Best enclosure/driver for a metal-core bass drop

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

Thanks AMC, that is definitely some good info!

So would a good (enough) setup plan be

Sound source (laptop or something)-> CX3400 Cross Over -> GPS 900 Amp -> Titan 48

i just wanted to be sure that i have that understood and in the proper order (ie. Xover before amp)

[Sydney]

Re: Best enclosure/driver for a metal-core bass drop

Well lets see... BFM claims 105db (IIRC) sensitivity in that cab

Of course that is for frequency above 60 - 65 Hz ( dropping 10db an octave down ).
Don't know how "Metal Core Drop" quantifies in terms of LF content but it is something to take into consideration.

[AMC]

Re: Best enclosure/driver for a metal-core bass drop

Would it perform well with 175 watts rated?? To me that just seems really low for a sub, but i dont fully understand the properties of the T48

Well lets see... BFM claims 105db (IIRC) sensitivity in that cab. so...175 watts should achieve about 127db. That is loud enough to cause serious hearing loss. And if you are running two of them, that is 130+db.

175 watts is very low for a sub, but the added sensitivity of the horn loaded design will make it plenty. Remember 3db is a doubling of power, so if you compare a t48 (105db/watt) to a normal cab at say 99db/watt, then that 'normal cab' would need 700 watts to do the same thing. (the 6db difference would mean 4X the power) And I have seen some commercial subs at about 95db/watt, that would require 1750 watts, to do what you can with 175.

Of course that all is assuming a properly built cab, and a proper driver. The BFM plans a well thought out enough to make building it something most people can do, and then just use the driver(s) he recommends.

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

Would it perform well with 175 watts rated?? To me that just seems really low for a sub, but i dont fully understand the properties of the T48

[AMC]

Re: Best enclosure/driver for a metal-core bass drop

660 WRMS in Bridge mode (typical value)
170 WRMS per channel (rated value)

is the 660 WRMS something like a "peak/max" value, where the sub (if we assume the Kappa-pro 15lf and Kappa 15lfa have similar max values) has a max handling value of 1200 Watts?

It is hard to tell exactly from the literature, but it should be able to deliver somewhere around 600 watts mono, in to 4 ohms.

BUT, regarding the driver watts rating, this is a limitation of the power the voice coil can take, in a LF driver, like these, it is almost NEVER the voice coil that limits the power, it is the x-max. And you WILL reach x-max well before 1200 watts. How much can they take? well that depends on the box. It your using the t48, ask BFM. (I'd guess about 350 for the kappa pro 15lf, but it's just a guess)

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

If a pickup a Peavey Pro GPS 900, and bridge it, it will put out

660 WRMS in Bridge mode (typical value)
170 WRMS per channel (rated value)

is the 660 WRMS something like a "peak/max" value, where the sub (if we assume the Kappa-pro 15lf and Kappa 15lfa have similar max values) has a max handling value of 1200 Watts?

If i were to run a CX3400 xover/limiter to the amp, to the sub, would it be acceptable to run that sub bridged off of the GPS 900??

[AMC]

Re: Best enclosure/driver for a metal-core bass drop

T48 would be better, and on the backline one would be quite sufficient.

Are the T48s going to get him to the mid thirty's like he needs?

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

Crown Com-tech 400 for $100 shipped??

according to the manual, will do 475 watts into 8 ohms in bridge/mono

That'll do better than my mixer i assume, so should i jump for it or what?

If i can keep from dragging my beast of a mixer around i would love it...

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

i have seen them use it, but these were very large stage shows, and i wasn't really paying attention to their PA equipment.

I believe i have decided to make the Titan 48- 27" wide version, loaded with a Kappa 15LF.

Since i have no immediate plans for intricate bass lines (like the ooh chick ooh chick ooh chick.... sound it out lol) in techno or house music, i don't believe i would need to sacrifice the low end for sensitivity, so I am NOT planning on using the baffle reducers.

I also purchased plans for the Wedgehorn 6 Vocal wedge, since i believe the singer (who believes himself a synth player) hooked up his Kaossilator to the monitor system, and blew out at least two of our monitors. So that should also be a nice project.

Thanks all, When i start my build i will surely be updating/ asking questions as I progress

[Randy L]

Re: Best enclosure/driver for a metal-core bass drop

Rogue, have you seen other bands actually "playing" this? If so, what speakers were they using? I'd use their lead as a starting point.

