Can polyfill affect output?

[Grinder1989 5,000+ posts]

The polyfill helps make an enclosure seem like it is bigger than it really is to a sub. However if you have a sub that is supposed to have 1^3 of space, and you jam two bags of polyfill in there, will the the output also change?

The reason I ask is my Uncle has two A/D/S subs in a 1^3 enclosure, sealed.(each sub is getting 1^3 in separate chambers) Four bags of Polyfill were in the box when I installed it. Gain is @ roughly 10% due to the line driver (around 8-10 volts) on the H/U. SQ is amazing but it does really have a good punch to it. I have removed the polyfill but I haven't got a chance to listen to the system. (old neighbors around him and I don't want them pissed off) Anyway should there be a change in output or should I increase the gain?

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[tcguy85 10+ year member]

why did u remove the polyfil?

 

[Grinder1989 5,000+ posts]

To see if it changed the output.

 

[Grinder1989 5,000+ posts]

Bump

 

[Immacomputer 10+ year member]

It can and then it cannot. It's different in every application. It doesn't make the sub think it's in a larger enclosure but rather changes the point of resonance and the Qtc of the sub and enclosure system.

Using polyfill usually lowers the Qtc which gives a smoother response with increased low end. Having a small sealed enclosure will give a higher Qtc value which can begin to give a peak in the upper frequencies and then it might be louder on a mic.

Try different amounts of polyfill until you get the desired sound. If you can't get the sound right, you might want to change enclosures.

 

[Grinder1989 5,000+ posts]

It can and then it cannot. It's different in every application. It doesn't make the sub think it's in a larger enclosure but rather changes the point of resonance and the Qtc of the sub and enclosure system.
Using polyfill usually lowers the Qtc which gives a smoother response with increased low end. Having a small sealed enclosure will give a higher Qtc value which can begin to give a peak in the upper frequencies and then it might be louder on a mic.

Try different amounts of polyfill until you get the desired sound. If you can't get the sound right, you might want to change enclosures.

Well thanks for your help. I'll play around with it.

 

[tcguy85 10+ year member]

It can and then it cannot. It's different in every application. It doesn't make the sub think it's in a larger enclosure but rather changes the point of resonance and the Qtc of the sub and enclosure system.
Using polyfill usually lowers the Qtc which gives a smoother response with increased low end. Having a small sealed enclosure will give a higher Qtc value which can begin to give a peak in the upper frequencies and then it might be louder on a mic.

Try different amounts of polyfill until you get the desired sound. If you can't get the sound right, you might want to change enclosures.

very good explanation! i like it!

 

[AllStar1500bd 5,000+ posts]

And if you add too much polyfil, you may doing the exact opposite of what you want. It should fit evenly and loosely, if you have to "cram" it in, it's likely you put too much in.