Questions on a mid's Vas. value....

[Beat_Dominator 5,000+ posts]

I have been shopping around for quite some time for the mids that I will use in my active setup. I have come across many that I feel will suit my needs but one pair has a Vas. value of only 12 liters. All of the other drives I have looked into tend to hover around 30 liters.

Anyone have any idea what kind of effect that could have on a mid? If I apply what I know of subs it's not going to be a very good IB driver.... but that might not matter through the midrange frequencies. So far my internet searches have turned up little //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Click to read more...

 

[Beat_Dominator 5,000+ posts]

I knew there were just too many n00bs here //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[pwnt by pat 10+ year member]

not sure, but want to learn

 

[Beat_Dominator 5,000+ posts]

If you wanted to learn, I found (kind of) my answer here:

http://everything2.com/index.pl?node_id=1282616

 

[PESteele 10+ year member]

jim probably know

 

[Beat_Dominator 5,000+ posts]

Jim doesn't know s*** //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[T3mpest 10+ year member]

I have been shopping around for quite some time for the mids that I will use in my active setup. I have come across many that I feel will suit my needs but one pair has a Vas. value of only 12 liters. All of the other drives I have looked into tend to hover around 30 liters.
Anyone have any idea what kind of effect that could have on a mid? If I apply what I know of subs it's not going to be a very good IB driver.... but that might not matter through the midrange frequencies. So far my internet searches have turned up little //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

will it be a dedicated midrange, or part of a 2 way? In midrange frequencies you don't have much excurision so I doubt it matters, however with a midbass driver yuo want to find something that will perform well IB. A low vas speaker would probably be a better choice, especially if it's a 2-way.

 

[Thnking 10+ year member]

A low Vas by itself without knowing the speaker specs is really only going to tell you that in an IB application, you'll need less air behind the diaphragm.

It doesn't tell you how well a midrange will perform, if that's your question.

 

[Beat_Dominator 5,000+ posts]

Close enough, I just wanted to know if that one spec. would have any positive or negative effects on midrange performance, all other specs being the same.

 

[squeak9798 5,000+ posts]

In midrange frequencies you don't have much excurision so I doubt it matters,

I would have to agree.

Midrange frequencies are extremely limited in excursion....so I really don't see how the compliance of the suspension would really have any drastic affects on it's performance. I know that the surround can alter the frequency response, but that's because of it's damping affects on the cone termination rather than being actually compliance related.

 

[Beat_Dominator 5,000+ posts]

Well it just seemed to me originally that a soft suspension might effect how the cone returns to center or something weird like that, but at the higher frequencies it seems that the motor is doing all of the work.

 

[helotaxi 5,000+ posts]

I'm assuming that you'll have it high passed well above its natural roll off in what ever enclosure it might find itself in? If so, Vas won't matter. For that matter neither will a lot of the T/S parameters. A dedicated midrange will move less than a mm ptp. All they really want in most cases is a separate chamber of some sort from any woofer in the same mounting location.

 

[Beat_Dominator 5,000+ posts]

As I run a 2-way and this is a 7" mid I do plan to run it down quite low, that was phase 2 of my research //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[helotaxi 5,000+ posts]

You can't reach a conclusion based solely on that one parameter, though. Model the driver and see if it will do what you need in the enclosure setup that you plan to give it.

 

[Beat_Dominator 5,000+ posts]

Well IB in the door would of course be preferable..... but I'm thinking I might need to fab an enclosure up for it.