2" 223Hz tractrix horns

[jwc]

15 degrees off. I believe this was one inside...it got late.

[jwc]

here is outside a 22.5 off axis...see the same outside dips....something out there.....like a broad faced bird house or something.

[mikebse2a3]

I measured several times with both drivers outside. I moved the JBL driver inside and continued to mess with pink noise. Outside I'm getting two areas of a dip that I don't get inside. The pink noise must be reflecting off something out there.

Anyway....in my house those two dips are gone and I get a different one at 2000Hz. So remember that when I post curves later.

JC

You could have a reflection outside or the other possibility is the in room curve has reflections that are filling in and masking the measured dip.

I believe if while outside and on the axis that the dips happen try maintaining the same axis while moving the mic (forward or back 1ft or 2ft) and also change the mic's height slightly and see if the dips are still at the same frequencies. If the area of the dips changes frequencies then that would be a good indication that yes you are measuring a reflection influence.

Thanks for the testing efforts jc! got to go and will check back later.

mike tn

[jwc]

30 degrees off..outside

[jwc]

I measured several times with both drivers outside. I moved the JBL driver inside and continued to mess with pink noise. Outside I'm getting two areas of a dip that I don't get inside. The pink noise must be reflecting off something out there.

Anyway....in my house those two dips are gone and I get a different one at 2000Hz. So remember that when I post curves later.

JC

You could have a reflection outside or the other possibility is the in room curve has reflections that are filling in and masking the measured dip.

I believe if while outside and on the axis that the dips happen try maintaining the same axis while moving the mic (forward or back 1ft or 2ft) and also change the mic's height slightly and see if the dips are still at the same frequencies. If the area of the dips changes frequencies then that would be a good indication that yes you are measuring a reflection influence.

Thanks for the testing efforts jc! got to go and will check back later.

mike tn

Ye Mike...did that.....they go away and different ones may develop if move to another area outside not gonna post all those:)

[jwc]

So guys....I posted one inside to show you that the two outdoor dips aren't real. You can see those two dips on the three outdoor curves. The inside curve had a dip at 2000. Ignore those.

Look at the top end and how it slowly rolls off as you move off axis. It falls of at 4000 at 30 degrees off axis.

jc

[jwc]

Jeremy. I will pay shipping to and fro ......your JBL driver. Just want to know if it gets to 300.

Let me know if your interested.

jc

[capo72]

I will gladly split the shipping cost with you since you are willing to do this. These things must weigh a good 30 lbs. Send me a pm with your info and i'll try to get one off to you tomarrow. Thanx for doing this. I really need to get back to my speaker project. I've got the wood about 90% cut and one speaker is clamped up.

Jeremy

[Guest David H]

I really need to get back to my speaker project. I've got the wood about 90% cut and one speaker is clamped up.

Ok I'll bite. Is there a thread with pics?

[Guest " "]

JC

I realize the focus is the 300hz range.

Does the nose dive at 3K and beyond imply that the horizontal flare is too narrow for use as a two way horn but OK for 3 way applications?

Is the horizontal or vertical flare rate the problem?

Would widening the flare rate to address the 3K and beyond nose dive, have a cost penalty in the 300hz range?

[jwc]

I don't know the answer SF. I never thought this horn would work as 2 way as it is straight tractrix w/o any compensation of the flares to get optimal polars for the high end. I can only assume that ALK's Trachorn is the same thing but won't suffer as much on the high end. I know there are a few using the trachorn as a 2 way.

The intent of this horn is for a mid horn only that can reach down to 300Hz for those out there that wanted the 300hz signal coming from a compression driver. I know there are some that XO their Khorn at 300...... Also...I had even imagined a 3 way with this horn on an MWM. The other goal is to get a "big" midhorn....and staying pure tractrix. I was afraid to go too big with a lower cutoff and possibly sacrifice too much high frequencies. The 223 was a "guess" for a cutoff to achieve waht I wanted. That part I think is successful to right now. Who knows....may sound like dung.......but I would bet not.

