Jump to content

Jack Russell

EV Interface foam tweeter surround

Recommended Posts

I am looking to get two replacement foam rubber tweeter surround kits for my vintage EV Interface C series II speakers (please see upper driver in the image).  The original two part surrounds have disintegrated over the years.  The inner part of the foam surround is made from a denser foam material than the outer ring.  I've tried to cut the circles myself from some foam rubber, but ended up with a jagged edge.  Can anyone please advise if they know of someone with the skills to do this work?  I can supply the dimensions of the two foam bits, where one foam circle fits inside the other.  

imageproxy.php.JPEG

Share this post


Link to post
Share on other sites
Posted (edited)
On 21/06/2020 at 5:10 PM, Jack Russell said:

I am looking to get two replacement foam rubber tweeter surround kits for my vintage EV Interface C series II speakers (please see upper driver in the image).  The original two part surrounds have disintegrated over the years.  The inner part of the foam surround is made from a denser foam material than the outer ring.  I've tried to cut the circles myself from some foam rubber, but ended up with a jagged edge.  Can anyone please advise if they know of someone with the skills to do this work?  I can supply the dimensions of the two foam bits, where one foam circle fits inside the other.  

imageproxy.php.JPEG

G'day JR!

I'm looking too!

1. Try emailing the Australian distributor as I just did..... EV Distributor Aus.

2. Not the original EV gear.- https://reconingspeakers.com/product/spex-replacement-for-electro-voice-entertainer-interface-sentry-tweeter-foam-set/

Edited by Doc M

Share this post


Link to post
Share on other sites

Thanks Doc M,  A couple of years ago I bought a set of the after market foam surrounds from the people in the link you provided.  Unfortunately the inner foam circle was made from the same coarser density foam as the outer one and thus doesn't provide the correct acoustic quality as the original EV ones did.

 

Can you please advise if you have any success with the EV Distributors out here?  I think EV are now concentrating on larger, venue type speakers these days.

 

 

Share this post


Link to post
Share on other sites
Posted (edited)

@Cheapdrinks embarked on an Electrovoice odyssey a while back to replicate the tweeter foams. We messaged back and forth for some time.

 

If I recall correctly, he obtained tooling to punch the foam at the correct diameter, but after significant experimentation and acoustic measurement, he couldn't obtain the right sonic performance. The foams looked OK but didn't perform correctly. This is critical if you are worried about the sound of the speaker, as opposed to simply cleaning up the appearance of the tweeters.

 

He later indicated that the Speaker Hospital in Sydney had developed a replacement which worked well from a sonic perspective. I'd suggest reaching out to them.

 

 

Edited by pete_mac

Share this post


Link to post
Share on other sites


Perhaps a couple of short offcut lengths of truck exhaust tubing to make scone cutter type tools that will cut concentric rings of mtaching diameters? I know you can get a range of foam density pieces at Clark Rubber.

Share this post


Link to post
Share on other sites
1 hour ago, Jack Russell said:

Thanks Doc M,  A couple of years ago I bought a set of the after market foam surrounds from the people in the link you provided.  Unfortunately the inner foam circle was made from the same coarser density foam as the outer one and thus doesn't provide the correct acoustic quality as the original EV ones did.

 

Can you please advise if you have any success with the EV Distributors out here?  I think EV are now concentrating on larger, venue type speakers these days.

 

 

Brian. I have had a return email from Bosch advising of This place in Aus!

I emailed them and await their response. Fingers and speaker wires crossed (Nah........)

Share this post


Link to post
Share on other sites

Thanks for the advice, it's very much appreciated.

I can try the Speaker Hospital in Sydney to see if they can assist.  I've attempted to replicate the originals myself using a scalpel and circular object of the right diameter placed on the foam as a trace.  It's proving difficult to get a nice, clean edge on the foam circles because of its flexible nature.

I've seen it done on youtube using a very sharp edged copper biscuit type cutter pressed and turned into the foam, but getting 3 cutters the correct diameter is difficult.

Share this post


Link to post
Share on other sites
2 minutes ago, Jack Russell said:

Thanks for the advice, it's very much appreciated.

I can try the Speaker Hospital in Sydney to see if they can assist.  I've attempted to replicate the originals myself using a scalpel and circular object of the right diameter placed on the foam as a trace.  It's proving difficult to get a nice, clean edge on the foam circles because of its flexible nature.

I've seen it done on youtube using a very sharp edged copper biscuit type cutter pressed and turned into the foam, but getting 3 cutters the correct diameter is difficult.

As to the diy fabrication and cutting of the foam, I can feel a headache approaching. Foam cutters use silicon oil based liquid for cutting larger foam, I read elsewhere that a leather cutting die may work. But I haven't seen the result of the efforts.

Share this post


Link to post
Share on other sites


Doc M,  I've just phoned a helpful guy at the Speaker Hospital in Sydney and I will send him my details.  Can you please let me know how you go with your latest inquiry with This Place in Aus?  Somehow, we should be able to find a satisfactory solution to our issue!

Share this post


Link to post
Share on other sites
Posted (edited)
43 minutes ago, Doc M said:

 I read elsewhere that a leather cutting die may work. But I haven't seen the result of the efforts.

 

I hope @Cheapdrinks doesn't mind me sharing, but yes, a leather cutting die works like a charm!

 

The challenge then becomes finding the correct density of foam to obtain the correct sonic performance. This is much easier said than done - last I heard, @Cheapdrinks found that commonly available foams were either too porus and did nothing, or were too dense and muffled the sound. This was backed up by measurements too - not just his ears. 

