DIY a rotary sub.

[tade]

After i finish my ESL setup i would like to look into a rotary sub to get lots of low.
How do they work? how do you hook up a motor to an audio signal?
basically, i want to know what you do.
thanks!

[simon5]

I can only point you to this thread...

PG Cyclone[non cone subdriver]

[tade]

maybe someday i will be any good at using the search function...

[Diogenes]

There was some brief discussion about a rotary vane transducer at another forum. Some of the posts regard a possible way to approach building one.

http://audiokarma.org/forums/showthr...ghlight=rotary

[BassAwdyO]

Did anyone look at that "fan" from eminent? Its a joke if you ask me. $12,900 for a fan thats probably like 1' in diameter!

http://www.eminent-tech.com/RWbrochure.htm

And they say recordings have infrasonic material in them below 10hz...

I've also heard that below 10hz becomes audible at over 120db.... has anyone here experienced 10hz at 120db in a house? You wont hear the 10hz... you'll hear rattles upon rattles upon rattles upon rattles. Ummm your walls would have cracks, pictures will fall. The neighbors would suffer the SAME effects!

Its useless for audio applications. It adds nothing to the music except maybe psychological effects and plain scaryness. For 12grand get the parthenon and at least you'd have something cool to look at!


I hate hearing infrasonic output to DC.... There is no DC pressure... DC means DIRECT CURRENT! CURRENT is electrical, not acoustical. DP (direct pressure) would be a much more intellegent thing to say

[DcibeL]

Originally posted by BassAwdyO
DP would be a much more intellegent thing to say

LOL!

[BassAwdyO]

OK ok i know that sounds kinda like DP double penetration..... LOL We need to get our minds out of the gutter...

Maybe CP would be better... Constant pressure. Actually I like that better because Direct pressure doesnt seem to make a whole lot of sense either

[mwmkravchenko]

Some guys did a bunch of environmental survey for low end. Busses can on takeoff squeek out almost that much. Heavy traffic over a bridge can produce high levels at around 5 hxz. Wish I could find the article to post it. I'll look.

Mark

[SY]

Its useless for audio applications. It adds nothing to the music except maybe psychological effects and plain scaryness.

I wonder if that's really true. One thing I noted when I extended the bass of my system down that way was an increased sense of "articulation" of notes even when played on instruments that do not reach the deep bass. I've speculated that it has to do with improvements in group delay for rapidly played notes, but have no evidence, other than my subjective observation. It's interesting, though, that the same sort of observation has been made by skeptics like Audio Critic when testing the ELF, which has a response down as low as 8 Hz.

[BassAwdyO]

SY,

I did not mean it doesnt add anything in a group delay or accuracy of the audible frequencys sort of way. Adding a infrasonic "fan" to your system probably isnt going to make the group delay up higher any better anyhow.... I meant that those infrasonic notes really add nothing to what you hear. Actually they smear it IMO.

I have laced music with infrasonics before(like the national phsyics lab did at a piano concert) and found that it did slightly add to the psychological aspect of the music. The way added the infrasound was mixing it directly into the recording. This really took away from the dynamics of the bass however because the infrasonic sine needed to be of large amplitude to achieve any effect without turning the music up to ear peircing levels. I find it very hard to believe that adding infrasonic output would make things sound better. Also infrasound can make things sound like you're talking through a fan. That cant be good for sound quality