Why not horns?

Hello Duke ,

Thanks for the response and i'm sure a polar plot on that 15 inch woofer will prove what we are discussing. The published data including the response curve on both drivers will require eq-ing IMO for that speaker to be listenable, well unless it is being used for Sound reinforcement.

I could not find any data on the horn driver with that Horn type that is being used. The horn is beautifully made and the type of wood being used , from experience offers decent damping off setting the natural ringing of the driver in the 5 K range as confirmed by it's impedance curve.

A pity they never published the phase response , the woofer
also shows appreciable breakup.

All in all actually pretty decent driver Specs on the horn and below such on the woofer. I would work with the horn driver , but get a much better woofer for the application as this one appears better for sound reinforcement and since this is for domestic use the super high power handling is not a concern.......

Macrojack,

Hello to you 2 sir and many happies, get well soon ....

Hi Weseixas,

"The published data including the response curve on both drivers will require eq-ing IMO for that speaker to be listenable..."

Quite right you are! Aggressive equalization is virtually always required with such systems, and it's the crossover designer's job to do it. The published curves for the drivers only indicate how they start out, not how they end up. If you were evaluating the system based on how the individual driver curves start out (which makes perfect sense until someone tells you otherwise), no wonder you were skeptical! The published "before crossover/EQ" curves for the drivers I use look pretty awful at first glance, and the curves I actually measure before starting on the crossover are even worse.

The most useful curve for evaluating a compression driver is the "plane wave tube" curve, which is supplied by some manufacturers. Ideally, this curve slopes down uniformly without significant peaks or dips. Any curve measured on a horn has that horn's characteristics superimposed on the compression driver's output, which complicates any attempt to evaluate the driver.

All this talk is passing over my head at this point but I found a specification page for my woofer that may provide some clarification or narrow the discussion.

http://www.rcf.it/products/precision-transducers/low-frequency-transducers/l15p530

Is there anything useful in there?

Bill suggested I replace my native JBL LE 15B woofers with these because they are lighter, faster and more efficient.

Macro,

Interesting technical details to learn, but if things sound good in your setup I think that's all that really matters from a user's perspective. Nuts and bolts specs on drivers and components are fine but do not indicate the final result as I believe has been pointed out already.

Mapman - I agree completely. The proof is in the pudding - not in the recipe. Nonetheless, there is a reasonable ability to predict outcome based on past trials and failures. In this regard, specifications are surely useful to designers and scientists in general. For a guy like me, they are just numbers and do not transfer information that can help me decide.

Long ago I realized that I could read people better than I can read blueprints, so I make it a practice to choose someone whose advice I feel I can trust. While this approach generally works out well for me, I have had a few bad haircuts. In the case of deciding to trust Bill Woods, I was rewarded handsomely. He has a sterling and lengthy resume and has been chosen to assist many manufacturers as a designer and consultant. So I called him on the phone and found someone I could relate to immediately.

That's what eventually brought me to where I am now believing that the potential for horn speaker systems is barely being scratched. Right now we seem to be in the eccentric, mad scientist phase but it seems likely that a bigger market and more conscious development are just around the corner.

Are you a cartographer?