I need a super portable sub for DJing in remote locations (beaches, islands, camping, etc.). 15-30 people. Keep in mind this is running off small generator power. I don't want to go over 150-200 watts on the subwoofer amp.
I was thinking of using this amp: http://www.parts-express.com/pe/showdet ... er=301-504
Or even better the $69 100 WATT version. I know the driver must be super efficient for this option.
I would like it to be no bigger than around 24" x 20" x 18"
I know there will be compromises, but I would like some decent SPL from 120hz down to around 50hz.
Will it produce decent output (112-115db) in these outdoor locations?
Thanks.
I was thinking of using this amp: http://www.parts-express.com/pe/showdet ... er=301-504
Or even better the $69 100 WATT version. I know the driver must be super efficient for this option.
I would like it to be no bigger than around 24" x 20" x 18"
I know there will be compromises, but I would like some decent SPL from 120hz down to around 50hz.
Will it produce decent output (112-115db) in these outdoor locations?
Thanks.
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So far I modeled this 6th order bandpass using the Eminence Delta 12 (Sensitivity 93db)
What do you think?
http://i40.tinypic.com/5cx3xz.jpg
What do you think?
http://i40.tinypic.com/5cx3xz.jpg
So 5 cu ft external volume.
Use well braced 1/2" Baltic birch, tune to 45hz and a simple 18" woofer with a lite cone. I mean for $100 on this bad boy, it seems like a good option to me...
Celestion 18" Cast Frame Professional Woofer 8 Ohm 299-420
Use well braced 1/2" Baltic birch, tune to 45hz and a simple 18" woofer with a lite cone. I mean for $100 on this bad boy, it seems like a good option to me...
Celestion 18" Cast Frame Professional Woofer 8 Ohm 299-420
I wouldn't bother with the 6th order bandpass. They are too difficult to tune the ports (WinISD is not very accurate with 6th order BP). Also, even when you do get them tuned they suffer badly with power compression. Sound great for the first hour or so but played loud they start loosing sensitivity, resulting in volume being turned up which makes them worse!
My attempt with a 6th order bandpass:
http://www.diyaudio.com/forums/subw...e-15-600w-dual-voice-coil-subwoofer-pa-2.html
You might be able to work out a taped horn for your cab volume, I doubt it though and then you will need some form of low cut/high pass filter. With your plate amp options (no low cut) I would go for a compact 15" using a PA driver in a well designed box with large vents to avoid power compression. Using a driver that will take 700W and then only supplying with 200W would probably work well if it's around 97db.
m R g S r, that Celestion 18" looks great, but the description does say that it requires 7.5 cu ft. for 45hz.
Also m R g S r, that Celestion is 8 ohms. That amp is designed for a 4 ohm load. And it sounds like that cabinet will easily weigh more than 50 lbs.
I was also considering a BFM Jack 112. Building it only with the woofer as a pure sub.
Looks like it's ultra sensitive and gets down to around 50hz with one 12" woofer in a 18'x 18' x 22' cabinet. Weighs in at 40 lbs.
What do you think?
I was also considering a BFM Jack 112. Building it only with the woofer as a pure sub.
Looks like it's ultra sensitive and gets down to around 50hz with one 12" woofer in a 18'x 18' x 22' cabinet. Weighs in at 40 lbs.
What do you think?
Hmmm...
The MCM site seems to be down at the minute, but I'm using a pair of these
Amazon.com: MCM Audio Select 55-1455 8'' Dual Voice Coil Woofer: Car Electronics
In a ~22L enclosure, tuned to 49Hz.
I'm using the dirt-cheap 12v class D boards off eBay - 15w/ch.
WinISD reckons if you use 4 of those woofers (you'll need a 44L box) and all 60w, you'll hit around 115dB peaks.
SPL at 50Hz is down a little, but there's plenty of kick in the 80-120Hz range, where you'll actually feel it. Going low outdoors is only an option if you've got plenty of speaker cone, and lots of power.
A pair will do ~109dB peaks, which IMO is plenty: its loud and clear over 50m away.
Chris
PS - I can get about 9 hours at full-tilt from 12v 10Ah of battery, no real need for a generator
The MCM site seems to be down at the minute, but I'm using a pair of these
Amazon.com: MCM Audio Select 55-1455 8'' Dual Voice Coil Woofer: Car Electronics
In a ~22L enclosure, tuned to 49Hz.
I'm using the dirt-cheap 12v class D boards off eBay - 15w/ch.
WinISD reckons if you use 4 of those woofers (you'll need a 44L box) and all 60w, you'll hit around 115dB peaks.
