[mgalusha]

Hoping this a good circle for this... I have a pair of EV SP12C 12" full range drivers that I bought new in about 1980 and they were the basis of my main speakers for many years. However some time back my loving cat learned he could remove the grills and use the drivers to assist in climbing on top of the speakers and as a result have some nice cat claw sized punctures in them. They've been sitting in a box unused for almost 10 years.

Seeing the box these are packed in the other day made me think about them and doing something with them. They are very sensitive, EV rated them at 100dB 1W/1M with a frequency response of 37-10000 +/- 6dB in a 5.5 cubic foot vented enclosure. PDF Data Sheet

Given the good things I've read about the Hemp cones I contacted A Brown Soun, seemingly the hemp cone guru's and asked if they could recone them with hemp cones. They believe they can do this but it's not cheap, they estimate $140/$150 per speaker. The question is, will the results be worth the $300 it will cost? Of course there is no easy answer to this question. I was very fond of these drivers for many years and was thinking about building a SET amp and of course that requires high sensitivity speakers. My current speakers are Meadowlark Blue Heron II's which have been modified for use with an active XO. The mids/tweeters are pretty sensitive and I could probably drive them with a 20W SET amp but I kind of have the itch to build some speakers and I have these drivers...

So I'm trying to figure out if I should drop the $300 to have these reconed with hemp and then from there build up some cabinets and see how things progress. While the end result may not end up being a single driver it will most certainly be high sensitivity and so I thought I'd solicit some other opinions from you HE guys. Of course lots of new drivers will cost me considerably more than $300 so it's all relative...

Mike

[Scott F.]

Hiya Mike,

Don't take too much heed in what I type here because I haven't heard the 12" hemps.

From what I've listened to past, I'm not sure you'd be happy with the sound of a 12" full ranger. The bass would likely be pretty good but the upper mids and treble would likely roll off pretty heavy. Now it may just be some of the drivers I've listened to but the impression I've been left with is that an 8 incher seems to be the sweet spot (on trade offs) between adequate bass and fair to good mids and treble. The only exception I've run across (and I haven't heard all of them our there by any stretch) is a vintage 9x15 with a whizzer.

I'm sure JLM or MJK (plus a few others) can help to fill in the huge gap I've left.

[JLM]

Your proposal is a real shot in the dark.  My 51 year old ears don't hear excessive high frequency beaming with my 8 inch whizerless single driver speakers, but I doubt most would be satisfied with it's rated top end of 10,000 Hz.  No guarantee of how they'd sound after reconing either.  For $300/pair I'd look for a new pair of drivers. 

This is really an old school speaker, where they've concentrated on the heart of music.  I appreciate this sort of honesty in design.  Better to let the top and bottom octaves go rather than push the driver to hard/far.  Modern marketing pushes the "need" for 20 - 20,000 Hz at 110 dB at the cost of complexity, expense, and all sorts of compromises.  This thinking sells a lot more gear than most realize or would like to admit. 

My college room mate worked for EV and took me to the factory/lab in Buchanan once in the 70s.  I heard a set of these (or ones similar) once in open baffle concoctions at Hurdy Gurdy Dave's (the guy who reworks the Hawthorne coaxial crossovers).  Dave can probably tell you how to repair the cones as he done some vintage speaker repair.  I believe he's a member here, but probably best to contact him via the Hawthorne site.

I loved the straight forward text from EV.  It was to the point, understandable, and useful.  I'm getting old, as I was just getting into my first audio prime when that was written in 1983.   

[Ed Schilling]

Mike,
Your question is typical of what has happened because of misinformation. Contrary to popular belief the cone material is not a "magic bullet". While all these magical properties seem to be attributed to hemp I believe it is the consumption of "hemp like substances" that is to blame. A driver is a "good one" because of ALL of the "little things" that make a driver. Hemp is simply another material that can be made into a cone. Period. You wouldn't think a Yugo is a Lexus just because it is made of steel would you?

While the Hemp driers may be very good it certainly is not because of any ONE thing. This includes the cone material. It is the sum of the parts not just one of them. The same can be said for speakers......the driver chosen DOES NOT guarantee a good sounding speaker. It helps but does not insure it. People get the idea that (for instance) the 126 is "the driver" and assume because it is being used to good effect in one design that it will "make a good speaker" just from the fact it is being used. Nope. Doesn't work that way. The same can be said when you read..." I don't like "Fostex" speakers (for instance). That is a ridiculous statement. They are NOT all the same and the same driver does NOT perform the same in all applications.

In your case, if you recone them with Hemp cones you will have a different speaker than if you recone them with the original cones. NO ONE can predict if the Hemps will actually improve them. And more importantly who is to say what is an "improvement"?

If you want to experiment then by all means do so but go into it full well knowing that is what you are doing. If you do it with that in mind it will be a success no matter how it actually turns out. I'd find originals, if it were me.

Ed

[JoshK]

I patch the holes with some glue, leave the drivers as is and try to use them as proposed to see if you like the results.   I don't think *I* could live with a 12" FR speaker because of beaming and droop in HF, but mostly because of the beaming.  Crossing a large mid to a tweeter is tough because of what goes on in the power response (combined on/off axis response).  You can typically get flat response on axis or off but not both.  The first usually doesn't sound right because of pronounced areas in the xo region, the later doesn't sound right because of the BBC dip, which leads to recessed upper mids.

PS. though you could try to cross them to a compression driver, like say the BMS 4540ND on a CD like waveguide such as the DDS ENG-90.  This keeps the power response more uniform down to the xo region and makes it easier and more seemless to cross.  The BMS drivers are suppose to be something. 

[jrebman]

Mike,

I think I more or less agree with Ed here, but on the other hand, if you can afford to do this as an experiment with the idea that it may not pan out, then I don't see any harm in giving it a try.

-- Jim

[miklorsmith]

I don't disagree with anything said, BUT I recently replaced the original paper cone Fostex 206Es in my TNT Big Fun Boxes with first generation Omega Hemptone 8"ers and WOW, so much better.  Yeah, I know the 206E wasn't meant for a BR box and the Omega driver is.  Sorry for the detour . . .