Large Advent Woofer (Masonite 1972) Measured Thiel and Small Parameters

[Pete B]

Just did a quick run of an original, never reconed, Large Advent woofer (masonite). woofer is not stamped with a date but other parts say 1972 in the system. I refoamed this woofer with an RSSOUND edge which was a perfect fit:

Measured voice coil DCR (Re) with a Fluke meter at 4.83 ohms.

Piston diameter measured (estimated) at 20 cm = 7.87"

Used Liberty Audio Suite (LAUD) added mass method, delta mass = 52 grams for -33% delta f.

Midband (80 Hz) test voltage was about .5 Vrms.

Woofer had been used (broken in if you believe in such things) with music before testing:

Fs = 18.23 Hz

Vas = 250 liters or 8.82 cu ft

Re = 4.83

Qe = .364

Qm = 2.93

Qts = .324

Mms = 42.28g

Cms = 1.80 mm/N

Bl = 8.02 Tm

no = .400 %

SPLref = 88 dB

These figures pass a sanity check from my perspective.

Pete B.

[Wally]

Hi Pete,

Have you done the specs on the Tonegen replacements for the 12" AR woofer?

Bret still has a pair to sell and I have been toying with the idea of building a 'modern' pair of ar11/ar58's....

Would I just copy the volume of the AR98 for optimom low end response? I would use the 'original' replacement tweeter and midrange that Layne Audio sells. Or [possibly an AR90 style speaker but using two Advent woofers which I can probably get cheaper than 4 AR's by buying complete Advents....

Any suggestions based on your reference speaker project?...

regards, Wally

>Just did a quick run of an original, never reconed, Large

>Advent woofer (masonite). woofer is not stamped with a date

>but other parts say 1972 in the system. I refoamed this

>woofer with an RSSOUND edge which was a perfect fit:

>

>Measured voice coil DCR (Re) with a Fluke meter at 4.83 ohms.

>Piston diameter measured (estimated) at 20 cm = 7.87"

>Used Liberty Audio Suite (LAUD) added mass method, delta mass

>= 52 grams for -33% delta f.

>Midband (80 Hz) test voltage was about .5 Vrms.

>Woofer had been used (broken in if you believe in such things)

>with music before testing:

>

>Fs = 18.23 Hz

>Vas = 250 liters or 8.82 cu ft

>Re = 4.83

>Qe = .364

>Qm = 2.93

>Qts = .324

>Mms = 42.28g

>Cms = 1.80 mm/N

>Bl = 8.02 Tm

>no = .400 %

>SPLref = 88 dB

>

>These figures pass a sanity check from my perspective.

>

>Pete B.

[Pete B]

I answered this here, as I'd like to try to keep this thread on topic:

http://www.classicspeakerpages.net/dc/dcbo...ype=search#6976