SPL at 50Hz is down a little, but there's plenty of kick in the 80-120Hz range, where you'll actually feel it. Going low outdoors is only an option if you've got plenty of speaker cone, and lots of power.
A pair will do ~109dB peaks, which IMO is plenty: its loud and clear over 50m away.
Chris
PS - I can get about 9 hours at full-tilt from 12v 10Ah of battery, no real need for a generator
If you go with class D car amplifiers and two parallel'd 12V batteries for power, you can up that power limit significantly and do without that generator for hours. And with just a little bit of work, you could come up with a solution that allows you to plug the rig into the car to recharge if needed.
FWIW, I used my Blastoramas and my POC TH sub based around the Dayton PA310 to provide music for a larger group (50+ people) using just class-D car amps in my car for power (the amps are Alpine PDXs, which provide a quick means for connecting speakers). I didn't need a super long run time and the system wasn't played at the highest level so the car's stock battery served me fine. The arrangement fed 75W each to the tops and about 500W to the sub.
If you are going to use a DJ mixer and inputs powered from a 120v/240v inverter it won't play nice with car amps off of the same power source , buzzzzzzz... back to the gennie.
Not so fast - I've powered a laptop running Virtual DJ off a 300W inverter and connected to the same system without any noise issues, so I don't see how you'd get worse results with a pro DJ system powered the same way. In any case, the target audience here is just 15~30 people - is a full DJ mixing board really required?
Interesting, Iv'e tried on numerous occassions to power 12v car amps and an inverter with 240v inputs off of the same battery and it always results in inverter switching noise going through the amps. If you have a solution please share.
The 15" celestion PE buyout in a BR cab might do the trick. Nice price and 98db!
Celestion 15" Professional Woofer 8 Ohm 299-418
Brian, will have to try that, maybe the USB soundcard is providing the isolation.
Celestion 15" Professional Woofer 8 Ohm 299-418
Brian, will have to try that, maybe the USB soundcard is providing the isolation.
well It's 5.8 ohms, near enough and anyway the 98db sensitivity will make up for the lower power usage ;-)
In the reviews there is someone using it in a 5.8cu ft cab. Seeing you only need 50Hz it should model fairly well. It could be a simple and cheap solution with one of those plate amp options.
In the reviews there is someone using it in a 5.8cu ft cab. Seeing you only need 50Hz it should model fairly well. It could be a simple and cheap solution with one of those plate amp options.
The Celestion 15" Professional Woofer 8 Ohm 299-418, it just doesn't work in a (OP) 5 cubic feet/~142L vented cab. I mean, F-3 dB=44 Hz for a sub with big lobing at 70-80Hz. So, I would rest my case with a bigger cab like is suggested from this previous post (5.8cuft) as it minimal limit for a driver requiring double that volume (300L). Good suggestion.
Another variant in a same sized cabinet VB = 127.7 L, LAMBDACOUSTICS TD15H, >94.0 dB. (If you are in the US this is the best suggestion, hands down.)
Or in another version, smaller cab (VB = 95.5 L), more SPL/sensitivity>96.5 dB, BEYMA SM115/K.
Another variant in a same sized cabinet VB = 127.7 L, LAMBDACOUSTICS TD15H, >94.0 dB. (If you are in the US this is the best suggestion, hands down.)
Or in another version, smaller cab (VB = 95.5 L), more SPL/sensitivity>96.5 dB, BEYMA SM115/K.
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how about this: Eminence Delta-12LFC 12" Driver 4 Ohm 290-464
in a 4.4 cu. ft. vented tuned to 36hz ?
looks mighty fine.
in a 4.4 cu. ft. vented tuned to 36hz ?
looks mighty fine.
F3 will likely be a bit above 50 Hz due to that fairly low Qts and high Fs.
Looks like it might be a good match for a ~40 Hz TH though.
a 24" x 18" x 18" cabinet would be ideal. Small and portable.
this will give me 3.84 cu. ft. internal if I use 1/2 inch Birch ply.
subtracting for basket and port etc. I could end up with around 3.2 cu. ft.
a 3.2 cab tuned to 48hz will give me a flat response down to an F3 around 44hz.
Not bad for a small cab. What do you think? SPL would be good with 200 watts?
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this will give me 3.84 cu. ft. internal if I use 1/2 inch Birch ply.
subtracting for basket and port etc. I could end up with around 3.2 cu. ft.
a 3.2 cab tuned to 48hz will give me a flat response down to an F3 around 44hz.
Not bad for a small cab. What do you think? SPL would be good with 200 watts?
>
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