vented/ported/sealed... design help

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Hey everybody, I'm new to the forum and I'm trying to get information on enclosure designs for 18 in subs. I run a dance club with a rectangular dance floor that's about 1,000 sq. ft. I have 4 JBL JRX 125's that I'm flying, 4 EV 18's in single cabinets that are coupled, and 1 EAW LA 128Z all powered with Crown XTi series amps. I have changed the configuration a few times; stacked, staggered, corner loaded at each end of the room, and now I have them all corner loaded together at one end. Regardless of the configuration in this solid, concrete, rectangular room, I'm still finding dead spots and not getting the low end that my clientele are craving.

I'm looking to build an enclosure for all the subs to help get rid of my low end disappointment; whether it's 3 dual cabinets, 1 gigantic cabinet, or any other options that would work. Size isn't an issue and I'm pretty good and glueing stuff together. ;) Any calculations that anyone has, or pictures of enclosures that could help with inspiration would be greatly appreciated.

I am running a dance club that plays a lot of electronic music with that super low, feel it in your chest, bass. I'm trying to create the best dance club possible. We all know that if it sounds like crap and you get listening fatigue, you can't (and don't want to) stay on the dance floor shaking your booty.

Thanks for your time and any/all help or advise anyone has.
 
Not quite enough information. :)

Hi blewett,

"...4 EV 18's in single cabinets..."

Are these all the same drivers? Model number? T/S parameters? Xmax? Would you consider building something like two (big) dual driver tapped horns using these drivers (provided they look promising)? What's your general budget?

Here is a design that might apply: http://www.diyaudio.com/forums/subwoofers/189784-gjallerhorn.html

You may want to do a little measuring to see what you are shooting for, e.g.: the JBL JRX 125's don't have much (any?) low end, so they would give you your general music SPL. If that's loud enough you could use that value as a target level to see how much you need to add at the sub level.

And, what Dave said:
http://www.diyaudio.com/forums/subwoofers/134568-multiple-small-subs-geddes-approach.html

Regards,
 
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Dave and Oliver, I have moved the subs from corner to corner, staggered along the big main wall, everything short of flying them (which would be -8 db or something. lol) We used to have a big vented box that was slotted in the middle, the sub itself was in the slot with the cones pushing air into the box. We called her Bertha, she was around 65in tall, 50in wide, and 30in deep. (If my description of how she was built doesn't make sense, I can do a rough drawing and upload it.) She died and that is when we got the EAW to replace her, since then it just has not been the same. Cancelation zones aside, we just haven't been able to reproduce the low end that we once had.

When it comes to drivers one of our "expert" DJ's that thought they knew everything, got into my office and turned the limiter up to something like +15 and actually fried the EAW's before they were even 2 weeks old. I've been taking my blown subs to Around the Sound in Seattle, WA to be repaired; cool old guy, super knowledgable, and does a great job with re-coning and fixing fried coils. 2 of the EV's are ELX 118 passive subs and the other 2 EV's are older generation T-18's, they load from the front through the grate and face up. The boxes are at least 10 years old, air is blowing through the 1/4" jack in the back and they just don't sound as good as they used to. I don't know if all the mixed matched equipment could be causing cancelation and if we put everything in the same enclosures if it would help uniform and tighten our low end up. When it comes to space and money, there is a fair amount of both for this project.

Thanks to both of you for responding, any information and direction I can get is greatly appreciated.

-Kemmeth
 
You run a club?
You have DJs that are allowed to play with your limiters?
You want the best sound "in the world" ?

I strongly advice you go to some professional sound company in your area in order to get a fast and solid solution.... Running a club is about making money (or losing the club if you don´t make any), you should not risk anything by trying to gain knowlege in an internetforum - this is fun, but takes too much time.. Obviously, you are at the very beginning of learning abot pro-audio. Get some local help. Some guys that can move some gear in the club, show you how what is done, how room problems can be dealt with, what amount of money has to be spend to acheive which result...

"The best club" will be very relative afterwards, but you will have your problems solved :)
 
Hi blewett,

Well, obviously Sabbelbacke makes a very valid point, but anyway....

