coolhandjjl

Horn 2

Horn 1

Feel free to make an offer.

For Sale: SOLD! Altec 811b Horns Looks like they may have been repainted, not sure. They're the nice Altec green color. A few paint marrs here and there, but generally speaking, in really nice condition. I have the VOTT reproduction bottom front edge mounting brackets, I'll throw them in at n/c. $250 for the pair, plus shipping.

I'm surprised no one mentioned cab placement. Boundary cancellation issues perhaps?

Thanks Dave, I'll keep that in mind.

Those are made of Baltic Birch plywood IIRC. Dark stain and finish can be hard to take out. Have you considered veneering then? It's not as hard as you'd think, not as messy as stripping, and would result in a superior surface for you to shellac, varnish, tint, tone, or whatever. Go to a Woodcrafters store and see what those guys think.

Isn't a 24 dB/octave Linkwitz-Riley slope supposed to minimize driver overlap?

On the ALK site, if you have Dave's Eliptrac 400 and wish to try the three-way route, they recomment either the Bob Crites' tweeter or Dave's Fastrac Contrac hybrid horn with a B&C DE10 driver. In either case, the drivers will not be aligned. Is there an electrical component designed to delay the tweeter, or does one simply give up on true time alignment. My active crossover does not have time delay features. How important is it to keep the center spread of the mid and HF drivers as tight as possible on the motorboard? The larger Contrac horn means the HF driver is further away above the mid driver than if one uses the Crites' tweeter.

So if you use it horizontally on a Klipsch type of speaker in a living room, you get nice up and down dispersion for sitting down, standing, up, etc, and since you have two speakers placed wide apart, that covers enough dispersion for walking around the room?

I'm almost done sanding Dave's Eliptrac 400 that I bought in kit form. It really is pretty easy to do, so for those wanting to save some bucks, don't be intimidated by the kit. Favorite drivers seem to be the B&C DE85TN and the Faital Pro HF200. I am actually doing a three-way, so the Elpitrac 400 is going to cover approximately 400~500 to 6000Hz. I was also considering a driver with some sort of poly diaphragm instead of titanium. Contenders are the Faital Pro HF204, and the 18Sound ND 2060A. If I venture away from the favored drivers mentioned earlier, am I sailing into uncharted waters here? Will this be a crap shoot?

I'm building a speaker that will do double duty as hi-fi and PA. It is a bi-amp system, I have a HF Eliptrac 400 tractrix horn that will most liikely cover it all from 400Hz and up, but if I heed to add a bit of sparkle on top, I'm looking at options. I currently have the Eminence ASD 1001 driver with a Selenium HC23-251" exponential horn, but if it's not what I am looking for, I'll look at other options suggested here.

I'm looking for suggestions on what might yield the wider HF dispersion, from 6~7kHz and up. The horn on the Crites CT125 tweeter, or one of the waveguides like the 18Sound XT120 tractrix horn?

chilipad- I see you are a new member. Welcome! The amount of knowledge here is huge! Best of luck with your project.

The drivers are facing down, mounted on a 1/2 in spacer ring directly behind those rectagular openings you see on the angled horn surface. The back edge of the angled horn panel does not meet up with the rear of the box, there is a opening of about 1-1/2" along the width of the box, that's the tuned port. If I strip out the present mid and tweet, the interior volume goes from 8800 to approx 9100 sq in, wonder if the gain will be helpful, or insignificant? I like my bins, they're cool looking, so I really should complete my project with the HF tops and start listening to music.

Dave and Chris- Everything you state makes sense to me. Perhaps I am trying to fit a square peg into a round hole? The bin pictured has approx 8800 cubic inches of volume above the horn/port area (less the volume of the mid/hi you see behind the grill, which are not hooked up and will not be used. Each bin has two 3012LF's in it, but those would have strong resale as they are in demand for folks building bass guitar cabs, PA's, etc. Would the better way to go be to build a proven winner, a Cornscala design with Bob Crites dedicated 15" driver? His designs have both the LF and HF components in one box. If I build the Cornscala just as a bass bin with the HF outside the bin on top, would I still use Bob's dimensions for the box, or would I subtract the volume that the Cornscala HF components normally occupy? The entire volume of my existing box is approx 11800 cubic inches, so I could re-purpose that cab it by removing the lower horn assembly, building a new motor board and making a larger grill.

This is only one speaker, up on a 18" stand for measurement purposes. Not placed in listening position. It's in the middle of my studio, a 10,000 cu ft, semi-partioned room into approx two equal halves. I didn't get even close to 100 dB, as it was getting loud, and I have no hearing protection. Mic was about 6' from bass bin. They are a PA style bin with two Eminence 3012LF drivers in a semi horn loaded vented box of approx 10~11,000 sq in. I am trying to see if it has potential to be part of a hi-fi system should I add the Eliptrac for for the high frequency. If these bins are just too weird or unsuitable for critical listening, I'll just build a real Cornscala pair as the style D.

Trace with no smoothing

I have a trace and an RTA on a bass bin, I have this pair I may try to re-appropriate for a set of modified Cornscalas, I plan to bi amp and cross anywhere from 400~600 with Dave's Eliptrac 400 as my top. I'm still not sure when to do a trace, or do an RTA, just a beginner here.

I know that Bob Crites has four Cornscala versions. Are there any response curves anyone has posted? I did some searches here, but struck out. /

That's a great idea. Thanks. So if I need to get something like 2.7Ω, I parallel a 3.0Ω and a 30Ω. And if my LC values are reasonably correct, it should work.

The Madison Sound calulator is pretty neat, I get to see dB drops in assorted neighboring frequencies, and adjust the width appropriatly. So two 25W 4.7ohm wirewounds from Madison wired in parralel would give me a resistor of approx 2.3 ohms with a 50 watt rating?

The 750 gets a bit pricey for my budget. For me, it will have to be either the Faital 140 or B&C 85, whichever one I can find at a better price when I am ready for drivers later this year. Your hammered finish is exactly where I wanted to go with mine. A few years back, I did a speaker project with metal corners, and I had a powder coater do a bronze colored hammer tone type of finish on them and they really look cool. Good to know there are spray can products I can use on wood-like surfaces that can create a similar look.

I thought you were using the B&C DE85TN. Whats the difference betrween that one and the one you are using? Has anybody considered laminating the horn layers with 3M Super 77 spray cement or a brush-on contact cement? Perhaps there's less opportunity for adhesive seepage into the sanding area that way.

I bought Dave's Eliptrac 400 kit earlier in the year, but life keeps getting in the way of building them. I'll be bi-amping with a TDM active crossover, so at least I wont have to worry about a network. Faital Pro HF 140 or the B&C driver? Both are good, seems Dave and Al K like the B&C a bit better, but didn't say why. So I wonder how the Eliptrac 400/B&C compare against the Faital HF140/Faital LTH142 horn?