Boomy bass in home theater room
This is kind of the poster child room for the PARC (Parametric Adaptive Room Compensation). You have a very high Q factor peak, and no amount of room treatment is going to deal with problems in that low frequency range except for one very large and very expensive custom design Helmhotz resonator (we can design it for you if you really decide to go that route). PARC |
I think Rives' suggestion is probably an excellent solution. Can you identify whether the midbass boom is in the region covered by the main speakers, or by the subwoofer? Does it go away when you turn off the sub? If so, then lower the crossover frequency of the sub and/or turn its volume down. I presume you've experimented with speaker placement. Have you likewise experimented with listener placement? That can make as much of a difference as speaker placement does. Just walk around the room listening to the bass, and see if there's a region where it sounds natural. If so, try to make that your listening area. I've had good results using speakers with dipolar radiation patterns in square rooms, as dipoles put about 5 dB less energy into the room's bass standing wave modes due to their figure-8 radiation pattern. If you ever do change speakers, you might consider dipoles (like Maggies), and maybe fill in just the very bottom with a conventional sub. You might try re-orienting the system along the room's diagonal dimension (not exactly on the diagonal, but close to it, so that you're maximally staggering woofer-to-boundary distances). Also, I'd suggest you replace most of the foam with diffusion (I use fake ficus trees). That's an enormous amount of sound absorption material for such a small room, and in small rooms a little goes a long ways. What all that sound absorption is doing is soaking up midrange and high frequency reverberant energy while having no effect on bass reverberant energy, so it's making the room even MORE bass-heavy. It's working against you, I think. Best of luck! Duke |
The Behringer DSP 90 something, for less than $300 as reviewed in Enjoy the Music and other sites will do what you expect for a lot less than the Rives and other such devices. Supposedly, the only drawback is that you need to read the manual pretty carefully to get the most out of it.....OR..... try to pull the sub out and away from the walls, until the boominess goes away. Sometimes, location is the most fundamental aspect of setting any loudspeaker/subwoofer in a room. Try this and see if you can save yourself some money. |
The limited thickness foam treatments that you have may actually be increasing the apparent "bass bloat" that you are experiencing. Due to their non-linear frequency absorption characteristics, which will suck up the highs and upper mids, the bass will tend to stand out even more. As such, you really have to treat the whole room / entire audio spectrum evenly or know exactly what you are doing when using "partial spectrum" sound absorption treatments. Other than that, your room acoustics will be very hard to work with. As Rives mentions, the room nodes will be very sharp and hard to tame due to the reinforcing measurements. All square rooms will suffer from this. While opening doors and windows in that room might help somewhat, that is obviously not a real solution, especially at this time of year. Other than the digital equalizer's mentioned above, an old fashioned graphic or parametric might be able to make things far more bearable for a just a few bucks. You can typically find used multi-band EQ's for anywhere from $20 - $50. Since you mentioned that this is primarily for HT use, the sonic degradation that takes place with an EQ would be far out-weighed by the benefits of a more neutral tonal balance. On top of this, you really don't have to read a manual as these "old fashioned" EQ's are nothing more than a fancy tone control that adjusts band by band. A little trial and error with various slider positions and a few bucks might get you a long way towards enjoyable viewing and listening. I only mention this as many people are "techno-phobes" and digital gear with thick manuals scares the hell out of them. This is not to mention that reasonable results for low dollars spent is always hard to beat. Sean > |
