Inverting 1 Sub only?

[da_bOm 10+ year member]

i want to invert 1 sub only and leave the other one normal, my question is will i loose/gain anything or is it just for looks, also if i do should i switch the positive and negative wire? its a SVC if that helps

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[Wonderbread 5,000+ posts]

it wont affect anything, except!

if its a seperate chamber box, each sub will have different air spaces, that WILL affect teh sound of the woofers...

if you are going to invert one sub.

wire teh normal one normally (duh) and then wire the inverted one reversed...

 

[ss3079 5,000+ posts]

Wonderbreads right, might need to make the inverted subs box a bit smaller - where in BC are you?

 

[nismo 10+ year member]

i HIGHLY doubt its gonna be enough to hear ANY difference. you might be able to measure fractions of a db difference on ouput, but nothing that youd be able to hear at all.

eric

 

[Wonderbread 5,000+ posts]

not necessarily on total volume..

if its sealed, the response curve changes...

larger airspaces generally cause a few things to happen...

lowers teh power handling of the drivers,

produces a flatter response curve (less peaks than in an optimum airspace)

Those are the main ones...

and, depending on teh drivers, (btw, which ones ar they?) the displacements could ahve a huge effect on teh airspace...

let us know and we can tell you how much you will need to compensate (eitehr with bracing or with poly fill (bracing or somethign like taht in teh inverted subs airspace may do better tho.

 

[nismo 10+ year member]

i honestly wouldnt worry about it at all. just b/c the box is ~ 10% bigger (assuming 1.5 cubes, and .15 sub displacement--no i didnt use a calc...but close enough //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif), doesnt mean that the mech powerhandling will go down 10% or anything along those lines.

just b/c there's a difference on paper doesnt mean that there will be a difference in performance. with such a small change, there's no reason for concern.

eric

 

[Wonderbread 5,000+ posts]

BUT, depending on teh reduction of airspace, the response can cahnge fairly dramatically, no?

 

[nismo 10+ year member]

i wouldnt say dramatically...it does ever so slightly. if you look at the picture, you see a yellow plot, and a blue plot. both are of the adire shiva (12") sub. in the pic, the blue curve is the .707 alignment, and the yellow is a slightly higher 'q' alignment...at ~.73. i would be willing to wager money that you couldnt hear any difference in performance, and would likely not see much using tools either.

eric

*edit* btw, this is a 10% difference in box sizes //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[nismo 10+ year member]

another thing i forgot to mention, is that unless you measure each and every driver you install, you arent gonna get the same alignment for a pair of subs, even if theyre identical, just b/c of manufacturing tolerances...they typically range from anywhere around 5% to about 10 or 15%

eric

 

[Wonderbread 5,000+ posts]

taht's for a shiva?

what about something iwtha much higher structure displacement?

ie. brahama, xxx, RF powers, anything with aton of magnet, etc?

larger differences...

i beg of you, at what point in the 'q' DOES it become noticeable?

 

[nismo 10+ year member]

just for comparison, i did the same setup with a pair of brahma 15's...the blue is still .707, and the yellow is still .73...both yellows are at 90% of the .707 box q...the 90% box on the brahma 15 figures that the difference in displacement is .27, although the brahma only displaces .15 ft3, but this would cover the fact that the cone is dished (and then a little extra)

here is another pic of the response curve (keep in mind that the response should be CLOSER than it shows.

as for when box q becomes noticable, im not totally sure, as im still learning...my guess is somewhere in the neighborhood of about .075 or .1 difference in box q...maybe a little less, maybe a little more...but probably not too far off.

eric

 

[Wonderbread 5,000+ posts]

hrm alwas good, to know, lol.

sometimes, i like to start arguments just to elarn, lol.

 

[nismo 10+ year member]

Originally posted by Wonderbread hrm alwas good, to know, lol.

sometimes, i like to start arguments just to elarn, lol.

you wouldnt believe how much ive learned from arguments (mostly watching them from dan vs. matt...but some of me doing it too). a lot of just having people question my thinking and having to back up my thoughts with things ive learned, and facts and other things ive picked up along the way.

eric