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The Eminence 20Hz Tapped Horn

After reading this thread I was wondering if I could use one of two 15″ I had left over from the Klipschorn. After some back and forth, an obsolete Eminence type EPS15-500 (Xmax 6,4mm) looked most promising. Even though the Xmax is limited I gave the following simulation a try (Note: as a direct replacement you can also use the current Eminence Kappalite 3015LF (Xmax 9,6mm), Eminence DEFINIMAX 4015LF (Xmax 9,0mm) or the MTX Audio T7515-04 (Xmax 16,5mm). Many others will work as well – just give them a try with hornresp).

The predicted response:


The parameters of the simulation:


The excursion simulation:


Regarding the room gain I like the idea of EQing the response down and gain some headroom.

The Eminence I’m using will reach Xmax with only a little above 15V @ 20Hz (115dB should be fine anyways).

This gives you an overview on the folding:


And this is what it looks like during building:


Except the inner bracing, which were 16mm, the thing is made from 22mm MDF. All connections are glued and screwed. It took me a weekend to build it.


Here is the baffle cutout for the 15″ speaker.


This is before sanding:


This is my old Eminence EPS15-500 in place. As I pointed out, the Kappalite 15LF will fit also (very similar response, more max SPL due to higher xmax – 9,6mm insted of 6.2mm).


When I brought it into my room first, I thought: Oh my god, this thing is big.


Here it is in my room. After errecting it in the corner it still looks large but not as bad as before, when it was laying in the middle of the rool. Paint will be applied in spring and of course, If I still like it then. The mouth points toward the left hand side.


In the evening I did some testing. I heard some music and watched a movie. It sounds very effortless and goes deep down. Great for HT and music.

I also made a less tall version of the TH (230 vs. 244cm). Low end is just a little compromised. Here is the comparison of predicted responses:


Plans can be found in the download section.