Radio Shack 8" DVC subwoofer

jr@mac

Hand exercised only. 

Loudspeaker parameters (Radio Shack advertised in paranthesis):

Fs  = 39.09 Hz (39)

Re  = 2.58 ohms[dc] (2.9)

Le  = 154.64 uH 

L2  = 516.05 uH

R2  = 13.01 ohms

Qt  = 0.58 (0.59)

Qes = 0.70 (0.72)

Qms = 3.35 (3.26)

Mms = 24.34 grams

Rms = 1.784746 kg/s

Cms = 0.000681 m/N

Vas = 43.72 liters (36.8L)

Sd= 213.82 cm^2

Bl  = 4.708406 Tm

ETA = 0.35 %

Lp(2.83V/1m) = 92.49 dB

Added Mass Method:

Added mass = 40.00 grams

Diameter= 16.50 cm

Soooo... reasonably close to advertised, and another good example of how drivers used to be engineered for sealed box applications, rather than just throwing a High Q motor under a cone and advertising them for use in sealed enclosures. 

To wit: in one heavily stuffed cubic foot, this driver has F3/6/10 of 55/43/33 and a Q of 0.74

I calculate about 5mm +/- of coil throw, and I was not able to bottom the coil out against the back plate, so even with the 3.35mm "peak to peak" excursion advertised, I am guessing this woofer will exceed that figure fairly gracefully. I used to have a pair in an old S-10 Blazer and my experience seems to indicate my guess to be fairly accurate. 

so here we have an 8" driver that will dig fairly low in a small sealed box whole offering very, very nice sensitivity (check out that 2.83V number, folks). This appears to be a reasonably well designed driver, even by modern budget driver standards. 

Here is the impedance curve along with the overlay I took for calculating Vas:


Here is a modeled response:


Here are a couple snapshots of the driver itself:

Classic treated, ribbed paper cone and stamped basket. Wonderful walk down memory lane holding this in my hands. 

Nicholas_23

Foam surround?

jr@mac

Yep, foam. Great shape. 

Wolf

My 5 say Realistic on them...