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

[mungkiman]

Why not place the tweeter inside the mouth of the 511 horn, like the K-5-J/K-77 combo on old Klipschorns? Sounds nice to me...

Chris

[mungkiman]

Oops. I guess the early tweeters were University, not K-77 as stated.

[colterphoto1]

Travis, I thought you were bluemonkey bidding on the ones on Ebay? They have 11 hours left on them! Where did you get yours? Can I ask how much?

I like the idea of the cream color. Less gestapo looking, probably nice WAF. I remember a friend in HS had some type of PA cab that looked like Peavy FH1/SP1 combo. But the big radial horns and interior of bass horn were white! Very striking.

What driver are you going to start out with?

have fun with your mods.

I'd bid on those ebay 511's, but just put a bid in on a Mackie 1604 console![Y]

Michael

[travisc]

Michael,

pair popped up with a buy it now on e-bay, turns out to be a forum member who had already cut the kerfs. Paid a little more than I wanted, but I am not regarded as the most patient of people[] and hell, whats money?

I stopped by and talked to the painter. Seems like the hardest part is going to be matching the paint without physically bringing the back panel of a Cornwall down to him. Turns out he is in need of technical assistance with a vehicle or two, so the paint job wont come out of my pocket. Yes I am going to use the 55's with the selenium adaptors that Bob and Al reccomended.

Bob,

you were right! Even finding a tap of 1 3/8 18 isnt easy. Other thoughts I have had are using a rubber stopper or cork to seal the 600's?

as always thanks for all the help!!

[sfogg]

" Other thoughts I have had are using a rubber stopper or cork to seal the 600's?"

Probably be fine with a rubber stopper. Since the cabinet of the Cornwall is ported there won't be much pressure on the stopper anyway.

Shawn

[travisc]

Thanks Shawn,

I was trying to imagine how much pressure/Vacuum there would be at volume in the hardware store today and came to the conclusion I was over thinking the whole thing

[colterphoto1]

leaving the horns in place, even if you bolt them to the back of a 'blanking' board, might be a good idea as it would keep the internal volume of the cabinet nearly the same. It's not hyper critical in case you want to remove them, but since you were overthinking, thought I'd join in the fun.

If you're happy with the mod you make, you might consider selling those K600's. They're pretty hard to find and someone wanting to make a center CW might make good use of them. Could recoup a lot of your 501 $$ that way. Just a thought.

Michael

[TRiv]

............."there seemed to be a hole in

the sound when the 511 was just on top of the cabinets in standard

orientation, so I flipped them, this puts the bass ports right below

the 511's, I like it!"...................

TRiv,

Interesting.......Could you post a photo?

I

always felt that the ports should be coupled to the floor plane, or

in a "dbb" application, to fire down the side-wall length.

Regards,

Terry

Some pics:

[TRiv]

Here's another:

[travisc]

TRiv,

Nice!! k-77 vertical...hmm

[travisc]

Colter, you got to wonder what the max bid was on those, I saw that you were winning them with 2 hours left. Ah well

[colterphoto1]

somebody else got them. There's been a pair sold for 103 and now 109. I had 107 in. The guy wanted 35 shipping so it was getting rather expensive. They are large and heavy, so have to consider that when bidding. Could I ask how much was 'too much' to pay for yours? PM if you don't want it out there.

I'd still like to do it, just have to wait for the right pair. People will be selling a lot of PA type items and spares from the garage for holiday money, so it should be a buyer's market.

I like the inverted CW cabinets. Anything that gets the sound sources closer together has got to be a good starting point.

What, pray tell, are the reasons for the 511 being preferred over K600 or even the K400? Do you lower the xover frequency when using the new horn? Is it a dispersion or ringing problem that is overcome? How about using the Altec 811B, or is that a step in the wrong direction?

Michael

[Deang]

Lower distortion.

[Al Klappenberger]

TRiv,

I suggest that you mount the tweeter to the edge of the 511. Here's how I did it when I had 511 horns in my Belles. I don't think centering it in the 511 mouth is a good idea.

