The legendary K-Horn using altec 511B and 808-8a

[tizman]

FYI/FWIW, way back when, I doubled up 511s, one with 802-8A (alum) and the other with the then just released 802-8G tangerine for a 1.5 way horn, which gave me more horn mouth, diaphragm area than the 805/288 multicells @ 500 Hz XO they replaced + much more extended HF and the 350 Hz XO capability I was hoping for.

That sounds like a great idea. I have two pairs of 511B and four Renkus-Heinz SSD-1800. I also have a nice pair of 811Bs. How did you orient the two 511Bs? Were they mounted on a common panel or stacked? Drivers in series?

 

[tizman]

Hi tizman, the Khorns are in use as the main sound reproducer in my ht system. They work just great but I haven’t spent time digging further with measurements and pressing them with some favourite ‘test tracks’. I’m afraid summer and travel became a more enticing use of time.

If I remeber correctly, I ended up lowering the XO below 500Hz as I don't run the horns hard the 511B’s never get stressed.

I am interested, when I get back to them, to explore the necessity / value of time alignment. If it’s only a marginal benefit then I can explore passive filters with a bi-amp setup rather than leaving my dsp permanently in place.

p.s. The dispersion of these speakers appears to work well with my ht set up, no centre channel needed.

I have a passive line level crossover made for 500 HZ that I feed into two stereo amps. Previously, I used a diy/, bi-amped, Hiraga Altec A5 crossover that worked well. I really wanted to make an electronic crossover work and tried three different ones, but every one had a noise penalty I was unwilling to accept. Physical time alignment is easy with a 511B on top of La Scala (or FH1) bass bin, but looks a bit awkward. I haven"t tried putting the 511Bs on the Khorns yet, so I'm not sure if they can be physically time aligned. There may not be enough room with the Khorn in the corner.

 

[Bigun]

There’s no real good way to physically time align a Khorn, it has to be done electronically if it’s done at all. And there’s not much choice there but to use a dsp. I have no qualms using the mini dsp HD, but I’d like to put all the electronics associated with each speaker close to each speaker rather than separately (such as in a central location between them), so then I’d have to use two dsp’s. Nevertheless, it’s not a big deal either way. I’m still curious as to how much difference the time alignment makes in practical hearing tests. These speakers have pretty attrocious time alignment as they were originally made but few people seem to have ever complained about it.

 

[GM]

That sounds like a great idea. I have two pairs of 511B and four Renkus-Heinz SSD-1800. I also have a nice pair of 811Bs. How did you orient the two 511Bs? Were they mounted on a common panel or stacked? Drivers in series?

Stacked with short plates to tie the flanges together and a DIY wooden fixture to clamp/mass load the horns/drivers with the 802-8A physically aligned with the woofers.

Wired in parallel and used an RC network to both raise effective Re and add CD horn EQ to flatten them out to 22 kHz+ just because I could , though had to dial it back a bunch when the then current SWMBO ran screaming from the room while playing an RTR tape of various steam trains. Seems between the high SPL, RTR tape's higher/hotter HF than records, cassette tapes ~literally 'struck a nerve' due to her near freakish hearing (she would 'perk up' when the neighbor used his dog whistle!).

D@#$, but I miss that woman, she was more fun than a yard full of puppies, but had already been bequeathed? by her parents to a yet to be determined spouse when I met her.

 

[tizman]

Stacked with short plates to tie the flanges together and a DIY wooden fixture to clamp/mass load the horns/drivers with the 802-8A physically aligned with the woofers.

Wired in parallel and used an RC network to both raise effective Re and add CD horn EQ to flatten them out to 22 kHz+ just because I could , though had to dial it back a bunch when the then current SWMBO ran screaming from the room while playing an RTR tape of various steam trains. Seems between the high SPL, RTR tape's higher/hotter HF than records, cassette tapes ~literally 'struck a nerve' due to her near freakish hearing (she would 'perk up' when the neighbor used his dog whistle!).

D@#$, but I miss that woman, she was more fun than a yard full of puppies, but had already been bequeathed? by her parents to a yet to be determined spouse when I met her

I tried dry fitting the two 511Bs together last night. I suppose that the end result would be like a larger sectoral. I'm going to put it on the list of future projects. Thanks!

 

[GM]

You're welcome! Correct, a ~ 90 x 90 Vs ~40 x 90.

 

[Bigun]

I’m slow at finishing projects… adding some pipe insulation to the edges that need to seal to the walls. Thinner weather sealing goes at the bottom against the skirting boards.

 

[Bigun]

I have now made and installed an aluminium bracket, with binding posts, on each speaker so that I can plug and play with bi-amping speaker cables. It also provides cable strain relief by isolating the cables to the drivers from those to the power amps.

I then wired up a pair of 4 x 25uF Vishay film caps in parallel blocks to give me a pair of 100uF series protection caps for the CD’s on the upper horns. Unfortunately they sucked some of life out of the sound so they had to be bypassed and will eventually be removed.

On some Chesky recorded jazz, the speakers are sounding good. On pop music they are not sounding right (hey, maybe these speakers have good taste!), a little fatigue in the treble and a bit boomy in the bass. I still need to get my virgin calibrated microphone set up, it has been sitting still unused for several years.