Electro Voice Interface Speakers

[Charles218]

I just acquired a pair of Interface B Series II speakers today, they came complete with the equalizer and foams that need to be replaced. Actually, I purchased them from the original owner and they were extremely well cared for, the cabinets are in beautiful condition. My question has to do with the various "Series" of EV speakers. What is the difference between my Series II and Series III or IV? I was able to download the manual for the Interface B Series III from Electro Voice's website but they did not have the Series II version. Does anyone know what the differences are between the various designations?

Charles

 

[dc270]

Recently I have seen & been exposed to several models in the EV Interface line. It is complex at best. I have found through some patient googling I could find several models. The two I know about & have the Interface 1 Series II and the Interface CII. The 1 is a two way 8" with a super dome, the CII is a 3 way 10". Other models have 8" mid woofers with 12" passives, and even more designs to numerous to mention here. Good luck- should be an ineresting look/see.....
DC

 

[Ohighway]

Lol, trends are a funny thing and I'll be darned if I haven't seen more information on the EV Interface series pop up here in the past month or so than I have in the previous 4.5 years.

Congrats to the OP on your find !! You'll like 'em.

 

[tomlinmgt]

Lol, trends are a funny thing and I'll be darned if I haven't seen more information on the EV Interface series pop up here in the past month or so than I have in the previous 4.5 years.

Congrats to the OP on your find !! You'll like 'em.

No doubt, Ohighway. Wer're gonna' have to quit telling these guys they're "rare and special". If they do an AK search on "EV Interface" and see all the recent activity they're gonna' think we're full of it!

- Michael

 

[dc270]

It's an odd thing but Ohighway is correct- the last month has brought out a plethora of EV Interface folks, me included, asking & showing their wares. I think EV Interface to be an exceptional but somewhat underated speaker. Everyone I have had the opportunity to work on and restore has been a pure delight and an education of good sound engineering.

Aside from perhaps Mcintosh, and maybe a very few others, EV used active EQ to accomplish much improved speaker results and design the unit to fit the speaker system- and many of these were near entry level speaker systems too! Who else made efforts with their entry level system like that? Not to mention they used two piece foam difraction suer dome tweeters, good xover components, good cabinet models to complete their designs and other great ideas.

When I see this kind of detail & engineering done for an entry level speaker then I AM impressed and find them more than worthwhile to restore and pass on to others. I hope your experience with an EV product is every bit as good!
DC

 

[Charles218]

So if I am understanding correctly, the different "Series" is consistent across several speaker models. Series I is the same configuration on the Interface A and Interface B, etc.? And the Series is only a description of how many and what sized drivers?

 

[tomlinmgt]

So if I am understanding correctly, the different "Series" is consistent across several speaker models. Series I is the same configuration on the Interface A and Interface B, etc.? And the Series is only a description of how many and what sized drivers?

No....EV would never make it that easy. For example...Interface B, C and D, all series II, have different driver complements and different cabinets (increasing in size as you go up the alphabet). I've read there are four different versions of the Interface C series. I've seen pics of three versions and all have different cabinets and driver complements. Some C's have horn loaded tweeters, some have domes. Some have passive radiators, others don't. EV was all over the place and not one to settle and let the grass grow under their asses!

- Michael

 

[tomlinmgt]

Do yours have the rear firing tweeter? Like the ones at the bottom of this page...

http://www.audioasylum.com/cgi/t.mpl?f=vintage&m=158017

- Michael

 

[spl225]

Interface B Series II.

 

[spl225]

Tried to upload Series III. Can't do it.

 

[spl225]

Interface B Series III.

 

[Charles218]

I've attached a couple of photos of my Interface B's, just to clarify what I have. I am not sure what the tweeters are and what it is that I see on the rear of the cabinet, I've read about various tweeters but am not sure what these are.

Also, as you can see the 12 inch passives need new foam as do the 8 inch woofers and I have heard that these need "filleted" surrounds. It's not clear to me what makes these "filleted" and if both the 12 inch and the 8 inch require them.

One final question, as you can see the 12 inch is badly sagging, this I assume from gravity pulling it down because the surround was missing. Is this going to be a problem after I install a new surround?

Thanks for all of the helpful responses!!!
Charles

 

[dc270]

I've attached a couple of photos of my Interface B's, just to clarify what I have. I am not sure what the tweeters are and what it is that I see on the rear of the cabinet, I've read about various tweeters but am not sure what these are.

Also, as you can see the 12 inch passives need new foam as do the 8 inch woofers and I have heard that these need "filleted" surrounds. It's not clear to me what makes these "filleted" and if both the 12 inch and the 8 inch require them.

One final question, as you can see the 12 inch is badly sagging, this I assume from gravity pulling it down because the surround was missing. Is this going to be a problem after I install a new surround?

