Understanding subwoofer specs

[wem003]

I have a front firing B&W ASW608. It's a great sub and works with my speakers beautifully.

That said, can some explain what the difference is between Frequency range and Frequency Response? I am new to this, and when I look at the specs for this sub, I see this:

Frequency range -6dB at 23Hz and 25/140Hz adjustable (EQ at A)

Frequency response ±3dB 32Hz – 40/140Hz adjustable (EQ at A)

Bass Extension -6dB at 23Hz (position A)
-6dB at 28Hz (position B)
-6dB at 36Hz (position C)

And I am not afraid to admit - I haven't got a clue what it means.

Thanks for any help.....

[rarredoa]

Originally Posted by wem003

I have a front firing B&W ASW608. It's a great sub and works with my speakers beautifully.

That said, can some explain what the difference is between Frequency range and Frequency Response? I am new to this, and when I look at the specs for this sub, I see this:

Frequency range -6dB at 23Hz and 25/140Hz adjustable (EQ at A)

Frequency response ±3dB 32Hz – 40/140Hz adjustable (EQ at A)

Bass Extension -6dB at 23Hz (position A)
-6dB at 28Hz (position B)
-6dB at 36Hz (position C)

And I am not afraid to admit - I haven't got a clue what it means.

Thanks for any help.....

Frequency range is the "potentially widest" range of frequencies that your sub can play, measureably. The Frequency response is the "more audible" frequencies that your sub can play. Notice the significant range difference between the two specs, that just means that the sub's tendency to reduce it's output begins to occur significantly, at the low 30's (Hz). I have seen the two terms 'frequency response' and "frequency range" used interchangably, but one thing i've noticed is that the narrower the band, the more realistic, or audible, it is.

The A, B and C positions equalize the output within it's own range of low frequencies, so the boost at A is higher than the boost at B. However these boosts tend to create distortion at louder volumes, so the more "accurate" or "true" sound will be the un-equalized or flat position on your sub.

Hope this helps

[welwynnick]

I think that when people refer to bandwidth, frequency range and frequency response, they generally mean the same thing. What’s significant in the example given is that the bandwidth criteria are different. +/-3 dB are typical limits that are generally applied to electronics, and perhaps rather less to speakers, which don’t usually meet such tight limits. Quoting a -6dB point makes the bandwidth or extension look rather better, and it’s often used to compare bass extension. To make any fair comparison, you must always know the basis or criteria.

The -3 dB point at the top of the upper or lower roll-off curves is also called the corner frequency, and is chosen because it’s where the signal power has fallen to half its nominal value. dBs are logarithmic, so minus means less than nominal, and -6dB means a quarter of nominal power (or sound pressure level, which is a power quantity – loudness is proportional to power, not amplitude).

Regards, Nick

[wem003]

Thanks for the replies - it helped quite a bit!