Cornwall 511B "voice of the Corn"[:)]

[sfogg]

No, it isn't required. Put some plumbers putting in the lips of the

horn and it damps them way down. I have a factory modded 511B and

compared to the older 511Bs it rings much less when hit out in the

open. But once you bolt them to a baffle and put the plumbers putty in

the lips there is basically no difference between the factory modded

unit and the unmodded 511s.

Shawn

[travisc]

the adaptors went out on wed morning, hope you dont have to wait too long. I would love to know what kind of spl's it would take to make them ring. As I understand its from vibration and not harmonic(like a champagne glass) the unmodded ones I have ring....when I whack my knuckle on it.

your in for a treat Michael, I am in heaven since this upgrade, hmmm whats next....I am shying away from anymore woodwork.

[sfogg]

"I would love to know what kind of spl's it would take to make them ring. "

Before I put the plumbers putty in the 511Bs I could make them ring

from 8 feet away just by clapping on axis with the unmodded ones. That

is with it completely bolted to the front baffle of my LaScalas with

foam rubber between the horn and the cabinet.

For the $5 the Plumbers Putty cost at HD it was a cheap way to really

deaden the horns and totally got rid of the ringing from the test above.

Shawn

[travisc]

I would call that harmonic then!! I will get some putty for the one I am using that hasnt been "treated".

thanks Shawn

[colterphoto1]

Travis, so do you have modded and unmodded models? Any chance you could put them side by side and give a good A/B test for the ringing? I wouldn't have a clue how to cut these welds out of here and they look so good I hate to get into that if I don't have to.

THanks,

Michael

[travisc]

I agree with Shawn, I dont think its neccesary to go to all the trouble. Just to clarify its the welds on the fins that people cut not the whole horn. I do have both. The ones that were cut and siliconed also have a pretty heavy coat of sound dampening paint. So it would be hard for me to tell whats what. If I press the palm of my hand against the unmodded horn it wont ring, the putty would do the same thing. Also the unmodded horn is in the cabinet I built and bolted down, I havent noticed any ringing.

[colterphoto1]

I've got my 600 CW horns puttied up, so I dont' mind tricking my 511's up. The weld mod seems like a lot of trouble to go to if it doesn't do much good. I read about 'factory' mod, did Altec themselves do this at one time? I'd rather not, but it does seem like a lot of people do this mod.

In any case, suppose I decide not to do the weld cut and silicone thing. If I also don't put the horn in a cabinet or bolted to a heavy motor board (leave it out in the open), would there be any other way to 'dampen' it? Could a couple staves of hardwood bolted across top and bottom serve the same dampening purpose as bolting to 3/4 motorboard, say? I note that Klipsches big KPT horns still are bolted to a motor board of sorts, is this for the same purpose? I would suppose that any stiff, dense material securely attached to the lip of the horn or mounting plate might serve the same purpose?

Also, should it be damped from the outside of the horn as well?

Michael

[sfogg]

"The ones that were cut and siliconed also have a pretty heavy coat of

sound dampening paint. So it would be hard for me to tell whats what."

That paint probably isn't factory. If those still have the stiffening

rod down in the throat they were modded by a user. The factory modded

units left out that rod down in the throat.

As far as the paint itself I doubt it did much of anything. I put the

putty over the entire outside of one of my 511Bs and compared against

one with the putty just in the lips there was really no difference

between them.

Shawn

[colterphoto1]

Hey Travis! Got your care package today. Thanks for the adapters man. Now I can thank you for being the inspiration for this project every time I listen to my BIG HORNS!

Michael

[travisc]

Awesome!! I am very pleased to be a part of all this. Again all you that have given inspiration, suggestions,opinions and info. I am very grateful, this project has given me alot of satisfaction and it wouldnt have happened without the help or the forum.

BTW I still have a few spare adaptors, anyone lurking around with this mod on their shortlist I will mail them to you no charge.

Oh Michael there is one string attached to those adaptors...........pics[]

[travisc]

Another question..

has anyone ever removed the mounting plate on these horns leavin just the horn itself. I ask this because one of the horns that I got had damage(one of the corners broken around a mounting hole). If I look at the horn, though it is cast in two pieces it looks as though I could remove everything but the horn stucture. This would be purely asthetic and I may do it, since the 511b's are just sitting atop the Cornwall and wont be mounted to anything. Other than the possibility of them ringing more can you think of other negetive outcomes?

