Newbie here...
I'm planning on building Two sub cabs..I already have four 18'' woofers 750 watts each.....what else do i need? Please help
Type o f wood.......Etc ..Thanx in advance.
IAD
I'm planning on building Two sub cabs..I already have four 18'' woofers 750 watts each.....what else do i need? Please help
Type o f wood.......Etc ..Thanx in advance.
IAD
You seem to go for the heavy stuff 😉
You'll probably want to use 1" thick MDF for these babies.
What speakers are they?
/Hugo 🙂
You'll probably want to use 1" thick MDF for these babies.
What speakers are they?
/Hugo 🙂
You need to know what the thiele/small parameters of your drivers are. If you have the brand and model, you can look this up (probably). When you have those, you can determine the box type and dimensions.
Regarding wood, you'll want to use void free plywood. DO NOT USE MDF!!!!!! There is no advantage except for low cost, and they will be impossible to move. For a permanent install, it may be tolerable as a cost saving measure.
I hate to say this, but so far my experience is that this is a poor forum to ask questions related to pro sound and PA. There is a dearth of real experience, for the most part, and an abundance of speculation and misinformation. The requirements of prosound are very different from those of home hifi. You may want to google for some pro sound forums and usenet groups.
GB
Regarding wood, you'll want to use void free plywood. DO NOT USE MDF!!!!!! There is no advantage except for low cost, and they will be impossible to move. For a permanent install, it may be tolerable as a cost saving measure.
I hate to say this, but so far my experience is that this is a poor forum to ask questions related to pro sound and PA. There is a dearth of real experience, for the most part, and an abundance of speculation and misinformation. The requirements of prosound are very different from those of home hifi. You may want to google for some pro sound forums and usenet groups.
GB
I would second EVERYTHING Greg B said!
For a good site with plans and a small forum, look at http://www.speakerplans.com
But then, your drivers may or may not be suitable for these designs. The T/S-parameters should tell.
/Magnus
For a good site with plans and a small forum, look at http://www.speakerplans.com
But then, your drivers may or may not be suitable for these designs. The T/S-parameters should tell.
/Magnus
Greg B said:
I just mentioned it because it's easy stuff to work with.
I'll remember your considerations.
/Hugo 🙂
Could we get some more info before making an educated guess at what kind of cabinet you're going to build, and the purpose of the woofer.
Eg, what speakers is it exactely? Is it going to be used for mobile applications? Is it going to be used outdoors, indoors or both?
And in regards to wood. Plywood is the better option in almost all cases when it comes to PA. 3/4" birch ply braced internally with 1/2" spruce ply always yielded good results for me.
Eg, what speakers is it exactely? Is it going to be used for mobile applications? Is it going to be used outdoors, indoors or both?
And in regards to wood. Plywood is the better option in almost all cases when it comes to PA. 3/4" birch ply braced internally with 1/2" spruce ply always yielded good results for me.
I have pro sound experience- not on the national tour level but anyway, the best is to use 13 ply baltic birch. Sometimes its called finland birch or russian birch. It is pretty expensive but it is heavy and durable for pro sound use.
You can model the speakers in any bass modeling program. For PA use, the goal is not bass extension, most of them play only down to 40 or so Hz. Also theres almost no sealed designs, its usually ported, horn loaded and sometimes bandpass. Also prepare for the enclosures to be rather large.
Also, www.prosoundweb.com has an excellent pro audio forum, also read the LAB subwoofer forum. Start out by posting on the LAB LOUNGE, NOT the LAB classic board.
You can model the speakers in any bass modeling program. For PA use, the goal is not bass extension, most of them play only down to 40 or so Hz. Also theres almost no sealed designs, its usually ported, horn loaded and sometimes bandpass. Also prepare for the enclosures to be rather large.
Also, www.prosoundweb.com has an excellent pro audio forum, also read the LAB subwoofer forum. Start out by posting on the LAB LOUNGE, NOT the LAB classic board.
I'm going to also agree that you shouldnt use MDF. I hav used it for a couple PA cabs, and it just doesnt stand up to being moved around so often. You'll most likely want to built ported boxes. Download winISD if you haven't already.
T/S is not that important for PA drivers as bass alingment only becomes an issue under 50Hz, most PA driver dont run so low so dont worry about bass alingment to much.
The cabnet should be strong but light, weather proof or not? are you worry about the finish?
do you want grills, normally a good idea on PA speakers 😉
Lots of power means lots of heat
have fun 🙂
The cabnet should be strong but light, weather proof or not? are you worry about the finish?
do you want grills, normally a good idea on PA speakers 😉
Lots of power means lots of heat
have fun 🙂
Paradise_Ice said:
Wha??????
Tuning is extremely critical in pro use due to the power involved - get it wrong and you shed drivers VERY easily. I have seen plenty of examples where well-known manufacturers have got it wrong. BTW, why don't you think PA should run very low?
Moonfu, what are the drivers you are planning to use? Just because they might have a thermal capability of 750W doesn't mean they will be any good at low frequencies.
