Hello everyone.
I'm sorry if this question has been post but at the moment i can't really find an answer. I Actually have a Cambridge Audio azur 640a integrated amplifier. I plan to purchase for a stereo system Axiom M3 V2 bookshelf speaker whit EP125 subwoofer to give some bass for my music and movies.
My question is. Can i only adjust the volume of the sub from the control panel via the sub or do my integrated will take in charge the volume of the sub ?
Otherwise i'm wondering how hard it is to adjust a subwoofer volume when you listing music and going high and low, as for movies.

Thx for tips or advise.

with any receiver or amplifier, you calibrate all your speakers and subwoofer to the SAME SPL in dB's, and leave it there by using a Radio Shack SPL meter, or the built in test tones and mic that comes with some receivers. You can adjust the gain (volume) of the sub either on the back of the sub, or by using the sub level adjustment in your receiver or integrated amp.

Normally you calibrate everything to 75dB's and leave it there, but some like to have the sub a little hotter (louder), it is your preference.

If you have the sub connected from the subwoofer pre-out on the a/v receiver or a/v preamp to the LFE in/line-level in on the subwoofer then you should be able to adjust the volume(gain) from both the subwoofer volume(gain) dial and the subwoofer gain setting on the receiver or preamp which shows up as number ranging from -12 - (+12) which represents the voltage(gain) signal being sent to the sub. The higher the number the more voltage is being sent to the sub.

When dialing in a sub with a SPL metre you are trying to strive for a happy medium between these two settings. Half or less on the dial(gain) of the subwoofer and a -3 to (+ 3) setting on the receiver/preamp for your calibrated setting.

With the amp you have you will need to use the high level inputs on that particular sub. You will have to calibrate the speakers to 75 db using the volume knob, remember where this setting is as you will need to know the position of the volume while setting up the sub. With the speakers disconnected and the volume knob at the same position as where you had it with the speakers. From there you will need to start turning up the gain knob on the sub til you reach 75 db on the sub. Hook the speakers back up. You now have calibrated the system.

BTW, you're going to need some test tones to do this.

Slow bass sweep tones are also good to help set the crossover, and verify a smooth transition from the mains to the sub.

Ok great, thx you i really appreciated it. Just need a tune up then.

You will have to set the crossover using the crossover knob on the subwoofer as well.

on your Cambridge Audio 640a ( i assume you have de v2.0 )
has no LFE output, so, your sub will be driven via the PRE-OUT.

simply ajust the output gain of the sub the volume of your amplifier & the sub volume will follow.

I assume that you are an audiophile & a small part of your listerning time are for movies.
I don't know about the performance of the M3's but i think that your choice for EP125 is little bit too small for movies applications. EP175 could be better & EP350 great !!! if you can afford them. Because on movie application you need more DEEP & PUNCH.

I own a Cambridge Audio 640r wich is mostly the Home theater receicer of your 640a. Actually i'm at 2.0 & for me adding a sub will be only for movies applications, so I'm looking for EP350 or EP500 (if a can afford the).

I think that you choice of an EP125 will be nice for music listerning but some deepness & punch will be missing on movies.

Dr House's advice for calibation are right

Good luck Phillippe !!!

Those M3s are a very nice speaker. Unless you have a tiny room, I would step up to the EP350. If you need to stay in that budget range, look at something like the SVS PB10NSD or something from HSU.