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Hi all,
After many many many years my M100 speakers need some work. Most speakers are okay, the woofer has no dried out rubber, and it's coil moves fine, and just has a dent in the paper dome. Alas, the one above it is gone. I opened up the case of the M100, but this speaker is in the sealed compartiment, and everything is glued, even the wires are glued tight.
I removed the speaker from the front and unsoldered it, hoping to find a brand and type, so I can replace it. But, there is not much. Just 8Ω and 770518, no brand, no type. Anyone an idea what it is? pic:
Would repairing the speaker itself work well? I see some workshops do that.
Thanks!
rick
PS The 3rd speaker from above had a bit of a dent in it's rubber dome. I tried to un-dent it with a bit of tape, but it does not stay un-dented.
PPS The tweeter has lost it's metal dome, but I don't think that matters much soundwise.
It is made by Peerless - it is the phase link unit. Mine was refoamed and works fine.
Peter
Try a vacuum cleaner on the dent! The supertweeter adds nothing for me as I cannot hear the frequencies it produces!!
Hi, I have a set of Beovox M100-2 speakers close to condition that you have. Here are the identifiers of the speakers from the service manual. The specific part numbers for the speakers are not provided (at least not in my copy).The speaker you are asking about is the 4 1/2 inch phase-link unit. It has a foam surround for the attachment of the speaker voice coil to the speaker frame. Many speakers from that era used foam surrounds and they eventually wear out. If the speaker isn't damaged then you should be able to have new surrounds attached and the speaker will be good as new.I haven't replaced my surrounds on the 4 1/2 inch phase-link yet but will be needing to soon. My 12 inch woofer surround is rubber and is in good shape. Is your woofer surround also rubber?
Here is my 4 1/2 Inch Phase-Link from one of my M100-2 speakers. The speaker is still functioning well but deterioration is beginning to show on the Phase-Link unit. I will need to stop using this M100-2 pair until I refoam the Phase-Link units in both speakers.
Here are my M100-2 tweeter units. That is the way I received them so I don't know if the top tweeter (3/4 Inch) is supposed to have any additional cover or not.
Here is a full view of one of my M100-2 speakers. Overall it is in excellent condition. When I refoam the 4 1/2 Inch Phase-Link unit I will also look at replacing the cross-over capacitors with a new set. If I don't already have the capacitors in my stock I typically check with Martin to see if he has a kit. I have used his kits on Beovox MC120.2, Beovox MS150 and Beovox S55 speakers.
I measured the diameter of my M100-2, 4 1/2 Inch Phase-Link Unit and it measures 4 Inches. I checked the Beoworld product information page and it lists these measurements for the speakers -
Woofer: 33cm (12.99 inch)Filler driver: 11.5cm (4.5 inch)Mid-range unit: 5.5cm (2.16 inch)Tweeter 1: 4cm (1.57 inch)Tweeter 2: 1.9cm (0.75 inch)
Beocentral provides this information -
12” woofer made by SEAS, a 3” cone midrange (mounted in a sealed and reflex ported section of the cabinet) made by Peerless, a 2” dome upper-midrange made by ITT in Germany, a 1½" dome tweeter made by SEAS and a miniature dome upper-tweeter made by Philips.
My actual measurements are these -
12" woofer4" Phase-Link2 1/2" Midrange1 1/2" dome tweeter3/4" upper-tweeterThe only one I am concerned with is the 4 Inch Phase-Link to order a correct foam surround replacement.
-sonavor
This archived Beoworld thread is about refoaming the similar (if not the same) Phase-Link on a Beovox M75. Since that thread has anyone found a source for an exact match replacement surround for the Phase-Link? The archived thread states that oversized foam surrounds were modified to fit.
I found this link to GoodHiFi regarding the M100-2 Phase-Link. I also found this link to AudioFriends. Both of their description of the Phase-Link driver surround being a foam surround for a 4 inch speaker matches my measurement of that driver.
