Hi there, i'm new to this place, seems like a helpful one too. So I ask you please help me out if you can?
I currently own 4 - 2 x 15" reflex cabs, the dimensions are 60x60x85cm. I will place a good 5-6cm of insulation inside them, but I am unsure as to which drivers would best suit them? something around just under £100 per woofer would be great, and if I can get near 1000w rms each side from a pair then I will hunt for that.
However, I understand that you can't just stick in any powerful woofers, and so some expertise on what woofers would be good with the size of these cabs, would be great.
Point to note, there are 4 port holes with no piping in them, so depending on what drivers I get, I will make the length of them suit.
I've seen some Eminence delta 500w LF's ... any good?
Any help would be great, sorry if it makes no sense i;m so very tired!
Cheers,
Tom
I currently own 4 - 2 x 15" reflex cabs, the dimensions are 60x60x85cm. I will place a good 5-6cm of insulation inside them, but I am unsure as to which drivers would best suit them? something around just under £100 per woofer would be great, and if I can get near 1000w rms each side from a pair then I will hunt for that.
However, I understand that you can't just stick in any powerful woofers, and so some expertise on what woofers would be good with the size of these cabs, would be great.
Point to note, there are 4 port holes with no piping in them, so depending on what drivers I get, I will make the length of them suit.
I've seen some Eminence delta 500w LF's ... any good?
Any help would be great, sorry if it makes no sense i;m so very tired!
Cheers,
Tom
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Still no replies..
Download WinISD Pro, and play around with some different drivers. The Eminence drivers are generally known to be decent: I'd told they're very difficult to kill.
I suspect that a pair of 15"s in a cabinet that small won't produce any real bass, but plenty of "kick" in the 120Hz region.
You might be better off blocking one of the driver holes, and using one driver per cabinet: you'd have a much better chance of getting some <80Hz stuff out of it. Consider blocking some of the ports, too (WinISD will be able to tell you what to do with them).
Chris
Download WinISD Pro, and play around with some different drivers. The Eminence drivers are generally known to be decent: I'd told they're very difficult to kill.
I suspect that a pair of 15"s in a cabinet that small won't produce any real bass, but plenty of "kick" in the 120Hz region.
You might be better off blocking one of the driver holes, and using one driver per cabinet: you'd have a much better chance of getting some <80Hz stuff out of it. Consider blocking some of the ports, too (WinISD will be able to tell you what to do with them).
Chris
Thanks for the reply 
Well I did some playing around, and with some Delta 15 lf 500w drivers (2 in each cab) it reckons I can get a solid 70-80Hz. Which tbh, from 15" in a small cab, isnt bad I don't think. Lets hope the maths doesn't lie.
For me 70-80Hz as my first system, ill be pleased with
Oh has anyone got any advice on tweeters or 2" comp drivers? my flare dimensions are 390mm x 240mm, but I can't seem to find a a flare that size. But ill keep looking. Can anyone suggest a good 2" comp driver?
Well I did some playing around, and with some Delta 15 lf 500w drivers (2 in each cab) it reckons I can get a solid 70-80Hz. Which tbh, from 15" in a small cab, isnt bad I don't think. Lets hope the maths doesn't lie.
For me 70-80Hz as my first system, ill be pleased with
Oh has anyone got any advice on tweeters or 2" comp drivers? my flare dimensions are 390mm x 240mm, but I can't seem to find a a flare that size. But ill keep looking. Can anyone suggest a good 2" comp driver?
given the size of the cabinet is approx 118 Liters per driver you could probably tune for a lower response than 70hz. Driver recommendations are usually dependent on your location. I suggest you add your location to your profile as this is a global forum!
Practical port size depends on what you can fit in the cabinet. Personally I would probably try for at least 6 X 10cm diameter ports for a double 15" to keep the port velocity down.
A pair of Eminence Kappa Pro15LF2 should be capable of a -3db response at 40Hz in this sized cab.
Practical port size depends on what you can fit in the cabinet. Personally I would probably try for at least 6 X 10cm diameter ports for a double 15" to keep the port velocity down.
A pair of Eminence Kappa Pro15LF2 should be capable of a -3db response at 40Hz in this sized cab.
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You will need some plastic drain pipe or similar tubing. See what you can source that will fit on the speaker baffle and use that to size the port holes. From that you can then calculate the total cross sectional area of the port. The ports need to be longer as the area increases. The small ports are probably sized to just use the thickness of the speaker baffle, unfortunately this makes them ineffective at higher power levels as the port velocity is too high.
