PDA

View Full Version : Variovent for Midbass?



xtremekustomz
11-08-2006, 10:47 PM
Anyone use a variovent (aperiodic vent) for their midbass? If so does it work well?

kicker06
11-09-2006, 12:07 AM
I think all sealed up tight keeps the midbass strong. Haven't really heard of a ported midbass setup. May be louder (probably not) but it wouldn't retain it's punchiness. This is just my opinion, it may be wrong it may not be.

T3mpest
11-09-2006, 03:06 AM
Anyone use a variovent (aperiodic vent) for their midbass? If so does it work well?

Depends on the driver I've never done anything AP before, never needed to.

xtremekustomz
11-09-2006, 08:50 PM
Well I've got a Dynaudio 8" that runs up to 900 hz and it isn't working well in the doors so I need to move it to the kick. A variovent doesn't work like a port. Basically you have the midbass in a sealed enclosure, and you have a variovent that goes into a large chamber or outside of the vehicle for extra air space. It is supposed to make the sealed enclosure seem like it is 20% larger than what it is. And I don't have a minimum of .5 cu ft. in each kick panel to spare for my midbass.

squeak9798
11-09-2006, 09:44 PM
I think all sealed up tight keeps the midbass strong.

Usually completely sealing kickpanels worsens the midbass....unless you have absolutely huge kickpanels.

squeak9798
11-09-2006, 09:52 PM
Anyone use a variovent (aperiodic vent) for their midbass? If so does it work well?

Never done a true AP enclosure myself. And frankly, they have kind of gone by the wayside these days.

But, when setup properly they should perform admirably. IIRC Dynaudio drivers perform well in AP setups.

Do some searching on this forum http://forum.elitecaraudio.com/index.php and you should find more AP info than you'll ever need.

heyman421
11-09-2006, 09:57 PM
all it would do is show the speaker a slightly larger enclosure.

you may be able to hold a flat response into lower frequencies than you would without it, but you wont gain any output.

i don't know enough about flow resistors to know whether or not there's any drawbacks, so i can't really recommend it.

Most people use polyfill to increase lowend response, rather than a resistor

squeak9798
11-09-2006, 10:09 PM
all it would do is show the speaker a slightly larger enclosure.

you may be able to hold a flat response into lower frequencies than you would without it, but you wont gain any output.

AP enclosures are used to flatten the impedance curve of the speaker, giving a relatively flat and relatively predictable frequency response (before vehicle acoustics are taken into account) while being very small in physical dimensions.

I guess I may be misreading, but I didn't see anywhere that the OP specifically stated output as being his primary problem. The 2nd poster confused his intentions with porting the enclosure.......


i don't know enough about flow resistors to know whether or not there's any drawbacks, so i can't really recommend it.

Two main drawbacks for AP (in general) is decreased low frequency output and decreased efficiency.


Most people use polyfill to increase lowend response, rather than a resistor

I guess the OP needs to clarify if lowend response/output is his main problem...because I guess that's not what I interpretted his posts to mean.

xtremekustomz
11-09-2006, 10:16 PM
My problem is with imaging from the doors with the frequencies going as high as they do. Some things tend to pull down towards the doors. Low end response and output is definately not a problem.

squeak9798
11-10-2006, 07:40 PM
My problem is with imaging from the doors with the frequencies going as high as they do. Some things tend to pull down towards the doors. Low end response and output is definately not a problem.

Then moving them to the kick and going AP very well could work out for you.

T3mpest
11-11-2006, 04:11 AM
Most stage height issues can be addressed with tuning, depends though. I'm assuming you've played with your x-over points, as well as phasing.

95stroked1500
11-11-2006, 08:38 PM
if you get the pre made variovent, be sure to have it vent into an area that won't come back around to the listening area easily. you might even use 2 of them in each kick if. if you start moving too much air through them, they get a greatly audible "hiss" through them.

extra info for those inquiring, you can AP tune to compensate for small space, you can also AP to keep box Q more constant in a sealed box. the more volume you go, the more the Q can swing from it's "on paper" design.

xtremekustomz
11-12-2006, 01:59 AM
Most stage height issues can be addressed with tuning, depends though. I'm assuming you've played with your x-over points, as well as phasing.

I've done a few things with the phase but it only gave me more depth on most things. Most of everyone I have talked to told me to put the midbass in the kick since the frequency went up so high.

T3mpest
11-13-2006, 04:10 AM
I'm assuming this is a 2 way setup, mids in doors tweets in A-pillars? That's just what I'm guessing though. If so then a AP setup might be a good idea.

xtremekustomz
11-13-2006, 09:14 PM
I'm assuming this is a 2 way setup, mids in doors tweets in A-pillars? That's just what I'm guessing though. If so then a AP setup might be a good idea.

No. 8" midbass in door running from 63-900 hz, 3" dome midrange running 900-4500 hz and 1.1" tweeter running from 4500hz and up. The midbass is in the door, the midrange and tweet are in the kick panel.

T3mpest
11-13-2006, 11:17 PM
Hmm, I'd say they are right then, 900hz is fairly high.