Your description of the condition of the assorted subs makes me wonder if it's just the room. The ELX 118 are bass reflex designs, and the T18 is not quite a tapped horn or scoop, and both designs aren't much below 50Hz. Your reconed EAW LA 128Z are, well, reconed, so they may be up to spec or even better, who knows? But it's another bass reflex design w/ ports that look like they would choke at low frequencies and high levels. The JBL JRX 125's don't add much to the low end, actually you would want to keep the low end out of them.

Big Bertha sounds like a nice size subwoofer, so you could contemplate building a dual 18" tapped horn for the very low end. Maybe something similar to the dual 12" DTS-10 just wider, e.g.: 60" x 48" x 24" (I'm just using this as an example, you don't want to just copy any design that was intended for a different driver):

Danley DTS-10 "Super Spud" DIY kit - AVS Forum

You could have your re-coner test the drivers in your EV T-18's for their T/S parameters. From that a test box could be designed to give this a try. Naturally, if your budget is sufficient I'd still recommend the Gjallerhorn (see link in Post #3), or maybe the Othorn: http://www.diyaudio.com/forums/subwoofers/193418-othorn-tapped-horn.html

But, you'll need at least one of these cheap SPL meters:

New Digital Sound Pressure Level Meter Tester Decibel Noise Measure 30 130 DB | eBay

Then, stick your EAW's in a corner, power them up w/ 1/3 octave warble tones, and get an idea what the SPL(s) is around the room @ different ranges.

A sketch of your layout wouldn't hurt either.

Regards,
 
No sub that goes to 30 hz (or really you're missing the strong 38-42 band, that's the physicality you're missing) is your problem. If I were you I would either order t60's, build t60's (see billfitzmaurice.info for more info) or if you're feeling adventurous you can try turning your existing drivers into single fold tapped horns, seeing as you have size at your disposal it is really easy to come up with a low compression ratio horn with low 30's hz extension(i spectrum analyze club edm on a daily basis, what you need is strong 35 hz extension) i have come up with two designs that are catered to that extension but they both require a specific (alpine sws or swe series) driver. The same can be built with B&C drivers but I don't have that kind of money. You need a horn to really hit those low notes at max output because most pa subs just aren't designed to go that low. If you can figure out the driver I the subs you have I'll come up with a recommended design for free or let you know that it doesn't model well if that's the case. Feel free to message me if you'd like to know more about a custom design. I could even cad out a design if necessary but we can talk about that if it comes to it.
 
Dave and Oliver, I have moved the subs from corner to corner, staggered along the big main wall, everything short of flying them (which would be -8 db or something. lol) We used to have a big vented box that was slotted in the middle, the sub itself was in the slot with the cones pushing air into the box. We called her Bertha, she was around 65in tall, 50in wide, and 30in deep. (If my description of how she was built doesn't make sense, I can do a rough drawing and upload it.) She died and that is when we got the EAW to replace her, since then it just has not been the same. Cancelation zones aside, we just haven't been able to reproduce the low end that we once had.

When it comes to drivers one of our "expert" DJ's that thought they knew everything, got into my office and turned the limiter up to something like +15 and actually fried the EAW's before they were even 2 weeks old. I've been taking my blown subs to Around the Sound in Seattle, WA to be repaired; cool old guy, super knowledgable, and does a great job with re-coning and fixing fried coils. 2 of the EV's are ELX 118 passive subs and the other 2 EV's are older generation T-18's, they load from the front through the grate and face up. The boxes are at least 10 years old, air is blowing through the 1/4" jack in the back and they just don't sound as good as they used to. I don't know if all the mixed matched equipment could be causing cancelation and if we put everything in the same enclosures if it would help uniform and tighten our low end up. When it comes to space and money, there is a fair amount of both for this project.

Thanks to both of you for responding, any information and direction I can get is greatly appreciated.

