I have a 1.25cf sealed enclosure for my sub, I am getting a .75cf box, more or less same dimensions, 12x12 with 11 top depth and like 13 bottom (thats all external of course...

So my problem with the big one was that at a certain power, the sub would be excursing about oh.. half of what it could, then on one level higher, it would start to exceed its max and hit, I beleive because the suspension was too soft. The recommended size by kenwood was .65, they did not say that included the woofer, so im guessing not, and thinking it is .1cf for the magnet and etc... so I should be matched...

Should I add polyfil to this new smaller box to help the low end? or would this hurt the performance because the box is not smaller than the recomended size? Would it have any bad effects on the stiffer air suspension I was going for with a smaller box?

 

1 bump, then I let it die

 

The polyfill wont hurt. Going to a smaller box it may actually "seem" like you pick up more bass, as it will peak more, but will fall off much faster, thus lowering the lower frequencies that were over excursioning your driver.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CooBlueDAB &raquo;</TD></TR><TR><TD CLASS="quote">I have a 1.25cf sealed enclosure for my sub, I am getting a .75cf box, more or less same dimensions, 12x12 with 11 top depth and like 13 bottom (thats all external of course...

So my problem with the big one was that at a certain power, the sub would be excursing about oh.. half of what it could, then on one level higher, it would start to exceed its max and hit, I beleive because the suspension was too soft. The recommended size by kenwood was .65, they did not say that included the woofer, so im guessing not, and thinking it is .1cf for the magnet and etc... so I should be matched...

Should I add polyfil to this new smaller box to help the low end? or would this hurt the performance because the box is not smaller than the recomended size? Would it have any bad effects on the stiffer air suspension I was going for with a smaller box?</TD></TR></TABLE>The sub must be in the right size box, to work properly, if the box is too big.... , [well you know what happens] and if the box is too small you will limit LF responce, polyfil in a smaller box will make the speaker "think" its in a bigger box, and how much polyfil you put into the box will make a diff. there is a point of diminishing returns.

The best thing to do is to build the right size box, or buy one, 10% +/- in box volume on a sealed box will not make a diff., if you can't find a box thats the right size, get one that is a little bigger, and use up the extra volume by installing bracing inside the box, using up the extra volume 94

 

aite, so as I thought I should add some polyfil, because my suspension will still be stiffer, but it will help sound some... so since it is a general rule... of about 1lb to 1sq ft... I guess Ill use about 1/2 lb and a little more only thing is, Ive been confused about this, I could fill my box with polyfil, and i doubt it would be 1lb, let alone 1/2 lb, so how exactly is it measured? the stuff is so freaking light... am I really supposed to have that much weight in there and just staple/glue it tightly against the walls?

How so? and which sides?(all or just a select few?) I have a trapazoidal box so you know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CooBlueDAB &raquo;</TD></TR><TR><TD CLASS="quote">aite, so as I thought I should add some polyfil, because my suspension will still be stiffer, but it will help sound some... so since it is a general rule... of about 1lb to 1sq ft... I guess Ill use about 1/2 lb and a little more only thing is, Ive been confused about this, I could fill my box with polyfil, and i doubt it would be 1lb, let alone 1/2 lb, so how exactly is it measured? the stuff is so freaking light... am I really supposed to have that much weight in there and just staple/glue it tightly against the walls?

How so? and which sides?(all or just a select few?) I have a trapazoidal box so you know.</TD></TR></TABLE>It will not change the speakers suspention, and lining the inside walls of a box is diff. then filling the box, lining one or more of the inside walls of a box is used for "dampening", controling standing waves, filling a box is used to make the speaker "think" its in a bigger box.
Most places that sell polyfil or spun dacron, do so in lb bags 94

 

so I should basically just put a little less than a lb in there huh? loose? I just want to make sure it will not hurt the speaker or conduct electricity with the wires

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CooBlueDAB &raquo;</TD></TR><TR><TD CLASS="quote">so I should basically just put a little less than a lb in there huh? loose? I just want to make sure it will not hurt the speaker or conduct electricity with the wires </TD></TR></TABLE> How much you put in will depend on a few things, the way I do it, I start with some, try it, add some more, if it sounds better. then I add some more, I keep adding till it stops making a diff. or I will remove some if it starts sounding worse.

It will not conduct electricity, a bigger problem would be if the fill is allowed to get into the speaker, and interfear with the cones movement, to avoid this, get a piece of "sheet" polyfill/dacron and place that right behind the speaker, covering all the speaker, make it the same size as the hight and width of the box 94

 

ahh good good, I get the sheets of polyfil, so that will work, Ill just leave it solid for that front layer, then the rear Ill cut out smaller squars and just randomly insert them., thank you

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CooBlueDAB &raquo;</TD></TR><TR><TD CLASS="quote">ahh good good, I get the sheets of polyfil, so that will work, Ill just leave it solid for that front layer, then the rear Ill cut out smaller squars and just randomly insert them., thank you</TD></TR></TABLE> You can keep it all in sheets and just keep adding layers. 94

 

well I added a little over half of one of those huge 1lb bags into the box... the magnet and assembly on this was much larger than I remember lol.. so the actual airspace may be smaller than recommended by a few inches cubed. In either case, I had no idea you had to stuff so much in there, It seemed like all the air would be gone with that in there.... well added it in, put in a large solid sheet to keep it out of the magnet and assembly.. FCM, it had to be bigger than the W and H of the box, because its behind the magnet and assembly, IE, needs more surface area to surround it...

The sub definitly can get louder now, by far, and is a much smoother climb... It seems peaky... but I guess that is natural, Ive got all the setting the same as when it was in a .5cf larger box... Ill go back to native neutral settings, run some sweep tones, do my usual musical run down, and give you the feed back on how it has improved or failed. If I have a lot of time, I may remove the polyfil, and then add it again, to compair, but with the screws and all, I dont want to take it apart anymore than I have to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CooBlueDAB &raquo;</TD></TR><TR><TD CLASS="quote">well I added a little over half of one of those huge 1lb bags into the box... the magnet and assembly on this was much larger than I remember lol.. so the actual airspace may be smaller than recommended by a few inches cubed. In either case, I had no idea you had to stuff so much in there, It seemed like all the air would be gone with that in there.... well added it in, put in a large solid sheet to keep it out of the magnet and assembly.. FCM, it had to be bigger than the W and H of the box, because its behind the magnet and assembly, IE, needs more surface area to surround it...

The sub definitly can get louder now, by far, and is a much smoother climb... It seems peaky... but I guess that is natural, Ive got all the setting the same as when it was in a .5cf larger box... Ill go back to native neutral settings, run some sweep tones, do my usual musical run down, and give you the feed back on how it has improved or failed. If I have a lot of time, I may remove the polyfil, and then add it again, to compair, but with the screws and all, I dont want to take it apart anymore than I have to.

</TD></TR></TABLE>Sorry..... forgot to mention to cut a hole for the magnet in the first layer 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">Sorry..... forgot to mention to cut a hole for the magnet in the first layer 94</TD></TR></TABLE>

lol, dont worry, it wouldnt keep it out of the assembly if I did that.. big port in the middle of it, for cooling I guess.. and the magnes is a wide mother... so if it went over it, even with a cut in it to sorta make it a u shape.. but not really... it would still get in there.

its fine the way it is, but I was suprised at how much of the stuff is needed for the avg ratio... youd think it would hinder it at that density... but I can tell, even the box seems to .. hrm, resonate might be the term.. but whatever... it seems to act as a speaker much more than before. soon as I actually tune this, maybe today... Ill let you know the full detailed results.