jbell's set of four tapped horns

[ttako]

Hi Jeff,

In that case the sensitivity of the 4 boxes are ca. 110-111 dB 20V 10m
Did you do your measurements with that SPL meter in free or in a room?
If it was in free, was there any Wind? It can greatly change things :-))

Tamas

[jbell]

Not sure what you're asking? I was outdoors, over grass (not hard surface, like typical 2pi readings) and the closest building was 5-7 meters away. I didn't measure it, but that's about where my driveway ends. (garage was behind, nothing either side for acres) I used a spl meter, not software, so I didn't have to worry about calibration. Nothing more than a 5mph wind that I remember.

So, if anything, my readings are a little understated. A true groundplane measurement over hard surface would be higher.

does that answer your question?

[ttako]

Originally posted by jbell
Not sure what you're asking? I was outdoors, over grass (not hard surface, like typical 2pi readings) and the closest building was 5-7 meters away. I didn't measure it, but that's about where my driveway ends. (garage was behind, nothing either side for acres) I used a spl meter, not software, so I didn't have to worry about calibration. Nothing more than a 5mph wind that I remember.

So, if anything, my readings are a little understated. A true groundplane measurement over hard surface would be higher.

does that answer your question?

Hi Jeff,

Yes! Thanks for your answer.

[jbell]

Subs are installed, and 'way up there.'
Very satisfying bass, from subs up in the air, outdoors, is not a casual feat.

Thanks david, for a great tool, that allowed me to easily come up with a TH design that serves my needs nicely.

[Don Snyder]

Good stuff, Guys -

I'm surprised that it's so wide (24" inside). Most tapped horns on the BIG thread are barely wide enough for the speaker.

I've done some CAD, and I get a path length that's 30-40 cm longer than the 17/230/17 that Jim reported here. Not a problem, as length is a good thing.

Am I doing something wrong?

[Don Snyder]

Oh, I did find one thing missing ... the length of the short flare that starts 4" above the baffle ... is 12"

[Chris8sirhC]

The football stadium at USC (columbia, SC) uses 16 TH 115's for the sound system there. Apparently it was just installed. My brother was at the game and he said the output capacity was easily doubled. I'm not 100% sure they are TH 115's, but my brother saw them from a distance when the coverings were off during band practice, and the guy who does the on field sound system said they were using some sorta new horns. I am assuming that they are using danley products. From where he was seating, he said there was so much output he had to cover his ears, yet it was still clean. I guess they are not used to having TOO much output capability at USC.

[Don Snyder]

Here's my version of Jim's Tapped Horn. I ran this by Jim, and he suggested that I share it with the forum. This thing is BIG, over 600 liters, but that's not a problem for a fixed install.

The average guy should be able to get all of the saw-work done at a decent lumber yard, and complete it in an afternoon. If all the 24" cuts are actually 23 3/4", and cut with one set-up, he can even use PVA and everything will fit perfect. If he's got a router and a laminate trimmer bit, he can even make it pretty.

The angle cuts on the front and the baffle are a little over 8 degrees, but Jim said he left them square and used PL Polyurethane expanding adhesive. No bracing is shown, which is either brave ... or foolish. Jim put triangles in the two back corners (see pic earlier in thread).

This is a great project !!!

~Don

[Don Snyder]

Oh, and the driver is centered on the baffle!

[danielm]

Originally posted by jbell
Yes, everything on pressbox.
My tops aren't dr's. They are my own designed slot loaded dual 10's with 18" long horn paths. I found the OT had too much boxy 250-500 sound and not enough mid-bass, and the longer horn path moved that cabinet gain down into the frequency range I really needed outdoors.

The only eq I 'have' to have is the 8.5khz piezo eq, to get rid of that spike. (-3db q10) The 1025's are just much better controlled than the 1016's.

This whole stadium project was an exercise in trying to get cabinets (tops and subs) to really provide the most output at the hardest to reproduce frequencies, knowing that everything else can be accomplished with a little eq.

I'm very interested in those tops Jbell.
How'd they do with the TH 3015s?
Tell us more.