-Kemmeth

Two things, if there is air flowing through a 1/4 inch jack than it was improperly designed or got damaged, fill that with epoxy, a plug, or PL as soon as possible as it leads to less low end and potential driver failure. Different designs have different phase response so yes, having different sub cabs and potential out of phase subs (did you check polarity when trying each of the locations?) could be part of the issue.
P.S. That ELX is -10 dB at 35 Hz and thus is a 50 Hz box --> This will not impress playing EDM. Trust me I have a 45 Hz FLH and even that leaves me with considerable amounts of "missing bass". I since built a 25 Hz FLH and thus know what it should have sounded like. In a club sub 30 hz is pointless if not downright dangerous (neighbor complaints from really low notes can be issues) but the power band from 32-42 or so really makes a difference.

Commercial options I know of that could fix your bass issue tend to run 2k per sub (the Dual stx jbl is one option). The boxes I would suggest building run about $550 per box in parts (2 quad 12 driver cabs would absolutely deck a club, we're talking 120 dB in the middle of the room down to 32 Hz kind of loud)
 
This is the ground plane response graph at full power (4.4kw full tilt) for the pair of boxes close coupled. This is 2 pi so no boundary loading is taken into account. 400 L per box internal (I'd guess about 520 L external aka 18.2 cu. ft or smaller than your average dual 18) but this would be a tall (~60 inch tall) wide (28-30 inches or so) and shallow box (roughly 18-20) that would stand upright and fit well against a corner or wherever realistically.

If you're into building your own boxes this would be how I would go, you'd spend 500 bucks or more just buying the Driver for a pro cab.

Those ELX subs aren't designed with extension or extreme power in mind and they are quite inexpensive at 500 a pop (considering). However, I don't think those drivers put into horns would work as well as selling what you have for subs (after buidling and testing a from scratch design) would be a better approach than trying to scrap drivers from cabinets. You can get more money from selling complete subs which you can put towards DIY than you can disassembling and repurposing them. You won't want to mix horns and direct radiators so whatever you build would probably have to replace your current subs.

Considring you already have >3k invested in subs I would highly recommend a DCX2496 for processing and limiting. I've never blown a driver when properly limiting my subs (I'm sorry for your DJ incident, they should be locked out permanently from advising levels or touching anything electronic). This is with a DJ permanently slamming my limiter whom I almost asked to leave he was so bad at level management...
 

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DCX is fine, but if he really runs a professional club, he should go get more professional gear. I love the DCX for it´s price/value ratio, it´s many features and it´s easy to use, too. I had about 20 of them myself, still use 3 in small racks and repaired hundreds... Even a vew are still in clubs..

BUT:

- It´s limiter section requires exact know how what it does since from the beginning there is da design flaw on the db-Range its using. (No Problem, if you know what you are doing and know of the fact and how to get around it).

- it´s internal wiring tends to break up after some time - some devices don´t show this for years, some get the phenomenom after a few weeks... So the flat-wiring should be replaced and fixed before the unit goes into a professional space... And again - this is more a DIY Issue.. takes time and knowledge he doesn´t have.

- The DCX is fine - but "best sound in the world" club deserves more... much more... Look for XTA, Ashly, the big dbx units (not the $200 Budget thingis), Xilica, etc.. (yes, those cost money... a lot. .. )

AGain - if we are really talking about a professionel environment, he really should go get some guys that are at his location. Someone he can grab if at night something is failing... you need guys that have the experience on how to deal with long-term high-power use and how to correctly setup limiters, etc... The guys that do this business every week for years are the once you have to talk to.

Maybe you should clarify your position and what kind of club we are talking about. If this is more like a hobby project of a club (which is great), than we can go DIY :)
 