 

The foam below was no good.

 

IMG-7818.thumb.JPG.3f75137ae39dd4ae715a0cdb7890afc7.jpg.b28f189d8653ab09606d144d6ac3551e.jpg

 

IMG-7819.thumb.JPG.102cb70912b2c3f35a9e51693a26ca4f.jpg.735e8e71dee633a1a16bc625f85d0ec8.jpg

Edited by pete_mac

Share this post


Link to post
Share on other sites

The leather cutting die looks impressive.  I don't know of anyone where I am that might have this tool.  If the correct foam density is unavailable or unknown, and this is obviously critical to the tweeters performance, I'm not sure what other options are out there?  

Share this post


Link to post
Share on other sites
Posted (edited)
49 minutes ago, Jack Russell said:

Doc M,  I've just phoned a helpful guy at the Speaker Hospital in Sydney and I will send him my details.  Can you please let me know how you go with your latest inquiry with This Place in Aus?  Somehow, we should be able to find a satisfactory solution to our issue!

Shall do Brian. Let the pacing begin.....

This place in Aus just got back to me and said he has the outer but to fabricate my own inner sourcing the rubber from a well know vendor that also does pools.

Edited by Doc M

Share this post


Link to post
Share on other sites


Doc M,  As you are into vintage speakers, I'm driving my EV's with a Phase Linear 400 power amp that I purchased new from Encel Electronics back in Feb. 1976.  Just bought a new Vincent SA-32 hybrid pre amp to replace the old NAD unit that was blowing capacitors.  They appear to work well together, the old with the new!

Share this post


Link to post
Share on other sites

Just about to do the same Brian. New NAD D 3020 V2 is in transit at this very juncture in time along with a Behringer Ultragraph Pro FBQ1502HD EQ for the strange acoustics in my house/headspace. Happy days huh?

Maybe if we can source the correct density in foams for the tweeters we could do a group of two buy seeing as we're in the same neck of the woods.

Share this post


Link to post
Share on other sites
4 minutes ago, Doc M said:

 

Maybe if we can source the correct density in foams for the tweeters we could do a group of two buy seeing as we're in the same neck of the woods.

 

That's the clincher... the 'correct density'.

 

Getting this right is critical - and I'd be wary of accepting foams without proper testing/measurements to verify the correct performance.

 

EV put considerable effort into this.

 

lens.PNG

 

superdome.jpg

 

 

 

I've restored several sets of EVs and was fortunate to buy some of the last available sets of original foams.

 

 

image_zps37c8f89b.jpg.ff6a20f1c4f26c5eaf69ad2a565344fa.jpgimage_zps7a8976a6.jpg.680edd1ce2db553ddf1b5511a2544c55.jpgimage_zpsd143f670.jpg.25bfedd9b18c203ab7495c5bc18f2c01.jpgevsale1_zpscdf41daf.jpg.fddab010f4f512ea3a10d4cdc4f86427.jpgevsale4_zps0a6e9958.jpg.91f3c6aebe726c814678d582299b8705.jpg

 

 

 

Share this post


Link to post
Share on other sites

Yes, that's possible.  The chap from the Speaker Hospital in Sydney can't guarantee the foams will be the exact same grade as the originals.  Maybe a compromise will be required by me in order to get the job done.  I'll keep you posted after he replies to my email today.

Share this post


Link to post
Share on other sites


Pete_Mac,  The array of drivers are different in my EV's Interface C's than the pics. you kindly provided.  The tweeter appears the same though.  A different EV model perhaps?

Share this post


Link to post
Share on other sites
Just now, Jack Russell said:

Pete_Mac,  The array of drivers are different in my EV's Interface C's than the pics. you kindly provided.  The tweeter appears the same though.  A different EV model perhaps?

 

My old speakers were Interface A Series III. 

 

Are yours the Interface C Series II by any chance? These feature the desirable "VMR" vented mid-range driver.

 

 

Interface C EDS.pdf

Share this post


Link to post
Share on other sites

Yes, they are.  Mine have the vented mid range drivers.

Share this post


Link to post
Share on other sites

Mine are Interface 2 Series II, different again, aside from the tweeter. Mine are passive woofers.

Share this post


Link to post
Share on other sites
11 minutes ago, Doc M said:

Mine are Interface 2 Series II, different again, aside from the tweeter. Mine are passive woofers.

 

Ah yes - that's where my last set of genuine tweeter foams went - a pair of Interface 2 Series II at Dad's place.

Share this post


Link to post
Share on other sites

Doc M,  the after market acoustic lens foam kit are the ones that I bought from Speaker Exchange a few years ago.  The inner lens they sent appears to be made from the same coarser foam as the outer lens ring, and not the much denser material that they should be.

Share this post


Link to post
Share on other sites

It appears to me that a specialist foam supplier/manufacturer needs to be considered. Possiblity is,  has the nouse to fabricate as well........ food for thought Brian. I'll look into that too.

A start.

Share this post


Link to post
Share on other sites

Good luck!  We all have to get points for trying!!  I suppose if we could get the outer lens from This Place In Aus. would be a good start.  The issue then would be to make certain the diameter of the hole in the outer lens married up to the outside diameter of the denser, inner lens so they could fit together nicely. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Classifieds Statistics


    Currently Active Ads

    Total Sales (Since 2018)

    Total Sales Value (Last 14 Days)

    Total Ads Value (Since March 2020)
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...