Bass cancelation-

[Mark-E-Mark]

I made a small goof when designing my new build. First build ever so im bound to "small goof". Anyway My intentions were to design a box for 2 12'' subs and have one inverted and the other normal sharing the same airspace. And I was going to set the phase opposites on the amps so that they don't cancel out. Yes each sub has its own amp- Autotek SM 3200.1. The one thing I over looked when I bought THREE of these amps is there is no phase setting on them. Which is still okay. Ive made charts for specs of box determining the position of the subs. 2 regular facing-49hz/ each opposing-32.5hz/ both inverted-28hz. so basically I can play with positions to get different tuning. Had fun with the 28hz lows, and the 49hz highs. Now I need in between the two. I could cut the ports down from the inside which will be tricky but drop the tunning from 49hz to what ever I want.

So basically will my 2 subs (1 regular facing & the other inverted) sharing same airspace on opposite sides (one in front of box and one on back of box) cancel out if my amps have no switchable phase setting? My answer is yes, just want confirmation. Still learning, Thanks!

http://www.stevemeadedesigns.com/board/garage/vehicle/2632-chevy-cavalier/?tab=images

My garage link with pictures of the system.

Signature equipment is all current.

[dangaranga]

If i am reading this right, you can just switch the positive and negative leads on one of the subs.

[Mark-E-Mark]

You know, that's not the first time I heard something like that. I will follow up some research on that. Good tip man thanks!

[REVOofRustler]

Any chance you could post specs on that box? You're saying you'll get a shift of 16hz just from inverting one sub. That's a huge difference from only adding/subtracting roughly .15 cubes.

[Mark-E-Mark]

I don't have my book on me but if I can remember right box is roughly 6.4ish cu ft gross. 3/4'' mdf with .5 cu ft port displacement and about 3.12 cu ft sub displacement. about 35 or 34 inches long, 20'' deep, about 15''ish high. after displacement I only have about 1.5 cubes internal space. There are 2 about 14'' long 4'' ports and 2 more 4'' tubes that run straight through the box (trunk ports). I want one sub (in the trunk) inverted and the other (sub facing into car) regular. To give me about 32.5hz. How can I do this if my amps are not phase switchable without cancellation? There is no separation inside the box for subs, same airspace is shared. Lanzar Opti's 1232d

Some of my calculations are not exact, I cannot find my book right now. I would just like to know if this is possible, thanks guys.

[jhmeg2]

3.12 ft^3 sub displacment? damn

[Mark-E-Mark]

3.12 ft^3 sub displacment? damn

Lol they are pretty beefy. Huge baskets

[REVOofRustler]

What subs are we talking about here?

[ChevyBoy95]

there is no reasonable sub with that much displacement.... ever. Even a 21in Warden only has .22 cuft of displacement.

How is 2 12's going to have 3.12 cu ft of displacement?

And by the way Vas isnt sub displacment bud. The displacement on those lanzar 12's is going to be about .15-.2 cu ft each.

edit: the reason i know that 3.12 figure came from the Vas spec, is because it is 1.56 cu ft for a single woofer.

[OrionStang]

Big goof LOL.