IMF Electronics Vintage Woofers and Mid-woofersSorry Folks these are sold!!!! Woofer and mid-woofer Replacement Drivers for vintage IMF Electonics transmission line speakers $400 for four drivers. I will sell them in separate pairs, but I ...400.00

IMF Electronics Vintage Woofers and Mid-woofers [Expired]

no longer for sale

Sorry Folks these are sold!!!! Woofer and mid-woofer Replacement Drivers for vintage IMF Electonics transmission line speakers $400 for four drivers. I will sell them in separate pairs, but I will not sell just one unit. These are perfect replacement drivers if you are rebuilding a vintage IMF transmission line. One Pair of 300 x 210mm (11.75"x8.25")8 ohmwoofers with large ceramic magnet + styrene/fiberglass cone and a rigid cast aluminum chassis.. Also one pair 130mm 8 ohm mid-woofers These drivers were sourced from IMF back in the 80's for use in a transmission-line cabinet. They have strong similarities to the legendary KEF B139, but they do not have the flat diaphragm of the B139. I think these are the same drivers that IMF used in their largest transmission lines. I read somewhere on the net that the oval woofer was made by Elac and that the 130mm mid-woofer unit was manufactured by KEF. I see no markings on the drivers to confirm this. The only labels on the drivers are located on the magnets and those labels clearly read: "IMF Electronics" They look very British to me. Precision construction and finish with a cast aluminum basket on the woofer. In 1970 I built a large transmission line using the data from Bailey's Wireless World article and I was very impressed with the excellent quality of the bass. i used a eminence 12" woofer for that transmission line because I couldn't afford to purchase the IMF driver nor did I know how to find the IMF driver. I loved listening to that transmission line, but I soon relocated to a small cottage in a rural area and I had no room for a pair of speakers the size of a 1948 kitchen refrigerator, so I sold those speakers to some happy guy who lived in a big house. I have missed the realistic bass quality of transmission line bass since then and I have always yearned to build a pair of transmission line cabinets using the designs of IMF electonics as inspiration. Back in the day, IMF built the finest transmission lines on the planet. My brother is a long-time dedicated speaker-builder and he acquired these drivers from IMF in the 1980"s. I envied his ownership of them, but never found out how he got them or how much he paid. He worked for a local company that manufactured speaker kits and perhaps these drivers were given to him as part of his compensation. They collected dust in storage until 2002 when he gave them to me. I began to design a transmission line cabinet so I could put them to good use. Again the size requirement was too much for me so I decided to shelve the project.. A couple years ago, I used both of the woofers and the midranges in an open baffle speaker inspired by Linkwitz. i used them not because they were ideal for that use, but because I had them- why buy new drivers when I already had these? They worked in the open baffle , but these drivers are not ideal for that use, so I quit using them about a year ago- still planning to build a transmission line for them. I'm sure they will sound fantastic in a correctly designed cabinet with a well designed crossover along wirh the mid-woofer and an appropriate tweeter. I am finally willing to accept that I will never have room for a big transmission line like the IMF boxes so I no longer have any good reason to hang on to these drivers. I plan to build a transmission line, but when I do it will have to be a smaller one using a 6 or 7" driver. Consequently these are for sale. They have all been used, but never abused. I never drove them with an amp that could deliver over 60 watts. I don' t think any of the British drivers from the 70's could handle 200 watt amps-so if you are planning on using a really big powerful amp I would suggest that you find some more modern drivers. I suspect the 130mm bextrene mid-woofer might work great in a LS 3/5A clone. It would make a fine driver for a mini-monitor with the addition of an appropriate tweeter. You will notice I glued a band of dense industrial felt to the magnet edge on the oval woofers. This can be removed with a knife. I mounted the driver from the magnet in my open baffle system. The felt made the mounting more secure, less resonant and protected the magnet edge from any damage. I see no reason to remove it-if it effects the drivers response it would only be for the better, however I did not detect any change in the sound of the driver with or without the felt. All these drivers are in great functional condition, but they have minor discolorations on the cones which you can see in the photos. Some of these minor discolorations only really show up in photographs. The woofers are heavy and the shipping guy says it will cost $25.00 to send one from Seattle to the East Coast using slow shipping (one week) and close to $50.00 for fast ship (2days). Buyer pays shipping. I will pack them very securely-I would hate to see such rare units destroyed in transit. I will email photos to interested persons. This site is not uploading photos todaydue to some bug in the system. I will accept pay pal if the buyer pays the pay-pal fee.
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