Stuffing/Lining a Sealed Box

[Ginobli07 0]

I know this question has been posted before all over, but many of the discussions just turn into b***hfests, and no straight good answer is given.

Would stuffing (polyfill etc...), or lining (vibration damper, mlv, etc...) a properly sized and well built box make any difference on the sound quality/characteristics of the subwoofer it contains?

I'm looking for one good answer please, not a million random opinions. My head is just in a daze after looking at how many odd forum posts that don't answer the question I'm posing.

Thanks to anyone who has good knowledge on this topic!

Edited March 29, 2010 by Ginobli07

[///M5 2,833]

Will it make a difference? Yes.

Will it do what you need? Not sure, you haven't described what your concern is. It is definitely a parameter that you need to design around.

[Ginobli07 0]

Well I'm planning to build a box for the new 12" Q and was looking for a Qtc of .707, theoretically. I've made boxes for other subs to get this Qtc (don't have exact equipment to measure though). I just haven't experimented with building the box slightly smaller and adding polyfill to see if it would help/change the sound versus making the box perfect and not adding polyfill, or for that matter any other "exotic" product. I'm just looking for the cleanest sound possible. I love tight snappy bass, and at around the theoretical Qtc of .707 I am very happy.

Hopefully this answers your question for me.

Also, do you the exact box size I would need to fabricate to get this Qtc for the 12" Q with HIgh Qts, and the inductance ring? There is a size range posted on the site, but it's not very informative for an exact size.

Thanks man

[KU40 173]

Put the speaker's parameters into a box building program such as winISD, and it'll tell you the QTC in a given enclosure.

[///M5 2,833]

A quick model will show you a ton.

Although being you are this critical of the box, perhaps you should look at other drivers as well. Hard to know how to respond though if you only concern is a .7 Q as you can do that with nearly any driver that is suitable for a sealed box.

[Ginobli07 0]

True. I was just wondering if there was any added dampening characteristics from stuffing or lining the box versus not doing so.

I've used Winisd but when you enter your own parameters it won't save because they don't match the programs calculated parameters. Is there a way around this? I've entered the parameters of the 12" Dual 2 Q wired in series into Winisd, but it won't save the driver parameters.

Also, without the High Qts woofer parameters I can't properly make a model. This is the biggest problem.

[sqjeep 9]

When entering the parameters in winisd you can't enter all the info, you have to let winisd enter some of the parameters itself. For example ... You put in the QES and the QMS, then keep hitting tab to the program doesn't add in anymore parameters. Do not adjust the parameters that the program inserts (will be in blue) or when you go to save it, it won't except it. Then jus keep adding the info in this manner.

Edited March 30, 2010 by sqjeep

[///M5 2,833]

Enter ONLY these and in this order:

Mms

Cms

Sd

Bl

Re

Qms

The rest will be calculated automatically. Expect VAS to be different as it will change for different environments and everyone makes different assumptions.

**Be careful as to how the BL is specified on DVC systems. It might be either in series or parallel and you need to make sure that you choose appropriately**

[Ginobli07 0]

Awesome info guys. I have Windows 7 and I can't access the help guide for some reason so I never knew how to enter the info properly. I'll give this a try and see what happens.

Also, should I tab completely around the page before entering another value, or can I skip around with a mouse and put the values in?

[///M5 2,833]

Just skip with the mouse and type in the value.

[Ginobli07 0]

Alright sounds good. I'll see what I get.

Thanks man

[///M5 2,833]

No worries. Hope that helps, if it gives you "more" questions don't hesitate to ask.

[KU40 173]

Yeah, winISD changed the alpha version a couple of months ago. You used to be able to put in whatever values you wanted whenever and it would calculate the ones you hadn't put in yet, but now it wants them in specific order. It took me a while to figure out that problem, too, which I solved by going to the help menu. But now I see your predicament with that option. Sucks that it won't work on windows 7. Kinda surprising considered the software was recently updated.