JBL 2269H in 4645B cabinet

[Andrew Maddison]

Hi everyone,

I’m part of a student cinema and we’re just looking for some advice on our audio setup

We currently have a bit of an issue with our subs where we can just about meet reference (shock horror we do sometimes play films at 7.0 and do want to be able to meet reference) but we don’t really have the power handling we need at the low end.

At the moment we have 3x JBL 4645B subs left, centre, right which are below and in front of the screen (we know this is awful, yes we hate it too), but unfortunately due to having the room loaned to us and the constraints of the setup we can’t really change their location to couple them. We are also looking at getting two JBL 5749 but as these would have to be in a left, right configuration could it actually end up being worse (in power alley) than our three across setup? (also it’d take a huge amount of work to get them to fit and we’d need to get permission).

Another option that has been suggested to us would be to put JBL 2269H drivers in our 4645B cabinets, which would give us more than enough power handling and potentially solve all our issues. The JBL 5628 box has the same tuning frequency, but we’re not actually sure how this driver/cabinet combination would react.

Any advice is really appreciated it’s just we don’t have anyone here that has enough understanding to model it.

[Steve Guttag]

The driver will work in that cabinet though it really isn't large enough for the 2269H to play as deep as it can. And, while it CAN take a lot more power than the 2242H, it is also 3dB less efficient...so you need to double your power to get it to play as loud as the 2242H that is in your 4645B cabinets. Do you put all three cabinets together or are they spaced apart? If they are spaced apart, I can find you some more output by doing nothing more than kissing them all together in a cluster.

The 2242 driver is pretty solid as a subwoofer driver and the 4645B/4645C system is also pretty darn good on the overall bang-for-the-buck category. I would not be as inclined to swap out the subs as I would be more interested in finding one more to make four subwoofers and improve the entire efficiency of the system. You'll pick up another 1.2dB of efficiency with the 4th sub...which might not sound like at lot but it could be the difference of say 1750-watts and 1325-watts.

I am using a pair of 5628s on a new project (ATMOS house). I have 6000-watts available for each cabinet (3000-watts per driver) or 12,000 watts for the subwoofer system (at least for short periods, 4,800-watts continuous all day...the amps are DPA 8K8Q with each driver running 2-outputs bridged. The amps are also powered via 208V. The 5628 is a great sub (though again, it would be better if the cabinet was larger, tuned lower) but you do need to realize that the 2269 drivers are not the most efficient. The subs are also sinked into a baffle wall and floor mounted to get the most mechanical amplification (without corner wall nodes).

[Jay Wyatt]

Hard to give a definitive answer without knowing your auditorium dimensions and amp pairing. Like Steve mentioned, you may be losing out on some "free" sensitivity (~4.5dB) by not clustering them. Do that first if at all possible. I'd be wary of dropping in 2269H's. Even if the box tunings line up, you'll end up needing a lot more amp and there's no guarantee the cabinet of the 4645B is braced to take on that kind of motor force.

[Andrew Maddison]

Thanks so much for the replies, the wisdom is appreciated!

We’d like nothing more than to move all the subs we have together and solve the issues in one fell swoop but it’s something we’ll never be able to do because of the constraints of the room and how we’re allowed to use it.

At least the 2269H don’t sound like an unreasonable option given the circumstances and we’ve got plenty of time before we’re allowed to reopen to have a think.

[Marcel Birgelen]

What are you using to drive your subs? The 2269H requires about 2700 to 3000 watts to perform, so double that for the preferred paired setup. Don't try to drive it with anything less, not only will the results be less stellar, you're not doing your amp any pleasure.