1803B horn plans available?

[Altec Best]

Is that true? The only measuring thing I have with me at the moment is in cm and the mouth opening of the 1803 cell is 20.5 cm or about 8 inches. Does anyone have another horn they could check?

I like the chart on page 2 that shows you just how big the darn things are.

All the cells for each horn are identical.. On my Tar 1005's all cells measure 6.25". So if your 1803's cells measure 8" ? They all will be 8"

[alancohen]

I will take many photos as well if I am doing the take off. I will email those directly as I can't post them all here.

A picture looking squarely down (or up) from at least 6' away with a "normal" 50mm lens (so as not to distort) would do the trick. That would give the curve. That photo can then be printed on a program like TilePrint BlackFlight Models and scaled to any length. Patterns can be made off that. A bit of length would have to be added to account for the upward curve. Calculus guys can figure that out. I would wing it.

[alancohen]

IMO, an important detail to keep in mind is the thickness of the cell walls where the cells will come together at their throats. Ideally, each cell will need to be carefully sanded at the throat end to a thickness as close as possible to the thickness of the tin. The better sounding multicells i've heard(and i've only heard a few) had been carefully hand sanded to a nearly knife edge at the throat junction such that there's no surface left to reflect energy back toward the driver.

That's why I was thinking 10 ply 3/16 plywood. Each ply would be <.02" thick. You could work that pretty fine an since it's enclosed in the flange, it is not really subject to damage. A small wedge of folded aluminum flashing on can even be fared into the ends without majot hassle.

[Cal Weldon]

All the cells for each horn are identical

OK, I misread, I thought you were implying that all horns had the same mouth size.

A picture looking squarely down (or up) from at least 6' away with a "normal" 50mm lens (so as not to distort) would do the trick. That would give the curve. That photo can then be printed on a program like TilePrint BlackFlight Models and scaled to any length. Patterns can be made off that. A bit of length would have to be added to account for the upward curve. Calculus guys can figure that out. I would wing it.

I would rather do a plot and have you draw it rather than try to photo and transfer. I know over at diyAudio Pano and someone else did a plot for the 1505 but I can't find it and besides that won't really help for the 1803 now would it?

This has to be done tomorrow as I don't seem to have a tape measure here but I will bring one tomorrow. I will also do lots of photos as mentioned.

[alancohen]

I'd be interested in that 1505 plot. I have GPA 802Gs so 500Hz is as low as I'd be going with my system. I can dream about 300Hz, but it's not likely going to happen without a lottery intervention. I would likely do a 1205 with a throat for a 1" driver. I might have the only 1205s this side of the Mississippi...or the other side.

I can also do just as well with photos. I build model airplanes from scratch and have drawn accurate plans from photos taken at museums.

[Cal Weldon]

I'll go look again.

EDIT: Found them:

First at post 712 http://www.diyaudio.com/forums/multi...ml#post3256289 is the plot and post 716 http://www.diyaudio.com/forums/multi...ml#post3256364 has a trace of the curve but as we age we forget things, I now note that is for the 1005 horn and I don't know the difference in length if any. The mouth size is the same.

EDIT2: Looking at the link provided before, they are indeed the same. Don't be fooled by what looks like a 0.5 inch difference. You'll figure out why. So there you go. All you need for a 1505 except the waveguide.

EDIT3: Check this post as well. http://www.diyaudio.com/forums/multi...ml#post3261117

[Panomaniac]

I have the 1005 and 803 horns and have spent quality time with the 1505. The cells are all the same within each of these horns. The cells on the 803 are just bigger and longer. AFAIK, you can just scale the curves to whatever size you need.

I have heard the Synergy horn twice. They are very nice. I'm still hoping to hear them in direct comparison to my Altec system.

[GM]

Not sure if I am understanding you but in my experience aren't we not continually fighting a "sinking" response with compression drivers? *especially those on big horns.

Myself I kind of chuckle when I see anyone using any multi cells close up in a small living room, it is kind of torturous to me. When I finally kicked the multi cells out of my living room for good, I brought my remaining pair and a split 210 box to store at a buddies warehouse until they were sold.


Now at 30 feet+ as you say, it was ideal, everything blends as it was intended and actually it was freakin' amazing, stunning, huge sounding and got me thinking about getting a warehouse of my own........just to listen to multi cells and bass horns(and do other cool stuff in of course, like build more giant speakers)


Heard Nick McKinney's Unity horn crossed from his way good 15" Lambda driver at around 300hz. It seemed to be quite a tweaky system to get right but when it was dialed in was way better than I expected. Had unfamiliar music playing but I remember the sound was huge, open and shocking that such a weird looking pile of crap could sound so amazing. (This was over 10 years ago now so at the time not many had ever seen this concept including myself so the unfinished prototype just looked like crap pieced together).

I would like to hear the some of the new Danley Synergy version's for sure again to hear if is as good as I remember and if the extra lower horn loading brings any improvements. I still think horns like the 1803 will always sound good no matter what comes next though. Kind of like some old race cars still going fast as hell even though some newer cars are technically faster around the track


Have you heard the Synergy?

True, some form of CD horn EQ is required to flatten out all compression loaded horns as all have a rising on axis response [HF beams with increasing frequency], so for flattest practical polar [power] response over the widest BW requires they be toe?d in to some extent.

Yeah, stacked, tweaked 511s worked well for me in my current ~16 ft x 24 ft open format room, though by far the best overall performing horn I had was a large conical WG based on a tar filled 1803 except no individual cells and driven with an 802.

After them, everything short of a Unity/Synergy concept sounds too ?colorful? to me in one way or another. The trade-off of course is huge size and modest efficiency that when combined with the tweaked 210/211s put the c-t-c spacing way too far apart for my now ~14.5 ft LP.

Agreed, the largest multi-cells in the right environment are really good and of the traditional horns only surpassed by the largest WE horns at least to my ears. Truly, these were engineering marvels of their time, but for me the three way DSL Synergy horn is in a league of its own except for its too bright/sharp HF; so yes, I?ve auditioned most of the DSL products since I?m only ~45 min. away. I need to get back up there for the latest products though.

Anyway, the Unity was a rather simple design and I?d planned to try my hand at marketing a finished speaker using them, but life happened to both of us, so never came to pass. There were some things I knew to do to make it more HIFI plus I wanted to build a three way, but the three way Synergy now has the major changes included, so not a lot left to tweak AFAIK.

The three way solves the c-t-c spacing, the only variable that kept me from meeting my HIFI performance goals.

GM

[Audiomind]

I moved this post because it was so long and of the topic of 1803B plans. The new thread is titled:

GPA "Classic" alnico's to tame highs on Synergy horn, looking for heated debate.

[Audiomind]

IMO, an important detail to keep in mind is the thickness of the cell walls where the cells will come together at their throats. Ideally, each cell will need to be carefully sanded at the throat end to a thickness as close as possible to the thickness of the tin. The better sounding multicells i've heard(and i've only heard a few) had been carefully hand sanded to a nearly knife edge at the throat junction such that there's no surface left to reflect energy back toward the driver.

Understood, very good point. I am not using tin though, doing them in wood, should not be a problem once the delicate fin is glued in though.