[zydeco]

Another complete novice to speaker building / open-baffle after some advice. I've just finished reading a bunch of articles on open-baffle and am, literally, baffled. The idea of a full-range driver coupled to 1 or 2 woofers per side is attractive but it seems as though there are issues associated with matching bass performance. Two quick questions:

• It seems as though most designs involve high-pass to full-range driver and low-pass to woofers. Why is this model preferred over that in which the full-range driver is run full-range and a low-pass to woofers is just used to augment bass?
• If I understand, then a pair of woofers will increase the effective sensitivity (although I'm not sure if this is by 3 or 6db). This model is used with pairs of Eminence Alpha 15 woofers. Why not go for, say, 4 x full-range drivers (e.g., B200) are used to get even higher efficiency into the woofers?

Any and all advice would be appreciated. As would a nudge towards simple, high-efficiency, open-baffle design

Regards
Zydeco
[/list]

seem

[mcgsxr]

Some good questions there, and I will answer the ones I think I can take a crack at.

Most people (myself included) Xover the full ranger, to take the bass stress off that driver.  Many full rangers produce more mid and high magic, when not asked to reproduce (or try to reproduce) low bass.

For those of us biamping, the need for more than 1 bass driver per panel is, as I understand it, simply a choice.  I am very happy with the performance of my b200 run 100Hz and up, and the MAW12 woofers down from there.

For those playing around with passive Xover, and dealing with high efficiency full rangers, the use of multiple woofers per panel is usually to bring the efficiency of the woofers closer to that of the full ranger, as you suggest.

If you search, there was a thread about a guy (Brit as I recall) who was using plural b200's per panel.  I forget if they were all full range, or if 1 was, and the others were trimmed on the top end to limit comb filtering.  He was very positive about them, I have never heard that implemented - the marriage of full range, OB and line arrays.

[opnly bafld]

If you search, there was a thread about a guy (Brit as I recall) who was using plural b200's per panel.  I forget if they were all full range, or if 1 was, and the others were trimmed on the top end to limit comb filtering.  He was very positive about them, I have never heard that implemented - the marriage of full range, OB and line arrays.

Paul Hynes in this thread:
http://www.audiocircle.com/index.php?topic=70643.0

Lin

[zydeco]

Thanks for the advice. Is there an issue with pairing a seal, sub/woofer, with open-baffle mid/high? The reason for the question is that most of the designs seem to focus on open-baffle or U-frame bass whereas my initial reading was that the reason for open-baffle was to get rid of box / diffraction effects in mid/high.

Regards
Zydeco

[Rudolf]

The advantages of dipoles are twofold:
In the bass region they are supposed to excite room modes less than conventional speakers. Trade off is the need for more cone displacement.

In the mids and treble dipoles avoid box resonances and box colorations, but diffraction effects in mid/high tend to be worse for dipoles than for monopoles.

If in fact you are talking about < 100 Hz (subwoofer), you might very well go the sealed route and could add more sealed subwoofers to control room modes - if necessary.