Looking for horn expert to help with the build.

R-Carpenter

Hey guys. Most of you have seen my main system at some point. It towers behind on all NY/NJ DIY get togethers.  I've had it for a few years and it's been going through one transformation in to another. Currently, it is a 3-way active DSP. After listening to a few humongous horn systems I formed an opinion that while top end and mid-range of the horns are not exactly to my liking. The bass is generally most life like. So, I would like to replace 8ft^3 ported boxes with a large J horn.
Main line array which consists of JX-92 drivers can play full range or can be filtered not to go below set frequency. I am thinking that the horn should cover 40hz to 200hz. The ceiling in my space is 16ft so there's room to go, however I am not looking to build a dedicated horn subwoofer, rather just a bass horn for a 3 way system.
I can 3-D model, CNC the parts and open to a joint build where I can cut you parts as well.
My horn design skills are limited to a very basic knowledge.

jr@mac

I think this thread is going to turn out some pretty cool information. Anyone? 

ani_101

I am waiting to learn....!

Face

http://www.hornresp.net/

There's a steep learning curve, but after reading a tutorial or two, it's nothing you couldn't learn.  Just have someone at DIYA go over your work when done.

jhollander

I can model and fold but no expert...most experience is with back horns and taped horns

R-Carpenter

Alright. I am going to start reading tutorials for hornresp and model a few thing. John, J-horn is technically front loaded horn? Same with spiral horns? (there will be some questions that some may consider silly. )

Face

http://horns-diy.pl/en/horns/j-horn/

jhollander

The J-horn I know of is a brand of horn by Tineo.  The from what I recall bass portion is a simple scoop horn.  With a scoop horn the woofer is typically sealed front loaded.  I've not messed with spiral horns.  They appear to just be another way to folded a horn, but some one can correct me.

What do you want to build?  15 inch pro woofers give a bunch of options.  I've go a taped horn fold I did for Craig S for the Lab 12 and another one for the Eminence 15LFA.

R-Carpenter

Is spiral horn any different from a front loaded horn aside from the footprint?

jhollander

Roman if you are asking me, the spiral horns I've seen are all rear loaded 

http://www.6moons.com/audioreviews/cornu/cornu.html

greywarden

Well for starters, what driver are you using?

Face

Front loaded: http://inlowsound.weebly.com/spiral-bass-horn.html

R-Carpenter

greywarden said:

Well for starters, what driver are you using?

15" probably. Whatever works.

R-Carpenter

jhollander said:

Roman if you are asking me, the spiral horns I've seen are all rear loaded 

May be I didn't phrase my question well. If you design and build transmission line as a straight pipe, measure it, then build the same pipe as folded line, measure it, the fundamental output will remain the same. There will be some modal resonances related to each folded section but the main output isn't going to change much. So, in a way this relates to the physical design/build of the horn and my question. If I design front loaded horn (say 12' long) and then start either spiraling it or folding it so it's less of a footprint, what am I changing in the output?

R-Carpenter

Face said:

Front loaded: http://inlowsound.weebly.com/spiral-bass-horn.html

Looks like the spiral horn is the most space saving option. It is a front loaded horn.

Face

This thread may help you make up your mind as far as what kind of horn to build.  The Tannoy Westminster reference on the second page is interesting: http://www.diyaudio.com/forums/subwoofers/235315-back-loaded-front-loaded-i-m-confused.html

More on the Westminster: http://www.positive-feedback.com/Issue49/tannoy.htm

ani_101

HI John, what did you use your Lab 15 4 ohm in? I'll message you...

PWRRYD

ani_101 said:

HI John, what did you use your Lab 15 4 ohm in? I'll message you...

I am interested as well.  I have two LAB15/4 drivers sitting on the shelf.

jhollander

R-Carpenter said:

show previous quotes

 

May be I didn't phrase my question well. If you design and build transmission line as a straight pipe, measure it, then build the same pipe as folded line, measure it, the fundamental output will remain the same. There will be some modal resonances related to each folded section but the main output isn't going to change much. So, in a way this relates to the physical design/build of the horn and my question. If I design front loaded horn (say 12' long) and then start either spiraling it or folding it so it's less of a footprint, what am I changing in the output?

You are correct, the output frequency response would not change as along as your folds are consistent with the design flare and length. 

jhollander

I did a Lab12.  The Lab15 4 ohm sounds interesting, It doesn't look like I've modeled that. Can either of you post the specs?

R-Carpenter

jhollander said:

You are correct, the output frequency response would not change as along as your folds are consistent with the design flare and length. 

This simplifies the challenge. I can model a straight tapered horn, build a 3d model in Rhino and then fold it every which way I want.

jhollander

found the Lab 15-4 specs, not that great, highest qts makes for a big horn even at 40 hz.

ani_101

yes, they don't go very low. I thought you had bought one of the ebay specials - but now I see you were considering it, but Chuck got one!

PWRRYD

I bought two of them cheap Ani.  With their Sd and xmax I think that even in reasonably sized sealed boxes with enough power and some eq 2 of them will pressurize my 15' x 25' family room down to deep Hz nicely for HT.  If I'm wrong, the drivers go on ebay and the boxes cook some winnies and smores.

ani_101

Let me know what you do with them.... I have a pair that I want to use as subs

greywarden

Ok, what about a "tapped horn"? uses less sq ft, but tall, you have the height, right?

http://www.hometheatershack.com/forums/ported-subwoofer-build-projects/68865-8-tall-stereo-integrity-tapped-horn-sub-ht15d2.html

http://industriumvita.com/folded-tapped-horn-subwoofer-tuned-for-17hz/ (T.A.R.D.I.S!!!)

jhollander

lab 15-4 ideas