Low Q design ?

[95Prober 10+ year member]

when i manufacturer puts this in the instuction sheets, like pioneer did for me, what does that mean? Low Q ?? just curious!

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[squeak9798 5,000+ posts]

If you remember my post from your other thread:

http://forums.caraudio.com/vb/showpost.php?p=930416&postcount=4

Low Q design is a box design with a low Qtc value //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif (which means it's a larger sized box)

 

[95Prober 10+ year member]

If you remember my post from your other thread:
http://forums.caraudio.com/vb/showpost.php?p=930416&postcount=4

Low Q design is a box design with a low Qtc value //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif (which means it's a larger sized box)

i see. but NOW that means i shouldnt go with the norm of .707 Qtc. coz that is a HIGH value, and therefore makes the box smaller at 0.364 cu.ft, INTERIOR. (i'm supposed to have a final result of 0.364 cu.ft, after the displacement is accounted for). the pioneer site says LOW-Q at 0.6 cu.ft. maybe i shouldnt go under it at 0.364 cu.ft.

now after calculating at a .5 Qtc. it does make the box bigger like you said it does. it gives me a 0.85 cu.ft , after the displacement is accounted for.

and at .577 Qtc it gives me - 0.573 cu.ft

what is the lowest Qtc possible that one should go? and which out of the 3 should i go with squeak ?? thanks!

my numbers i used are these -

Fs - 25

Qts. - .28

VAS - 1.86 cu.ft

Qtc - will be either .5 OR .577 OR .707

 

[DFW40 10+ year member]

go for the .707

 

[95Prober 10+ year member]

go for the .707

but if i go with the .707, a HIGH value, it makes the box so small and it goes against what pioneer says. so im debating with myself on this. pioneer says, Low-Q design at 0.6 cu.ft. you and others say go with the standard of .707, but then others say, go with the manufacturers number or a little higher.

this is getting confusing! actaully im making myself more confused haha

what do u think squeak on my last post before this one ???

 

[DFW40 10+ year member]

Ok Ok go with the .6 design becasue you can always make the box smaller with blocks of wood. This is also a good way to experiment with the different qtc's.

 

[95Prober 10+ year member]

Ok Ok go with the .6 design becasue you can always make the box smaller with blocks of wood. This is also a good way to experiment with the different qtc's.

good idea!

now is there an even lower # than .5 Qtc. or is that basically what people consider the lowest point on average boxes?

 

[DFW40 10+ year member]

The lowest QTC would be .0 and that would be running the sub without an enclosure.

 

[95Prober 10+ year member]

The lowest QTC would be .0 and that would be running the sub without an enclosure.

well, i know technically you can go lower. but is it often done or do people generally and companies generally base the numbers at 0.5 Qtc. and higher? quoting squeak, he doesnt say under .5 in this post. so i was just wondering if .5 is kind of a rule of thumb not to go under?? thx

http://forums.caraudio.com/vb/showpost.php?p=930416&postcount=4

 

[squeak9798 5,000+ posts]

The lowest QTC would be .0 and that would be running the sub without an enclosure.

Running a sub without an enclosure results in the subs Qts becoming the Qtc (Qts = Qtc), hence you would not have a Qtc of .0 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif You'll never have a Qtc that is lower than the sub's Qts.

 

[squeak9798 5,000+ posts]

95Prober; Just build the damned box already //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Learn through experience //content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif

As was said; build the box to Pioneer's specs if you want, then experiment with adding wood to the interior of the box to decrease the volume. Listen for changes and see what you like.

 

[DFW40 10+ year member]

Running a sub without an enclosure results in the subs Qts becoming the Qtc (Qts = Qtc), hence you would not have a Qtc of .0 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif You'll never have a Qtc that is lower than the sub's Qts.

I'll take your word on that one. But I agree build a f-ing box before the foam surround on your subs rott.

 

[squeak9798 5,000+ posts]

But I agree build a f-ing box before the foam surround on your subs rott.

//content.invisioncic.com/y282845/emoticons/word.gif.64b12e39f936af3b4fff38a1c0bd0244.gif

We can sit here and discuss theory all day long. But it won't make the least bit of sense until you actually hear it and experience it for yourself.

 

[95Prober 10+ year member]

got it guys! thx! one more quicky, and im done, when they say 0.6 cu.ft, i assume thats INTERIOR after the displacement ?? so 0.6 PLUS 0.089 for my TOTAL ?? .689 cu.ft ???

 

[squeak9798 5,000+ posts]

Yup.

Now get to work