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EV Sentry 100a: best source for surrounds?

waggs098

waggs098

Super Member
Working at a small auditorium installing a new sound system. In the sound booth they had the mentioned speakers. We replaced them and I asked if I could have them and they said ok.

Inspection of the speaker shows the woofer surrounds are about to go south (you know the feeling, a little sticky but not torn YET). Was wondering what the best source would be for for the surrounds and the concentric foam around the tweeter.

Thanks
 
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waggs098 said:
Working at a small auditorium installing a new sound system. In the sound booth they had the mentioned speakers. We replaced them and I asked if I could have them and they said ok.

Inspection of the speaker shows the woofer surrounds are about to go south (you know the feeling, a little sticky but not torn YET). Was wondering what the best source would be for for the surrounds and the concentric foam around the tweeter.

Thanks
Click to expand...

Rick Cobb will have the correct surrounds for those. They're common and were the monitors in many of the radio stations I had charge of. Nice speakers.
 
Same foam as is used on Boston Acoustics A-series, EPI and Snell 8" woofers. Filleted inner edge.

Regards,
Gordon.
 
The outer foam for the tweeter is still available, but the inner foam is not.

The inner foam is a much denser and physically attenuates the distortion from outer edge of the large dome tweeter.

It is a must or the tweeter will sound brash. I used Armacell foam from the hardware store. It’s the stuff for wrapping copper pipes.

I created a thread on how to make these here, but I currently can’t find it.

ok I found it
https://www.audiokarma.org/forums/i...-for-the-ev-interface-c.802612/#post-11171565
 
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tonyk said:
The outer foam for the tweeter is still available, but the inner foam is not.

The inner foam is a much denser and physically attenuates the distortion from outer edge of the large dome tweeter.

It is a must or the tweeter will sound brash. I used Armacell foam from the hardware store. It’s the stuff for wrapping copper pipes.

I created a thread on how to make these here, but I currently can’t find it.

ok I found it
https://www.audiokarma.org/forums/i...-for-the-ev-interface-c.802612/#post-11171565
Click to expand...

Yeah been doing research on those and apparently the only place to get "sonically correct" replacement tweeter foam is from a place in Australia. Here is the link.

https://www.openearaudioshop.com.au...replacement-set-for-pair-of-ev-89478-tweeters

This is a thread on another forum I found where a guy was determined to get correct foam and contacted this place and they did testing to match as close as they could. Here is the link to that thread. Just a note I went back to the site to get the link and it won't let me read anymore without becoming a member of the site.

https://www.stereonet.com/forums/topic/312998-ev-interface-foam-tweeter-surround/
 
Here they are. Going to take the wall mounts off the back, which I have to pull the woofers to get to the nuts inside, then going to give them a listen.

As I said the foam is still intact but can tell it won't last much longer.

20230224_175540.jpg
20230224_175517.jpg
20230224_175611.jpg
 
EV is not in business for consumer sound, only pro audio.

The tweeter foam is NLA. I checked out that Aussie site and it does not appear to be the correct dimensions. The hole over the tweeter has to be almost the exact size of a dime and be closed cell polyurethane. For the same price of $55/ea you can almost get 2 used drivers.

Also, for $80 you can get a die made to the spec, which I'm thinking of doing.

They are really great tweeters though, musical but tough, and able to take crazy power.
 
C Hart said:
EV is not in business for consumer sound, only pro audio.

The tweeter foam is NLA. I checked out that Aussie site and it does not appear to be the correct dimensions. The hole over the tweeter has to be almost the exact size of a dime and be closed cell polyurethane. For the same price of $55/ea you can almost get 2 used drivers.

Also, for $80 you can get a die made to the spec, which I'm thinking of doing.

They are really great tweeters though, musical but tough, and able to take crazy power.
Click to expand...

Yeah EV is a pro audio company. Have installed quite few of their speakers.

$55 is for a pair of foams for 2 tweeters. Buying a used tweeter wouldn't, to me, solve the problem since the foam would be old and on its last leg I would assume, of course I don't know how long replacement tweeters were made so if someone got one of the last made it could last a while.

Where did you see dimensions listed, or did you ask them?

I just sent them a message asking dimensions and what testing process they did to make sure the foam is sonically true. I'll see what they say.
 
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Correction: The pic I saw was in a different post (the pipe insulation DIY). So it could be correct. According to all my reading, the outer ring is to prevent refraction from the cabinet. The inner ring is an acoustic lens to widen dispersion. So it is important to get that hole size right.

Re the $55 price, I would definitely pay it but not unless the acoustics and dimensions are correct. So would you kindly post any info you receive from the inquiry?

Re post #13 I love the 8" woofers also. I have Interface:As and Sentry 100As and both sound great. I often wonder how they'd do in a sealed enclosure a la EPI 100s.
 
C Hart said:
Correction: The pic I saw was in a different post (the pipe insulation DIY). So it could be correct. According to all my reading, the outer ring is to prevent refraction from the cabinet. The inner ring is an acoustic lens to widen dispersion. So it is important to get that hole size right.

Re the $55 price, I would definitely pay it but not unless the acoustics and dimensions are correct. So would you kindly post any info you receive from the inquiry?

Re post #13 I love the 8" woofers also. I have Interface:As and Sentry 100As and both sound great. I often wonder how they'd do in a sealed enclosure a la EPI 100s.
Click to expand...