Also second the use of plywood. If the baltic birch is not an option, a marine grade plywood should be fine. You can even get away with constructional ply if the finish is not a big problem, and the cabinet is well braced.
Cheers
Ideally you would have decided on the cabinet design first, then obtained the appropriate drivers for it. As for the wattage rating, it is the single most overused yet meaningless driver parameter. as it tells you nothing about the drivers' performance.
As noted already only if you never plan on moving them. Baltic is nice, but not an absolute necessity. What you build them out of is far less than how you build them in importance.
True, but some of us have a clue. It's up to the poster to separate the wheat from the chaff.
It's OK, but not really attuned to DIY. And the Lab is the last box I'd expect a newbie to attempt.
Absolutely untrue. If you go with the default settings a program wiil go for the maximally flat alignment, and that is not what you're usually after in pro-sound. You can use a program to arrive at a jammed alignment that is good for pro-sound use, but not if you don't know what the requirements are.
Once again my down-under colleague has got it pretty much right on. I'd only disagree on the down-low part, as for the most part flat to 50Hz is quite adequate for pro-sound, the power requirements below that dropping drastically with the exception of some genres like hip-hop, or in the case of just plain bad taste.
Being that you have the drivers you'll just have to find out what their T/S specs are and then search for a design that will work with them, and then hope it is appropriate for the intended application. If not, chalk it up to experience and start from the beginning, finding a suitable cabinet design first and drivers for it second.
www.billfitzmaurice.com
BillFitzmaurice said:
I know the labsub forum is supposed to be about the labhorn, however inside there is usually always discussion inside that forum as well as the lounge about people DIY'ing subs.
As for the program, I feel you can use any bass designing box to model the system for freq response. While it may default to a flat setting, you can certainly use them to change box sizes, tuning freq/port size/shape/length to see the projected results. I usually use a few different programs to see what they all say. Of course theres other parameters like excursion/mechanical power handling vs thermal power handling but its all part of the learning process....
We are talking PA drivers and PA drivers are not that well known for the sub bass output and i have found that they are very low group dely and very un fussy about the enclosure, PA drivers just get on with the business of making loud music, and the music signal below 50Hz gets very hot indeed.
No wonder PA driver last hours with hundreds of watts passing over the coils 😉
No wonder PA driver last hours with hundreds of watts passing over the coils 😉
WHAT???? 😕 😕 😕 😕
True indeed, and personally I can not think of anyone here with better knowledge and experience than Bill in the pro sound bass department.
It has been said more elegantly in another threaf but building pro-sound stuff is NOT about just putting some drivers in a box and hope they will make the most noise.
/M
Thanks for the kudos. I try.
Well put, and very true. Two very well known examples of non-audio engineers who did just that are Leo Fender and Jim Marshall. As a result of their not having an audio background neither one ever built a bass cabinet worth beans. On the other hand, they built some great guitar cabs, the electric guitar being the one instrument where distortion is actually a good thing. The '59 Bassman 4x10 (which Jim Marshall copied) was likely the worst bass amp/speaker combination ever produced by a major manufacturer, but also perhaps the best electric guitar rig.
The venerable Ampeg SVT is another example of stuffing as many drivers as possible into a box and hoping that it works, though in this case it actually does. Kind of like the Phantoms I used to occasionally hitch a ride in, which proved that with a big enough engine you can make anything fly.
Well put, and very true. Two very well known examples of non-audio engineers who did just that are Leo Fender and Jim Marshall. As a result of their not having an audio background neither one ever built a bass cabinet worth beans. On the other hand, they built some great guitar cabs, the electric guitar being the one instrument where distortion is actually a good thing. The '59 Bassman 4x10 (which Jim Marshall copied) was likely the worst bass amp/speaker combination ever produced by a major manufacturer, but also perhaps the best electric guitar rig.
The venerable Ampeg SVT is another example of stuffing as many drivers as possible into a box and hoping that it works, though in this case it actually does. Kind of like the Phantoms I used to occasionally hitch a ride in, which proved that with a big enough engine you can make anything fly.
Very true, Bill is the Big Bull of PA on here, i would listen to him over anybody else, but thats not to say nobody esle can comment 🙂
Anyway PA drives with limited excursion do not have very good sub bass performance but thats not what there made for now is it 😉
Anyway PA drives with limited excursion do not have very good sub bass performance but thats not what there made for now is it 😉
On that point you're correct, the classic PA/MI driver has a combination of low Qts/high Fs/low Xmax necessary for high SPLs from small boxes. When you make a driver that way and load it into a direct radiator box it will play loud but what you aren't going to get is strong bass response. That was OK, as until quite recently a 50Hz F3 was considered quite acceptable in pro-sound.
However, what is being demanded today, from garage bands to pro-touring sound, is extended bass response at high SPLs. There's only one way you can get both, and that's with horn loaded enclosures.
Ten years ago the horn loaded box was dead; today they account for perhaps 80% of pro-sound subwooofer sales in the over $3,000 price range. But they aren't loaded with typical 15-18 inch PA/MI drivers; they're loaded with high excursion 10s and 12s that when horn loaded will get both the bass and the SPLs that today's sound requires.
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