GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Horn-Loaded Speakers
In the Thread: Adding one more spherical to Macondo.

Post Subject: New options for Fundamentals channels.Posted by Romy the Cat on: 6/10/2009

Romy the Cat wrote:

Yes. I’m exiting to see how the new horn I shaping up. Still I do not think that it is about second orders. Obviously in context of 5 channels system, the more channels one gets then less room between them. I still feel that in order to do it correct my new channel should be no 250Hz but I would say 180Hz-150Hz and then I would still try to for a first order at 750Hz. In the barrow bandwidth satiation as I needed to get out of this driver the second order was God sent but at think point I do not know what kind negative manifestation it would have on overall system presentation. I will be able to see it when I put the second channel in use and tune the crossover more precisely.
I went for Bessel Q, 600Hz. Since I have no sensitivity burn I’m searching now for the series air-core coil with DCR of around <0.05R and 8-6ga wires.
The Vitavox barbarianism? Yes, I know the CN458 schematic, opened it up as studied what they were trying to do. I do not think that it is about barbarianism but about the typical for vintage solution luck of precision, accuracy and exactness. The imaging demands that Vitavox System CN191 had were very restricted, as any other corner loaded system. Also, did you have change to measure a properly installed CN191? I did. I do not have the file now handy but I remember that each channel (!!!) did something like this:
Sure, the decision to go for second order in their 330Hz horn was correct but was in beneficial? I do not think so.
Still, generally the compression drivers that run all the way down and crossed at 500Hz never use first order; at least I did not see it. As I told above I never used drivers at 500Hz and now I see why people go for second order in this situation. Interesting that Vitavox when for 500Hz 12dB per octave for thier 330Hz but I do not feel that it is a “secure” cut off and I went for 600Hz 12dB per octave for 250Hz horn… I feel that ~700Hz of their RH330 would be more suitable cut off.
The Cat

If you spend time to listen a Fundamental Channel alone then you know that it does not do a lot. It is a very marrow bandwidth, very much attenuated and it does not do a lot of sound but rather some useful noise. The benefit of the Fundamental Channel can’t be understood without a framework of the rest drivers. Anyhow, it is not the subject….
The subject is that Macondo uses for its Fundamental Channel a whole bloom horn channel. It certainly does not hurt but a full bloom horn channel request a lot of infrastructure to support itself and a loudspeaker like Macondo that uses a bloom horn channel for a very narrow band-pass do pay some penalties for accommodation a horn for Fundamentals. Horn is large, add a lot of height out of the system height and make the Injection Channel to be too far from the acoustic horizontal central of the speaker. (In case of Macondo the Injection Channel is large).

So, I was wondering the following: if to found a good direct radiator MF driver that will be able to substitute the Fundamental Channel horn than it would be possible to locate the direct radiator Fundamental Channel very closer to the MF and tweeter and to locate the Injection Channel much lower. The picture below is well illustrating it. The requirement for the direct radiator Fundamental Channel driver would not be difficult as it works in VERY narrow band.

What I am saying is not a motivation for me to change anything with Macondo but for others, who interested in advancement of the horn system configuration ideas, it might be a useful direction to think and to experiment.

The Cat

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