DIY Subwoofers For An Outdoor Nightclub

[stiffler359]

Hi Everyone!

Years ago (1994-97) I co owned a car audio company, where I was in charge of sub woofer design & construction. During that time I built literally hundreds of cabinets, several of which were used in competitive (winning) sound systems, and ranged from simple MDF sealed enclosures to complicated glass fiber reinforced dual reflex band-pass enclosures. Back then there was no internet, and my design software was literally hand typed using BASIC computer language. I got out of the business to get a "real" job & have regretted it ever since.

Fast forward to the present- I got rid of my real job years ago, and currently I co own a lighting & special effects company where I specialize in nightclub lighting design & installation. I also share a large, well equipped work studio with a furniture designer that I use for product development. Over the past year or so friends & colleagues have asked me to come out of retirement & help them with their systems, but it wasn't until recently that I really felt compelled to do so.

Which brings me to the topic at hand- Subs for an outdoor nightclub.

My current business partner is building an outdoor, rooftop nightclub that will also be used for private events, weddings, concerts, etc. As with every other nightclub project that I have worked on, little consideration was given to sound & lighting, so I have agreed to take this on as a pet project over the winter (the venue will open in the spring). While I no doubt have the skills & tools to build pretty much anything, I have been out of the industry and need some good honest advice regarding driver selection & cabinet design. I have spent the last several weeks reading the forums, and now I have paralysis of analysis. HELP!! lol

While I'm pretty sure I want to use a tapped horn design, I'm not sure which "style" would work best, or if it even matters. Additionally, I have not worked with any of the drivers that I see others using, so I have no Idea where I should be looking. I have spent a great deal of time on the parts express website, and just from the comments there it looks like B&C & RCF might be good choices, and Eminence might be a good cheaper alternative. Ultimately, the drivers need to either be cheap & easy to fix, or cheap to replace. As for the enclosure, while size really doesn't matter, my partner isn't going to let me stick 6 LABhorns up there. The subs will either need to be low & long (like under a stage/VIP area), or be large cubes (3'-4') that can double as dance platforms.

While I am not looking for festival level sound, it needs to fill a 100' X 50' area and survive the occasional dubstep track.

Thanks in advance,

Eric

[chris661]

SS15?

Loud to ~40Hz IIRC, and will stand plenty of power. Drivers are Eminence 3015LF.

All tapped horns need a high pass filter set to just below their lowest tuning frequency - the driver unloads completely below that frequency, resulting in lots of excursion, very little sound, and ultimately driver death.

Chris

[m R g S r]

It's more like a 50 Hz box. (The ss15)

For nightclub (EDM) id want something that digs down into the 30's. that's just me.

[stiffler359]

I had originally dismissed using horns because I really won't be able to couple them, but should I also consider this type of design (1 or 2 per side)? Many of the nightclub systems around here still use the EAW Avalon system, so I am very familiar with the DCS2 boxes.

[m R g S r]

I guess post the exact space you have to use first. Then we can see if a horn will even fit. A slim tapped pipe might work, or maybe a simple Bass reflex setup will better suit your needs.

[stiffler359]

The venue is still under construction, so there is a lot of flexibility regarding size. If we decide to line all of the subs up where a stage would be, I probably have 12'-16' of width, 6'-8' of depth & 1'-2' of height. If I mount them in the corners (2 or 4) they will need to double as dance platforms, and can be as large as 4' w X 4' d X 3' tall. I also don't see the owners spending more than $1500-2000 on drivers & wood, so that has to be taken into consideration as well.

[maxo]

Stiffler
take a look at this one nice powerfull 15" loaded Taped horn sub
that can be made with one sheet of 1/2" Birch Plywood

Single sheet TH challenge

check out the spl and freq response here on this table where are compared
to other subs even with 18's

Single sheet TH challenge

[Jack Caldwell]

I recently did a large sound system for a church, using 8 Eminence Alpha 15 per side. Mounted to the side walls in 12ft tall vertical line arrays, but with a twist - I made them "1/2 open baffle" on the side, that is, no enclosure behind the drivers, open on the side that aims into the room, and with the side that goes against the wall completely sealed. The front baffles are only 18"wide, so the housing that contains the whole thing looks fairly elegant and unobtrusive. I'll try to attach some pics in a subsequent post.

Due to their combined efficiency, running in series/parallel to present a 4 ohm load for the bass amps, these things can reach stunningly loud levels. They clock in at 107dB @2.83V at 1m, equivalent. to 104dB/1W/1m and their distortion at that level is extremely low.

Surprisingly, they extend much lower and flatter than what the sims predicted, and this without any eq. Mostly due to the coupling and the reinforcement from the side walls, their bass response extends down to 32 Hz without eq, and easily reach 20Hz with just a touch of added eq.

The impact and transparency of these things just has to be heard to be believed. They are easily the match for any bass horn I've ever heard, even the big'uns.

You could implement a similar approach and set them up as columns on the sides, or running along the bottom of the stage. It's a ridiculously easy and inexpensive build of course, but the payoff is in the sound. If you want you could easily slip in the Eminence Beta15, but they would need a little more eq.

Due to the line array configuration, the attenuation is proportional to the inverse of the distance, whereas a horn unit will attenuate relative to the square of the distance. The result is the bass projects to the back of the room with much less attenuation than a horn.
If you had the bass units running like this across the floor, with a 48 ft line array, with suitable series/parallel configurations to get a 2 ohm load, you'd able to create a bass section with over 115dB @2.87V/1m and peak levels exceeding 140dB within 25ft of the array! It could easily generate overwhelmingly loud bass throughout the whole club - but with a slam, dynamic linearity impact and clarity that need to be heard to be believed. Truly high end performance for pennies. And no big hulking subwoofer boxes to be seen!

[stiffler359]

I would be interested in seeing some pics, primarily because I'm not sure I understand. Thanks for the info though:-)

[epa]

Originally Posted by stiffler359

Hi Everyone!

Ultimately, the drivers need to either be cheap & easy to fix, or cheap to replace. As for the enclosure,

Eric

hi eric
imho ,its the wrong aproach.
what if the speaker breakes while your in the middle of a preformance.
youd better buy pro drivers ,and set it up with the apropriate filters and limmiters,and amps with enough headroom.
that wil last for years without problems.
b&c ,eighteen sound rcf beyma are the way to go.

for outdoor use i would indeed use a th with the low knee @35~40 hz.
i can help you to model something,or you could use one of the existing desings out here.

regards erik