For a capacitor replacement of the M100-2, I have determined this list per the service manual. Those values don't always match what is actually in the manufactured units so does anyone have a good list of the electrolytic capacitors for these speakers? (I am not ready to open mine up yet).C2 - 16uF 50VC3 - 50uF 50VC4 - 50uF 50V (or 5uF ?) ...The schematic in the manual states 50uF but the parts list says 5uF. I think it should be 50uF.C5 - 8uF 50VC6 - 50uF 50VC7 - 16uF 50VC8 - 8uF 50VC9 - 12uF 50VC10 - 50uF 50VC11 - 4uF 50V
---Protection CircuitC14 - 100uF 40VC16 - 1uF 100V
Thanks for all the info!
I found a link in the old forum to http://www.speakerreparatie.nl (same as http://www.audiolab.nl/) who repair these, called them and sent off my speakers already (I am in The Netherlands).
The link to the special foam ring for the phase link is also them! :-) (http://speakerrepairshop.nl/index.php?item=foam-ring-for-bang-_amp_-olufsen-beovox-m100_2-mid-toner&action=article&group_id=10000013&aid=2742&lang=en#.V_3fMLwY57E)
He also mentioned this speaker is made by Peerless.
What is a "phase link" actually? I also see them mentioned as "filler"..
"Is your woofer surround also rubber?" - yes, and it looks fine apart from the dent in the paper dome in the middle. I'll leave that as is, I don't think the center dome adds to the sound.
Same for the 3rd speaker. I don't dare to put a vacuum cleaner onto it, even on low power, afraid to break it. Is there anything behind that thin rubber layer that is also dented?
Beware of recapping: I have this not very clear image of the schematic, and some of the caps seem to be unipolar ones! At least, they are drawn with two non-black-filled rectangles as opposed to the "true" electrolytics. Can't discern any +/- signs in my schematic. Just one is drawn truly "polar":
Not sure if recapping really is necessary. If the caps don't get warm they may last a very long time.
The schematic says M100-2 type 6319. I have M100, and it's type is 6309, so probably a bit earlier.
Mine have (had) a perforated metal dome, but they were only glued on. Just for protection I guess. I still have them, but where...
I have recapped a number of my Beovox speakers and yes, the cross-over, electrolytic capacitors are bipolar (uni-polar). Dillen on this forum (Martin) has some capacitor kits for the various Beovox speakers. There are also speaker supply shops online that sell capacitors in the ranges speaker require as well. I haven't found any difference between the more expensive, poly type speaker capacitors and the electrolytic ones. One way to determine if a recap is needed it to remove the cross-over, then unsolder and test the capacitors with an ESR meter. You ought to at least examine the cross-over boards. If they are still clean (nothing leaking) then there is no hurry to leave them intact. I still plan on recapping mine.
Regarding your phase-link question, Phase-Link was Bang & Olufsen's design solution to speaker phase distortion. Here are some snippets from the M100-2 literature.
rickjansen: Mine have (had) a perforated metal dome, but they were only glued on. Just for protection I guess. I still have them, but where... rick
If you find them can you take a picture of them and post it? I might want to see if I can make a replacement for mine as the protective domes are missing on mine.
Will do! May take a few months as I'm in the middle of packing for moving house, so I don't know where they are right now! :-)
Thanks for all info people! Much obliged. Will report back on the repair of the phase link speaker.
Just got the repaired phaselinks back from http://www.audiolab.nl/ and they look as new:
Putting the speakers back in the box is not easy, the wires are very very short, and glued to the casing. I ended up extending them a few cm.
Unfortunately, now my Beomaster 8000 refuses to startup properly. I'll start a new thread for that.
Where on Earth did my post yesterday go??
Out into space or?
Anyway,new trial.
The filler is a Peerless KU45MRF since it has foam surround.
There also exists a version with doped surround called KU45MR.
Moving house, so going through all my "stuff", and found the dome (just one), the ruler is [cm]:
Hope this helps!