GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Horn-Loaded Speakers
In the Thread: Macondo’s Midbass Project – the grown up time.

Post Subject: Writing midbass-horn encyclopedia....Posted by Romy the Cat on: 8/31/2010

I just wish before I start my project I read a few detail descriptions of the similar projects. Unfortunately they do not exist and I well understand that my project is in away an exemplary for the horn-minded people. All midbass horn are different and when I say exemplary I do not mean the my horn is “better” (sane people understand it) but I feel that my approach of thinking about the midbass-horn, visualize different aspects of construction, usage, operation etc and then render the actions in accordance to the visualized idea is very exemplary approach and I hope I will bring positive results.

Playing 3 days with the first unfinished horn in test configuration I discovered a few interesting monuments that I never heard anyone talked. I would like to share one of them and some of you will get it. I have received a few emails from different people (some of them I do not even know) who told me that my projects encourage them to think about this own midbass horns. Good, the continuation of this post is for you, my recipients.

Playing with driver impedance I come across to a very interesting observation. Let pretend that you play a normal some kind of horn with a lot of air in it. The air drives the driver impedance down and the horns have impedance pick under the horn rate. There are plenty of horns like this out there; did you even try to EQ them? When you add to such a bass horn extra 10Hz below then the horn turns to sound very bad. Sure, the bass the driver move more, pumping more pressure but the horn mouth cut it off. At the result the horn gets choked with bass. However, as soon the driver resonance kills the throat reactance the horn got miraculously equalizeable!!! The impedance-balanced horn does comply with bass boost lower than the horn rate!!!

Now, here is a kinky part. Back to my photography time we use “forced development”. We took a film with excessive amount of silver, the film with sensitivity let say 400ASA. Then we expose it as it was let say 2000ASA and developed it as it was 2000ASA. What is to do the same trick with horn? Let take my horn of 42Hz and to boost 10Hz but then to set the resonance frequency at 32Hz or somewhere between 32Hz and 42Hz. At this point I know it works but I need to do very accurate assessment of sound while the horn does it. I am not familiar with the sound of my horn at this point and my horns are not set at this point to be a reference tool. As time come I will try to experiment with this and post my observation about sonic consequences. It is “works” it might open a new chapter in midbass horns.

Rgs, Romy the Cat

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