811 Horn Mods Completed

[RonSSS]

Or as they used to say on Monty Python:
"And now for something completely different"

I cut the divider sections out with a saws-all. A brutal tool. Cleaned up the remaining areas with a die grinder and then used auto body filler in the flare to make them look nice again. Painted them with semi flat black. They end up looking radically different.

To eliminate the ringing, I used the latex paint and sand method. It took six coats to get them dead. I finished off this job by painting the outsides with semi flat black latex.
They now weigh about 2 times as much as they did before I started.
I took pictures of the whole process if anyone is interested.

I mounted them back in the 19's with weather stripping between the horn and the cab to seal the mounting. A knuckle rap test reveals the horn to be as dead as the wood around them.

I have no idea how this is going to sound. But it's an experiment I've always wanted to try.

GPA goofed and didn't send my cone kits, so after 2 weeks of waiting, I called and they should be here this week. So maybe by next week some time I'll be able to listen to my 19's for the first time.

Ron

[boltupright]

Yeah, I was thinking about what it would look & sound like if those multicell dividers were cut off, could you send some pics & keep us posted on how it sounds?

[Adhoc]

I'm in the process of building new cabinets for my 416B and 811B (posted a thread on it recently and am waiting for response/proposals). Killing the hornringing on 811B is a part of that, so pictures would be much apprecaited.

[Mike Gibson]

Ron, I would definetly be interested in pictures.
As an aside I pulled the back off of one of my Valencia's and was astonished at how clean everything inside is. Considering where they have been and what they have been through. I never realized that the bass vent/port was around the ends of the horn and that they had no actual vent/port other than that.

[RonSSS]

I'd be happy to post some pictures.
I have to get them out of the camera onto the PC and then fins a web site to post them to. So give me a week or so.

Mike, nice to see you on board!

Ron

[gearjammer]

This is just MHO but if you cut out the divider fins you will change the dispersion of the horn. These fins were not designed to just connect the top and bottom of the horns. Altec in the last few years of production of the horns did not weld the fins togeather but just applied some black caulking type of sealent to fill the void between the fins.

[RonSSS]

Like I said, just an experiment.
Since the horns were more or less disigned for theatres, and the goal was to give even sound for all of the seats, I figure that in the nearfield where I listen, the dispersion won't be an issue. I might be wrong, but I'll be the first to know!
I'd really like to find a pair of the Constant Directivity horns for the small format drivers to try. I really like the CD horns in my duplexes.
Ron

[cclark65]

I just bought a pair of the horns from the model 14's off ebay for 20 bucks for the pair. Another pair just went for about 50 bucks, they were pretty much brand new. If you watch, they are out there...

On that note, I am really looking for some of the really small MR horns that were on the MR902 series horns. I would be willing to trade these from the model 14's for a pair of them!

[RonSSS]

I had a pair of the model 14 CD horns and didn't care for them. They just seemed off to me. Long gone I'm afraid.
The ones I'd like to try are bigger and go down to 500 hz.
If I'm not mistaken, the itty bitty ones were also used in the Duplex drivers.......
I also emailed the gentleman who had a pair with his 902 drivers, but he didn't respond. I expect to see them on ebay with a large reserve.....Ha!
Ron

[cclark65]

If those model 14 horns didn't sound right to you, then you might not like any of the MR series horns
I have 4 of the MRII594b's, and a couple MRII564's that I use for PA work. They seem to do the job pretty good, but I run them higher than 500Hz (1500 actually) since I am doing loud live stuff.

If I am correct, even these horns are too small to handle down to 500Hz and keep directional. I talked a while back to a guy from the current Altec Pro, and he mentioned that the 594's were directional only down to about 1500, and the 564's lost it below 2000.
If you want true directionality down that low, you are going to get a pretty big horn. But then as you said, you are listening in the nearfield, so that might not be an issue either for you.