Collaborative Tapped horn project

[MaVo]

yes, it is, if implemented correct.

[GM]

Originally posted by hm

"Adding multiple tapped horns together does NOT lower the cutoff. "

if you use membran movement cross setting and bass horn mouth distance it worked:

Greets!

The cut-off (Fc) of each does not change, so they can not sum to some different Fc, though you are right that their outputs (SPL) can sum in various ways depending on how they are oriented to each other, which is not the same thing.

GM

[GM]

Originally posted by AndrewT
using a single driver and a straight horn, how many octaves can one get from this set up?

With a point source driver, ~three octaves of actual horn loading due to compression ratio (CR) limitations. Horns are normally designed to be a combination of compression plus rising on axis output though, so can cover many octaves if a very narrow 'sweet spot' is acceptable and a proper phase plug is used.

GM

[MaVo]

Originally posted by GM
AFAIK, without using mass quantities of EQ there's no 'replacement for displacement' to get a ~smooth TH response from top to bottom, like ~3945 L! in the case of a $100 Eminence Delta 15LFA:
...
Oh well, back to reality........ How about this MTX 9515 sim? It should EQ/XO easily enough and it's 'only' ~836 L, so dividing it up into multiples is probably the way to go

Thanks GM, i am frying my brain right now by thinking about all the different tradeoffs one can make in order to get good response in the modal range of the room and below it. Well, thats not really on topic, so i quit here.

[GM]

You're welcome! Been there, done that and why I finally decided treating the room was a lot easier..........

GM

[Naudio]

so far so good, should get it ready to test today

one question if i invert the driver in the horn so the magnet is facing out (like i have to) do i need to wire it in reverse?

[MikeHunt79]

Originally posted by Naudio
so far so good, should get it ready to test today

one question if i invert the driver in the horn so the magnet is facing out (like i have to) do i need to wire it in reverse?

I wired mine normally. I have the luxury of being able to invert the phase on my DCX2496 tho, but right now I've got it set to not invert.

The best thing to do it do some sweeps around your XO frequency, and see which sounds better, wired normally or reversed.

[MaVo]

Originally posted by MikeHunt79
The best thing to do it do some sweeps around your XO frequency, and see which sounds better, wired normally or reversed.

Do this only if you are prepared to start thinking about room treatment. The little notch due to unperfect addition around the xo will be swamped by numbers of much bigger peaks and notches from the room modes. I would say, if it sounds good, let it be, since you probably cant see it anyways.

As an example i added a picture of the inroom response of a loudspeaker, which would be flat from 20-300hz without the modes.

[Chris8sirhC]

yikes...

[JLH]

I finally decided to pull the pictures of my 40Hz tapped horns off the digital camera. Below are a few shots during construction. The outer dimensions are 8.5” deep X 10” wide X 54” tall. So, for 40Hz performance it is quite small.

First picture is of the folding without the braces in.






The below picture shows the access door and where the woofer mounts.






This next picture is the horn with the braces in place. The braces are ½” birch ply and the rest of the horn is ¾” birch ply. This is right before the last side goes on and it is sealed up forever.






Here the B&C 8PE21-16 is going into the horn. It is a tight fit, but worth it because the horn is very small compared to my old ones.






Lastly, the woofer nestled into its final place. The bass output from a pair of these is very impressive. Especially considering their rated Xmax is 1mm and Xmech is 4.5mm.






I would encourage anyone to model and build tapped horns. They perform great, they are easy to build, and are the real deal.

Rgs, JLH