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I don't normally listen to stuff over reference anyway. I couldn't until this second horn... the room is open to the rest of the basement, which in turn is open to the whole house. Takes a lot of SPL to fill all that up. That's why I was so unhappy with one 18" in a vented box.
Great documentation, design, and build :T

My house seems quite similar, and all the subs I listed below (18" & two 12"s) do a good job, but nothing like others have with a lone 15" in a small room. I've vowed to use an infinite baffle for any future house to achieve desired spl without taking up space, but thanks to you, a tapped horn built as a second row riser will now be a definite possibility.
 

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Discussion Starter #102 (Edited)
Got some measurements today. Still waiting on better measuring gear, but these should do for now.

Before I show y'all these, just remember - they were done with a cheap eBay SPL meter, no cal file, with the C weighting option checked. The most accurate part of this setup is the Behringer UCA222 used to capture these.

Current placement is corner firing, like so... SDX horn is on the bottom, Tang Band dual 8x12" horn on top:



First, Wolfhorn SDX by itself, listening position. 90dB sweep. This is the loudest I can run it without wall panels vibrating, and the loudest I will run it without a highpass. SDX drivers don't grow on trees, and I can't afford to replace them.



Now, before I show the other two graphs of both horns through the Reckhorn, I want to remind you how the B-2's highpass and EQ is currently set (purple line):



Ok, now both horns through the B-2, 90dB sweep:



Now, take this one with a BIG grain of salt. This one had the walls rattling, which almost certainly got picked up by the meter. 95dB sweep (or so it should have been):



All of this is with the meter at LP.
 

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Correct me if I'm wrong, but aren't those going pretty deep for TH's? What kind of spl do you reckon you'd get from only the Wolfhorn SDX at LP? That build really has me excited about a possible riser somewhere down the road!
 

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Discussion Starter #104
Not for 16Hz TH's ;)

I have usable extension to 14Hz in room, but the two horns will not quite do 14Hz at reference in here without second order distortion (the further you go below the corner, the more distortion of this type there will be). YMMV - if you have a less challenging room than I do, you'll probably get more below the corner than I do due to room gain.

I've already had the SDX horn do just over reference at LP by itself without too much trouble, but I didn't have a good enough highpass on it to get the most from it. As a result, the coils were clattering on the backplates ever so slightly from trying to play too low. A proper highpass, and it should match or even beat what the dual Tang Band horn can do, which is 120dB at LP. Together, I have insane headroom. Right now the two horns combined will do 120dB at LP with the drivers maybe at about half of Xmech.

Both designs are able to rival the SPL of a Danley DTS-10, but I can't promise they will match it in any other ways. The SDX isn't quite ideal for tapped horn use (the drivers in the DTS are), but it's close enough to do the job. The idea is really to present a cheap alternative to the DTS, and I think I managed to do that successfully. This way, people with really big spaces to fill can get a couple of these built without breaking the bank.

Just be sure to highpass properly. 48db/octave is strongly recommended. Start rolling it off by 16Hz already if you have a room open to the rest of the house, like I do. A MiniDSP is your friend.
 

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I know this is a tough question but I'm curious :whistling:, but you anticipated greater output from the SDX TH and it seems to have fallen a hair shy of your expectations and I'm wondering if you can say with any certainty what modification to your design would achieve that superior output rather than the equal output compared to the Tang Band TH you are describing.
 

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Discussion Starter #106 (Edited)
Here's the thing - the Tang Band horn does sound slightly better, at least for music. This is because the drivers are electrically more suited to tapped horn use. The drawback to that, however, is they need a whole of a lot of space to do the job. As a result, you'd be looking at 4 sheets of ply to build one. And that's assuming you get two good drivers from Tang Band - one of mine had debris in the gap.

The SDX driver, on the other hand, requires less space and is way better build quality but has a higher Qes than I'd like to see. As a result, it sounds just a mite on the sloppy side for music. That said, this thing wasn't designed for music. Movies. It's not that it sounds bad, because it doesn't. It's just that it's got tradeoffs, just like the Tang Band horn does.

I personally prefer the SDX design. I could fit four of them behind my screen, the drivers are way better quality (and from a Canadian company), and a MiniDSP will take care of the stricter highpass needs the design has.

The problem is, when you're designing a 16Hz tapped horn you start running low on drivers that will do the job. I've now used two of those drivers, and I only know of two more offhand - the TC Epic 10 and the Kicker CVX 15." Neither one of those were an option for me, mostly due to money and availability. Well, the DTS-10 drivers would work too, but good luck getting them.

As for greater output - the SDX design has the slight edge there on paper. Remember, the clattering coils were due to the highpass being set too low. My B-2 only gives me 24dB/octave, and it's hard to get it set up properly without multiple passes through REW. The SDX motors just have more strength past Xmax than the Tang Band motors do. So, you do have more protection from misconfigured highpasses on the TB design. But the design of that one is just... so... big! 850L is a lot of real estate for a subwoofer. Everyone who's asked me for the plans on that one has changed their mind when they realized how gigantic it is.

Modifications? Well... a more ideal horn flare would add some output and sensitivity, but then you're back to monster 850L boxes and 4 sheets of ply. Not gonna happen in this house. More Xmech from the drivers is really what would help most. This is why you don't see many horn designs that go this low. Most are just too big to bother, and driver selection is extremely limited.

Hope that makes sense - brain's a bit scattered today.
 

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Discussion Starter #108
No problem - I please to aim to please :D

Should mention - I had no idea the TB horn was going to turn out as well as it did. I completely by accident stumbled on a tapped horn that was better in reality than modeled. The SDX horn was my attempt to do it better on purpose this time. I'm satisfied with the result.

