I thought I should start a new thread just for this specific issue, although it's obviously related to my ongoing attempt to source replacement drivers, contained in another thread.
I've successfully removed the 4 bolts (including their washers) holding in one LF driver, using the correctly sized metric Allen key as per PMC's own instructions.
Unfortunately the driver simply won't come out. I've tried using gravity, then all kinds of prising techniques, but it's just stuck fast!
I can't afford to cause damage, as I need to quickly put this driver in my other box. The other makes no noise at all, but after gluing up the worst tears in the first driver I'm trying to remove, it makes a passable sound.
Hence I want to check it in the other box, where the driver shows no physical damage and makes no noise at all. I want to ensure I have only blown that driver, rather that caused damage to the crossover as well/instead.
I'm trying to do this as quickly as possible, having found potential replacement drivers in Norway. I've managed to borrow a soldering iron for today, but it never occurred to me that I'd struggle to get the driver out of box after I've removed the Allen head bolts.
I'm really worried about causing damage, like I said I can't afford to break this driver any further, I really need what's left of it to test that it's just the driver in the other cabinet that's damaged, not the crossover. I also want to be able to buy these replacement drivers from Norway before someone else does, and I've only borrowed this soldering iron for tonight, expecting it to be an easy swap and test procedure.
For those unfamiliar with this cabinet, there's no access to the rear of the drivers due to the transmission line inside. Hence removing them from the front seems the only option. The help materials I managed to find all referred to much larger, PA sized type drivers, and the way this little 13cm one is built in seems quite different.
Help me diyaudio.com/community, you're my only hope!
I've successfully removed the 4 bolts (including their washers) holding in one LF driver, using the correctly sized metric Allen key as per PMC's own instructions.
Unfortunately the driver simply won't come out. I've tried using gravity, then all kinds of prising techniques, but it's just stuck fast!
I can't afford to cause damage, as I need to quickly put this driver in my other box. The other makes no noise at all, but after gluing up the worst tears in the first driver I'm trying to remove, it makes a passable sound.
Hence I want to check it in the other box, where the driver shows no physical damage and makes no noise at all. I want to ensure I have only blown that driver, rather that caused damage to the crossover as well/instead.
I'm trying to do this as quickly as possible, having found potential replacement drivers in Norway. I've managed to borrow a soldering iron for today, but it never occurred to me that I'd struggle to get the driver out of box after I've removed the Allen head bolts.
I'm really worried about causing damage, like I said I can't afford to break this driver any further, I really need what's left of it to test that it's just the driver in the other cabinet that's damaged, not the crossover. I also want to be able to buy these replacement drivers from Norway before someone else does, and I've only borrowed this soldering iron for tonight, expecting it to be an easy swap and test procedure.
For those unfamiliar with this cabinet, there's no access to the rear of the drivers due to the transmission line inside. Hence removing them from the front seems the only option. The help materials I managed to find all referred to much larger, PA sized type drivers, and the way this little 13cm one is built in seems quite different.
Help me diyaudio.com/community, you're my only hope!
What size and depth holes are drilled in the basket edge?
Pic would be great.
Pic would be great.
The one with the Vifa 14cm bassmid and the Vifa D25AG dome? If the tweeter can be unmounted, try reaching the woofer from that hole and gently push the magnet outwards. Your other option would be cutting some thread in the mounting holes of the woofer and push the woofer out by screwing a bolt in.
Had a similar issue with different speakers. It was due to a sticky gasket behind the drivers. Applying a constant pull over some time sorted it out.
@markbakk (sorry I can't quote your post for some reason)
BINGO...We have a winner, thank you so very much!
Yes, the drivers are Vifa M13WG and D25AG. I never thought about removing the latter, but fortunately they came out real easy. The LF was still properly stuck in, but after applying lots of very, very careful pressure they finally popped out.
Turns out I never even needed the soldering iron, as the clips are just pushed on. Thankfully the glued up cone works in both boxes, so my crossovers are OK.
Unfortunately my high volume testing seems to be revealing a bit of scratchiness in both HF drivers during some loud passages. However after trying some other well recorded material, it seems confined to CD-Rs I've burned with lossless FLAC to WAV conversions. I'd never noticed it before, but I guessing having 2 tweeters and only one ripped up/glued up LF driver is highlighting high frequency issues.
I've not actually managed to get the LF drivers properly back in, but the fit is so tight that just pushing the working one halfway in, without using any bolts, has managed to create enough of a seal to get the regular bass response from that cabinet.
I've been giving them a good high volume workout, currently using Sun Kil Moon's April, as I wanted a well known good quality recording with lots of well recorded details, especially transients (in this case, close mic'd nylon strung guitar and prominent vocals) and some unusual use of stereo imaging (he likes hard panning both doubletracked and slightly delayed main vocals and harmonies) and fortunately everything's sounding really good. If I move away from the stereo sweet spot, material without lots of extreme low end content sounds very good indeed, except at certain peaks where the ripped driver suddenly starts flapping horribly.
The bad news is that the replacement drivers I've found in Norway (which hopefully haven't gone!) are the magnetically shielded models, with a great big metal cover over the voice coil magnet. It looks like I'm going to have to cut out a big section of the dampening foam behind the LF driver to get something so much bigger in.
I can only presume that's what PMC themselves did when building the shielded models, such as for AV centre speakers. Hopefully I'll be able to cut just enough away so as to keep the same relative amount of dampening, as I know that element is very important to the transmission line design.