I think this horn is good to 4000Hz 30 degrees off the horizontal axis. If you look closely at the last image...I think it is good to 4000....not 3000. I ran other curves at other places in the yard and the house which seem to point to the 4000 drop really.

This followed Edgars philosophy that the width needed to be twice the height to prevent impedence swings. I guess we could squash the horn a little and bring it down to 10" height instead of 12". Then make the horn a little wider to accomidate. This could help with the horizontal coverage???????

jeremy.....about to PM you.

I'll do these curves again with a 300Hz driver. That is what I'm most interested in. Infact.....SF.....you have the drivers that I originally was gonna test on this design. Project was stuck in storage until GotHover got me fired up again.

jc

[Marvel]

...I had even imagined a 3 way with this horn on an MWM.

Now you're talkin'. I have been looking at a B&C 6 PEV 13 - 6.5":

Nominal Basket Diameter	6.5" / 170mm
Impedance	8 ohms
RMS Power Rating	120 Watts
Program Power	240 Watts
Frequency Response	150Hz - 8.0kHz
Sensitivity (1W/1m)	99dB
Voice Coil Diameter	1.5" / 38mm
Winding Material	Aluminum
Former Material	Fiber Glass
Winding Depth	.28" / 7mm
Magnetic Gap Depth	.25" / 6mm
Flux Density	1.4T

Since John Warren used those JBL 10" drivers to replace the K-55/K400 on the Khorn, it has had me wondering. What is the gain you get form using the horn?

Bruce

[Guest David H]

Completed pair.

[Guest David H]

Throat

[Guest David H]

Side view

[Guest David H]

Motor mount

[greg928gts]

GotHover - looks good, you've been busy. I have a request, would you please take pictures of the process you use to install a mounting flange with a round hole for the driver and what, if anything, you do to round out the throat of the horn?

How thick are the sides of the horn? How about the tops and bottoms? Do you think the bracing is necessary for the horn, or did you install the bracing to help hold the driver mounting board?

Greg

[Guest David H]

GotHover - looks good, you've been busy. I have a request, would you please take pictures of the process you use to install a mounting flange with a round hole for the driver and what, if anything, you do to round out the throat of the horn?

How thick are the sides of the horn? How about the tops and bottoms? Do you think the bracing is necessary for the horn, or did you install the bracing to help hold the driver mounting board?

Greg

I will take pictures next time I have something to assemble, but in the mean time, I do not round the horn throat. A simple way to line up the throat and the mounting plate is to drill your 2 inch round hole in the mounting plate and fit a 2 inch dowel, pvc, whatever fits, use this as the alignment tool.

The tops and bottoms are 3/4 ply the sides are triple laminated 3/16 masonite. The bracing gussets are to support them weight of the motor.

Keep in mind it is necessary to keep the motor mount hardware near the outer edges of the mount, so it can be removed to mount the driver. Take a look at the mount pic I posted.

[jwc]

Awesome. Just Awesome.

So what are you gonna do with them? Keep them and get a 2" driver or sell?

jc

[jwc]

GotHover - looks good, you've been busy. I have a request, would you please take pictures of the process you use to install a mounting flange with a round hole for the driver and what, if anything, you do to round out the throat of the horn?

How thick are the sides of the horn? How about the tops and bottoms? Do you think the bracing is necessary for the horn, or did you install the bracing to help hold the driver mounting board?

Greg

I will take pictures next time I have something to assemble, but in the mean time, I do not round the horn throat. A simple way to line up the throat and the mounting plate is to drill your 2 inch round hole in the mounting plate and fit a 2 inch dowel, pvc, whatever fits, use this as the alignment tool.

The tops and bottoms are 3/4 ply the sides are triple laminated 3/16 masonite. The bracing gussets are to support them weight of the motor.

Keep in mind it is necessary to keep the motor mount hardware near the outer edges of the mount, so it can be removed to mount the driver. Take a look at the mount pic I posted.

That square hole baffle to the horn throat lines up well.

I may make a circle hole baffle on the one you sent here and see if that does anything on the FR. Probably not but for some reason.....I like the circle idea.

I can't believe how fast you are with these.

jc