Simple 12" Infinity Kappa VQ MidQ Plans

[annunaki]

That's why they make respirators and vacuum systems.

 

[armstrr]

thanks for the response. my preference would be to leave the dimensions as is. i'll just have to measure and see if i can fit 1 or 2 (if i get greedy!!) in the speaker bumpouts i have. this will put them very close to a corner...inches in fact. the walls are uncovered and have between 4 and 9" of dense packed blown in cellulose insulation. i'm not sure if this info is of any value.

already found a used amp for 150$

 

[armstrr]

an interesting read on mdf vs a new "greener" panel product.

http://www.edesignaudio.com/pdf/EFS.pdf

i'm curious (not arguing) why plywood was spec'ed for this. i would think mdf is a less resonant material and would be better. i imagine the bracing would level the field. so for the sake of curiosity, what would one loose real world if this was done in mdf vs 3/4" ply?

 

[jamie2112]

Tomorrow I am taking the sub to myer emco and play a little bit.I have a buddy who is going to let me a/b it with what they have. I am sure he is going to freak out when he hears this thing. I cannot stress enough that this thing has destroyed anything I have heard yet.......

 

[Matt34]

Tomorrow I am taking the sub to myer emco and play a little bit.I have a buddy who is going to let me a/b it with what they have. I am sure he is going to freak out when he hears this thing. I cannot stress enough that this thing has destroyed anything I have heard yet.......

Your resurrection of this build really has been leaning towards doing a pair of these again. I just need to find someone that can build them for me.

 

[avaserfi]

an interesting read on mdf vs a new "greener" panel product.

http://www.edesignaudio.com/pdf/EFS.pdf

Sounds like marketing fluff to me.

i'm curious (not arguing) why plywood was spec'ed for this. i would think mdf is a less resonant material and would be better. i imagine the bracing would level the field. so for the sake of curiosity, what would one loose real world if this was done in mdf vs 3/4" ply?

MDF is heavier and less stiff than plywood. So all things equal a plywood box will have less resonances and be lighter than the MDF box. Additionally, MDF is hazardous to work with due to the chemicals used to bond the fibers.

 

[armstrr]

sounds good. Plywood it shall be. Ply is much easier to handle than mdf anyway.

really, i hate mdf and love it at the same time. you can't beat it for its stability and crisp edges that rout well. a few months ago i ripped EIGHT sheets down to 4" and 3" strips for some simple trim in my basement. i had two industrial size garbage bags of dust from ripping them down. and yes, my friend and i wore respirators!

 

[just-some-guy]

i GOTTA quit reading this thread. that sub WOULD get me arrested.

 

[avaserfi]

i GOTTA quit reading this thread. that sub WOULD get me arrested.

The cop who heard mine built one....

 

[T2T]

Tomorrow I am taking the sub to myer emco and play a little bit.I have a buddy who is going to let me a/b it with what they have. I am sure he is going to freak out when he hears this thing. I cannot stress enough that this thing has destroyed anything I have heard yet.......

It seems like you're on the other side of the city - now, that's one listening session I'd like to hear at Myer-Emco. My last trip to M.E. didn't reveal too many *all that good subs*. Sure, there were Velodyne, B&W - I think that's it for brands. I don't recall the price of the top model, though. This was in the main speaker/sub listening room. I'm not sure if they have better subs tucked out into the other theater and higher end spots.

 

[T2T]

Sounds like marketing fluff to me.

Sure. Lots of it is marketing fluff when it comes to companies wanting to call their product "green". However, getting the formaldehyde out of the product was a major step. IMO, formaldehyde was too often used and many new homes would be full of it with some of the materials used.

 

[Guiria]

I have to ask since I'm considering some 15" drivers for a new sub build.

Given my design constraints below would you still recommend this sub over a sealed 15" design?

600 watts
No DCX, only BFD

 

[Matt34]

I have to ask since I'm considering some 15" drivers for a new sub build.

Is this sub still very good to excellent without the DCX? Down the road I may get a DCX but for now if I built this sub it would be with BFD only and 600 watts.

I think if you can handle the size of this enclosure, it will, in the long run be the better deal compared to the other subs your looking at in a sealed box. Especially if your stuck using the amp you have.

 

[avaserfi]

I have to ask since I'm considering some 15" drivers for a new sub build.

Given my design constraints below would you still recommend this sub over a sealed 15" design?

600 watts
No DCX, only BFD

Without the DCX you will need some sort of infrasonic filter. There are less expensive, less ideal, options such as the Reckhorn I have previously mentioned within this thread. The VQ with 600 watts and an infrasonic filter will be a superb subwoofer.

 

[annunaki]

Without the DCX you will need some sort of infrasonic filter. There are less expensive, less ideal, options such as the Reckhorn I have previously mentioned within this thread. The VQ with 600 watts and an infrasonic filter will be a superb subwoofer.

Though it will limit the low end response below 20hz (which I assume is the tuning frequency here) the Harrison Labs F-mod highpass filters at 20hz are a really cheap option. I believe they are around $30.00 or so. I used them on the BASH plate amp I did for lbolts20 as the enclosure was tuned to 21hz. They worked very well.

Due to enclosure roll off and the F-mods it was an effective overall 36db/oct. slope beginning at 20hz.

 

[Guiria]

Does the subsonic filter need to start at the Fs of the driver or the F3 of the box or neither? I understand the subsonic filter, just not sure what frequency the filter needs to start at?

 

[avaserfi]

Does the subsonic filter need to start at the Fs of the driver or the F3 of the box or neither? I understand the subsonic filter, just not sure what frequency the filter needs to start at?

20Hz max, 18Hz will be fine. These values are chosen based on how they limit driver excursion.

 

[Guiria]

Though it will limit the low end response below 20hz (which I assume is the tuning frequency here) the Harrison Labs F-mod highpass filters at 20hz are a really cheap option. I believe they are around $30.00 or so. I used them on the BASH plate amp I did for lbolts20 as the enclosure was tuned to 21hz. They worked very well.

Due to enclosure roll off and the F-mods it was an effective overall 36db/oct. slope beginning at 20hz.

The F-mods are only 12 db/octave slope which I don't think is steep enough. If the roll off of the enclosure is already 24 db/octave is another 12 db/octave sufficient?

If you buy 2 F-mods with their F-mod attenuator you get a 24 db slope but it doubles the filter frequency so I'd be rolling off at 40 Hz (no thanks).

I sent an email off to Harrison Labs to see what they say about an 18 Hz filter 4th or 5th order.

 

[Guiria]

... I recommend you put a second order highpass filter at 20Hz. This will act as a protection filter such that at high SPL at low frequencies (below 20Hz) there is minimal chance of the driver bottoming out.

So I guess 12db/octave is sufficient.

Answered my own question.

 

[jamie2112]

Myer Chumpco

Well my trip to Myer chumpco was a waste of time. The manager said because the cabinet was not stained or finished in some piano finish that he would not allow us to play with it in the store. It looks too much like homemade from what he said., I told him and my friend who set up the ill fated demo that this sub would smoke anything he had in the store and he almost caved. I am going up on sunday when the Manager is not in and me and Steve will play then. I am very dissapointed as I was hoping to post results here today. Oh well I am sorry but I will get it done.......Almost finished the 2nd sub, most likely by tomorrow night it will be running full on...