Macdon's JL Audio 12W6v2 DIY

[mike c]

i have a friend who has this driver ... he needs help in designing his DIY

350watts input
21hz tuning ... should he go 20hz? (FR has a bump when going 20)

please check out these WinISD graphs to see if i made any mistakes:

4.5 cubes is already on the big side for him

i'm stumped on the port area though ...

he already has a 4" flared port:

how bad is the port velocity?

if he goes slot port, any port size recommendations? the idea is the 1st port resonance should be as high as possible right?

 

[WmAx]

i have a friend who has this driver ... he needs help in designing his DIY

350watts input
21hz tuning ... should he go 20hz? (FR has a bump when going 20)

please check out these WinISD graphs to see if i made any mistakes:

4.5 cubes is already on the big side for him

i'm stumped on the port area though ...

he already has a 4" flared port:

how bad is the port velocity?

if he goes slot port, any port size recommendations? the idea is the 1st port resonance should be as high as possible right?

Port velocity is unacceptable. I recommend using a slot port as large as possible. Keep port resonance at 110-115Hz range and it will be inaudible under normal subwoofer usage (crossed at 80Hz or lower, 4th order).

-Chris

 

[mike c]

what about the tuning? pros and cons of going 20hz from 21hz?

 

[annunaki]

There is next to no difference in the tuning frequency in terms of audible response.

I have sent him enclosure dimensions along with a proper slot vent option.

2.5" x 15.5" x 46.5" yields a vent velocity of just under 17 m/s with 500 watts of input power.

 

[mike c]

sent to who?

 

[annunaki]

sent to who?

You know who!

 

[mike c]

You know who!

got it thanks

 

[macdon]

I just wanna say thanks to MikeC, Chris & of course Rob for helping me out in this DIY sub project.

After checking with winISD, the Kappa box build should do just fine - all I did was lessen the port length to 50" than the original 55" as that is the plot of the winISD program tuned at 20Hz.

After doing some computations, sketches/drawings - here's what was derived:

Internal dimensions of the Kappa box - 6.125 ft^3

Port, braces & driver displacement - 1.76 ft^3

This gives me a net volume of 4.4 ft^3, which I am closely matching to the 4.5 ft^3 of winISD.

Hope to get started on building the box this week

 

[macdon]

My apologies for wasting this post - but I needed 5 posts before I can post any pics

 

[macdon]

Just thought I'd post some pics of the finished Kappa build.

Construction pics:










Finished pics:

With grille:



Without grille:



Graph:



System:
Powered by a Behringer A500 at about 400watts in bridged 8ohm and processed by Velodyne SMS1.

 

[annunaki]

Wow!

That turned out really well.

It looks great. I like your veneer!!

Some slight tweaking on your eq and you will be all set!

 

[macdon]

Wow!

That turned out really well.

It looks great. I like your veneer!!

Some slight tweaking on your eq and you will be all set!

Of course, many thanks to you Rob for helping me thru this project
Will email you again shortly for some recommendations

 

[jostenmeat]

Wow!

That turned out really well.

It looks great. I like your veneer!!

+1. It looks fantastic. That must have felt very rewarding for you to build.

 

[mike c]

Wow!

That turned out really well.

It looks great. I like your veneer!!

Some slight tweaking on your eq and you will be all set!

Annunaki,

what's the tuning frequency on this build? (i just remembered that his has a shorter port than the simple kappa build)

what subsonic filter should he set?

 

[jboogie]

Would you mind sharing some finishing details? Type of veneer, stain color, etc...?

Looks great!

 

[adwilk]

Seriously, Nice work on that build. It looks really fantastic. Something to be proud of for sure.

How does it sound?

 

[annunaki]

Annunaki,

what's the tuning frequency on this build? (i just remembered that his has a shorter port than the simple kappa build)

what subsonic filter should he set?

I believe the tuning frequency was 21hz. The infrasonic filter should not be set any lower than 18hz at 12db/oct. minimum with 18db/oct. preferred if using 18hz as a cutoff. Using 20hz one could get by with 12db/oct.

 

[macdon]

Would you mind sharing some finishing details? Type of veneer, stain color, etc...?

Looks great!

Thanks!

Nothing much special in the construction according to our DIY speaker master who did the enclosure for me.
It was a straight forward construction, rounded the edges & imported speaker vinyl was applied. Color of the vinyl is called "black oak".


Basically, it was a large long vinyl which wrapped the whole sub that started from the bottom of the sub, sides, top, sides till it meets under the sub. Then both front & back where vinyl covered separately.

Another 3/4" MDF was added to the face to make the impression that the sub is recessed, then another MDF was made like a frame & covered with black speaker cloth to act as grille to both the sub & port.

 

[macdon]

Seriously, Nice work on that build. It looks really fantastic. Something to be proud of for sure.

How does it sound?

Well, I came from a Paradigm PDR-10 and this is just my 2nd HT sub & a DIY at that, so for me the difference is worlds apart. While I am also familiar with other commercial subs like the Velodyne CHT-R series, i believe this DIY sub belongs to a different league altogether.

The opportunity of a sub that goes low due to the enclosure size is an experience that I didnt get/feel/heard from other commercial subs I've auditioned - much less the force & ramblings of something this size.

Because of this project, I got kinda addicted & went on to research how to make my experience even better. I dug deeper in educating myself with how the sub interacts within my HT room & looked for ways to both improve & prolong my experience - which is why I tested a Velodyne sms1.

If this was just an ordinary commercial subwoofer - I would've probably just plugged it in & be done with it

 

[sawzalot]

Very nice finished product, clean and professional, enjoy the rewards.