SPL and Db levels and basic setup?

[snodog]

Can anyone direct me with this? I am wondering what Db to set my speakers at and which ones I want to be set to small and which to large? I have two mains, a center, two surrounds and a sub. Also what LFE do I set my sub at? I do not have an spl meter and really dont want to spend $40 on one. I wish there was a simple guide to explain it.

[Woochifer]

It doesn't matter what level you're listening at, so long as the output from all of your speakers is equal. You have to use a test tone and adjust the levels for all of the speakers so that they all play the test tone at the same level. If you want your system calibrated as accurately as possible, there's no way around it -- invest the $40 and get yourself a SPL meter. Having your speakers level matched makes a huge improvement in how well the surround effect gets conveyed. The human ear can perceive shifts in the levels between different speakers, but it's not consistent enough to accurately match five or seven speakers simultaneously. You need a consistent reference point, and the SPL meter gives you that.

I don't know how much you already spent on your system, but a $40 investment in a SPL meter is not much in light of how important it is to keep your system properly calibrated.

As far as the bass management settings go. If you use a subwoofer, typically you will set all of your speakers to SMALL and send all of the bass signals through the subwoofer. And using a test tone and the volume adjustment on the back of the subwoofer, you need to match the subwoofer level with the levels for the other speakers (a frequent recommendation is to bump up the subwoofer between 4 and 6 db higher than the mains because of reduced hearing sensitivity in the bass range). Again, you won't get an accurate reading just using your ears, you need a SPL meter to do it right.

[paul_pci]

As Wooch indicates, the SPL meter is not a gimmick and there is no magic number to set your speakers at. It all has to do with the speaker itself, distance to listening position and room acoustics and those variations can only be leveled by measuring the sound pressure level coming out of each individual speaker.

[snodog]

But if my receiver tells me what decibel that each speaker is putting out then isnt that adequate enough? The small rear speakers have to be at the same level as the large fronts? That seems strange to me but you guys probably know alot more than me.

[Woochifer]

But if my receiver tells me what decibel that each speaker is putting out then isnt that adequate enough? The small rear speakers have to be at the same level as the large fronts? That seems strange to me but you guys probably know alot more than me.

On the contrary, your receiver is only telling you the output level going to the speaker, NOT the decibel level that the speaker is actually putting out. Once the signal from the receiver/amp reaches your speaker, then the ACTUAL output that you hear depends on the sensitivity of the speaker, the distance from the listening position, and the room acoustics. Some speakers are more sensitive than others, some rooms reinforce the sound more than others, and some people sit closer or farther away from their speakers. Just because the receiver has a volume setting of -35 db does not mean the decibel level that you actually HEAR will be identical for every speaker and every room.

- A less sensitive speaker will not sound as loud as a higher sensitivity speaker
- A larger room will require a higher volume position to achieve the same actual decibel level as a smaller room
- A speaker placed further away from the listening position will need a higher volume position to achieve the same actual decibel level as an identical speaker placed closer to you.

These variations are why you need a SPL meter to measure the ACTUAL output that you hear from each speaker at your listening position.

[snodog]

I guess that makes sense. Had I not just spent a bunch of money on a subwoofer and new cables and a damn expensive remote control I would gladly buy an spl meter...Anywhere I can find one for cheap? Besides ebay

[Woochifer]

I guess that makes sense. Had I not just spent a bunch of money on a subwoofer and new cables and a damn expensive remote control I would gladly buy an spl meter...Anywhere I can find one for cheap? Besides ebay

Just go to Radio Shack and pay the $40 (probably a lot less than those cables and the remote cost). That's just about the lowest priced SPL meter you can buy. Every other model on the market (the ones with higher precision mics) will run you into triple digit territory.

[Mike Anderson]

Parts express offers a couple SPL meters under $100. But I don't know anything about their quality compared with the Radio Shack meter.