Spicatto Dipoles

[Bose(o)]

I thought the primary reason for mounting the drivers in opposite directions was to cancel out the mechanical distortions? The drivers work together in-phase to produce their overall sound.

$0.02

 

[paulspencer]

I was hoping to have this thread go back to a discussion of Raka's speakers.

I do not want to get into a back and forth with you, I simply offered a comment to what I see as casual and flawed discussions by John K.

I mentioned John's work as a source of information on how to deal with resonances in a U frame. It is a good example and is accompanied by measurements. You then proceeded to offer criticisms which did not appear relevant to this. I do not like to see what I consider valid and sound work criticised unfairly.

Your criticisms may in fact be valid and well founded. In this case they should be clearly stated and backed up. But in this case I can't see how any such criticisms are relevant.

You state that it is not a transmission line and are wrong, he himself calls it a duct.

If you re-read my post you will notice that I did not say this. I said that:

TL doesn't really adequately describe it, even though it has a resonance in a similar way to a TL.

If you make unsubstantiated criticisms and statements like "you said ...... and you are wrong" then you should expect counter arguments. You can't simply say things like this and expect the discussion to return to Raka's dipoles without diversion.

Everyone should be cautious of non peer reviewed work and I am simply offering a caution. [/B]

A valid point.

Why don't we get back to Raka's work? [/B]

Sounds like a good idea to me.

 

[PB2]

I used to offer long explanations and background for my positions where most often others simply dismissed the analysis. Not saying you'd do this but that is my experience and therefore I don't waste my time offering detailed analysis with online discussions. I'm certainly not going to derive a TL model as proof of my position, it's simply not practical. You seem to be nit picking my position.

I happened to come across this analysis by Linkwitz that shows that the claim of 6dB gain for a U frame over an H frame down to the lowest frequencies is flawed. I came to the same conclusion independently from a volume velocity perspective, it should be obvious by inspection especially at DC.

Here's Linkwitz's analysis see his figures (5) and (6). He states: "The polar diagram in this flawed analysis is a cardioid (5) with 6 dB higher output than the H-frame on axis.":
http://www.linkwitzlab.com/H-U woofer2.htm

I'm not interested in a back and forth, just interested in accurate facts. Take it for what it's worth.