coaxial drivers. These are the 206 AXA models with crossovers. It seems to me I can remove the baffle from the bozaks and shoehorn in a new one, with the driver placed closer to the top of the baffle and some ports at the bottom.
My worry is that I am told that’s just not enough volume for 15” drivers. The bozak’s are 24 x 24 x 22 = 12,672 cubic inches. HOWEVER, the Tannoy Ardens (which also use 15” drivers) are just 36 x 24 x 14 = 12,096 cubic inches. Ie, 12,000 cubic inches would seem to support a 15” driver in a bass reflex enclosure. Where have I gone wrong?
"Where have I gone wrong? " -assuming you can make decisions like this without the driver parameters
The driver Thiele-Small parameters are used to determine what sized box and box tuning are appropriate. Do you have them for the drivers you intend to use? I'm guessing not... the Stephens drivers appear to have been made well before Thiele-Small parameters were ever used. In that case, you'll need to measure them. It's not just a matter of assuming a certain size box is required for drivers of a given diameter.
Measuring Loudspeaker Driver Parameters
Measuring Loudspeaker Driver Parameters
Unless you want to keep them closed, then it would be easier to decide whether you think they would be better in a different box and there would be things you could do instead.
I saw those stephenson in a classic Karlson K-15 cabinet and they sounded good in that with reasonable bass, so that may be an option if you can't measure them. But i would also measure them as that is the only way to be sure you build the right cabinet for it.
Just assuming a volume on the driver's diameter is shooting in the dark, some 15" drivers need a very small and others a very big cabinet, some work in sealed config, others in reflex or TL type and others only in horns. T/S parameters tell you what is fit for your drivers.
Just assuming a volume on the driver's diameter is shooting in the dark, some 15" drivers need a very small and others a very big cabinet, some work in sealed config, others in reflex or TL type and others only in horns. T/S parameters tell you what is fit for your drivers.
Using those parameters, I get a 180L box tuned to 42Hz will give an F3 of 39Hz.
Whatever 180L is in the Inferial system, I don't know.....
Whatever 180L is in the Inferial system, I don't know.....
180l is a bit over (6) cubic feet. His Bozaks' are a bit over (7) cubic feet. He's in the ballpark.
The original Karlson "K15" design from 1951 (~113 liters rear chamber) should be a good fit and would optimize impact and upper bass definition vs direct radiator.
Karlson K-15 cabinet with Stephens 206 AXA
Karlson K-15 cabinet with Stephens 206 AXA
+1 based on the above T/S specs and a 1/2 ohm series resistance for wiring losses [~0.425 Qts'] = 0.707 Qtc' max flat sealed = ~105.64 L.........
[Qts']: [Qts] + any added series resistance [Rs]: Calculate new Qts with Series Resistor
[Rs] = 0.5 ohm minimum for wiring, so may be higher if driven with a high output impedance and/or a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
[Qts']: [Qts] + any added series resistance [Rs]: Calculate new Qts with Series Resistor
[Rs] = 0.5 ohm minimum for wiring, so may be higher if driven with a high output impedance and/or a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.