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To Mr. Hyde: you appear experienced with Bose 501 Series III speakers. I need to replace a burned out glass bulb fuse inside the right speaker, the fuse for the woofer I believe. I think that you said that...
Hello whit_hughes,
Just received your request for some information regarding Bose 501's......... Series III. Your looking for te manufacturers part # for the fuse which is in line with the woofer? The fuses used ON the Series III Crossovers (hard wired/soldered directly to crossover board/componants) have been Identified as BUSS #2494, 2amp, Quick-Blow Glass Tube Type Fuses. The fuse which is in-series with the woofer & the fuse which is in-series with the pair of tweeters are the same! In theory this means that the woofer is capable of twice the wattage of the tweeters due to the tweeters being wired in series with each other..... which in turn divides the power beween the two equaly. On the woofer circuit there is only the one speaker or voice coil obsorbing the power. The woofer circuit being wired in parallel with the tweeter circuit again splits the power between the two cuircuits..... so in an ideal situation the woofer sees 50% total input power while the tweeters each see 25% total input power;;;; totaling 100% total. The way Bose has fused them in the Series III's is such that each branch can obsorb a total of 2 amps before shutting down each indivigual branch. This can be adventageous..... should peak power be exceeded causing loss of full load abruptly, Amplifier Power Output Transistors usually blow..... however when only half of the full cuircuit shuts down due to peak power exeeding limits causing one fuse to open (blow) ... the actual impedance (resistance) of the speaker increases protecting the Amplifiers Output Transistors! Thats the reason for the 2 fuses. Each of them are identical. They are soldered into place.... via the wire which is attached to each end of the fuse. (Note; the fuse "kit" Bose is trying to sell you is an external in line fuse holder for each speaker {costing 1.29 each} & 2 fuses for each holder, One for now & One for Later aftr it blows {costing 1.00 each}..... costing Bose 6.58, neting Bose $13.42 Profit!!!! Keep in mind that this fuse WILL NOT FIX YOUR PROBLEM EITHER! DUE TO THE FUSE WHICH IS PRESENTLY BLOWN HAS NOT BEEN REPLACED!!!!! ) The one that has to be replaced is on the crossover... not between the Amplifier & the Speaker Enclosure. Tools required = 1 Long Big Straight Blade Screwdriver to pry off speaker grill, 1 Phyllips Screwdriver to remove screws seccuring woofer to encloser... be carefull not to damage/tear gasket, 1 pair side cutters to cut blown fuse out of crossover curcuit, 1 pair needle nose pliers to attach NEW fuse to crossover curcuit, 1 soldering Iron & a small piece of solder to re-solder fuses leads securly to crossover curcuit. ( replace gasket, woofer, screws, & speaker grill. ENJOY! Should additionaL informaton be required please let me know.... you'll have to leave me your e-mail address for pictures or drawings.... as I don't think they can be sent through this site. Hope this helps ya..... Its an EASY JOB...... you CAN DO IT! & will be glad you did when your done, they'll sound GREAT! ) GOOD LUCK!
Jun 22, 2011 |
Audio Players & Recorders
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