[colterphoto1]

ringing, resale value.

Is there any way to bend it back, or is a section snapped off entirely? Maybe have a new section welded on there, wouldn't that be less work than unwelding or cutting the whole perimeter away?

You might want to mount them or put em in LS one day and you'll need that plate. I'd leave it.

[travisc]

I am just weighing options, corner is broken right off, though if I were to do this I would do it to two of them. Painted a cream color with the plate removed sitting ontop of the Corns would look purdy. It looks fine now with the black ones but, It would really pop cream without the unused mounting plate.

I dont think this speaker setup is going anywhere, anytime soon[], so resale wont matter

how ya comin with your "mod"

[colterphoto1]

They're sitting under the tree.

It's my gift to me.

Probably the only one this year.

Except for your adapters, thanks man.

M

[TRiv]

Another question..

has anyone ever removed the mounting plate on these horns leavin just the horn itself. I ask this because one of the horns that I got had damage(one of the corners broken around a mounting hole). If I look at the horn, though it is cast in two pieces it looks as though I could remove everything but the horn stucture. This would be purely asthetic and I may do it, since the 511b's are just sitting atop the Cornwall and wont be mounted to anything. Other than the possibility of them ringing more can you think of other negetive outcomes?

Have thought about it for same reason, though holding off, not because of resale value or ringing, but may still mount in cabinet. Still experimenting here with driver arrangment, though if the 511 is on top of CW cabinets, cutting flange off at least the top half flange would work, not sure about bottom half, could still mount that to a base. Of course, removing entire flange and leaving the bosses with the hook and chain holes could be used to mount them, but leaving the bottom flange, which is out of site anyway, would be best. Cutting off will not be easy though, sabre saw or sawsall will not get in there all the way, cut off wheels don't work with aluminum, a die grinder would work. Finish grinding with a 90 degree grinder (Dotco)3" grinding disk loaded with bees wax will grind down remaining flange quick and smooth. It will take some time but would look better for sure.

My latest configuration with the CW/511 ( Voice of the Corn) is as before, inverted cabinet, 511 on top, but raised cabinet 12" off floor, and K77 horizontal between 511 and K33. My reason for this, I like the sound to be more true to a real performance (most floor speakers including CW's, are too low) the places I've been to hear live music, the singers are standing with band behind, and the average height is 4-6' for vocals ( lead singers don't usually sit while performing). With the centerline of the 511's voicecoils at 31/2" and the K33 at 2", the vocals sound 3-3 1/2' off the floor, too low ( don't forget the K33 handles some of the vocals), and not right, so I raised the cabinets. I'll have to post picture later , but so far WOW!, played "Honeydrippers" cd with Robert Plant ( LED Zepplin) and sounded like the band was live in the basement! The only thing is raising the cabinet so high is the bass drops a bit more, thinking of either another pair of CW's as bass bins only crossed over at 400hz (run with separate SAE 2100 amp), or finding/waiting for an empty Khorn cabinet/s (add K33, AA crossover) to do the same. Really though, the bass is tight and accurate as is, so will wait and see/try.

By the way, do you still have any adaptors left, would be interested to buy (mine are 3/4 plywood pieces with K-55 just threaded in to them, works!)

[travisc]

TRiv,

for the info youve given me thus far, and the term "voice of the Corn"[] Its on me. E-mail or PM me your address and I will send them out to you. I have a plasma cutter at work and will experiment with some aluminum to see if thats a good idea, but I think it will heat up the horn more than it should be. Well it sounds like a plan

Happy Holidays

[travisc]

[]

[Tom Mobley]

"Voice of the Corn" There's something just good and right about that....

[colterphoto1]

Couldn't talk you guys into Wall-tec, could I?

Voice of the Corn I think it is. Looks like we got ourselves a little club here fellas.

Michael

[travisc]

I started taking off the mounting plates, Wish I hadn't started this endeavor. It is a ton of work!! and messy!

I have something like 7hrs of prep into this one horn, counting the paint removal that seemed more like several coats of white wash. Theres no turning back now, in the long run I think it will be worth it.

Michael,

you still have some pre horn work to get done, youve got to wire the k-33 to the Cabinet connector remove and seal the other two drivers.