I found this website http://www.volvotreter.de/pics_plans.htm which has plans available for download for a 150Hz tractrix horn using a 12" electrovoice EVM12L driver. Has anyone used this driver before? If so, how high do you think this design can reach? (the actual plans can be downloaded from here http://www.volvotreter.de/files/150Hz_Midbass_Tractrix_Horn_v1.3a.pdf). Is this even a good design? Has anybody got any other designs for 8 to 12" cone drivers for midrange horns with a cutoff around 200Hz?

If anyone has the time to download the plans above, can you please explain what the angles in the bottom left picture means. The diagram looks very similar to the one in the middle right, it is confusing me !!!!!!! please help if you have the time, or if you can!

Thanks in advance!
Adrian

I reckon it looks good too. Without running the design through HornResp (which I find hard to use, even though I have not really read any instructions!) do you think it would perform well up to 1.6KHz?

I can get the Electrovoice EVM12L used in that horn for AU$350 each (converts to US$208). Do you think this is a good price? I was thinking maybe an Eminence type driver could be used in its place, or would this screw up the design?

Thanks!
Adrian

http://www.usspeaker.com/evm 12L-1.htm has some specs on it. Freq response is 80Hz-5KHz. Also here's some really kewl pics of it http://www.proaudio.com.au/shspec/ev1_lg.jpg

From the above, what would you say about this woofer?

Thanks again!
Adrian

I've been toying with midhorns using those drivers and I must say they're looking pretty good.

Thanks for the suggestions. Do you think I will be able to use for example the JBL 2020 or the Eminence Delta 12 as a direct substitute for the electrovoice EVM12L if I wanted to? Or would I have to redesign the horn on the page in my other post for the new drivers?

Do these sorts of midrange horns need any compensation, or any other filter corrections for the response? (you have told me guitar speakers have a rising response, does the horn correct this?)

Thanks again!
Adrian

A phase plug would extend the upper response limits but I only need output to 2kHz. It is fine for the path length differences to start rolling off output above that because the cone starts entering breakup around that point anyway. What I'm finding is response to 1kHz is pretty easy but it's harder to hit 2kHz, especially with larger drivers. But I don't need output much above 1kHz anyway, just enough to sum with the tweeter as it comes online.