Polyfill. Chime in please. (yes I googled it too)

  • 4
    Participant count
  • Participants list

ThatChevyGuy
5,000+ posts

sue me, its a ford.
13,454
26
Georgia
EDIT: INFO FOUND Thanks

Okay, been reading and reading.  Still can't find answer I'm after exactly...

Specs say  5.5 cu ft net enclosure volume sealed.

It's an Infinite Baffle suited subwoofer, and box space is limited, I Like sealed boxes, so going ported is not an option

I don't have a trunk, so I'm building an 8 cu ft net shared chamber enclosure...

Can I Stuff The 8 cube box with enough fill to where the subs would behave as if In the recommended 11 cubes?

How much can I add without big negative effects? is there a chart with fill amounts and expected volume correlation the sub "sees" ?

Sub info: Lanzar dctoa18 (IB suited)

Qts : 0.75

Vas: 14

FS: 30hz

 
Last edited by a moderator:
I wouldn't. That poly fil will change how the sub sounds and I think shrink the internal volume if I'm not mistaken. Poly fil is mainly used in home audio, not car audio. If you have a well designed box for a sealed enclosure and built properly, shouldn't need poly fil.

 
My past experiences with polyfil yielded amazing results.

15" in 2.25 cu ft SEALED with about 2 lb (iIRC) of poly REALLY brought the lows out

It made the sub behave as it was in a bigger enclosure 

 
Last edited by a moderator:
I'm using a Free Air (IB) subwoofer, it's more like a home audio driver 

 It would not do well ported I believe, most IB subs dont.

I prefer sealed over ported For my listening and music preferences

I'm trying to make the best with the equipment I have

Guess I'll just build a 4 cube sealed per sub box then play with a 5lb bag of polyfil if I'm not happy.

Thanks

 
Last edited by a moderator:
Oh I missed that part. You do realize that IB is utilized by your trunk as an enclosure. And everything inside must be sealed up to sound good?

 
Oh I missed that part. You do realize that IB is utilized by your trunk as an enclosure. And everything inside must be sealed up to sound good?
Indeed I do. But Infinite baffle is just a large sealed enclosure basically, right?

Manufacturer specs are 5.5 cubes each for sealed enclosure on these

I have 8-9 cubes max for space. I don't have a trunk, and im doing a very low budget setup.

2 18" is a lot of cone area (and I paid $99 for both) 

It should have decent enough output for me.

 I'm just trying to understand more about how the drivers are going to behave in my alignment before hand 

Capiche? Thanks

 
Last edited by a moderator:
Indeed I do. But Infinite baffle is just a large sealed enclosure basically, right?

Manufacturer specs out 5.5 cubes in a sealed enclosure on drivers I have.

I have 8-9 cubes max for space. I don't have a trunk, and im doing a very low budget setup.

2 18" is a lot of cone area (and I paid $99 for both) 

It should have decent enough output for me, I'm just trying to understand more about how the drivers are going to behave in my alignment before hand 
Good point since I've never messed around with IB subs before and they weren't around long, not to mention that very little people used them. Wonder if @THATpurpleKUSH could help ya on your quest. Or @shredder2 for a design.

 
Poly fill does nothing but slightly absorb or rather diffuse the rear wave of the sub. This results in a cleaner sound which in return sounds similar to a larger box. 

A better product that works much better is fiberglass insulation.

Different subs would be the solution or just try the subs you got worst case they sound bad and you can change them later

 
I read and searched for quite a while, I finally found the Info I was after and educated myself more on the subject.

Post can be disregarded now, thanks guys

 
I read and searched for quite a while, I finally found the Info I was after and educated myself more on the subject.

Post can be disregarded now, thanks guys
For the record, the frequency response will more model like a larger box for you but you will not gain efficiency you would if you actually had that airspace.   Bear in mind your cabin gain may give you enough low extension where you don't need the curve you think you need to sound "good" and sealed boxes are quite forgiving anyway.   A 30% change in volume doesn't really even change the response graph much.

Easiest check is model the sub in WinISD to compare what you could even expect, or just buy 10$ worth of batting and test for yourself.

 
For the record, the frequency response will more model like a larger box for you but you will not gain efficiency you would if you actually had that airspace.   Bear in mind your cabin gain may give you enough low extension where you don't need the curve you think you need to sound "good" and sealed boxes are quite forgiving anyway.   A 30% change in volume doesn't really even change the response graph much.

Easiest check is model the sub in WinISD to compare what you could even expect, or just buy 10$ worth of batting and test for yourself.
10-4.

Thanks

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

Similar threads

Poly fill traps the rear wave of the speaker keeping it from reflecting back and hitting the cone. This reduces 2nd order and 3rd order distortion...
9
2K
I think you're gonna have to get good with fiberglass or something, or find someone with a 3d laser scanner that can 3d print or mold you some...
7
601
Is this a blue or blue/white wire from the Kenwood? The ACC wire is red and although that should turn on the amp, it is not the prefered wiring...
1
528
The sound deadening is going to be more about preventing vibration from metal surfaces and adding unwanted noise. Does it have the JBL system...
1
526
It's called the K.I.S.S. preciniple ("Keep it simple, stupid!")... Takes the guesswork out of parallel/series wiring.
2
760

About this thread

ThatChevyGuy

5,000+ posts
sue me, its a ford.
Thread starter
ThatChevyGuy
Joined
Location
Georgia
Start date
Participants
Who Replied
Replies
12
Views
1,392
Last reply date
Last reply from
ThatChevyGuy
Screenshot 2024-03-07 184329.png

Doxquzme

    Mar 27, 2024
  • 0
  • 0
IMG_3075.jpeg

Daniel Lee

    Mar 27, 2024
  • 0
  • 0

Latest topics

Top