| For more info on loudspeakers and loudspeaker repair, here are a few good resources: |
| Someone on the Madisound message board asked for a graph for the old Peerless KO40MRF midrange. Seeing as I had to go back to catalogs from a decade ago just to find it, I thought it would be a good idea to post it up here, on the assumption that it would be rather hard for him to find. Here goes: |
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| I figured this might be useful, too: |
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| Loudspeaker Data |
| This page is a repository I'm creating, for hard-to-find loudspeaker datasheets, graphs, specs, or whatnot. |
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| My partner, Robert Cheng, owns a full LEAP/LMS loudspeaker measurement system. We've been measuring lots of drivers for use in our projects... here's a few graphs of some drivers commonly of interest on speaker-building message boards, lately. |
| Dayton 10" (Parts Express 295-315) |
| Note that beyond a general "tilt down" shape of a half-dB/oct. or so and a small dip at about 750 Hz, this driver does very little wrong between 50-2000 Hz! This graph is sixth-octave resolution, and was measured in a semi- infinte baffle (4 foot square) at about 15 degrees off-axis; it is fairly representative of an "averaged-out" curve shape, of on-axis vs. off-axis... pretty close to a representation of the average power response. |
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| Dayton 8" (Parts Express 295-310) |
| On the other hand, this driver has a few more problems. Good up to 1000 Hz, but above that, watch out! This one was measured in twentieth-octave resolution, in order to pin down the exact magnitude and location of the spikes in the curve. Looks like some rather nasty surround and/or dustcap resonances... and yes, that is really a fifteen dB differential between 1200 and 2600 Hz! |
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| MCM 55-1200 4.5" |
| This is a very neat little 4.5" mid-woofer I've been using lately. Not much wrong to speak of here! |
| Old Driver Datasheets |
| Here are some factory datasheets for various drivers. I post things here when I see old stuff asked about on message boards, if I happen to have the spec sheets... |