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Saddelbacke, My club has been up and running for over 30 years under one owner. I myself have been there for 11 years and hope to own it some day. As for a DJ touching the gear, there was one time that someone forgot to lock the office where the rack is kept and someone decided to mess with the levels. That DJ no longer works at the club and since then that door is always locked.
Yes, I am fairly new to pro audio and pro lighting, I have been doing it for about 4 years now but I enjoy looking at what other info is out there and getting opinions, advice and general knowledge from those who know more than me. I do have some understanding of sound and gear, at home I have a marantz receiver with a pair of focal chorus 726 with a Rel T9, it's not pro stuff but it has good clean sound.
As for the dead zones on the dance floor, the guy's at Reference Media introduced me to this guy with 20+ years of sound setup experience come in and gave me a lot of advice. Reference Media is a local hi-fi audio store that specializes in high end theater systems. He gave me a lot of pointers and I have been moving subs around the room in pairs, not in pairs, corner loading, in the middle, and staggered along the one long concrete wall that can be used. (I have to be careful with placement because drunk people are drunk people. Lol.) The part in my original post about the dead zones was meant as a side note, I was mainly asking about different enclosure designs and if what I have is compatible.
I build pretty much everything in the bar myself, I make and run all the xlr and dmx cables for our lighting and sound system, I spend my holidays there, refinishing bar tops and re-doing the floors with an anti-slip paint because we live in a world where everyone is sue happy. I am currently designing a lounge in our coat check room that will have a pole in it and can be rented out for private parties. I need to build a new bar in it as well. On top of all the other stuff, I bartend 5-6 nights a week and we never do less than 200 people through the door except the occasional Sunday. On busy nights we push over 1000 people. I do not want the best sounding club "in the world" and I never said that. The club "Q" right down the road in Seattle and their sound is amazing, they have a function 1 system.
I just want to make the best, most informed decisions I can. That's why I posted on here, to see if someone had any good designs, suggestions, ideas, or anything that might help. I want to know if I can use the drivers I have to help get the low end like we had with Bertha, I believe she was a bandpass system. The jrx 125's and 225's seem to be plenty loud enough and I would think that with the right enclosures, six 18's should be making people hit the brown note. One of my DJ's just built a pair of bills 12' tubas they are super loud and seem to go pretty low but it seems our EAW goes lower but not as loud. The best configuration I have found is everything centered along the long concrete wall of the room. So I was thinking about building something similar to bertha with a trapezoid shape. I have about fifteen feet of wall and about three feet of depth and as tall as you want. All in all I am looking for possible designs and people's helpful opinions on what I can do myself. The more info and input I can get, the better. I want to make my establishment memorable and keep people coming back. "Best in the world" is not what I said or meant, I said that I want my club to be the best club possible, as in the best it can be with what I am working with. If you are intrested in seeing the club we have a web site and are on (the social stalking site) facebook. The name of the establishment is Rumors Cabaret in Washington. (No we are not a titty bar but an alternative anti-hate establishment.

Thank you for all your time
Kemmeth
 
No she is gone over years of foam parties she was water logged and just done... But I have the go ahead to spend sone $ and build new cabnits. I think I am going to go with the same design just need to figure out the equation to see how big she well need to be and I think she was a bandpass vented hybres of some sort. ..
 
@blewett
Thanx for the detailed information. This gives a clearer picture of your situation.
Don´t get me wrong, of course I want to help, too... But I(we) can only deal with the information you give us and your first post gave an impression which is different from what you are writing now. Now the situation is much clearer to me.

Could you provide a drawing of the floor und state which materials are used on the floor, ceiling and walls?
Which Budget do you have at hand, which budget could be used in the next year (ofr a step by step solution)?
Exactly what equipment is installed right now? Speakers, X-Overs, Amps...
 
I've heard of a lot of people using dcx 2496 in a pro environment with a backup one completely setup so if it breaks your backup is a 5 minute fix. Seeing as a stationary processor would probably have at least a 5 year lifespan I find it cheaper to have a backup and use the dcx than spend 4x on a 'high end' one. Sure there is better but that gets back to the budget question, imo while you're sub designing you should eq the jbl's to the room, it will make them sound considerably better. All that costs is a processor and umk mic with rew. You're best bet considering that you don't know the t/s parameters of the drivers you have is to go to someone who has the equipment and measure them yourself. Keep all like drivers in seperate cabinets meaning in a given box don't mix and match driver types, that would be nigh impossible to limit properly. You can totally go with a bandpass design but I strongly suggest a tall simple tapped horn as the design because they are as easy to build as a box with the exception of one angled cut for the baffle, and will get you more output and sound better at high levels than any bandpass box.
 
