Rerurn to Romy the Cat's Site

Horn-Loaded Speakers
Topic: A horn arc

Page 1 of 1 (4 items)


Posted by anthony on 08-18-2014
fiogf49gjkf0d

Hi Romy,

As a recent convert to horn-speakers I have greatly enjoyed trawling through your website and I have learnt plenty not only about horns but also about questioning my own motives and the desired end result of a possible "from scratch" speaker build.

The Macondo looks inspiring but I do have a question about the mid-range horn.

For the lower frequencies you have put in a lot of effort so that the horns operate comfortably within their ranges (i.e. not to their very base or upper loaded frequencies of the horn geometry).  I also assume that when you designed/specified these horns that they were built to the full mouth area for the base frequency and were not truncated/shortened.  When I look at the 400Hz MF Horn you seem to use it between about 1kHz and 12.5kHz which is a 5 octave spread from its base frequency...my understanding is that the horn will be direct radiating from 3.2kHz upward (after 3 octaves).

So my question here is whether this 5 octave spread has been a specific design element to suit the Vitavox S2 driver or is it to do with real-estate and limits of raising the height of the Macondo or is there some other reason?  I have not been able to find an answer in other threads here so I apologise if this topic has been covered elsewhere.

Regards,
Anthony


Posted by Romy the Cat on 08-18-2014
fiogf49gjkf0d
Yes, Anthony, any horn by nature has what I call horn arc. At the bottom of the range the channel boost output, then the gain slowly decay and become almost like a direct radiator and then the output begin to roll off at HF by horn until the driver roll off kicks in.many people use the MF drivers across a few octaves of MF what indeed the driver acts almost like a direct radiator. I need to say that many compression driver in fact are very good direct radiator in bypass mode and there are many reasons for that.

Yes, from a perspective of "purest horn" the MF shall be divided by 3-4 drivers where driver use ONLY in the region of horn boost. Would it be practical? Hmmmm, I do not know. The lobbing of the individual relatable HF channel, the comb-filter distortions and issues with use or multiple or non-first order crossover in my view would create much more problem. What we gain if we do it? Just 6dB in most of the cases - I do not feel that it worth it.

I need to note that the conflict between "5 octave spread" and plying multiple MF driver has not theoretical resolution and could be explored only by imperative means. The specific of this of that driver and the way how it would be driven dives to a person a felling if it might be used in the application he wants. My Vitavox S2 does very nice in my view at 500 to 5000. I do have issues with it's sound upper but I also do have some issues with introduction of another upper MF driver. So, in a way the 5 octave spread of S2 was a compromise but how could be in audio to figure out if the compromise was worthy? Well, I wish to have answer to this question myself. I do feel that the result is acceptable. Could I do better? We always could. Will I do better? Hm, I do not know. It is all about priorities, If I compile a list of the problems that I hear in Macondo sound then "5 octave spread" of S2 driver will be not very high.

Rgs,
Romy the Cat

Posted by anthony on 08-18-2014
fiogf49gjkf0d
Thank-you for the detailed response Romy.  I can understand your reasoning.

I have noticed that there are several commercial horn offerings that push a wide bandwidth through a single horn (eg. Martion Einhorn 370Hz - 20kHz, BD Designs Orphean MKIII 270Hz - 22kHz) and I just wonder how they do it in a decent fashion.  I suppose it all comes down to the quality of the driver across that wide bandwidth and its implementation into the acoustic system.  Your approach of breaking up the bandwidth into segments that suit the strengths of each chosen driver seems more logical to me if chasing the "ultimate sound".

Your point of priorities in regards to the Macondo sound is interesting.  Would you care to elaborate where your priorities would be in making improvements to the Macondo sound? (if it is not beyond the scope of this thread)

Regards,

Anthony

Posted by Romy the Cat on 08-18-2014
fiogf49gjkf0d
 anthony wrote:
I have noticed that there are several commercial horn offerings that push a wide bandwidth through a single horn (eg. Martion Einhorn 370Hz - 20kHz, BD Designs Orphean MKIII 270Hz - 22kHz) and I just wonder how they do it in a decent fashion.  I suppose it all comes down to the quality of the driver across that wide bandwidth and its implementation into the acoustic system.

The irony is that while we might or not might criticize the implementation of MF in other designs we forget one very important moment: high-end audio is all about implementation of upper bass and only if upper bass (upper mid bass and lower MF) is done decently only then we light look deeper about the whole complexions of MF. The problem with many other designs, including those you have mentioned that the upperbass in there is made very badley that makes all conversations about MF worthless.
 anthony wrote:
Your point of priorities in regards to the Macondo sound is interesting.  Would you care to elaborate where your priorities would be in making improvements to the Macondo sound? (if it is not beyond the scope of this thread)

Yes, I was planning for years a write up to criticize Macondo sound. Sometime I will do it…. Not now.

Page 1 of 1 (4 items)