Radio Shack 1272, anyone?

[GM]

if i'm not mistaken, that particular RS 6 inch was made like an oversized boombox speaker, so its capabilities suggest it was made for large boombox replacement or PA use.

Greets!

OK, I've never bothered to scope out any boombox designs, but I can see where that could work, though it's nowhere near durable enough for PA.

GM

 

[Slam630]

Greets!

FWIW, the one's I have plot ~ identical on an old dbx RTA as a 40-1271C, though they sound different, which means OB or aperiodic. BTW, they both benefit from the $0.98 tweak and mass loading the driver to the baffle as well as epoxying the motor to the frame and damping the basket.

http://web.archive.org/web/20020628234451/http://www.mindspring.com/~darmah/lowther/mods.htm

GM

I found the specs in the archives:

8" 5.4-Ounce Replacement Speaker
(400-1272) Specifications Faxback Doc. # 48799

Size: ........................................................... 8 inches
Type: ............................................................... Cone
Input Power: ................................... 5 W Nominal; 15 W Maximum
Impedance: ........................................................ 8 Ohms
Program Source Operation: ........................................... 15 W
Peak Music Source: .................................................. 15 W
Resonance: ......................................... 90 Hz +/- 25 Hz at 1V
SPL: ............................................. 90 dB +/- 2 dB at 1W 1M
Frequency Response: ..................... 80 ~ 10kHz with 20 dB deviation
Distortion: ...................................................... 5% Max

I couldnt find anything about mass loading the driver to the baffle. I forgot to mention that my drivers came with a coat of dammar aleady applied.

 

[GM]

I couldnt find anything about mass loading the driver to the baffle.

Greets!

Mass loading a driver is making it part of the structure. For a box, this is usually done by adding a brace that the driver's motor attaches to. This is a nifty/easier way that allows some adjustability also: http://melhuish.org/audio/images/press-screw.gif With OBs though, you'll have to make a cradle to attach the screw block to so that it doesn't obstruct air flow too much.

GM

 

[Slam630]

Thanks for the info GM. That link doesnt work for me. It says access forbidden.

 

[GM]

Huh! Works for me. OK, try this and scroll down the page to the 'pressure screw' section: http://melhuish.org/audio/DIYTQ4.html

 

[Slam630]

Just got these speakers back from my mom. I gave them to her after I got some Visaton b200s and she was using them for a few years. Last year my daughter accidentally blew up one of the Visatons. They were replaced with some old KLHs

So it is nice to hear some open baffles again. I am running them with the KLHs off a Rotel receiver. Makes me want to get a replacement Visaton though.