Good Home Theater Sub Specs: What should they be?

[KASR]

In the pursuit I'm working hard to understand the best possible configuration for a home theater setup - with that said, I also listen to music with the setup - but can safely say that the HT is used 85% for movies/games and 15% for music. So what range in the following spec areas should I be looking for in a HT sub to fill a soundstage that is roughly 16 x 13 in a room that is 17 x 21ft?

Driver Size:
Dynamic Power:
Continous Power:
Overall Freq. Response:
Lower Limit -3db:
Upper Limit -3db:
Crossover:

For example:
Driver Size: 10inch
Dynamic Power: 200W
Continous Power: 100W
Overall Freq. Response: 32Hz - 250Hz
Lower Limit -3db: 38Hz db
Upper Limit -3db:
Crossover: 60Hz-160Hz

 

[j_garcia]

Unfortunately, the specs may not tell you the whole story. A 10" sub with 200w is unlikely to yeild similar performance from one manufacturer to another. There are 10" subs that will shame 12" subs from others, so it isn't a simple question. For me it comes down to how big is your room and how much do you plan to spend? In addition to that, how much impact are you looking for? Another factor will be how deep do you want to dig? Getting really low (and still sounding good) typically costs more.

Driver Size: probably a 12" for that room.
Dynamic Power: ?
Continous Power: ?
Overall Freq. Response: see below
Upper limit: doesn't matter since your receiver will handle the crossover.
Lower limit: up to you. I would shoot for 20Hz capability at minimum.
Crossover: Irrelevant, see above

 

[monsterman]

I think Garcia began to explain this well.
Whenever you embark on something like this; building a home theater system, HTPC, hot rod. You ask yourself the questions that dictate your decision making. Budget, End Result, Likes/Dislikes. Then you can begin to narrow it down. Speaking from experience in many DIY adventures in the electronics world... try not to rush it and take a very good look at your budget (it usually comes out to more than you expected to spend).

 

[fredk]

It really depends how low you want to reach and how much you want to spend, at least if its a commercial sub.

I get satisfying results from a sub the plays flat to 20Hz in my room. It gives decent impact to movies, but...

There is lfe content in some movies well below 20Hz. To get down into the teens with authority (ie: headroom so your sub doesn't distort) starts to cost $$.

How low a sub reaches is not the only consideration. Some subs squeeze a lot out of the bottom end, but sacrifice headroom in the mid/upper bass region. Its always about compromises.

 

[Pyrrho]

In the pursuit I'm working hard to understand the best possible configuration for a home theater setup - with that said, I also listen to music with the setup - but can safely say that the HT is used 85% for movies/games and 15% for music. So what range in the following spec areas should I be looking for in a HT sub to fill a soundstage that is roughly 16 x 13 in a room that is 17 x 21ft?

Driver Size:
Dynamic Power:
Continous Power:
Overall Freq. Response:
Lower Limit -3db:
Upper Limit -3db:
Crossover:

For example:
Driver Size: 10inch
Dynamic Power: 200W
Continous Power: 100W
Overall Freq. Response: 32Hz - 250Hz
Lower Limit -3db: 38Hz db
Upper Limit -3db:
Crossover: 60Hz-160Hz

I think you are looking at the wrong specifications. The driver size tells you almost nothing, and the power really tells you nothing, because the power you need depends upon the efficiency of the speaker, which can vary so much that one might need 10 times the power (or more) than another for the exact same volume. The frequency response should be given +/- 3 dB, and if you want the lowest notes of a pipe organ, it should go down to about 15 Hz or lower. The crossover you want depends upon your other speakers, though in most cases, you want the subwoofer to be at least able to be good up to 80 Hz or higher. What you want to know is maximum SPL at a specific level of distortion into various frequencies, and this is almost never stated.

If you want practical advice, I recommend that you buy the best SVS subwoofer you can afford. Then set it up to give you flat bass response (if you have an automatic setup in your receiver, read the manual and follow its advice). You cannot have too good of a subwoofer for a room, though it can be set too high and then it would give one boomy bass.