Thanks for all of the helpful responses!!!
Charles

Charles, you have some valid questions. MSound sells the "filled" filet 8" surrounds you need as does Roy Cobb- maybe others but I know they do for sure. MSound sells a very complete kit with instruction & all- he is on EBay- sorry no link allowed here.

The 12" is eash needing only a regular type surround, there are no filled types for them anyway. Again check with John or Julie at MSound. The sag of the 12" is of no consiquence as when you get it refoamed you can flip it 180- it has no voice coil to be concerned with centering. Good luck- you will be in EV heaaven before you know it!!
DC

 

[futureman]

To complicate matters further, I have a model 'B' series IV. I have never found anything on this specific incarnation. They appear to be just like the B IIIs, but with a high frequency control on the cabinet. I do not get any use from the control (I leave at the 'flat' setting and use the EQ).

I think these speakers are just great, and my little Maggie 9302 pushes them just fine. I'm very curious to hear what the Cs sound like compared to these, especially in the lower register. And I can only dream of having the Ds.

 

[dc270]

To complicate matters further, I have a model 'B' series IV. I have never found anything on this specific incarnation. They appear to be just like the B IIIs, but with a high frequency control on the cabinet. I do not get any use from the control (I leave at the 'flat' setting and use the EQ).

I think these speakers are just great, and my little Maggie 9302 pushes them just fine. I'm very curious to hear what the Cs sound like compared to these, especially in the lower register. And I can only dream of having the Ds.

I can speak to the lower register of the "CII's"- while my Cii's did not arrive with their factory woofers, or tweeters, the substitutes I made seemed to work very well. I used one of the better Dayton 10" wooers that fit the cabinet volume and tuned out pretty well. The low end has authority and can reach well into the mid 30's! Better yet the power handling has improved over stock and SPL is still at 93db efficient. While have the original woofers might have be nice, these Daytons do show a certain improvement I can really like and live with.
DC.

 

[Noreaster]

Just adding a little more info on the Interface line....

I bought a set of Electro-Voice Interface: A for the princely sum of one dollar back in March and only now have finished fixing them up. They are circa 1974. The components are a 12-inch passive radiator (with a very strange-looking tube in the middle), 8-inch woofer, rear-firing tweeter and a front tweeter surrounded by a thick piece of felt and a very thin layer of foam. The speaker hook-ups are like my ARs, wherein the tweeter and woofer are connected by a wire. It also uses an equalizer (which I didn't know when I got them) and which I don't have. Interestingly, I found both the service manual and owner's manual available for free on the E-V website.

My set needed four new foams plus I had to undo a previous owner's fairly disastrous attempt at a re-foam involving gallons of rubber cement and unnecessary gaskets. The cones are thick paper, so inevitably getting the glue off took off a little layer of paper. This process took several hours with a pick and razor blade. While not the prettiest, they seem to be working okay. Luckily, the grilles and the walnut veneer cabinets were in almost perfect condition. The attached photos were taken after finally freeing the drivers of the old foams.

I'm listening to them for the first time now and they sound pretty darned good at low volume (even without the equalizer.) Haven't had a chance yet to really crank them. If there are any other Interface: A owners out there, I'd be curious to know how essential the equalizer is. (I have seen them listed on ebay but pretty pricey.)

 

[totem]

Nice to see all the EV interest since my thoughts mirror those that they are an
under considered line with tons of engineering and high quality parts.

Most seem very satisfied with EVs efforts in the smaller/mid sized cabinets with EQs,
then there are the much larger ones Sentry III and Ds that have been a known commodity
for some time. :thmbsp:

 

[typesix]

I'm listening to them for the first time now and they sound pretty darned good at low volume (even without the equalizer.) Haven't had a chance yet to really crank them. If there are any other Interface: A owners out there, I'd be curious to know how essential the equalizer is. (I have seen them listed on ebay but pretty pricey.)

I don't have an A, but remember reading about it. The equalizer provides 6dB boost at 32Hz(providing flat response to 32Hz) and then rolls off rapidly below as a low frequency filter. The equalizer also had a high frequency setting for flat or boost or rolloff around 10kHz. High Fidelity magazine tested it and found extremely flat response. Without the equalizer, response starts to rolloff gently below 100Hz? and should use a low filter.

 

[Noreaster]

Thanks for the info. The owner's manual has all the specs for the EQ (but I don't pretend to understand it all!)

I will say that having listened to the "A"s for a week or so, I find them totally non-fatiguing with a very articulate bass...especially for a cabinet only 6 1/2 inches deep.

 

[futureman]

I recently sold my B's and bought some C's from a fellow AKer. They only intensify my admiration of the vintage EV lines.