fet Posted March 17, 2001 Share Posted March 17, 2001 In the "combo amps" thread you alluded to plugging a Radio Shack piezo tweeter into the extension speaker of your Polytone amp. Can you elaborate? What RS tweeter and how is it wired? I'm looking for more treble from my P-tone for acoustic-electric guitar. Thanks much. Link to comment Share on other sites More sharing options...
Ed Friedland Posted March 17, 2001 Share Posted March 17, 2001 Sure, I don't know what exact model tweeter it is, it's black, has a square lip around a 3" diameter circular tweeter. It's got a resistor in it so it doesn't need a crossover. I just wired a 1/4" phone jack to it and plug it into the extension speaker jack in the P-Tone. It works fine. Actually, I've taken that tweeter and installed it into a homemade cab with a Carvin 4 ohm 15" speaker. I use this with my Acoustic Image Clarus for upright and small gigs. The box itself is pretty durable, the Carvin speaker is rated at 600 watts, and it's a sealed cab. I pump 350 through it sometimes with my Trace, and it takes it. www.edfriedland.com The Bass Whisperer Bass Whisperer TV Link to comment Share on other sites More sharing options...
Jeff Addicott Posted March 17, 2001 Share Posted March 17, 2001 Instant full-range. What a cool idea! I'll have to try that on my GK. ------------------ Jeff Addicott http://www.jeffnet.org/~addicott/bass.html Jeff Addicott http://www.jeffnet.org/~addicott/bass.html Link to comment Share on other sites More sharing options...
bspangleyahoo.com Posted March 17, 2001 Share Posted March 17, 2001 Hey Ed, Could you give us the the dimensions of your sealed speaker box with the Carvin 15 and the Radio Trash tweeter, please? Thanks. Link to comment Share on other sites More sharing options...
Ed Friedland Posted March 18, 2001 Share Posted March 18, 2001 Well, here's a picture of it! www.edfriedland.com/gallery.html It's not a bad little thing, no science involved, it's a good utility cab. ------------------ www.edfriedland.com www.edfriedland.com The Bass Whisperer Bass Whisperer TV Link to comment Share on other sites More sharing options...
ricongacharter.net Posted March 18, 2001 Share Posted March 18, 2001 Ed, cool picture, but what is the possibility of your sharing the dimensions? (re:bspangle's request) also Ive been meaning to ask you if youve ever run into a Bassist named Curtis Stoval. I used to go hear him alaot when i lived in phoenix in the eighties and someone told me he was playing in Tucson as well. just curious thanks rrrrrrrr Link to comment Share on other sites More sharing options...
Jim T. Posted March 19, 2001 Share Posted March 19, 2001 Hi Ed, I have a hopefully related question. I own an SWR Workinman's 10 that I love except for the HISS from the piezo tweeter. Do you have a similar problem with the Radio Shack set-up? Do you know of a very cheap Radio Shack or other-noise gate or any other tricks for getting rid of the treble hiss. It drives me nuts in the headphones when practicing. Thanks. Jim T. "When people hear good music, it makes them homesick for something they never had, and never will have." Edgar Watson Howe "Don't play what's there. Play what's not there" Miles Davis Link to comment Share on other sites More sharing options...
g. Posted March 19, 2001 Share Posted March 19, 2001 JimT, you have piezo tweeters in your headphones? Wow! . Link to comment Share on other sites More sharing options...
Ed Friedland Posted March 19, 2001 Share Posted March 19, 2001 Oh, alright, youse wanna get all technical about it? I just brought it in from the back of my truck.....it's 20"X20"X11". As I said the dimensions were accidental, I wanted it to be the same size as my Polytone box. It really did surprise me when I started pumping big watts into it. The tweeter is far from adequate for high volume slapping, but it gets the sizzle heard at low to moderate levels, and for adding prescence to my upright sound it's great. The low end is pretty tight. I'll share this quote from Jim Berganitino on the subject. "Sealed boxes always give you the best bass definition due to their shallower roll off as compared to vented boxes. ( Techinally they have less group delay which means the bass fundamentals don't lag the overtones.) Their F3 point however is generally higher. (There are no free lunches in the world of physics.) " - Jim Bergantino Now, I basically understand that except for the group delay and the F3 point thingie. Anyone want to 'splain? I love the quote, "There are no free lunches in the world of physics". That should be made into a T-Shirt! As far as the tweeter hiss on your WM 10. That's more a product of the circuitry, I don't have that problem with the Clarus, that amp is clean and quiet! I'm not familiar with any Radio Shack noise gates, it's probably an easy thing to make if you're a Heathkit kinda guy. They make foot pedal ones as well. The problem with noise gates is you need a good one that can respond quickly with sensitivity or you cut off the stuff you want to keep. I'd say just roll off some highs, deal with it, or get a WM 10 extension cab and a Clarus! You'll get 120 watts into 8ohms, 200 into 4 or 300 into 2ohms. Actually, I've been told that a new Clarus is coming out soon with 2 channels, one with a mic input and more power. ------------------ www.edfriedland.com www.edfriedland.com The Bass Whisperer Bass Whisperer TV Link to comment Share on other sites More sharing options...
g. Posted March 19, 2001 Share Posted March 19, 2001 Yeah, the piezo horn is not responsible for hiss in the headphones; noisy circuitry is (single coil pickups or bad cavity shielding can contribute when in proximity). Choosing one is as simple as getting about the same SPL as the cabinet makes at lower frequencies to get something near a flat response, and the radiation pattern the attached mouth gives. Two inefficient piezos (add 3dB) can be matched to a woofer, but at least one Radio Shack Motorala design actually has two drivers attached to a flared horn. <-- greenboy ---<<<< Phoenix Developer Consortium [http://phinixi.com] . Link to comment Share on other sites More sharing options...
g. Posted March 19, 2001 Share Posted March 19, 2001 "Sealed boxes always give you the best bass definition due to their shallower roll off as compared to vented boxes." With caveats. >"(Techinally they have less group delay which means the bass fundamentals don't lag the overtones.)" Group delay (in ported/vented designs) comes from the delay of sound from the port, versus what comes from direct (front) radiation. Good ported designs minimize group delay; ie Theile-Small parameters are used to design and no humpy quasi-bass is designed in by tuning the box wrong for the driver's free-air resonance. And the driver is chosen for the desired box size. Strangely, many commercial designs have accentuated group delay in order to make the box more efficient in mid-bass freqencies and thus have the customer thinking it is making major low end. "Their F3 point however is generally higher. (There are no free lunches in the world of physics.) " - Jim Bergantino The F3 point is the low frequency in Hertz where the response is 3 decibels down from the stated SPL efficiency of the cabinet. With the right driver and cabinet size/tuning in ported designs the F3 point can be low enough to do fundamentals on basses more efficiently than a closed/sealed box can, thus the caveat mentioned above. Of course, as Jim Bergantino mentions, group delay can make a mockery of this in a bad design. Generally speaking, sealed boxes sound a little tighter but are not generally favored for loud bass applications because of their relative inefficiency. Home entertainment afficiandos use them a fair amount along with vented, transmission tunnel, isobaric, etc designs. Then, weight and size do not matter so much. A good, easy-to-use cabinet parameter software can be downloaded at http://www.linearteam.dk and will with Theile-Small parameters for your driver allow you to design the best size of cabinet for your uses, whether ported or sealed enclosure is desired. <-- greenboy ---<<<< Phoenix Developer Consortium [http://phinixi.com] . Link to comment Share on other sites More sharing options...
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