Also, pro sound people are still human beings, they aren't perfect and while yeah its easy to say oh just hire pros, I'd like to think that the combined knowledge of this forum can give a better suggestion than they can which we all know will be : buy funktion one. In all honesty to get the sound you desire it may require 2 dual t60's, those aren't the tubas your friend built, trust me, these monsters go to 25 loud and assuming your dance floor isn't 100 ft long they will be loud enough. You. May be able to tapped horn your existimg drivers but there lies a grey area, if you don't know the mechanical limits of the driver it is hard to design around because you have no clue how much excursion they can take. Power limit can be looked up easily in spec sheets but unless you can identify the driver they are using or have a klippel you won't know the excursion limit. If you want bullet proof clunky level bass I would (besides bill's t60's) recommend investing in B&C sub drivers to design your horns around as that is what they use in a lot of high end (5k per box) subs. Also then you know your subs are overbuilt and can withstand some thrashing worst comes to worst.

People have commented multiple times that DR280's with T60's can go toe to toe with Funktion one, if not best it in certain ratios. If you're not comfortable with the complexity of the build then there are dedicated cab builders that will build it for you. Dual T60 runs 2k, so a pair of those would be 4k. You'd need a total of 1600 watts into 4 ohms (two channels of 800) and that would be all.

Again, you can design your own cab with the 18's you've got but you have maybe a 30% chance that they will even look decent in a horn loaded enclosure, horns are picky about drivers.
 
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Maybe we have different definitions of "pro sound"... of course there are those guys who have fun buliding speakers, know a lot about how they are built, how to use hornresp and did so many cabs, that they are able to get results which are superoiur to tthe vast majority of stuff you can buy... These guys are also able to merge a mini-DSP Plate thingy with a PC/Raspberry pi, do a android remote APP for this.. etc.... I am one of these guys and I know a lot of people like this. It´s fun, it´s great, yeah....

BUT

Most of our customers are pro-Sound guys. Does means:
They do nothing else to earn their money.
They are driving very big trucks, every day.
They have to move tons of equipment, every day.
They are not simple people who know what they do - they had years of education on these matters (don´t know about the US, in Europe, there are schools for this kind of business).
They buy tools that have to do theyr job. Every day, 20 years...
If something is´nt working, they don´t go fix it themselves - they have a contract with the company that dry-hired the 96 Subs to them - somebody is coming within half an hour and gets everything fixed
All equipment is tested, every year (TÜV, etc...). This has a lot do do with insurrances.
If a Xover is included in a System, its not only important that it does it´s job - it needs to be able to talk with the 30 Digital consoles that are at stock. So if Dante is there, Dante is what you buy.
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at some point, 500 Dollars more or less simply isn´t the point any more... Of course - this is not the DIY World anymore.. This is the world where meyersound sells 40 Subs at one time to a company...

And there are clubs that work this way... Instead of someone in the club just "getting it right", there are contractors which deal with all the 40 locations of the club-franchise. People like this cost money... And it´s easy to see that it´s cheaper to get euipment which has a much lesser probability to fail then to call up the service guy all the time...


This is what I mean by "pro"... Of course, there are tons of people out there doing a very good job, makinh great sound, know exactly what they do, builiding they cabs, using behringer DCX (and fix the issues by themselfes (like me)), reconing the speakers by themselfes......



Ask a company how much they want to build a house - then check out how much the material would cost you to do it yourself - and then ask a craftsman (correct term in english for a "bob the builder guy?") what he is paying for the concrete, screws, woods, handsaw, etc.....

If the house falls apart - what can you do if a company did it?
If you did it - what then


etc....

In Pro-Sound (Big ones), the price often is not the first priority...

DCX... Yes, I have some DCX still installed in some locations. I fixed the design flaws, so everything is ok. All my other fellow collegues who used DCX replaced them with something different, because they got tired of the failures. And yes, after a few years, theyr clubs ran so well that it was no problem to replace it with something better....

Among these guys, I am still the one holding on to the DCX, because i like it - and because I can fix it...

While all others actualy go buy F1, we go for DIY Stuff in our club....

ok, back to topic.

If you have some more detailed info, I can help you better. See my last post.
 
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