From goffmac747@aol.com Sat Jan 31 10:53:08 2009
Subject:Re: 12 speaker in custom cab?


I'll second this on the cabinet size vs. a workable speaker on the ideal volume.. Speakers are designed for specific applications, vs. size of cabinet and whether they work best in a sealed or acoustic suspension enclosure or a ported or vented one. Although there are speakers that can produce low bass in smaller enclosures it's more than likely not a musical instrument speaker However new editions of bass cabs are going with smaller speakers but in an array fashion which ends up pushing enough air to rival a 15 or two....

Reason I posted trying out a car audio speaker. The technology in those applications try to get as much thump out of a small enclosure. But it may need gobs of power. I just don't know what models would work or even if they would sound good for a leslie. Since you are experimenting maybe you could drive your porta leslie to a car audio shop and test drive some of those models, should you find a shop that would agree to do it, and see...A leslie has a specific tone it wants to produce and not just any speaker seems to suit the traditional. But basically speakers are designed to react at certain frequencies and in a given enclosure. If leslie upgrading were as big an industry as car audio is, someone might've invented a 12 or a 10 that could get you down there in a small space, or if you had money to burn, you might approach a speaker maker and have them make one...

Still the issue would be if the replacement speaker helps faithfully reproduce a good ramp/up/down tone. I know from my own experience, trying to use a different brand of 15 in my studio 222 like a Goodman's Audiom 81 which is an old '60's English organ speaker with a free air of 25hz,? the 81 did not suit my tastes when it came to ramp up and down. Hard to explain but the "vibratone" effect became unnatural as regards the lower rotor... Sounded like the effect was "quivering" in the wrong frequency range..? So I went back to the original that came with the 222, although I don't know what the brand or model is as there are no markings on the speaker and efforts to find out have failed. It has a square magnet..... All I know it is, its the speaker that came from the factory when the 222 was new. Even reconed, as it was reconed previously and done wrong according to the present reconer, the voice coil was wound for an 8 ohm ( I had nothing to do with this) and now, with an off the shelf cone and a new 16 ohm voice coil, the original sounded better (meaning more natural to a traditional leslie tone) than the Goodman's..And I have no idea why...



http://i150.photobucket.com/albums/s98/dragongoff/GoodmansAudiom81-1.jpg

http://www.radiomuseum.org/r/goodmans_audiom_81.html

Having said that, I made a 142 cabinet... you can see it on the clonewheel page under goff's 142, for the same purpose you made your porta leslie and stuffed it with stock 122 parts, an old silver jensen 15 etc., and the bass is not bad. The cabinet materials might've helped with the bass tone being more resonant, but more of its that the cabinet was patterned as close to the 145 as possible taking note of internal dimensions..

Goff



-----Original Message-----
From: Bruce Wahler
To: CloneWheel@yahoogroups.com
Sent: Sat, 31 Jan 2009 8:41 pm
Subject: Re: [CWSG] Re: 12 speaker in custom cab?

Now the bad news: Speakers cannot produce much sound below their resonant frequency, even in a tuned cabinet. So, while the '12B might provide BETTER bass than presently heard, it's not possible to get down to the "feel it in your bones" frequencies of 15-30Hz. You'll have to settle for solid bass at 50Hz and up with the '12B vs. 40Hz and up for the 15B.

_,___





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