How much EQ can JBL 4645c take?

[Jonas_h]

I just bought a JBL 4645c and so far, i am VERY impressed with it. I am missing som freq. response at around 20hz - but I knew that it dropped a lot below 25hz.

But my question is, how much are one "allowed" to EQ it at 20-25hz? I know JBL recommends 6db at 25hz, but as far as I know, this is in a cinema-environment. The driver will not be pressured nearly as hard in a home environment, and therefore I would think that it would be safe to EQ some more? But I am afraid I would end up with a broken driver if I do it...

Any comments?

[timc]

I just bought a JBL 4645c and so far, i am VERY impressed with it. I am missing som freq. response at around 20hz - but I knew that it dropped a lot below 25hz.

But my question is, how much are one "allowed" to EQ it at 20-25hz? I know JBL recommends 6db at 25hz, but as far as I know, this is in a cinema-environment. The driver will not be pressured nearly as hard in a home environment, and therefore I would think that it would be safe to EQ some more? But I am afraid I would end up with a broken driver if I do it...

Any comments?


I don't think you will have to worry about blowing the woofer. However, what you should consider is this: If you put more LF EQ into it, it has to use more of its excursion. This means more power put through the coil, and more heat generated. It also means that the energy the driver has to get rid of to stop increases. If overdone, it will lead to degradation of the sound. You get more LF extension, but less prescission.


-Tim

[Jonas_h]

THat makes perfect sense. Then i'm in a bit of a dilemma: It is the precision I just love about this sub. But i'll have to try playing with different EQ settings then - maybe I wont even notice a degradation in sound when boosting the LF.

If others, with hands-on experience, have comments, then you are more than welcome to post.

[timc]

THat makes perfect sense. Then i'm in a bit of a dilemma: It is the precision I just love about this sub. But i'll have to try playing with different EQ settings then - maybe I wont even notice a degradation in sound when boosting the LF.

If others, with hands-on experience, have comments, then you are more than welcome to post.

I think you just have to try different settings to see what suits you. Or buy more of them ;)

OT: I actually have som first hand experience, but not for music use. At work we use two of these in a 4.5 sqrm room, for high level noise simulation.

[JuniorJBL]

I use 2 2242's with boost +6db at 20hz narrow Q with very good results. Powered by a Crown K2.:D