pete_mac
Super Member
I restored a pair of Electro-Voice Interface 1 Series II speakers last night. I scored these on ebay quite cheaply as the 'foam had deteriorated' according to the seller. I figured that the woofer surrounds were rotten and would require repair (they are 30 year old speakers after all!). Apparently they are the first range of speakers designed using Neville Thiele's research (ie. Thiele-Small parameters). Some tech info here: http://archives.telex.com/archives/EV/Speakers/EDS/Interface 1,2,3 EDS.pdf
Turns out that the woofers had been replaced with inferior aftermarket items from Dai-1chi which had cloth surrounds, and the foam surround and 'lens' over the tweeter was actually cactus. I was pretty disappointed as the replacement woofers were very average. Luckily the seller still had the original EV woofers in storage. I couldn't believe my luck as they are pretty much impossible to source these days, particularly in Australia. The foam surrounds were goneski, hence why they were replaced.
So, I ordered a set of proper fillet-less EV-style surrounds as well as the tweeter surround/lense from Msound and fixed them up. The tweeter surrounds are important as they are an 'acoustic lens' design coupled with EV's 'Superdome' 1.5" dome tweeter, so a deteriorated surround means they block too much sound, and no lens at all means the tweeters are too bright. Msound was an absolute pleasure to deal with, answering all of my questions extremely quickly and thoroughly. If it weren't for his comments regarding no EV hifi speakers having cloth surrounds, I would never have thought to check the branding of the woofer, and therefore would never have discovered that they were replacement items. Externally they looked like EV woofers to me, so I had no reason to think otherwise! Very grateful for his insight.
Despite buying a full refoam kit, I chickened out on shimming the voice coils. I've had great success doing it manually in the past with the assistance of either a test tone, a 1.5v battery, or just by feel, and the voice coil gap in these woofers felt no different in this regard. I found it to be very straight-forward indeed.
The cabinets are in great condition apart from some minor swelling of the cabinet in one corner due to exposure to some kind of liquid, and some minor shrinking of the veneer in the corners on the front face. The cabinets themselves were covered in a light vinyl to better match the seller's furniture. Thankfully this protected the cabinet from any scratches or dings, and the vinyl was really easy to remove.
Before vs after:
Replacement woofers and dead foam tweeter surround and acoustic lens:
Original woofers before refoaming (one on the left is cleaned, one on the right yet to be cleaned/prepared for refoaming):
Refoaming - one down, one to go!
Replacement Dai-1chi woofer on the left, original on the right. Very similar in appearance, but worlds apart in performance. The original is far more efficient and musical, plus it is 6ohms vs 8ohms:
Crossover (one capacitor is on the way out judging by the corrosion on the lead - will be replaced with poly film caps soon). Not sure what type of cap the big one is (wax/oil)? It is 26uf. The two blue electrolytic caps are 4.5uf each. The resistor is 5ohm 10W and pads the tweeter.
Beefy Superdome tweeter magnet:
All drivers refitted and she's as good as new! Sounds fantastic. Very happy with the outcome given the cost, and these will now last for another 15+ years easily.
The EVs are noticeably more efficient than my Energy ESM2s and have much stronger midrange performance (I think the ESMs are quite laid back in this regard).
Turns out that the woofers had been replaced with inferior aftermarket items from Dai-1chi which had cloth surrounds, and the foam surround and 'lens' over the tweeter was actually cactus. I was pretty disappointed as the replacement woofers were very average. Luckily the seller still had the original EV woofers in storage. I couldn't believe my luck as they are pretty much impossible to source these days, particularly in Australia. The foam surrounds were goneski, hence why they were replaced.
So, I ordered a set of proper fillet-less EV-style surrounds as well as the tweeter surround/lense from Msound and fixed them up. The tweeter surrounds are important as they are an 'acoustic lens' design coupled with EV's 'Superdome' 1.5" dome tweeter, so a deteriorated surround means they block too much sound, and no lens at all means the tweeters are too bright. Msound was an absolute pleasure to deal with, answering all of my questions extremely quickly and thoroughly. If it weren't for his comments regarding no EV hifi speakers having cloth surrounds, I would never have thought to check the branding of the woofer, and therefore would never have discovered that they were replacement items. Externally they looked like EV woofers to me, so I had no reason to think otherwise! Very grateful for his insight.
Despite buying a full refoam kit, I chickened out on shimming the voice coils. I've had great success doing it manually in the past with the assistance of either a test tone, a 1.5v battery, or just by feel, and the voice coil gap in these woofers felt no different in this regard. I found it to be very straight-forward indeed.
The cabinets are in great condition apart from some minor swelling of the cabinet in one corner due to exposure to some kind of liquid, and some minor shrinking of the veneer in the corners on the front face. The cabinets themselves were covered in a light vinyl to better match the seller's furniture. Thankfully this protected the cabinet from any scratches or dings, and the vinyl was really easy to remove.
Before vs after:
Replacement woofers and dead foam tweeter surround and acoustic lens:
Original woofers before refoaming (one on the left is cleaned, one on the right yet to be cleaned/prepared for refoaming):
Refoaming - one down, one to go!
Replacement Dai-1chi woofer on the left, original on the right. Very similar in appearance, but worlds apart in performance. The original is far more efficient and musical, plus it is 6ohms vs 8ohms:
Crossover (one capacitor is on the way out judging by the corrosion on the lead - will be replaced with poly film caps soon). Not sure what type of cap the big one is (wax/oil)? It is 26uf. The two blue electrolytic caps are 4.5uf each. The resistor is 5ohm 10W and pads the tweeter.
Beefy Superdome tweeter magnet:
All drivers refitted and she's as good as new! Sounds fantastic. Very happy with the outcome given the cost, and these will now last for another 15+ years easily.
The EVs are noticeably more efficient than my Energy ESM2s and have much stronger midrange performance (I think the ESMs are quite laid back in this regard).
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Most importantly, it functions and performs perfectly.
