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In the Forum: Audio Discussions
In the Thread: The loudspeakers for a powerful SET

Post Subject: A few clarificationsPosted by Gregm on: 4/16/2008

Romy the Cat wrote:
...it is difficult to design an objectionably performing powerful full-range SET without considering speaker, particularly the moment of LF section damping. It is not always the case the MF, HF and LF would require the same loading but it said by the person spoiled with DSET. So, in a case of powerful full-range SET we need to determine loading only by LF. The caT

That is exactly what I am proposing further up. In fact, I went further daring to propose that we help the matter of loading through judicious choice of driver...

Romy the Cat wrote:
Well, there in doubts in my mind that for more or less objectionable acoustic system the MF and LF should be separated in different locations a they serve functionally different purpose. I have written about it in multiple places of my site. However for the sake of the given exercise the separate cabinets are no acceptable as it would defeat the whole purpose.

Not necessarily: they could be separate boxes, interconnected by short cable. This allows some freedom of movement between top & bottom (like some of Wilson's products or A-Physic's et aliae).

Paul S wrote:
Greg, do you have any experience with the Eminence drivers?

Yes, I used 2 Alphas and 2 Betas per side in a double W config, and I had an impedance drop somewhere (25??) -- which was insignificant in practical terms since the woofs were in connected in series-parallel and I was driving them separately anyway with a PLL xover.
As to the ripol thingy, it's here: http://www.lautsprechershop.de/hifi/aka_sub_sonder_en.htm It just gives an idea of how it's done. I'm sorry the link didn't work for you. Linkwitz also has an explanation of the W & H configs on his site.

As you note, size does matter of course. Not to damp any enthusiasm, but the w construction with 2 x 15" is quite large: nearly 3' high in the first place, not to mention the width. In practical terms, getting to 20Hz in passive mode will take up real estate -- except for the ripol where, purportedly, the footprint is slightly smaller while, allegedly, the sound is... just as good. Whatever. The points with size are:

We all seem to be doggedly pursuing ~20Hz as if our lives depended on it
We're passive, so tricky electronic short-cuts are out of scope; the construction will be big.
The 15" are already quite large; add to this that if you use a couple, you need to play with the actual audible radiating distance between the two to determine cancellations & resonances (spikes, etc)

As a side question -- and please forgive my idiocy: what is a DEBZ?

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