8040 unity horn build

snowflake wrote: Hi nearly finished new unity prototype was hoping to try out a textreme driver - either Eminence N314X or Faital HF1460 - but they have both been on order for ages and it looks like the Eminence one might be discontinued as they have taken it off their website. I've got an HF146, an N314T should be arriving soon and an HF146R is on order. Anyone got suggestions for other drivers worth trying on unity horns? Needs to be 1.4" bolt on, 8ohm, resonance around 500Hz. and less than 65mm deep or it won't fit in the box.

Nice build!

Teunos wrote: Looking good! EighteenSound ND3x series is only 53mm deep, resonance ~450Hz. Recommended crossover on entire series is 1.2kHz though. Have you done any initial dispersion measurements already on low/mid sections? How do you plan to adapt the 1.4"driver to the rectangular hole? planning on doing some 3D printed modeling or using clay/putty?

the compression driver will bolt onto a small piece of 18mm ply which covers over the rectangular opening. will start with a 36mm round hole and create a flare with a round file. some of the compression drivers have a 0 degree exit angle and some have about 30 degree exit angle to will create different flares for different drivers.

Keen wrote: snowflake wrote: Anyone got suggestions for other drivers worth trying on unity horns? Needs to be 1.4" bolt on, 8ohm, resonance around 500Hz. and less than 65mm deep or it won't fit in the box. Is the Oberton NDC72CN Textreme?  Think it might be.

don't think it's the same woven textreme material but it is probably a carbon/cotton composite like in this driver:

Test Bench: Oberton ND72CT/HB 1.4” Compression Driver | audioXpress
https://audioxpress.com/article/test-bench-oberton-nd72ct-hb-1-4-compression-driver

that one was too deep to fit into the box I have built and I didn't realise they did several others. The ND72CN and ND100-1.4 should fit and the curves look like they will work well in a unity horn. Will give them a go if I can find someone selling them - seem to be new products.

I have managed to get hold of the faital HF1460 and the eminence N314X and have tested them in the last few days. both are very good drivers but the faital edged it for me. The eminence has slightly higher sensitivity from 1-2kHz which makes it harder to achieve flat response on a CD horn (at least using a combination of standard filters). The HF1460 had slightly less ripple in response, slightly less THD, and performed better up to 15kHz. The eminence had a bit more above 15kHz but most of us can't hear that. Minor niggles with the eminence are the imperial threaded studs and fractionally different stud OD; and the eminence magnet had a lot of stray flux meaning tools and nuts were getting stuck to it all the time. The faital has a much more contained magnetic circuit and nothing seems attracted to it.

also tested the titanium version of the eminence but it had much higher distortion than the textreme drivers. Tried an HF146 which I had previously used successfully in a 60*60 horn with 6" mids but couldn't get it to work well with the 5" mids in 80*40 horn - didn't seem to have enough overlap to achieve flat response.

haven't done a flare on the first 18mm of the horn yet so it's just a 1.4" hole with a discontinuity to the rectangular horn - so the hf response should improve. Didn't have the back of the cabinet on for these measurements either so LF response will also improve a lot - think the vents are tuned to about 45Hz. SPL isn't calibrated and mic was 20cm from mouth. lf, mid and hf responses are gated, overall response has smoothing applied.




Edited by snowflake - 23 February 2025 at 9:31pm

Timebomb wrote: Looks good,  what mids are you using?

Celestion TF0510MR

wow, those J-Box things are handy. nice one