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

I was joking about the scoops lol, it seems they are almost unanimously looked down upon here...

Placement wise, the placement of whatever sub box i choose to run will indeed be behind the action against a wall, or off the the side of the stage in a corner.

When you say T48 you mean Titan correct? I actually spent most of my day today reading up on the design and supposed performance and was going to check out some reciews to learn more.

Thanks

[Taterworks]

Re: Best enclosure/driver for a metal-core bass drop

Alright... So it seems like rule number one is that scoops are awesome?

Right?

...

Right now my main focus is to create a standalone bass drop system, perhaps with the capability to run some kick to it.

1-2 Tuba 30's could be a good start??

1) Scoops have the same drawback as any other bass horn, which is that they are large. You do get high efficiency, but you don't get the most output for a given enclosure volume by using any sort of horn. Bass reflex will maximize the available bass extension in the minimum enclosure volume. Don Keele has published an AES paper that explains this. Horns are useful when speaker drivers and amplifier power are too expensive, or in the case of mid-frequency and high-frequency horns where maintaining optimal point-source behavior requires maximizing output from a single driver, or where pattern control is required.

2) I have heard both the Tuba 24 (HL-10 loaded), Tuba 30 Slim, and Tuba 30 (Eminence Magnum 12HO loaded) with a variety of music and there was virtually nothing on offer below 50 Hz from either of them. )The person who built them eventually changed to a pair of JBL 2241s in reflex enclosures). They would be useful for rock, country, and bluegrass, but not as useful for electronic dance music, hip-hop, or these electronically-generated bass drops that you refer to. These horns will give you plenty of dBs, but not where it counts. Other horn designs do exist that will give you the kind of bass extension you want, but they are much too large for someone in your situation to move around. They would be viable options for permanent installation or for use by a large sound company.

[billfitzmaurice]

Re: Best enclosure/driver for a metal-core bass drop

Alright... So it seems like rule number one is that scoops are awesome?

Right?

Quite poor, actually. That's why so few exist.

1-2 Tuba 30's could be a good start??

T48 would be better, and on the backline one would be quite sufficient.

perhaps with the capability to run some kick to it

If that's the plan run T48s on the PA, and don't bother with one on the backline. You don't need subs in both locations, where they'd end up fighting each other.

[RogueCow]

Re: Best enclosure/driver for a metal-core bass drop

Alright... So it seems like rule number one is that scoops are awesome?

Right?

As far as vocals go, that has never really been a problem. The PA we use at venues is powerful enough to shoot the vocals over the band, but not powerful enough to run the bass drop through.

Right now my main focus is to create a standalone bass drop system, perhaps with the capability to run some kick to it.

1-2 Tuba 30's could be a good start??

[mdocod]

Re: Best enclosure/driver for a metal-core bass drop

Hi Rory,

I'm reasonably confident that the pro sound brand drivers are UV stabilised. If the ST385 is in fact, made by eminence using their regular rubbers, then I'm sure they will be fine. I've seen rubber surrounds on non-pro-sound drivers left in the sun fall apart in less than a year. Sounds like these will be used primarily indoors so it's not an issue anyways.

PA460's work fine in relatively small reflex boxes. Sure they can be put in larger boxes, but there is a point of diminishing returns. 7-8ft^3 is the absolute maximum size I would suggest for portability vs performance at any tuning from 20-45hz, more volume than that just buys a peak in max output around tuning, but when EQ'd flat, more than 7-8ft^3 will not buy any output, only some reduced amplifier load. I'm not sure what you had in mind when saying that the PA460 needed "extremely large" enclosures. 7ft3 is pretty small by bassbin standards. Tuning options from 20-45hz are all perfectly viable in a 7ft^3 box depending on the intended program material and SPL requirements, Smaller than 7ft^3 is also viable...

Here's the PA460's output capability charted against the ST385 in equal boxes. These box sizes would be considered appropriate for the ST385 in a PA application, and perhaps a bit undersized for the PA460, but the results speak for themselves, the ST385 doesn't make any better use of the box size regardless.

3, 4, and 5 ft^3 boxes, 30hz tune.
PA460, charted maximum SPL in blues
ST385, charted maximum SPL in yellow/orange/red.

(darker shades are progressively larger boxes)



Regards,
Eric