What is secret/s of Theatres

[abulgan]

guy i sold my SW and using now 2 Built-in subs,each has 8" woofer and pair of radiator with 300 Class D amp,so total 600watts,hope this is enough

and i've just received the SPL meter and adjusted all channel levels by that,80 db speakers and 85 db for SW,bass is not enough 4 me now,or gott used much more Bass when making levels by Ear,cause SW's r now at mininum according Meter which was near Max.

[Woochifer]

Keep in mind that the bass response from where your tower speakers are located will likely have an entirely different response curve from the bass that emanated from your sub. This is a byproduct of the room acoustics and the boundary reinforcement. A corner placement (where subwoofers are likely located) will have a far more reinforced bass than something located along the middle of the front wall (where the imaging is typically optimal, but bass reinforcement is minimized). In most typical rooms, these two locations will also produce very different sounding bass.

If you feel that having your subwoofer output set to +4 db is not enough, then you need to check and make sure that you don't have a boomy peak somewhere in the bass response. With a wideband test tone, a large peak somewhere in that response curve will drive up the overall level reading that you get from the SPL meter. This means that for most of the bass range, the level will be too low, but for those problem frequencies, the levels will be way too high. These peaks are caused by the room acoustics, and will vary depending on where your seating position is located relative to the speaker location.

The only solution to this problem is to move the speakers, change your seating position, or use a combination of room treatments and equalization.

Another issue that you need to double check is to make sure that everything is setup and connected properly, and that the measurement was done correctly. With your speakers, do they have separate subwoofer inputs, or do they only have the speaker wire connections? Is the test tone from a CD or from the receiver's tone generator? Do you have your speakers set to large or small? Those all factor into whether you have other adjustments that you need to make before ascertaining whether your bass is actually at the correct level.

[abulgan]

i have SPL meter from RS and just waiting Rives Audio Test Cd to arrive to check freqs.
but there is something i can't decide,my towers has sub at sides,so sides facing each other or facing the side walls make more Bass?
i mean 2 Subs facing each other,one is on the left and other on the right

Towers both have LFE and Speaker Wire connections(both r connected to Receiver)So,Sub getting 80 hz below bass and speaker getting its speaker signal,just like one SW and a Speaker in same cabin.

[Woochifer]

Since your speakers have a separate LFE input for the built-in subwoofers, you should set all of the speakers on your receiver's bass management settings to SMALL and have the bass output from both the L/C/R/LS/RS speakers and the LFE track directed into the receiver's subwoofer output. This will direct all of the lower frequencies into your tower speakers' subwoofers.

Once you've done this, then use either a calibration DVD or your receiver's tone generator with a SPL meter to set the levels. If you feel that the bass output is too small with the subwoofer set to +4, then you can simply raise it. If there are still issues with how full or even the bass sounds, then you will need to use that Rives disc and measure your lower frequency response. Any peaks and dips that you see are room related, and will keep you from obtaining an accurate SPL reading with a wideband test tone like the one that your receiver puts out.

Like I said earlier, you might need to consider moving the speakers around, changing your seating location, using bass traps in the corners, or equalizing the sub.