Jump to content

Elliptrac horn


Recommended Posts

I’ve just finished a pair of Dave Harris elliptrac horns and am curious if there are any current users of these and their thoughts and driver suggestion.

 

My plan is to construct a new HF cabinet, that will allow me to retain my original top end intact, and to allow me to install Dave A’s smahl’s above. I do not like the tweeter on the side, my OCD won’t allow it and I don’t anticipate any degrading effects with the minimal added overall height.

 

The choice of drivers seems narrowed down to a 2” unit, likely the B&C DCM50. I have read about using an adapter that allows use of my K-55’s, specifically the PRV From Parts express. I purchased one (<$9.00) to have a look see and it’s a disastrous fit being in the neighborhood of 3/16-1/4” larger than the horns 2” mouth, which to me is unacceptable. Can’t say what the effect might be but it doesn’t seem right.

 

Thanks in advance, I look forward to your comments!

07FE8812-6766-495F-8708-7420808A1436.jpeg

  • Like 1
Link to comment
Share on other sites

6 minutes ago, Deang said:

DCM50 or BMS 4592-mid. There are a lot of BMS users out there. 

I believe I’m going to stay three way since I already have the smahl’s. It is interesting though in that I could use my existing upper cabinet with only a new motorboard.

Link to comment
Share on other sites


On my speakers 

Drivers used are as follows 

Woofers - Crites - CW1526C 15 inch cast alloy 

Mid Range - Great Plains Audio - GPA 399 Compression driver 

Fitted to a pair of Eliptrac 400 timber mid range horns 

Tweeters - JBL 2404H Baby Cheeks tweeters.

 

post-112724-0-21481400-1397346590_thumb.


 


IMG_2675 (Medium).JPG

  • Like 3
  • Thanks 1
Link to comment
Share on other sites

You may choose to consider this 

 

The horn exterior has bituminous paint applied to it for sound deadening 

As you know the horn started its life as cut panels on a CNC machine 

 

A photo for members to use as a visual reference 

 

post-112724-0-91245100-1397357614_thumb.

Link to comment
Share on other sites

46 minutes ago, Full Range said:

On my speakers 

Drivers used are as follows 

Mid Range - Great Plains Audio - GPA 399 Compression driver 

 

 

Apologies for straying off-topic, but I've been trying for some time to find the price of GPA 399 drivers, with no luck. Evidently one has to call Bill Hanuschak directly, but I just haven't had time. Hoping you don't mind my asking, but how much did they cost?

Link to comment
Share on other sites

1 hour ago, Ol_mcdonald said:

I’ve just finished a pair of Dave Harris elliptrac horns

beautiful work , did you have a hard time , sanding the horn ------what kind of paint finish is this , it has quite a lustre -

Link to comment
Share on other sites

4 hours ago, Edgar said:

 

Apologies for straying off-topic, but I've been trying for some time to find the price of GPA 399 drivers, with no luck. Evidently one has to call Bill Hanuschak directly, but I just haven't had time. Hoping you don't mind my asking, but how much did they cost?


The member you need to ask is @sootshe 

He built them, then I purchased them from him and tweaked them to what they have become 

 

I see that Great Plains Audio does not display the the 399 for sale ( But the Specs are still accessible) so you need to find a driver that fits in your spectrum and budget 

They are Models 288, 802 and 902 

 

 

Link to comment
Share on other sites

4 hours ago, Wirrunna said:

What is your bass bin ?

Are you going active crossover or sticking with passive ?

 

There are new B&C drivers, the DCX464 and DCX462, I have a pair of the DCX464s on  a pair of Eminence 1.4 to 2" adapters on my Eliptrac horns with active crossovers.

 

https://www.bcspeakers.com/en/products/coaxials-hf

 

 

Sorry , I left that out, KLIPSCHORNS! I’ll take a look at those drivers. Thanks!

Link to comment
Share on other sites

9 hours ago, RandyH001 said:

beautiful work , did you have a hard time , sanding the horn ------what kind of paint finish is this , it has quite a lustre -

Thank you! I used a wood rasp that is flat on one side and rounded on the other to rough it in, then used 80 grit to get it smoothed out to the point I could work my way up to about 220.
 

Then I used Zinnser  123 primer to seal it and give me a sandable finish to prep for paint. I sanded it to about 220 or 60 micron whichever was in reach.

 

The paint I used was Rustoleum rattle can “Appliance Epoxy”. It cures hard and provides a good finish. I sprayed them with one good coat and let it cure for a week. I then wet sanded them with 1000 grit paper to smooth out the first coat and remove one small sag I had and any jetsam or flotsam that was in the air when I sprayed the outdoors at home. I took them after wet sanding to a friends spray booth to spray the final coat. They aren’t perfect but they will likely exist behind grille cloth anyway. 

