Is it aperiodic or isobaric or both?

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I am looking for help identifying an encloser type I havenever seen before. I have a per of towers that I am rebuilding. The were speciallymade for a studio. They look like a takeoff of the Dynaudio Consequence. They area 5-way meaning you can see 5 different speakers. In the consequence there aretwo 30w100 in an isobaric ported box. In my setup I have one 30w100 loaded in asealed box connected to a second seal box by a verovent. After re-foaming the speakers,they did not sound quite right. Upon further digging I found a second speaker. Thereis a 21w54 loading the second sealed box. First, I have never seen an isobaricusing two different type of speakers let alone two different sizes. I have alsonever seen an isobaric setup separated by a verovent. Has anyone ever seenanything like this?
 
Aperiodic Isobaric is possible with the aperiodic on the 2nd woofer, meaning the chamber between the two woofers should be sealed. The verovent is ofc tuned to match the driver and cabinet size, so the stuffing has to be the same as before - or you need to do a new measurement and possibly work on the crossover values.
 
frugal-phile™
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VarioVent is a crude aperiodic technique. An isobarik has a rear woofer which can be in any type of box, with a 2nd isolating the 1st from the outside world in as small a sealed box as possible (the smaller it is, the higher the isobarik can go. 2 different drivers can be used, but usually they are the same. One could also use EQ to tune the back driver. The primary purpose is to ~halve the size of the box.

Pictures?

dave
 
Thanks, I can see that working with two different size drivers. but the second driver is not loaded into a aperiodic box. it is in between the two woofers. The back wave of the second speaker fires into the second sealed box. The front wave into the verovent into the first camber. The first chamber is a little bigger then the second one. so they did not halve the box volume. Could they be trying to control the Q of the 30w100. the 21w54 cannot be repaired. I've been looking for a used pair or a replacement (Seas H1659 or Scan-speak 21w/8555). Or I might just go with the 30w100 by itself. I'm trying to figure out what the initial design goal was.
 
Sorry, I should have done a picture to start with. Kind of hard to explain. I have seen aperiodic membranes used in front of speakers for car audio, but again nothing like this. I also included the crossover.
Thanks
 

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The halving of box volume mentioned earlier was in regards to the rearmost chamber of a typical compound/isobaric setup (in comparison to a single woofer of the same type).

I'm not familiar with your design, but the post below describes a similar compound variovent alignment, so it was a thing at some point.

Unfortunately, the poster didn't seem to get to the bottom of it either. Hopefully someone else here has experience with it or has software that can handle it.

Dynaudio 30W100 sub design problem
 
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