GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Horn-Loaded Speakers
In the Thread: Good midbass is complicated, if not unobtainable.

Post Subject: Extra 20" will do.Posted by Romy the Cat on: 12/18/2015

noviygera wrote:
Romy, I have somewhat different possibilities than you are seeing. My system is physically higher than most because my listening position is at standing height or sitting in a high stool. I have used this litening height for a few years and grew to appreciate for a number of reasons (worth separate discussion). One of which is increased space under the midrange horn and less interaction from floor. So I gain about 20" of height below mid. In fact I measure easy 46" from floor to mid horn edge. Another contraversial thing I use is DSP crossover. It is not perfect but I have DELAY in my arsenal! So I can use full length horn. This, at least covers TWO of your rightly noted concerns. Does this open options to continue discussion further? If so I am happy to further formulate my requirements. 1. Gracefully integration with midrange horn at 250-300hz with 6db/oct crossover and absolutely no allowed EQ. 2. Staright rectangular or five sided vs folded: this is something I do not know.

Sure, if you have your listening position 20" higher then this is absolutely different story that changes everything. With extra 20" you shall be able to put your 60hz horn under your MF with no problems. Also, if you insist to use the DSP crossover then the time alignment become no problem. Certainly it would not be something that I endorse but my approval should not be your design criteria. I am a little concern why you insist on 6dB crossover with no EQ. "No EQ" is fine demand but usually no one EQ horns explicitly. That will be your personal playback and if you do not want to EQ it then juts do not do it. What I mean that "NO EQ" is not a design objective. Abut the 6dB crossover - that what I disagree. Of cause it would be great to have 6dB crossover BUT it is VERY and complitly not necessary to do have as a design objective if you do not have characteristics of horn and driver in your head. You might choose a driver that shoot all the way to 6-7khz with large horn throat and you will never kill the channel output with 6dB crossover. Anyhow, I think you need to start with throat size. Knowing the throat and measuring the size of the space you have under MF channel you will get the horn length and the horn rate (presumably it will be 60Hz). Then you need to start modeling how your system will look like. The shape of the horn and folds is complitly up to you. There are many slippery slopes with any of the approaches but it it possible to deal with all of them.

I think the biggest problem that people like you will face (I mean people who are in design phase of Midbass horn) is that they do not know what throat they need to target as they do not know what driver they will be using. In reality the driver is the key. You can buy zillion of them, found the one that you love but no one knows how this driver will sound in your horn. So, you can't pick driver withe have horn built and you can't design a horn until you know your throat size that is dictated by your driver. That is the main bitch of the midbass horns. So, what we all do is building some kind of approximation that can be move to one or to another direction. The best solution that I found and that always recommend is to implement a joint 2" away from throat and make the driver part of the horn along with the final throat size removable.

Rgs, the Cat

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