How to deal with a drop ceiling that eats bass?

Digital correction is okay to a point. However, in this case I would not recommend it. The problem is that you are going to want to boost bass in areas that are lacking due to the dropped ceiling. This can put some real strain on your speakers and amplifier and increase distortion dramatically. Artificial boosts like this are very prone to some real world problems and should be avoided if at all possible.

Perhaps digital room correction.

Dipoles in frequencies above 65 Hz can have directionality. I own ML IIs, the crossover is at 125 Hz. However, low frequencies do not have directionality. This is not to say that you can not detect where a subwoofer is coming from (one of the myths about subwoofer placement). The lower the crossover frequency the less the ability to detect the placement of a subwoofer. However, the point that was brought up by foreverhifi, regarding dipoles is correct (if I read the original statement correctly). Dipoles in the bass change the speaker power (energy dispersion pattern), but they do not create directionality. This is because the port and the speaker (or speakers--bass only here) are located within 1/8 of a wavelength of the crossover point. The result is a relatively coherent "point source". By point source, I mean you can not detect multiple sources of sound. The ports and dipoles are used effectively for the sound dispersion power, which according to most speaker manufacturers is a good thing (even dispersion). However, new designs, such as Earthworks, are trying to have very uneven dispersions on purpose so that the speaker does not interact with the room as much. I think this whole part has gotten a bit off subject, as the effect of the drop ceiling remains relatively the same for dipoles, bipoles, conventional dynamic speakers and even horms. There will of course be some differences based on the speaker, but it is unlikely these differences would account for very much in terms of the changes due to the dropped ceiling (I hope I stated that clearly).

Sorry to rain on AUDIOKINESIS'S parade in regards to his info on "dirrectional bass". But that advice is about at WRONG AND TECHNICALLY INCORRECT as I've ever heard from an audio forum post! There is no technical, physical, or practical data available to support those statements!
Infact, I'd like to hear Rives's resonse to what Audiokinesis said about dipoles, dirrectional-bass from di-poles(?), and drop ceilings!
Rives???...

It almost sounds like your room has increased in size since the bass has disappeared. Once you have real bass it is difficult to give up. If you really like the room you might want to try a bigger speaker with better bass. I personally like big speakers in rooms that are medium sized and are more on the dead side as compared to lively rooms (hardwood).

the easiest way to check is to replace the tile with drywall- cut the drywall the same size as the ceiling tiles. drop ceilings will support this. there are actually ceiling tiles made out of drywall and vinal covering, which is significantly heavier than plain sheetrock. I have many times used grid ceilings as the framing for a sheetrock ceiling, the grid ceiling holds more than it would seem to most poeple, and these all meet code. being an audiophile, you would want to experiment before you go to the expence of buying vinal rapped tiles or finishing a ceilng, and besides you might not mind the plain sheetrock. if it is feasable, you might experiment with removing the tile altogether.

Audiowill -

A speaker system that is directional in the bass might offer a practical solution. Dipoles come to mind, because that's the easiest way to make a directional bass system. A dipole will have a bass null in the plane of the driver, but would project bass forward and backwards. The very low amount of bass energy directed upwards towards the drop ceiling would minimize the ceiling's effect on bass performance.

Speakers with dipole bass systems include full-range planars such as Maggies, Quads, Sound Labs, and Martin Logan CLS's; as well as dynamic dipoles like the Gradient Revolution and the Audio Artistry line. I sell some of these, and I'd be glad to answer questions about any of them.

Best of luck to you!

Duke

My experience is that you live with it, or better yet get rid of it! Drop ceilings do what Rives said, and are an EASY source for noise and rattles. They suck up highs and some mid, and bass goes right through them.
How high is the SOLID ceiling above? What's it made of?
One solution might be to add some REFLECTION to places on the drop ceiling, so it will ad more diffusion and reflection. However, this depends on what else is going on in your room. If you have a carpet and lots of absorbtion around the room, your drop ceiling is DEFINTELY not helping your DEAD ROOM sound. Rooms will vary.
Good luck

You need something solid and rigid to support bass. Dropped ceilings have 2 problems. One is the tiles, they are absorb in the upper frequencies and are transparent in lower frequencies. The second problem is the structure, it is not rigid. You have to fix both of these problems, and I doubt I can give you a "cheap" solution. It does depend greatly on the structure, but if there is a way to get rigidly supported drywall, that would be the preference. Mass loading is an idea. But it's unlikely you will acheive good rigidity at any lesser expense, since the metal channels for the dropped ceiling are not designed to support any significant mass.