3-4% difference. Sound deadening your trunk, makes a 50% difference.

 

loool so basically a waste of money, **** that then

 

there's many other things that would make noticable improvement before fine-tuning the enclosure.

 

I have a similar box (the 3/4" MDF one with two side ports, 3.4 cubes, 38Hz). I deadened the entire box. Probably 15lbs easily in there, maybe closer to 20. Then I used 1lb or so of that fluffy crap from Walmart (polyfill?) per chamber.

It will make a big difference. I cannot quantify if for you in percentages, but it tightened up the bass VERY noticably. "Deeper" is as good a word as any.

Then I decided to block the ports with expanding foam and turn it into a sealed enclosure. Best decision ever, but again, it will take a bit more power to hit the volume levels of the ported version.

You might have to feed the subs a little more gain, or power if you have it on tap. I did.

I've read from some installers and builders on here that the polyfill makes the sub sound like its in a bigger box.

Anyway, I'm happy with the results.

Cheers

 

anyone have pictures of how i can put the polyfil in their

 

if somebody could test with and without polyfill on a termlab that should be able to quantify any real difference. Is the sub louder if so, buy how much and at what frequency. The termlab could tell us these things.

 

How can a termlab tell you what you are hearing? It makes a difference to my ears in the vehicles I install it into. Not all customers use it, that does not mean that it is not worth it. For all the effort people put into their boxes, a further $50 is totally worth it. I let my local customers try it for themselves, if they like it, they keep it. If not, out it comes.

 

I am a firm beleiver that it is hard to actually remember what something sounded like and compare it hours or days or even minutes between listening sessions.

An RTA type measuring device can show the differences, if any. Of course it won't say if those differences are good or bad to the ear but at least it is quantifiable and it can't be said to only be "in your head".

 

Of course I disagree to a point, I think something that makes a significant difference in the mechanical performance of the sub would be quite audible, certainly more than any HU, amp, wire swap would. But the conditions of the comparison should be similar

I think there are 2 questions being asked here
1) does it make you louder? that's all that matters for some and TermLab will answer this and it will answer how or if it affected peak frequency and any over or under tones the box produces
2) does it sound better? A before and after frequency sweep on a sub will tell you overall linearity (this is one of the ways to do AAAAA's comment on RTA using a TermLab without the RTA function at 140 dB volume just sit down and plot the responce) but will not answer whether or not it sounds better as AAAAA said

 

I was talking about small differences, if you go from one setup to another that is 3 times as loud of course one can tell the difference or if you do something drastic such as blocking the port of a ported box or porting a sealed one.