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Hi, l have recently purchased these beovox 4703's. Two woofers weren't working when l got them, one had an open voice coil and the other had a bad solder at one voice coil to flexible lead wire junction.
I bought four more original woofers but 3 of the 4 turned up with jammed voice coils (shifted magnets). I have since read on here that this is common on p-45/50's etc, possibly common on these as well? I have repaired 3 woofers so far, thinking of doing them all so l don't have to worry and so l have fully functional spares as well.
I also recapped the crossovers, replaced resistors and replaced the woofer wiring. If it helps anyone the shims used for centering the magnets are 0.94mm and shims for centering voice coil are 0.14mm.
I have them all back together and they do sound very nice, l have found mids to be more pronounced than the lows and highs, have my amp loudness on to compensate for this, don't know if this is normal for these. The lower frequencies are better served on these than my little 1702's which is to be completely expected however l am not sure the mids and highs are really any better.
I do have 3 questions:
-The yellow cabinet insulation (packing) is still in the plastic bags, is this normal? It kind of seems to defeat the purpose with the plastic.
-The large crossover caps that l have pictured are supposed to be 75uF, all four measured between 125uF and 157uF, surely they weren't marked "incorrectly" from Wicon factory?
-I will have to re-veneer the cabinets as they are unfortunately rough, should l go with golden teak as original or perhaps American oak. I know they came out in oak and l can get this much cheaper. https://www.veneersonline.co.uk/collections/stair-stringer-veneer-iron-on-and-unglued/products/oak-wood-veneer-sheet-unglued-fleece-backed-3500mm-x300mm
Some guidance on the veneering would be much appreciated as l haven't attempted before, should l be using iron on or would the fleece backed be ok to use with a spray contact adhesive?
I appreciate any feedback. Here are some photos of my progress.
Here is the link to photos.
http://s61.photobucket.com/user/miltonbj/library/
I have just realised, should l have posted this in the vintage products forum?
Beovoxnewbie: I have just realised, should l have posted this in the vintage products forum?
Moved to Workbench
Martin
Thanks very much Martin
Regards, Milton
Nice work.Two comments though;The resistors - I generally wouldn't recommend increasing the wattage.Some resistors double as very good fuses in overload situations. Resistors with a higher wattage range will not burn at the same level andnot give the same passive protection.
The capacitors - glue them to the board and/or eachother or they will rattle audible and eventually work lose.
Thanks Martin for your reply.
Yes l understand what you are saying about the resistors, i have seen them open in other speakers. l normally always replace with same wattage rating as originals, in this case l couldn't find a schematic or service manual anywhere for the beovox 4703's so didn't have the specs. Thought 5w would be a safe rating, maybe the originals are only 3w?
Great advice on the capacitors, l must do that.
The original resistors are 3W.
Thanks for your confirmation,
Regards, Milton.