I recently found a need to replace both of the woofers in my Vistas and wanted to share what I learned and did.
During a long listening session at substantial levels the woofers started sounding bad and bottoming out a lot. After inspection I discovered that both cones had cracked just inside of the rubber surround at the flange. Further inspection revealed that the spider had also come unglued from the voicecoil former. Given my amp (Sunfire Cinema Grand Bob Carver Signature Edition) and listening habits, I'm only surprised it didn't happen sooner.
During my research for a replacement I found a thread on this site that gave some of the Thiele-Small parameters that came from ML Support. Vista Woofer Parameters, Ideal Replacement plus Crossover Improvements For various reasons, none of the replacements mentioned in that thread worked for me. At this point, I wouldn't be able to recall why a particular speaker wasn't suitable...just that I personally felt it wasn't the right choice for me. So, I cranked up Google and spent an inordinate amount of time looking at Thiele-Small parameters and frequency response curves for every 4-Ohm 8" driver I could find. The one that looked the best, for me, was the Seas RW 220. RW 220 L0022-04S While there are more Thiele-Small parameters given at the Seas site than ML provided here, this Seas woofer hits 4 of the 5 that they did provide. Mechanically, the screw holes were on the same bolt pattern, as best as I could measure, so that was a win, too. I ended up pulling the trigger on them from a store in Finland (Audio-hi.fi) and they took 2-3 weeks to show up. They certainly weren't the cheapest I could find but they were also a long, long way from the most expensive. I felt like they were priced appropriately for 14 year old Vistas.
When I finally received the woofers from Finland and tested their fit I found that they wouldn't sit all the way down into the existing hole. It was close (like, within 1/8" or so) but the "fingers" of the Seas basket were sitting on the edge of the hole. An option would be to enlarge the hole but, from experience, enlarging an existing hole of this size is somewhat difficult as there is nothing to use as a center pivot. Another option was to make a shimming ring. (I should mention that the OEM woofer in the Vista has a non-round flange shape and I had some anxiety about finding a woofer with a round flange that wouldn't interfere with the rails that carry the Estat panel.) So, shimming the speaker toward the rails would have made it more likely that the flange would interfere with the rails. What I noticed with the speaker was that there would be no problem with the hole size _between_ the fingers so I only needed to create clearance around each of the fingers. And, the clearance needed was not much at all. A depth of 1/4" would allow the speaker to sit flat. As there were 6 screws and 6 fingers, I ended up designing a router template that would cut clearance for 1 finger at a time. The template would then be indexed 6 times around to make 6 clearance pockets.
The tape in the hole was to keep sawdust from dropping into the box as it was still full of fiberfill.
After cutting the pockets, they looked like this.
The only unexpected thing about the Seas woofer is that it didn't come with a gasket. The OEM gasket was glued to the OEM speaker so I had to improvise. I used a very sticky weatherstrip tape made by 3M that you can buy at auto parts stores and is about 1/4" wide. While it is double-sided, I left the liner on because I don't actually want it to be stuck to the box...I'm interested in it for the squishy-ness.
The rest of the assembly was straight-forward and it ended up looking like you'd probably imagine.
Subsequent to this, I washed the Estat panels in the shower with instructions found on this site. While it was out of the rails drying I tested the fit of the rails over the round Seas flange. If there was going to a problem, my solution was going to be either machine flats on the Seas flange or cut into the into the aluminum ML rails where the interference was. It may be impossible to imagine how happy (!) I was to find that there was clearance and I didn't have to do either.
After complete assembly of the speaker, I can say that I am absolutely thrilled with how the woofers sound and how the Vistas sound with them. I feel like I am not sufficiently qualified or able to properly/fully express all the nuances of the sound (and sound is very dependent on the room they are in) but I will say that, to me, the woofers sound better than the OEMs. The best explanation I can give is that I bought Hsu Research subs because the OEM woofers didn't do it for me, even for 2-ch SQ listening at the lower end of moderate volume. I am now borderline on whether subs are needed for 2-ch. If I'm SQ listening at low to moderate++ levels the Seas woofers are fantastic and I run the Vistas full-range. When I listen at very high levels for mood (which may include bass-head music) I do still turn on the subs and cross-over the Vistas to keep the Seas woofer from bottoming out.
So, there's my story about replacing the woofers in my Vistas. If you made it this far, thanks! My hope is that it is useful to another ML Vista (or other) owner that has damaged woofers. I've given some thought to bi-amping the Vistas with an active crossover and/or upgrading the internal passive crossovers but there are some tasks for other hobbies that are higher on the priority list now that these work as well as they do.
