Hi All,

Quick question.

Just this week I was testing my speakers because an annoying vibration had started between the facia and the cabinet, where one of the screws had not been tightened sufficiently after they were recapped.

After tightening the screw, I pushed the the volume up a bit higher to make sure I had gotten rid of the problem, and to my surprise at just over 40 on the 0 - 60 volume scale the override tripped the speakers. Now, I thought this was rather low considering this is only about two thirds of the full volume. At the time I was playing a CD  through the TP2 input, it was a rather bassy 'bargrooves' style track which was a good test for this problem.. I also always leave the 'loudness' switch on as I like the fullness this provides, could this have created an unusual high frequency situation?

Normally, I don't get up to these volume levels (only 25 - 30 at best) as I live in a terrace house and don't want to drive my neighbours crazy, but sometimes you know how it is .... I would like to turn it right up, every now and then to see how it handles things and would be disappointed if this always happens. Haven't had the chance to test again to see if it happens ... but... Would like anyones thoughts as to why it may have happened.

Thanks!

Playing at "level 40" could be compared to driving a car at a speed of "gas pedal halfway down".
It doesn't give any indication of the speed just as it doesn't give any indication of the volume at all.
It all depends on the source, the tone control setup, the speakers, programme sound contents etc.

The safety circuit kicks in when the speakers are pressed beyond their maximum effect handling,
in other words; When the contents of what you are playing x the sources output level x the volume setting x several other factors equals the speakers factory set maximum.

Larger speakers safety circuit may kick in even earlier if the factors above match their maximum.

It will happen again if the factors are the same. Change one factor and you will have a different situation. To make sure nothing bad happens, you need to keep all factors within reason = keep the sound free of distortion and you will be on the safe side.

The Beovox S80.2 speakers have a safety circuit that can be reset from the front, without opening the cabinets.

Martin

Hi Martin,

Thanks for your quick reply. Based on your points... my guess is that the input signal created this 'high point' as I have read that CD frequencies are higher than either record / tapes which would have been the normal input of this era of equipment. Is this true? But I must say at the time there was absolutely no audible distortion.

Thanks, I reset them, no issue there.. just seeking ways to prevent possible repeats if that is possible..

The frequencies on a CD and vinyls are the "tones" you hear, they are the same
on a CD and a vinyl record of the same work if your record deck rotates at the correct speed.

The amplitude (volume) however, can be very different;
- From a CD with one work to a CD with a different work
- From one CD issue to another of the same work
- From one vinyl to another vinyl
- From one CD player playing a CD to a different CD player playing the same CD
- From one vinyl record played on one deck to the same record played on a different deck.
- From vinyl to CD

The effect is what counts when it comes to the speakers safety circuit.
Effect equals voltage times current so depends on the amplitude, speaker impedance and the amplifiers output impedance but also damping factor etc. play a role.
And just to add to the confusion, even more factors join in because we are
talking about AC voltages and currents.

The input signal gets amplified and output to the speakers. The input signal isn't what trips the safety circuit. The output, where all the math's "results" are presented, is where things get serious.

Play, listen and enjoy. Bring the volume down if you reach a point of distortion.
Distortion is when the sound is no longer "clean" but becomes "scarred" and "unpleasant".

Martin

Hey Martin,

Thanks for the very detailed feedback. Its obviously quite complex and seems there are no hard and fast rules to follow due to the variables you have outlined. But I'm sure that there are many others, who, like me will appreciate your detailed description to come someway towards understanding how volume works.

I think I will however heed your wise words and try to sit back, relax and just enjoy that music. 

Thanks for your guidance once again.