9C078982-F563-4B33-B61F-CEA244C406B1.jpeg

  • Like 8
Link to comment
Share on other sites

1 hour ago, The Dude said:

I ran the B&C DE750 with great results. 

 

I completely agree. I expected the B&C DE750 (on the Dave Harris Tractrix) to result in an unnatural midrange due to the metal diaphragm, but was surprised by the opposite. Openness, clarity, fatigue-free even at stupid volumes. When I'm biased against something and it turns out to be great, or vice-versa, that's pretty convincing subjectively. I tested it as the top part of a Klipschorn two-way. Bass horn 6th order LR 400Hz (acoustic) low pass, DE750 6th order LR 500Hz (acoustic) high pass 7dB lower than LF passband, active, time aligned at crossover using outdoor ground-plane reflection-free measurements.

 

I also tried the Faital Pro HF206 and expected better results, but while it was very, very good, it was short of the openness, clarity and dynamic ease of the DE750 using the same setup (completely different processing, but same acoustic results). It was interesting to see virtually identical unprocessed LF rolloffs on both the HF206 and DE750 with the Tractrix horn, obviously dictated by the horn.

 

About a week ago I got the B&C DCX464, ME464 horn and Eminence 2 inch adapter for the Tractrix horn that @Wirrunna is using, but haven't had the weather needed to do the measurements. Rain, heat, rain, heat, ugh. Impedance is dead-on and indoor nearfield acoustic measurements prove the drivers are proper. Maybe tonight..

 

Once I figure out what I like best, inverse filtering (FIR) will be involved, but for now I'm putting everything on an even footing so I can hear what they sound like on their own.

 

God bless you and your precious family - Langston

 

PS: Beautiful work @Ol_mcdonald !

  • Like 1
Link to comment
Share on other sites

4 hours ago, The Dude said:

BMS, B&C, or Faital. I ran the B&C DE750 with great results. 

 

Looking at the B&C 750 and seeing conflicting specs, one page says 500-18k Frequency response and another says 1k-18k. Looks like its way down at 500 hz (their graph is fuzzy) maybe 6-9 db.(?) If the elliptrac horn has an Fs of 310/320 hz (I have read both) and the bass bin of the K horn extends to 400 how are these going to pair? Great price on the 750, but the DE50 seems to go lower and have a smoother response. Where do you crossover your 750 and does it extend low enough to properly mesh with the K horn bass bin?

Link to comment
Share on other sites

20 hours ago, Ol_mcdonald said:

I’ve just finished a pair of Dave Harris elliptrac horns and am curious if there are any current users of these and their thoughts and driver suggestion.

 

My plan is to construct a new HF cabinet, that will allow me to retain my original top end intact, and to allow me to install Dave A’s smahl’s above. I do not like the tweeter on the side, my OCD won’t allow it and I don’t anticipate any degrading effects with the minimal added overall height.

 

 

To satisfy your OCD, why not put each tweeter on the opposite side, so that you have a mirror image pair of speakers?  When I first set up my JubScalas with the small K510 tweeter horns sitting on top of the cabinets, they didn’t look right to me in the middle, so I moved each one to the outer edge of the cabinet, reasoning that it might provide a wider soundstage.  The same reasoning might work for you.

Link to comment
Share on other sites

6 hours ago, Ol_mcdonald said:

Looking at the B&C 750 and seeing conflicting specs

 

B&C tends to be pretty honest with their specs in my limited experience.

 

Here's a screenshot of the magnitude response using their ME75 90x40 horn from the B&C brochure:

48685999_BCDE750Mag.thumb.png.50f8c1145458083ac0277d6ef09fb326.png

Here's an outdoor reflection-free measurement I made of the DE750 on the Tractrix horn. This is with no processing and no smoothing. The B&C brochure nailed it. My measurement shows lower SPL mainly because it was made at 15 ft. The DE750 has got to be one of the easiest compression drivers in the world to EQ. I know you're after a 3-way system, but I'm after a 2-way and this may be the end game. TBD.

 

1446618219_DE750Tractrix.thumb.png.c8db9748c8580b7db32979741b5b27de.png

 

God bless you and your precious family - Langston

Link to comment
Share on other sites

3 hours ago, Islander said:

 

To satisfy your OCD, why not put each tweeter on the opposite side, so that you have a mirror image pair of speakers?  When I first set up my JubScalas with the small K510 tweeter horns sitting on top of the cabinets, they didn’t look right to me in the middle, so I moved each one to the outer edge of the cabinet, reasoning that it might provide a wider soundstage.  The same reasoning might work for you.

It would be easier…just can’t bring myself to do it.🤷

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...