Sealed 4Pi ??? [message #68182] |
Tue, 14 June 2011 12:22 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
smokarz
Messages: 56 Registered: June 2011 Location: CT - USA
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Baron |
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did anyone build a sealed 4pi?
i saw the picture of the one Wayne custom built, and it looks really nice with the horn and woof centered.
my primary usage is in HT room with 4x 15" subs, so i wouldn't mind loosing the lf exntension of the original ported version.
if you did build a sealed 4pi, did you use the original plan, or did you have to modify the cab (make it smaller)?
thanks!
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Re: Sealed 4Pi ??? [message #68183 is a reply to message #68182] |
Tue, 14 June 2011 13:14 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I wouldn't do a sealed version of the four π loudspeaker, except for one application. The center channel of a home theater system having four π speakers can be made sealed, with the left and right being standard models, mirror imaged as usual. In this configuration, the left and right channels will provide more output below 100Hz than the center, but in all other respects, the speakers will have the same spectral balance. Below 100Hz, room modes dominate anyway, and multisubs should be employed to mitigate that.
The sealed center channel variant is made the same as the standard vented model except the port is removed and the tweeter shifted to the center. No other changes are made.
The reason I wouldn't go sealed for any other reason is it simply gives no advantage, yet reduces output below 100Hz. The standard build has smooth gradual rolloff that blends very well with multisubs, better than a a sealed version, in my opinion. The goal of the multisub approach is to have multiple bass sound sources, and a sealed version has basically no output below 100Hz, so you lose one source in the modal region. When used with a pair of left/right mains that are built standard, this is not much of a consequence because you still have two mains running low. But I wouldn't want all the mains to lack bottom end. There's just less to blend.
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