Aperiodic vents

[jeffsg4mac]

Hey guys,

Any of you ever build a aperiodic vented enclosure? I have always wondered about them, but there is not much info available on them. I wondered if they would be worth trying or not.

 

[highfigh]

Hey guys,

Any of you ever build a aperiodic vented enclosure? I have always wondered about them, but there is not much info available on them. I wondered if they would be worth trying or not.

Not much info? I googled it and got 21,500 hits. Dynaudio used aperiodic dampers for years, Madisound has sold them for years and they're cheap. They're called 'Variovent'.

Here's an interesting link:
http://www.northcreekmusic.com/MAPD1.htm

 

[jeffsg4mac]

I knew about the dynaudio vents and that they had used them, and a saw you could still buy them. I just don't remember ever seeing them used by anyone else.

Thanks that had some of the info I was looking for. particularly the part about how it controls the driver.

 

[highfigh]

I knew about the dynaudio vents and that they had used them, and a saw you could still buy them. I just don't remember ever seeing them used by anyone else.

Thanks that had some of the info I was looking for. particularly the part about how it controls the driver.

You mean the part about how it lowers the Qts to allow using a smaller box?

 

[jeffsg4mac]

You mean the part about how it lowers the Qts to allow using a smaller box?

That and how the excursion is no longer controlled by the box. As with most things in audio whenever you solve one problem you create another. I don't think that is a good trade off myself. Maybe for some good two channel speakers but certainly not for sub designs.

 

[TLS Guy]

That and how the excursion is no longer controlled by the box. As with most things in audio whenever you solve one problem you create another. I don't think that is a good trade off myself. Maybe for some good two channel speakers but certainly not for sub designs.

You are correct. I have played with it, since I have Dynaudio drivers suitable in one set of speakers. However, I think the variovent spoiled a good set of speakers. The bass sounded better, even if total system Q rose a little and the bass was a little warmer. So the variovent had a short life in my speakers..

The only systems I have built that have a truly realistic deep but non resonant bass have been aperiodic TLs. That is why if space permits, it is my preferred design technique by far.

 

[audiofox]

I built these, which are the main (front L & R) speakers in my primary HT:

http://www.gattiweb.com/images/dynaudio/aries_1.pdf

The two chambers inside the enclosure are "connected" by a Variovent. They are a bit thin at the bottom (20W75 has a Fs of only 30 Hz), but the D260 tweeter and the 20W75 mids are fantastic for everything above 40 Hz or so. I built them in 1994 and they are still going strong.