Hi all,
Anybody have a Dayton 6.5" woofer (Parts Express #295-305 or #295-306) handy to measure the diameter of the actual cone surface?
I'm building a stereo pair of transmission line subs and I want to use the shielded #295-306 as the driver. Here's the thread. It has pictures...
http://www.diyaudio.com/forums/showthread.php?s=&threadid=17485
I'm trying to decide whether to go 1 driver/box or 2 drivers/box and the Sd is required for calculating the line dimensions. Martin J. King has advised that he measure Sd based on the diameter at half the surround to (my guess) approximate the moving part vs the non-moving part of the driver. This dimension is never 6.5" but always much smaller and depend on the size of the frame and baffle mount.
Thanks in advance!
🙂ensen.
Anybody have a Dayton 6.5" woofer (Parts Express #295-305 or #295-306) handy to measure the diameter of the actual cone surface?
I'm building a stereo pair of transmission line subs and I want to use the shielded #295-306 as the driver. Here's the thread. It has pictures...
http://www.diyaudio.com/forums/showthread.php?s=&threadid=17485
I'm trying to decide whether to go 1 driver/box or 2 drivers/box and the Sd is required for calculating the line dimensions. Martin J. King has advised that he measure Sd based on the diameter at half the surround to (my guess) approximate the moving part vs the non-moving part of the driver. This dimension is never 6.5" but always much smaller and depend on the size of the frame and baffle mount.
Thanks in advance!
🙂ensen.
Ron E said:
Hi Ron E,
Based on 130 sq.cm. I get r = 6.433 cm = 2.533 in. Is the cone diameter really only 5.066 inches?! And how did you reverse engineer this from the specs on their site.
🙂ensen.
Hmm, according to PE's measured specs, the 295-305/306 has an effective diameter = 130/132mm, or ~5.12/5.20". I assume Clio calculates it from T/S specs, so it should be pretty accurate, certainly 'close enough' for cab design purposes.
Really, (Vas/desired Vb)/pipe length is the most accurate way to determine the optimum cross sectional area of the pipe (or its equivalent straight pipe Vb if tapered) since it wants to 'feel' a certain amount of compliance, just like when it's in a sealed or vented cab.
GM
Really, (Vas/desired Vb)/pipe length is the most accurate way to determine the optimum cross sectional area of the pipe (or its equivalent straight pipe Vb if tapered) since it wants to 'feel' a certain amount of compliance, just like when it's in a sealed or vented cab.
GM
When I don't know the Sd (or diameter) of a driver, I use the following diameters - close enough for Govm't work.
Frame" - piston in cm
4" - 8.2cm
5" - 10cm
6.5" - 13cm
8" - 17cm
10" - 21cm
12" - 26mm
15" - 33mm
18" - 40cm
Piston Diameter is usually about 2" (5cm) less than driver frame diameter.
For really long excursion drivers, take 2-3mm off the number above.
Back calculation from T/S requires rearranging:
Vas=1000*rho*c^2*Sd^2/((2*pi*Fs)^2*Mt)
rho=1.18
c=345
Mt in kg.
Vas in liters
Frame" - piston in cm
4" - 8.2cm
5" - 10cm
6.5" - 13cm
8" - 17cm
10" - 21cm
12" - 26mm
15" - 33mm
18" - 40cm
Piston Diameter is usually about 2" (5cm) less than driver frame diameter.
For really long excursion drivers, take 2-3mm off the number above.
Back calculation from T/S requires rearranging:
Vas=1000*rho*c^2*Sd^2/((2*pi*Fs)^2*Mt)
rho=1.18
c=345
Mt in kg.
Vas in liters
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