Wolfhorn SDX Design Finished - Page 9

MiniDSP.

The iNuke NU3000DSP may be worth looking into if you don't have the EP4K yet... not too familiar with it. As long as it will do a 12Hz or so highpass at better than 24dB/octave it should do the job.

How big a space are you filling?

Doh! I think I'll take that suggestion off the table then. No point building this design if you're going to highpass that high.

You're going to have so much fun with these

My room's open to the rest of the house, and I still can't run the two horns wide open. They break things when they get that loud.

Folks, we have another driver alternate. The Fi X10 also works in this horn.

So, there are options now if the SDX10 goes away, or changes into something incompatible.

Yep. Take that with a grain of salt, though. I don't know if the specs are totally accurate, have no interest at this time in testing them out, and am not sure how they like the compression ratio.

I'd put the Seas driver ahead of it. And the SDX ahead of both.


Glad to hear it

I would do plywood.

You don't have to do BB - it's expensive, and the plans are designed around 4x8' sheets.

Any decent relatively void free 3/4" ply will do.

Yep - make sure you go easy on the horns until you know what they can do. If your room is as challenging as mine is, 450W each may be enough to bottom the drivers if the highpass is incorrectly set. 450W above 15Hz won't get them into trouble though.

Looking forward to seeing how yours turn out. Any questions, just ask.

Unfortunately, horns don't work like that... if you want to keep that 16Hz corner, it'll still need to be long enough to support it. You might be able to re-fold it so that it's shorter and taller, but that's about it. You have to get that 20+ feet of horn in there somehow. I just folded it this way because it was easiest.

Changing the depth would completely change the design. Not sure what the result would be - some increase is ok, but 19" is a long way from 13.5." Goes without saying it would take a lot more wood.

How much shorter do you need it? My Tang Band horn is a little shorter and wider. Still a 16Hz design though, so that only amounts to a few inches.

The Tang Band drivers are actually more electrically optimal for tapped horn use. As a result, it sounds just a bit better in general than the SDX horn. Not that I notice it very often. The tradeoff there is that they require so much more space it's not worth building that horn. I learned from it and did a better one

Transmission lines and tapped horns do share that 1/4 wave resonator, but are not really the same beast. The SDX design is an undersized tapped horn... it doesn't have an ideal horn flare, and this does have some sonic drawbacks, but it is still a horn nonetheless. Had to compromise if I wanted it to fit in three sheets of plywood.

As far as the ragged response goes, Hornresp assumes perfect conditions. A lot of those peaks and dips aren't there in real life. If you take a look at my measurements elsewhere in this thread, you'll see how my pair do in room. The two of them are remarkably flat without EQ over three octaves or so.

I'd get more into horn theory, but it's been an insanely busy week and I can't think straight anymore. There are others who can probably explain it better than I can... I'm still getting my head around some of it.


Muahahaha! Soon, the earthquakes begin...

Got bored, did another video. Well, actually six videos but I put them all together. Apologies for the terrible quality - I just don't have a good camera.

Just a demonstration of what happens in this house when I put sine waves through the horns below the corner frequency. Started at 12Hz, ended at 15Hz. Though not loud enough to register on the SPL meter due to the highpass, 12Hz was already loud enough at the fundamental to get ductwork rattling - not sure if you can hear that in the video due to the quality.

15Hz is pretty much high enough in frequency that I can't turn it up loud enough to find the limits of the two horns. As it is, it was pretty violent. The couch was visibly shaking, the screen was flapping, the door to my bedroom was rattling hard, the light fixture on the ceiling was moving up and down by more than half an inch... it was nuts. This is why that fixture no longer has a shade on it. This is why I have to change that light bulb frequently. I actually had to pop my ears after this one ended.

Final part of the clip is the first music demo of the horns I've recorded... they were set 8dB over reference for this. Used a recording of the world's largest pipe organ... this track has strong content down to 8Hz. Blew a woofer in the mains near the end (already replaced with a spare). 121dB at listening position from the horns. The camera couldn't handle the SPL on some of those peaks... you can sort of hear it distorting in places despite the sucktastic sound quality.

Probably the last video I'll be making of these. I can't let them get any louder in a place I'm only renting, but they will do it if I ask them to.



Now, to go design me some new mains. I shouldn't have asked them to try and keep up with the two monsters

Since it looks like the SDX10 may be replaced by an updated model in the near or far future, and I am not exactly sure what the new guy will be like, I've found another driver alternate for this design: the Dayton TIT280C-4.

Standard disclaimer - I have not tried this driver, have not measured this driver, try it at your own risk. It's not as ideal for the design as the Seas L26ROY would be, but it's cheaper and still models quite well. Better than the SDX, in some ways.

Hornresp file attached.

For now, the SDX10 seems to still be around and will always be the driver this horn was meant for. I'll investigate the replacement when it's around to be investigated. But if you can't get the SDX, there are options.

Edit - Bob at CSS has told me the SDX is going nowhere. So, we're good for the foreseeable future.

 

titansdx.txt 0.423828125k . file

The W8-740P in pairs would be best kept to around 20Hz... they really don't have the displacement to pull off a 16Hz design that would end up being worth building.

The SDX10 was literally the smallest thing I could find that would do the job, though there are other 10's that will work in this design.

Nope, sorry... the Lab12 is all wrong for this design.

Bumping this thread again on account of the fact that I now have actual electrical impedance measurements for this beast. Did them with the help of lilmike's DIY impedance jig, REW, and my Behringer UCA222.

What have I learned? Well, for one thing, I learned I got way closer to the model on this build than I did my Tang Band horn.

Hornresp model:



Impedance measurement with phase:


Edited by Oklahoma Wolf - 6/11/12 at 10:03am