Polyfilll?
1000 Watt CAFz'r
Joined: Oct 2003
Posts: 1,783
Stupid Dukk. [img]smile.gif[/img]
I have had the pleasure of playing with lots of stuffing techniques in high end home audio. Here is what I've found:
The results are measureable below 100hz on an RTA, and easily audible.
Fiberglass and polyfill respond differently. If you are porting a box, (of doing a 6th order band-pass) there will be a notable difference between the two. It will be up to the listener's ears to decide which one is best.
The amount of stuffing deppends a great amount on how close you are to having the optimum box size. If you have a smaller box with a "Q" above a value of about 1, filling does help to smooth things gut. For boxes with a low "Q" of below 0.7, you will have a much harder time hearing your results.
The greatest improvements in SQ that I have heard from stuffing, (weather fiberglass or polyfill) is above 100hz. If you have a midrange or high playing midbass driver, there will be an improvement in low level detail. I've even heard some speakers sound constrained without stuffing, and effortless with stuffing. Even frequencies above 1khz can benifit from stuffing.
How much stuffing you use is up to your ears. There are a few rough guidelines, but I've found exceptions to those.
Experiment.
Adam
I have had the pleasure of playing with lots of stuffing techniques in high end home audio. Here is what I've found:
The results are measureable below 100hz on an RTA, and easily audible.
Fiberglass and polyfill respond differently. If you are porting a box, (of doing a 6th order band-pass) there will be a notable difference between the two. It will be up to the listener's ears to decide which one is best.
The amount of stuffing deppends a great amount on how close you are to having the optimum box size. If you have a smaller box with a "Q" above a value of about 1, filling does help to smooth things gut. For boxes with a low "Q" of below 0.7, you will have a much harder time hearing your results.
The greatest improvements in SQ that I have heard from stuffing, (weather fiberglass or polyfill) is above 100hz. If you have a midrange or high playing midbass driver, there will be an improvement in low level detail. I've even heard some speakers sound constrained without stuffing, and effortless with stuffing. Even frequencies above 1khz can benifit from stuffing.
How much stuffing you use is up to your ears. There are a few rough guidelines, but I've found exceptions to those.
Experiment.
Adam
50 Watt CAFz'r
Joined: Apr 2004
Posts: 456
Originally posted by Dukk:
Wow - I got the "stupid" twice today [img]tongue.gif[/img] I'm on a roll [img]graemlins/thumb.gif[/img]
I was just poking fun MrNissanDood. Snobby boxdorks use the cromulant terms Isothermic and Adiabatic to embiggen themselves instead of just saying: "I stuffed 'er good"
The loose correlation being that the stuffing does indeed convert energy to heat so you could make a LONG stretch and say that it absorbs heat from the enclosure (Isothermic). Conversely an un-stuffed enclosure will have no internal temperature gradient so again the loooooooooooong stretch to to it being "adiabatic"
My point was that the woofer system will always generate heat as a whole and thus it is exothermic. Well from a thermal dynamics point of view anyway [img]tongue.gif[/img] I don't want to hear no conservation of energy crap...
Wow - I got the "stupid" twice today [img]tongue.gif[/img] I'm on a roll [img]graemlins/thumb.gif[/img]
I was just poking fun MrNissanDood. Snobby boxdorks use the cromulant terms Isothermic and Adiabatic to embiggen themselves instead of just saying: "I stuffed 'er good"
The loose correlation being that the stuffing does indeed convert energy to heat so you could make a LONG stretch and say that it absorbs heat from the enclosure (Isothermic). Conversely an un-stuffed enclosure will have no internal temperature gradient so again the loooooooooooong stretch to to it being "adiabatic"
My point was that the woofer system will always generate heat as a whole and thus it is exothermic. Well from a thermal dynamics point of view anyway [img]tongue.gif[/img] I don't want to hear no conservation of energy crap...
50 Watt CAFz'r
Joined: Apr 2004
Posts: 456
What are your opinions on,
1: what kind of stuffing for a small, sealed kick panel. Fiberglass, or dacron line or fill entirely?
2: lining of IB setups, Doors trunk etc. (I know, water in doors, but it's summer comp season!)
3: oversized sealed sub enclosures,(I usually go a little bigger than spec for low extension) stuff, line or none?
Thanks
1: what kind of stuffing for a small, sealed kick panel. Fiberglass, or dacron line or fill entirely?
2: lining of IB setups, Doors trunk etc. (I know, water in doors, but it's summer comp season!)
3: oversized sealed sub enclosures,(I usually go a little bigger than spec for low extension) stuff, line or none?
Thanks
1000 Watt CAFz'r
Joined: Oct 2003
Posts: 1,783
Stupid Dukk [img]smile.gif[/img]
1.) I'll let you know about kicks, I'm still working on that one myself.
2.) It makes me nervous to have water "held" in my doors
3.) Make a removable panel, or an easy way of removing the driver to experiment with fill. Remember, your car will sound different than everyone offering their opinion. In the end...tune it for your car.
Adam
1.) I'll let you know about kicks, I'm still working on that one myself.
2.) It makes me nervous to have water "held" in my doors
3.) Make a removable panel, or an easy way of removing the driver to experiment with fill. Remember, your car will sound different than everyone offering their opinion. In the end...tune it for your car.
Adam
1000 Watt CAFz'r
Joined: Oct 2003
Posts: 1,783
^^^Well you've love my headaches too then!
http://www.canadiancaraudio.com/ubb/...;f=10;t=001189
Adam
[ May 16, 2004, 02:09 PM: Message edited by: PEI330Ci ]
http://www.canadiancaraudio.com/ubb/...;f=10;t=001189
Adam
[ May 16, 2004, 02:09 PM: Message edited by: PEI330Ci ]
