+/- 3db spec

[55katest55]

Or 2db or 1db. What exactly does this spec indicate? How flat the FR vs. db graph is? Thanks, sorry for the noob question.

 

[GranteedEV]

Or 2db or 1db. What exactly does this spec indicate? How flat the FR vs. db graph is? Thanks, sorry for the noob question.

In the small passband of a subwoofer, it doesn't really look at the narrow blips from suspension/cone etc resonances.

Mostly, it looks how deep the bass goes at the bottom (minus 3db point, although we still preceive at least down to the minus 10db point especially if it's a sub setup without limitation) and how high the bass goes up top (other minus 3db point)

 

[j_garcia]

3dB is a vairance of 50% in output. So for a given speaker it indicates that the peaks do not vary by more than 50% above or below ideal over the range measured.

3dB is used because it is easily heard and measured. You can definitely hear a drop of half of the output.

 

[MDS]

Or 2db or 1db. What exactly does this spec indicate? How flat the FR vs. db graph is? Thanks, sorry for the noob question.

It tells you that over the stated frequency range, the output varies from the input by no more than 3 dB lower or 3 dB higher. However, it does not tell you where the +/- 3 dB variance occurs in that frequency range nor does it tell if those dips and/or peaks occur multiple times over that range.

That's one reason why two speakers that are seeminly simlar based on the stated specs may well sound very different.

 

[j_garcia]

It tells you that over the stated frequency range, the output varies from the input by no more than 3 dB lower or 3 dB higher. However, it does not tell you where the +/- 3 dB variance occurs in that frequency range nor does it tell if those dips and/or peaks occur multiple times over that range.

That's one reason why two speakers that are seeminly simlar based on the stated specs may well sound very different.

Yep. Unless you actually see the FR chart, it doesn't really tell you much.