Yes, if I hear back from them I will definitely post what they tell me.

How you described how the foam works is all I have read also.
 
So I have had these hooked up for the weekend and the longer I listen the more I like them. Midrange seems to be very good. They seem to be excellent for low to medium volume levels. Seem to be much more detailed at lower volumes then my Monitor Audio B4 towers. Of course they don't play quite as low as the towers but I have a sub for that.

At higher volumes the tweeter seems to get a little harsh but I know the tweeter pots need cleaned and possibly a recap could help which brings me to my first question.

Would it be suggested to replace both caps in the crossover? I'm assuming the blue cap is a film cap and would most likely be ok. I don't know what kind of cap the silver one is though. Is it an axial electrolytic cap, or some style of film cap?

Second question: searching for woofer surrounds all I find that is suggested for theses speakers are all flat edge attach to the cone. These are angle edge attach foams on the originals as you can see in the previous photos. Any suggestions?
 
C Hart said:
Correction: The pic I saw was in a different post (the pipe insulation DIY). So it could be correct. According to all my reading, the outer ring is to prevent refraction from the cabinet. The inner ring is an acoustic lens to widen dispersion. So it is important to get that hole size right.

Re the $55 price, I would definitely pay it but not unless the acoustics and dimensions are correct. So would you kindly post any info you receive from the inquiry?

Re post #13 I love the 8" woofers also. I have Interface:As and Sentry 100As and both sound great. I often wonder how they'd do in a sealed enclosure a la EPI 100s.
Click to expand...

So here is the response I got about the tweeter foam from Open Ear Audio.

"I’m not in the shop while writing this, but can guarantee the dimensions are same as the original. I’ve been doing EV repairs for a long time and know what the originals were like. The only testing I can refer to is real world results - we are a repair centre and have fitted a lot of these ourselves. The first difference (which I believe we advise in the product listing) is that that there is no bevelled edge on the perimeter of the large/outer ring. this makes no sonic change - only a cosmetic difference. The inner ring is far more critical. And to be honest this is where I can’t guarantee an exact match. We do supply two options for this - one more dense, the other more open cell foam. I prefer the response from the lighter open cell foam, personally, although the denser option is closer to original. The next run we do of these will be made somewhere in between if I can source a better/closer foam grade. The original inner ring part was a denser material from the outer ring, but as I said, from our experience with fitting these, I prefer the lighter option. Basically, we’re supplying a solution to repair old obsolete parts and can’t manufacture with the same volume and machine setup that the original manufacturer could. I can only reassure you that they are better with, than without. Hope this helps!"

Sounds like an honest answer to me.

I asked if I buy the kit if I kit both inner rings and also ask what he liked better about the sound of the lighter foam compared to the denser foam.
 
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I may have to invest. Thanks for the excellent legwork. Based on my readings of Don Keele's papers I think the closed cell is the stuff but I actually think they sound OK without anything, so who knows?

EDIT: Missed the earlier post. On my Interface:As I had a high frequency attenuation on one side, so I replaced all the caps (Mylars like your blue one) with Daytons. Problem solved (could have been bad solder but it's done now). I also think that's a silver electrolytic cap in the pic, so that is more reason to replace it.

Those woofer surrounds are out there - I remember distinctly seeing "EV 8" Woofer Surround" somewhere - maybe Parts Express? But if you can't find the specific model, get an EPI 8" surround. I just measured and they are the same size cone (~6.5"). Compliance might not be exact but I doubt most aftermarket suppliers match the OEM anyway.

I just reread where @GordonW advised the same thing. So you have it from me, plus from a guy who knows what he's doing.
 
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C Hart said:
I may have to invest. Thanks for the excellent legwork. Based on my readings of Don Keele's papers I think the closed cell is the stuff but I actually think they sound OK without anything, so who knows?

EDIT: Missed the earlier post. On my Interface:As I had a high frequency attenuation on one side, so I replaced all the caps (Mylars like your blue one) with Daytons. Problem solved (could have been bad solder but it's done now). I also think that's a silver electrolytic cap in the pic, so that is more reason to replace it.

Those woofer surrounds are out there - I remember distinctly seeing "EV 8" Woofer Surround" somewhere - maybe Parts Express? But if you can't find the specific model, get an EPI 8" surround. I just measured and they are the same size cone (~6.5"). Compliance might not be exact but I doubt most aftermarket suppliers match the OEM anyway.

I just reread where @GordonW advised the same thing. So you have it from me, plus from a guy who knows what he's doing.
Click to expand...

Thanks C hart. I'll get the caps replaced at some point.

I have found these two that have what is apparently called a fillited edge. The Springfield says its fillited. The Midwest surrounds look fillited.

https://www.springfieldspeakerrepair.com/products/bos8-ev-bulk

https://www.midwestspeakerrepair.co...kits-by-brand/epi/epi-8-inch-refoam-kit-f8-3/

Others I have found do have the angled edge just a more pronounced roll. Any suggestions, anyone had issues with the 2 companies I posted?
 
I think I will recap these speakers first. The values I need are 2.84 uf and 26 uf.

What I can find at parts express is:

Dayton audio 25 uf and 1 uf paralleled for 26 uf.

And Dayton audio 2.7 uf and Audyn Cap Plus 0.15 uf paralleled to make 2.85 uf.

Close as I can get. Any objections to the Audyn caps? Any other suggestions?
 
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