AP
During a long listening session at substantial levels the woofers started sounding bad and bottoming out a lot. After inspection I discovered that both cones had cracked just inside of the rubber surround at the flange. Further inspection revealed that the spider had also come unglued from the voicecoil former. Given my amp (Sunfire Cinema Grand Bob Carver Signature Edition) and listening habits, I'm only surprised it didn't happen sooner.
During my research for a replacement I found a thread on this site that gave some of the Thiele-Small parameters that came from ML Support. Vista Woofer Parameters, Ideal Replacement plus Crossover Improvements For various reasons, none of the replacements mentioned in that thread worked for me. At this point, I wouldn't be able to recall why a particular speaker wasn't suitable...just that I personally felt it wasn't the right choice for me. So, I cranked up Google and spent an inordinate amount of time looking at Thiele-Small parameters and frequency response curves for every 4-Ohm 8" driver I could find. The one that looked the best, for me, was the Seas RW 220. RW 220 L0022-04S While there are more Thiele-Small parameters given at the Seas site than ML provided here, this Seas woofer hits 4 of the 5 that they did provide. Mechanically, the screw holes were on the same bolt pattern, as best as I could measure, so that was a win, too. I ended up pulling the trigger on them from a store in Finland (Audio-hi.fi) and they took 2-3 weeks to show up. They certainly weren't the cheapest I could find but they were also a long, long way from the most expensive. I felt like they were priced appropriately for 14 year old Vistas.
When I finally received the woofers from Finland and tested their fit I found that they wouldn't sit all the way down into the existing hole. It was close (like, within 1/8" or so) but the "fingers" of the Seas basket were sitting on the edge of the hole. An option would be to enlarge the hole but, from experience, enlarging an existing hole of this size is somewhat difficult as there is nothing to use as a center pivot. Another option was to make a shimming ring. (I should mention that the OEM woofer in the Vista has a non-round flange shape and I had some anxiety about finding a woofer with a round flange that wouldn't interfere with the rails that carry the Estat panel.) So, shimming the speaker toward the rails would have made it more likely that the flange would interfere with the rails. What I noticed with the speaker was that there would be no problem with the hole size _between_ the fingers so I only needed to create clearance around each of the fingers. And, the clearance needed was not much at all. A depth of 1/4" would allow the speaker to sit flat. As there were 6 screws and 6 fingers, I ended up designing a router template that would cut clearance for 1 finger at a time. The template would then be indexed 6 times around to make 6 clearance pockets.
The tape in the hole was to keep sawdust from dropping into the box as it was still full of fiberfill.
After cutting the pockets, they looked like this.
The only unexpected thing about the Seas woofer is that it didn't come with a gasket. The OEM gasket was glued to the OEM speaker so I had to improvise. I used a very sticky weatherstrip tape made by 3M that you can buy at auto parts stores and is about 1/4" wide. While it is double-sided, I left the liner on because I don't actually want it to be stuck to the box...I'm interested in it for the squishy-ness.
The rest of the assembly was straight-forward and it ended up looking like you'd probably imagine.
Subsequent to this, I washed the Estat panels in the shower with instructions found on this site. While it was out of the rails drying I tested the fit of the rails over the round Seas flange. If there was going to a problem, my solution was going to be either machine flats on the Seas flange or cut into the into the aluminum ML rails where the interference was. It may be impossible to imagine how happy (!) I was to find that there was clearance and I didn't have to do either.
After complete assembly of the speaker, I can say that I am absolutely thrilled with how the woofers sound and how the Vistas sound with them. I feel like I am not sufficiently qualified or able to properly/fully express all the nuances of the sound (and sound is very dependent on the room they are in) but I will say that, to me, the woofers sound better than the OEMs. The best explanation I can give is that I bought Hsu Research subs because the OEM woofers didn't do it for me, even for 2-ch SQ listening at the lower end of moderate volume. I am now borderline on whether subs are needed for 2-ch. If I'm SQ listening at low to moderate++ levels the Seas woofers are fantastic and I run the Vistas full-range. When I listen at very high levels for mood (which may include bass-head music) I do still turn on the subs and cross-over the Vistas to keep the Seas woofer from bottoming out.
So, there's my story about replacing the woofers in my Vistas. If you made it this far, thanks! My hope is that it is useful to another ML Vista (or other) owner that has damaged woofers. I've given some thought to bi-amping the Vistas with an active crossover and/or upgrading the internal passive crossovers but there are some tasks for other hobbies that are higher on the priority list now that these work as well as they do.
AP