Wadding is not necessary for a sub. What frequency are you planning to use as the upper frequency limit for the 2 X 15" cabs?
Wadding is not necessary for a sub. What frequency are you planning to use as the upper frequency limit for the 2 X 15" cabs?
These guys sell quite a range of Eminence, Fane and Faital Pro drivers, and their prices are decent.
I hadn't looked so closely at the cabinet volume - looks like there's plenty there (I've seen other 2x15" cabs where the drivers barely fit in the cabinet, and assumed similar).
The driver that Xoc1 has suggested will do about 125dB per cabinet, down to ~40Hz.
You could run a 1kW amp into it fairly safely: excursion goes to ~8mm one-way around 60Hz (that's probably the most I'd ask from them). The progressive suspension used in most PA drivers ought to stop them bottoming out, but listen carefully to check if the drivers are being abused.
For high power use, adding a low-cut filter below port tuning is mandatory. The cabinet provides no resistance to the cone motion below Fb, so the drivers will quickly bottom out.
Chris
I hadn't looked so closely at the cabinet volume - looks like there's plenty there (I've seen other 2x15" cabs where the drivers barely fit in the cabinet, and assumed similar).
The driver that Xoc1 has suggested will do about 125dB per cabinet, down to ~40Hz.
You could run a 1kW amp into it fairly safely: excursion goes to ~8mm one-way around 60Hz (that's probably the most I'd ask from them). The progressive suspension used in most PA drivers ought to stop them bottoming out, but listen carefully to check if the drivers are being abused.
For high power use, adding a low-cut filter below port tuning is mandatory. The cabinet provides no resistance to the cone motion below Fb, so the drivers will quickly bottom out.
Chris
Hi guys, sorry for the late reply, been away for new years. Speakers have arrived, got some Eminence Delta 15- LF's (I know not the absolute best, but I have a budget here guys! im only 18! haha)
So I've had a look at making the port holes bigger, but there just inst the room, unless I want to break the front of the cab cause it would be too weak. (the holes would be too close together)
So my only worry is blowing the speakers because the port holes are too small, I understand that the air needs to escape quickly at high volume, but truth is I wont be using them at full
tilt much! So how much risk is there of that happening, if I leave the ports how they are?
Oh and my upper freq limit will be about 150-160Hz max! Perhaps lower, not sure yet.
Tom
So I've had a look at making the port holes bigger, but there just inst the room, unless I want to break the front of the cab cause it would be too weak. (the holes would be too close together)
So my only worry is blowing the speakers
because the port holes are too small, I understand that the air needs to escape quickly at high volume, but truth is I wont be using them at full tilt much! So how much risk is there of that happening, if I leave the ports how they are?
Oh and my upper freq limit will be about 150-160Hz max! Perhaps lower, not sure yet.
Tom
The Delta 15 LF requires a far bigger cabinet to get a smooth frequency response. In fact Chris661's suggestion to use only one driver per cab is not to impractical. But this would severely limit the power handing.
have a look at the cabs on the Eminence site
http://www.eminence.com/pdf/Delta_15LFA_cab.pdf
Notice the big cab is limited to 175W & the medium size cab is 250w.
For a double 15 simply use twice the volume shown for a single cab to get the same response. Note that Eminence are suggesting 4 X 4" 100mm ports per speaker.
One suggestion. If you can not get the ports to fit in the front how about putting them in the back of the speaker? Not common I know, but would work better that you might expect!
We know the outside dimensions of the box and the drivers that you have. If you can post some pics of the cabinets and maybe some details about how you plan to use them that would help people to help you get the best out of them.
have a look at the cabs on the Eminence site
http://www.eminence.com/pdf/Delta_15LFA_cab.pdf
Notice the big cab is limited to 175W & the medium size cab is 250w.
For a double 15 simply use twice the volume shown for a single cab to get the same response. Note that Eminence are suggesting 4 X 4" 100mm ports per speaker.
One suggestion. If you can not get the ports to fit in the front how about putting them in the back of the speaker? Not common I know, but would work better that you might expect!
We know the outside dimensions of the box and the drivers that you have. If you can post some pics of the cabinets and maybe some details about how you plan to use them that would help people to help you get the best out of them.
Hi,
Forget about ports, they wont work with your drivers and cabinets,
go sealed and stuffed. The lower your maximum levels, the more
low bass boost you can use, making the set up very flexible.
Small space - use them unassisted with bass boost,
big space - use them flat with some additional big subs.