Al K.

[sfogg]

"What, pray tell, are the reasons for the 511 being preferred over K600 or even the K400? "

The 511 sounds more open then the K400. It has an ease and naturalness to the sound. The K400 sounds sort of pinched, shouty and compressed in comparison.

Distortion is possibly one aspect of it, different dispersion is likely another. Time domain aspects such as diffraction/internal reflections and things of that nature very likely play a role too.

"How about using the Altec 811B, or is that a step in the wrong direction? "

It is good down to about 700hz so it can't replace the K400 like the 511B can.

Shawn

[J.4knee]

Michael,

The 511 is very noticeabley more detailed in it presentation. As Shawn indicated it is much more open and smooth by comparison then the K400. THe dispersion and sound stage are improved as well. As far as using the 811b I suggested that in this thread but I was not sure hore low it would go. I'd say if you can get it to 650 HZ it would be a great replacement for the K600 in the CW. The K33 will go up to meet it and it should be more pronounced (slightly hotter and cleaner sounding than the K 600) so it should balance the mids to the bass better. A benefit I seem to notice better definition between the bass and mids in my LS with the 511b almost like a steeper roll off on the 511b.

R/Jim

[TRiv]

TRiv,

I suggest that you mount

the tweeter to the edge of the 511. Here's how I did it when I had 511

horns in my Belles. I don't think centering it in the 511 mouth is a

good idea.

Al K.

Trying a few tweeter locations right now before final mounting, was in

same position only horizontal for a few weeks, then change to vertical

as pictured. Actually have no plans to mount incenter of horn mouthe,

but rather above flange as pictured, but am planing to try side mount

as you have and as others have done k-horns. Searching previous posts

on horizontal vs. verticle looks to be evenly sided, so personal

preference must be a factor! so far my preference is the vertical

mounting, now to settle on location, though mounted on top center,

maybe another inch or so higher with 511 and k-77 flanges on the same

plane works good ( a bit hard to make look good though ), and as of

now, there is a folded terry washcloth in the top bowl-like area of 511

top to cut down highs reflecting in there, seems to work.

Before using the 511's, I put a small

triangular (corner) piece of terry-cloth inside the mouth lower surface

of the k-600 horn which made a noticable taming of the mid shrill. The

cloth was just enough to cover the lower surface without plugging the

throat in anyway, sort of like carpeting a bare floor room, actually

tried this with the 511 also, which does'nt really need much help, but

again, seems to get rid of some of what little shrill there is.

Al, you mentioned that the "A" type crossover

would have overpowering mids and highs compared to the Cornwall low

end, I know you are the one to ask on crossovers, so what would be the

advice here on going to a 400hz crossover that would work for the

Cornwall/511 setup, retaining the use of the k-55-v driver? others here

believe the 511b is capable of going down to 400 and rolling of

quickly, though most everyone with K-horns, Belles, LaScalas are happy

with the 511 upgrade, so the Cornwall should be too at 400 but the

crossover would be a bit different? One more question here, at 400

crossover, is there any human voice coming through the woofer? there is

notice of this with the 600 crossover, or are my crossovers getting old

(original 1977) i.e. capacitors breaking down?

colterphoto1,

watching ebay for several weeks and buying a

pair of 511's there, $100-$150 seems to be the range. Just like

(travisc), I bought now, paid $129 plus $25 shipping for a pair in near

mint condition. There is no shortage of these and for the price really

worth it! Now if someone here could say if the 311-90 or 311-60 is

worth it, they are kind of up there$$!

[sfogg]

"at 400

crossover, is there any human voice coming through the woofer?"

Quite a bit.

Shawn

[mungkiman]

TRiv, as long as you are trying a few tweeter locations before final

mounting, you should at least try in the horn mouth. You just might

like it. PWK did.

[Duke Spinner]

re: 811

will the k-33 go up that high ......???

all of my favorite speakers x-over at 1200 hz .....

these are all True "monitors"....4430, model 19.....