Both designs rival the DTS-10 in SPL abilities. One sounds slightly better and is more sensitive but is bigger with questionable quality drivers. The other is smaller with less electrically optimal drivers but with slightly more top end SPL capabilities. Neither really matches the DTS-10 in every conceivable way - the driver list gets really short by that point. Pick yer poison ;)

Before anyone asks - no plans on doing anything with the Epic 10. I'm done with the big tapped horns for a while, unless someone straight up gives me a pair. And the CVX is bigger than I want to work with. I have no need for more SPL in this home theater - I've already hurt the house with the two I have :R
 

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I'm cleaning out the garage to give this a go in the next few weeks...I just want to hear/feel it for myself. Anything you'd do differently in retrospect (given the same drivers and overall design)?

Maybe I missed something, but did you ever get a miniDSP for the steeper crossover?
 

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Discussion Starter #110
Nope - I'm satisfied.

MiniDSP is not needed here... I have enough headroom that bottoming out the drivers is almost impossible even with a poorly configured highpass, and response is quite flat at LP.

Since I don't make a lot of money, a MiniDSP is not a priority. A wise decision for those expecting to run the design wide open, but I'm not currently able to do that in this room without breaking pieces off the house.

Since my last post, two more Wolfhorn SDX's have been built... someone at AVS put together a couple of them a week or so ago. He hasn't posted much lately, but seems happy so far.
 

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I need to check AVS again. I'd been following it when you started your build, but got distracted over the summer. [It's suprisingly tough to get nice grass to grow in sand]

I still have a compulsion to turn the thing into a couch, but I'm pretty sure I'll never actually get around to doing that...maybe a waterbed:gulp:
 

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Discussion Starter #112
I totally forgot to mention - I now know of an alternate driver for this design in the Seas L26ROY. It is actually a better modeling driver than the SDX, and shares similar Xmax and Xmech numbers.

It is also, however, much more expensive than the SDX. Try it at your own risk... I will not be. It's not so good that I would recommend it over the SDX. And really... just those drivers alone will cost you what the SDX's and materials cost me in total.
 

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I saw you mentioned those drivers in that AVS thread. Personally, I'm much more comfortable with the SDX10 price point, besides the fact that I already have 4 of them.

It'd be interesting to see what others do. I, for one, never would have felt like tackling a tapped horn without documentation/design like you have shown.
 

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Discussion Starter #114
Yeah - the price difference makes the decision an easy one. Just thought I'd mention it for the benefit of those who may have the Seas drivers and have no idea what to do with them ;)
 

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Discussion Starter #115 (Edited)
Another video for interested peoples. Excursion on the SDX horn was starting to get a bit high again... I suspect the B-2 highpass setting has drifted off my desired settings. It's done that before. Not a big worry for me as I do have that other horn helping out, but once again this shows why a MiniDSP is the better option for the SDX design.

Even so, my LFE was set above reference here... not a problem for either horn. This is way above my usual listening levels. It was so loud, the horns had the dogs thinking there was a thunderstorm coming. The dogs were outside.


Edit - no drift on the highpass, says REW. After re-watching the video, SDX excursion was nowhere near high enough to worry about. An inch peak to peak.
 

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Hey, I've got a couple more questions--

First, I just wanted to make sure, since my dimensions are a bit different--that piece at the throat is placed to make the start of the horn 300 mm from the center of the two drivers and the mouth needs to be 390mm, correct?

Second, do you think there is any need to compensate for the volume of the dual drivers when calculating the volume at the mouth?

Also, why did you put the batting where you did and not anywhere else?

Finally, do you think there would be any benefit to adding pieces in the corners of the largest turns?

I know some of this probably gets into miniscule differences, but until I can run to pick up a large enough sheet of ply, I'm just stewing.
 

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Discussion Starter #117
First, I just wanted to make sure, since my dimensions are a bit different--that piece at the throat is placed to make the start of the horn 300 mm from the center of the two drivers and the mouth needs to be 390mm, correct?
Yup.

Second, do you think there is any need to compensate for the volume of the dual drivers when calculating the volume at the mouth?
Nope.

Also, why did you put the batting where you did and not anywhere else?
Thought it would help with standing waves in the horn and cut down ringing. It does... kind of. Not sure the benefit is large enough to bother.

Finally, do you think there would be any benefit to adding pieces in the corners of the largest turns?
Nope.
 

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Well, after fruitlessly trying all sorts of alternative dimensions, here is the plan I've decided to try. It's a little thicker but not as wide as the original. The calculations were re-done today basically as a pencil-doodle while I was bored out of my mind during a teleconference. As such, there may be a slight error, but the math should be much more accurate than my woodworking anyway.

Just under 14" x 77-1/4" x 38-1/4"

My basic goal was to keep the dimensions such that I could build a back and arms, add some padding and fit a pre-made couch slip-cover from Ikea over it. Well, that and the obvious--some nice bass.

 

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Discussion Starter #119
It's not too far off. Biggest difference is a raising of the low corner due to shorter length. It's probably up to about 17Hz there. Acoustic impedance and reactance is still good, as is compression ratio.

Don't really see a reason not to build it that way, unless you absolutely must have that last 1Hz extension or so.
 

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Discussion Starter #120 (Edited)
Just a quick December update - there are now two alternate drivers for this horn: the Seas L26ROY and the Fi X10.

Note that I have tried neither of these, so can't say for sure whether they cooperate with the horn. It was designed for the SDX10... that's all I can guarantee unless and until these alternates are tried.
 
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