The high Qts of the raw drivers, 0.6, prevents simply venting for
power handling and SPL rather than extension, though you could
still do that with advanced EQ, to cut the upper bass boost.
rgds, sreten.
Forget about ports, they wont work with your drivers and cabinets,
go sealed and stuffed. The lower your maximum levels, the more
low bass boost you can use, making the set up very flexible.
Small space - use them unassisted with bass boost,
big space - use them flat with some additional big subs.
The high Qts of the raw drivers, 0.6, prevents simply venting for
power handling and SPL rather than extension, though you could
still do that with advanced EQ, to cut the upper bass boost.
rgds, sreten.
Riiigghht ok. Well I plan to use them as subs, but I've only bought enough drivers to fill 2 of the cab atm, so the other 2 could have better drivers in them.
So you think ill have know chance of getting a decent sound out of them? I mean i've done some calculations on ISDwin (forget the name, correct if wrong) and it says with the cabs I have and 4 - 4" ports with a 13cm length I could get a good 45-50Hz. But maths, weirdly, can lie.
I desperately need to use these cabs, and these drivers some how, as I can't afford anything else atm. In future I will purchase some good RCF or better eminence.
And, tbh, I don't really want a closed box, unless it will really benefit?
So you think ill have know chance of getting a decent sound out of them? I mean i've done some calculations on ISDwin (forget the name, correct if wrong) and it says with the cabs I have and 4 - 4" ports with a 13cm length I could get a good 45-50Hz. But maths, weirdly, can lie.
I desperately need to use these cabs, and these drivers some how, as I can't afford anything else atm. In future I will purchase some good RCF or better eminence.
And, tbh, I don't really want a closed box, unless it will really benefit?
Undersized cabinets give higher cutoffs. WinISD will show you (to some extent) what you can get away with.
Block the existing ports, add your own at the back - you'll have far more control over the system performance.
The biggest problem with small ports is that they work fine at lower volumes, but when the cones start moving, they can't move the air fast enough (too much friction) so kind-of "lock up": you won't get much more output from them.
Alternatively, go sealed.
Still not sure why you want to end up with 8x 15" drivers: you will be able to cause structural damage to buildings. What's your application?
Chris
Hello, update! i'm sacking the deltas! your right of course, the cabinets are way too small!
Gonna go with some Kappa's like you suggested, thank you. sorry for being a pain, but i'm new to all the mathy stuff and i'm just finding a leg to stand on. Thanks for the help, no doubt ill need more soon :L
Cheers, Tom
Gonna go with some Kappa's like you suggested, thank you. sorry for being a pain, but i'm new to all the mathy stuff and i'm just finding a leg to stand on. Thanks for the help, no doubt ill need more soon :L
Cheers, Tom
The Eminence Kappa Pro15LF2 is a nice sounding driver.
So a plan of action might be......
Block the existing ports with decent thickness timber and lots of glue. Do this on the outside face of the baffle to keep the inside volume as large as possible.
Source some plastic drainpipe for ports maybe 100mm dia or similar, measure the inside diameter for calculating the cross sectional area.
Carefully measure the cabinet internals to calculate the true volume.
Input all the data for the cab and driver into winISD pro which is a free download program.
Tune the cabinet sim for a flat response.
Add additional ports matching the pipe diameter and see how this increases the port length required. The ports meed to be short enough to fit in to the box with at least the port diameter clearance to the back of the box, ie the port tube needs to be at least 100mm less than the box depth to breathe.
Cut out holes and fit the new port tubes.
Preferably measure the speaker using a frequency generator, amplifier & DVM to confirm the port tuning is correct.
Lots of steps maybe, but if you do it right you wil have something to be proud of at the end!
So a plan of action might be......
Block the existing ports with decent thickness timber and lots of glue. Do this on the outside face of the baffle to keep the inside volume as large as possible.
Source some plastic drainpipe for ports maybe 100mm dia or similar, measure the inside diameter for calculating the cross sectional area.
Carefully measure the cabinet internals to calculate the true volume.
Input all the data for the cab and driver into winISD pro which is a free download program.
Tune the cabinet sim for a flat response.
Add additional ports matching the pipe diameter and see how this increases the port length required. The ports meed to be short enough to fit in to the box with at least the port diameter clearance to the back of the box, ie the port tube needs to be at least 100mm less than the box depth to breathe.
Cut out holes and fit the new port tubes.
Preferably measure the speaker using a frequency generator, amplifier & DVM to confirm the port tuning is correct.
Lots of steps maybe, but if you do it right you wil have something to be proud of at the end!
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