Rerurn to Romy the Cat's Site


In the Forum: Horn-Loaded Speakers
In the Thread: Phase plug for midbass
Post Subject: Midbass followupPosted by ulf on: 9/29/2007

Dear Malinowski,

 

Here are the input data used in the HornResp simulation for the tractrix midbass.

This is a 117cm long tractrix horn with the TD-1201. Throat area 84 cm2, mouth 10000cm2 with 5,6 liters back cavity.

Ang: 1Pi; FTA 89,80; S1 84; S2 10000; Tra 117,64; F12 97,04;
Sd 531; CMS 1,57E-4; MMD 53,63; RE 11; BL 36,8; RMS 13,63; LE 1,38; EG 4
VRC 5,6; FR 40; VTC 531;
LRC 5; TAL 2; ATC 531;

If you have no experience of HornResp I suggest that you download a copy and try it out. It is a very neat software that is useful when designing horn speakers. You can easily make simulations and get a decent result concerning frequenzy response and so on.

About how you should design your midbass?? Hard to say really. It all depends. But I would at least recommend that whatever design you choose you should make a full size horn.  Tractrix, Lecleach and Klangfilms kugelwellen profile all share a similar mouth termination. They all exit at  90 degrees (or more) from the axis. This seems to be the main feature that makes them different from hypex and other common types. I have only experience of the tractrix but I Kugelwellen and Lecleach could be as good or even better.

Lecleach has based his designs  on a new calculation method which seems to make sense. Many of the old designs semms to be based on just trying a curve and then see how it works or on methods that were manageble to calculate at the time.

We have tried a few oval and rectaungular tractrix horns. Yes, you're right, they are not real tractrix but sound fine anyway.

So I think the mouth termination has major impact on the sound quality. But the best way to get there from the throat is still a mystery to me.

Yes the midbass horns are still in use and sounds Grand!


Best Regards: ULF



Rerurn to Romy the Cat's Site