Right, so now I've gotta see whether I can still buy that pair of Vifa M13SG from Norway. Here's hoping Google Translate still works when I'm providing payment details and other important information, otherwise things could get real tricky!
BINGO...We have a winner, thank you so very much!
Yes, the drivers are Vifa M13WG and D25AG. I never thought about removing the latter, but fortunately they came out real easy. The LF was still properly stuck in, but after applying lots of very, very careful pressure they finally popped out.
Turns out I never even needed the soldering iron, as the clips are just pushed on. Thankfully the glued up cone works in both boxes, so my crossovers are OK.
Unfortunately my high volume testing seems to be revealing a bit of scratchiness in both HF drivers during some loud passages. However after trying some other well recorded material, it seems confined to CD-Rs I've burned with lossless FLAC to WAV conversions. I'd never noticed it before, but I guessing having 2 tweeters and only one ripped up/glued up LF driver is highlighting high frequency issues.
I've not actually managed to get the LF drivers properly back in, but the fit is so tight that just pushing the working one halfway in, without using any bolts, has managed to create enough of a seal to get the regular bass response from that cabinet.
I've been giving them a good high volume workout, currently using Sun Kil Moon's April, as I wanted a well known good quality recording with lots of well recorded details, especially transients (in this case, close mic'd nylon strung guitar and prominent vocals) and some unusual use of stereo imaging (he likes hard panning both doubletracked and slightly delayed main vocals and harmonies) and fortunately everything's sounding really good. If I move away from the stereo sweet spot, material without lots of extreme low end content sounds very good indeed, except at certain peaks where the ripped driver suddenly starts flapping horribly.
The bad news is that the replacement drivers I've found in Norway (which hopefully haven't gone!) are the magnetically shielded models, with a great big metal cover over the voice coil magnet. It looks like I'm going to have to cut out a big section of the dampening foam behind the LF driver to get something so much bigger in.
I can only presume that's what PMC themselves did when building the shielded models, such as for AV centre speakers. Hopefully I'll be able to cut just enough away so as to keep the same relative amount of dampening, as I know that element is very important to the transmission line design.
Right, so now I've gotta see whether I can still buy that pair of Vifa M13SG from Norway. Here's hoping Google Translate still works when I'm providing payment details and other important information, otherwise things could get real tricky!
FYI/FWIW, have had good luck with attaching a couple of handles to a length of dental floss or reasonably small monofilament fishing line and slowly tightening it at the joint to 'slice' it loose.
Not relevant here🙂
I've only had sticky 15" Tannoy front loaded drivers.
No other drivers to pop as they are dual concentric.
The basket fronts where the bolt holes are, are 5/8 or 3/4 inch deep. I put 2 or more 8mm twist drills in the holes, snug fit, shank end in and gently rotate / lift by grabbing the drills.
2 people on 4 opposing drills always does the trick.
Wear thick leather gloves as the drills are sharp.
I've only had sticky 15" Tannoy front loaded drivers.
No other drivers to pop as they are dual concentric.
The basket fronts where the bolt holes are, are 5/8 or 3/4 inch deep. I put 2 or more 8mm twist drills in the holes, snug fit, shank end in and gently rotate / lift by grabbing the drills.
2 people on 4 opposing drills always does the trick.
Wear thick leather gloves as the drills are sharp.
Are you sure about that M13WG? PMC mentions a 140mm chassis width and Vifa did offer 14cm bassmids later (PL14WJ amongst others). It seems those still can be found new (or NOS).
That tweeter is quite something though. Still up with the better metal domes nowadays. And like 35 year old design now.
That tweeter is quite something though. Still up with the better metal domes nowadays. And like 35 year old design now.
Indeed! At the time it was the only tweeter I had available to me that came closest in overall performance to my Altec 802 CD w/alum. diaphragm 'tweeter' where the throat was aperiodically loaded and rear cover removed with DIY'd conical WG.
PL14 cutout was 149mm. OP didn't seem to want to mess with cabs so only other drop-in for M13 is P13 at 140mm
Thanks for pointing that out, but I can confirm the two drivers in my DB1 are definitely M13WG, which have been impossible to find outside of PMC's own spares.
Hence I'm taking advantage of a very reasonably priced pair of M13SG, which a very kind member of this forum located for me. Also Falcon Acoustics went above and beyond to find spec sheets and explain only one tiny spec difference between the shielded and unshielded drivers, which makes sense as when the DB1 launched you could order shielded pairs and the centre AV model, for placement near CRT screens.
I was an early adopter, with serial numbers 000111 and 112. I do recall that it didn't seem long before they introduced the next iteration, which kept the same LF driver but changed the tweeter, possibly to a soft dome design. I was originally going to buy the "Studio" models, which originally did have a soft dome tweeter, but someone who introduced me to transmission line and tapped horn sub designs, suggested I'd be happier with that specific metal dome driver both for monitoring and regular hifi listening.
I remember learning a bit about hifi tweeter design, which seemed different to the drivers I was familiar with from PA gear. I've forgotten most of that now, so really couldn't say whether the Vifa metal domes in my DB1s are particularly good or otherwise - I just know I like their sound, for both mixing and regular listening in small rooms. With a brick wall behind the rear transmission line exit, they produce a phenomenal amount of clean bass for such a little loudspeaker!