Electro Voice Interface D Speakers (Equalizer)

[Terry Whalen]

I have been very fortunate to have acquired a pair of Electro Voice Interface D speakers, they are in mint condition, one owner. The surrounds on the bass driver speakers have been replaced so I am good to go long term. These are speakers I would never have thought I would be in a position to own.

Question. I have the the owners manual and have read it a few times to try and figure out how to properly hook up the equalize. I am certain I am being stunned but I want to make sure it is correct.

I have a very basic setup - a NAD 3155 amp, a turntable and CD player.

Can anyone provide a straight forward explanation. I think I have hooked up the speakers correctly, they sound awesome but being careful running them without the equalize attached. Thank you in advance!

 

[soundmig]

It is important to use the EQ as it steeply rolls off bass below 28 Hz to protect the woofer. In your set-up the easiest way to use the Interface EQ will be to remove the jumpers on your NAD (from Pre-Out to Main-In) and hook it up there. Run a cable from the NAD's Pre-Out to the EQ's input. Then run a cable from the EQ's output into the Main-In on your NAD. Don't use the tape in-out on the EQ as that won't be needed in your set-up. I hope that helps

 

[Terry Whalen]

It is important to use the EQ as it steeply rolls off bass below 28 Hz to protect the woofer. In your set-up the easiest way to use the Interface EQ will be to remove the jumpers on your NAD (from Pre-Out to Main-In) and hook it up there. Run a cable from the NAD's Pre-Out to the EQ's input. Then run a cable from the EQ's output into the Main-In on your NAD. Don't use the tape in-out on the EQ as that won't be needed in your set-up. I hope that helps

This is very helpful, I really appreciate your time in providing your response!

 

[Coytee]

If the new surrounds on the woofers are similar to the originals, you have about 10 years before they're gone again.

(owned a pair for over 30 years)

 

[JustinCase]

Congrats! The D's are just plain awesome. Once you have that eq in place select some tracks with great midrange and deep bass, sit back and enjoy. They dig deeeeep.

 

[Coytee]

He's right (JustinCase about them digging deep).... go find some pipe organ and feed them some power...

I never in my life felt the need for a subwoofer because of their bottom end output (-3 db @ 28 hz 106 db max according to the manual)

 

[JustinCase]

FYI there's a pair on CL in SF right now.

 

[MCM_Fan]

FYI there's a pair on CL in SF right now.

Those are the same early version as the one's I'm restoring. Those are in better shape than mine, have had the woofers refoamed and come with an equalizer. Is the Interface A Equalizer, but you should be able to convert it to an Interface D Equalizer. Mine didn't come with the EQ. So, I picked up an Interface B/Q Equalizer off eBay and converted it to a proper Interface D Equalizer by changing the values of four resistors. I wend ahead and replaced all the 40 year old electrolytic caps (there's only 8 of them) while I had it apart.

 

[JustinCase]

What's always puzzled me a bit is why the series 1 D's had the attenuation controls on the speakers themselves while series 2 didn't. Not sure but I think they're redundant if you've already got the setting set on the eq. I think I've just answered my own question.

 

[Terry Whalen]

It is important to use the EQ as it steeply rolls off bass below 28 Hz to protect the woofer. In your set-up the easiest way to use the Interface EQ will be to remove the jumpers on your NAD (from Pre-Out to Main-In) and hook it up there. Run a cable from the NAD's Pre-Out to the EQ's input. Then run a cable from the EQ's output into the Main-In on your NAD. Don't use the tape in-out on the EQ as that won't be needed in your set-up. I hope that helps

I got the EQ hooked up this morning and WOW, thanks so much for your assistance. I didn't think they could sound any better, but I believe they do. I was afraid to turn them up too much without the EQ so today was the first time pushing them to the point of feeling the bass in the center of my chest. I have a blues band so it was really cool listening to my own music, on that level for the first time. ....but everything sounded so good. FYI, I did a trade with my best friend to get these speakers and part of the deal was my giving up one of my Gibson Les Paul's....so worth it!!! Thanks again!

 

[Coytee]

Irrespective of what some purists say.... add in a dbx subharmonic synthesizer and a 3bx....

It'll take them to another level... (of shaking your foundation)

(and might require new surrounds in 5 years instead of 10)



Sure makes them fun though.

 

[Terry Whalen]

All I want to say is KUDOS to you. I'd love a pair of the D. Almost snagged a pair from Ontario but by the time I called in, a fellow picked them up not 45min before.... Good on you! Fabulous speakers and keepers for sure..

Out of curiosity how much did they want for them? Thanks

 

[Terry Whalen]

Came across this: http://www.ebay.com/itm/302177557985?rmvSB=true
I am no affiliation but wanted to send it along because having the original literature would, I believe, would increase their value at the point you may decide to sell on at a later date. Because of our horrible dollar you'd be able to save. There is also a reprint of the 1978 test review on the bay as well. That would be interesting however you might wish to hold out for the originals to pop up and get...
Love them D's... Kudos to you...

Thanks so much for pointing this out, I will consider it...but I'm not likely to sell these speakers. What a joy they are to listen to!

 

[Ed D]

Those are the same early version as the one's I'm restoring. Those are in better shape than mine, have had the woofers refoamed and come with an equalizer. Is the Interface A Equalizer, but you should be able to convert it to an Interface D Equalizer. Mine didn't come with the EQ. So, I picked up an Interface B/Q Equalizer off eBay and converted it to a proper Interface D Equalizer by changing the values of four resistors. I wend ahead and replaced all the 40 year old electrolytic caps (there's only 8 of them) while I had it apart.

I also own a pair of Interface D's and lost my equalizer in a flood. I recently bought an Interface A eq. Can you help me with the conversion to Interface D specs? I am fair at soldering and will try it myself. Are there articles, instructions, or pictures available?
I would be very grateful for any assistance or direction you could lend.
Ed DeLucca
Edelucca337@comcast.net