Pub sterio system - Dimmer swiches

[Richard83]

Hi there, Im currently setting up a stereo system for a local pub, Because the PA/amp is wanted to be so high up i decided to put the speakers on to dimmer switchers lower down, But there’s barely any sound coming out when the dimmer is on full!

Amp is on half with left in the 8ohm screw-in output and the other is in the 0 output (I assume this is the common! When i take the 2 wires out of the dimmer and put the wires together sound comes out load and clear! The dimmers are 1 pole! What am i doing wrong?
There is other out puts ladled 70v 100v ect.

Thanks, Richard

 

[Spark123]

You need a proper volume control potentiometer, a dimmer switch as used on mains won't work.

 

[Taylortwocities]

Please state the type and make of the "dimmers". I hope that you don't really mean dimmer as these are meant to lighting circuits.

A 50Ω variable resistor is what you should be using.

 

[ban-all-sheds]

What am i doing wrong?

Displaying monumental ignorance of the way things you are fiddling with work, incompetence, and a serious lack of judgement in taking on a task you know nothing about.

 

[Richard83]

I posted this for a friend who is doing the job to save him some money, time & effort because he would not believe me! I think i have now proven myself right (again)
Can any C&G approved electrician give an explanation - so I can print this off to show him?

Thanks, Rich

 

[bernardgreen]

Can any C&G approved electrician give an explanation

Probably not. but an audio engineer could.

In short a mains dimmer switch is a switch that switches On and Off 100 times a second. For a brigh light it is on 95% of the time and for a dim light it is on for 10% of the time ( those max and min figures vary from make to make ).

It synchronises it's switching to the 50Hz mains waveform which is a simple single frequency sinusoidal shape of constant 230 volts

In loudspeakers there is a complex audio waveform of many frequencies of varying voltages to which the switch cannot synchronise so it remains Off all the time.

 

[ban-all-sheds]

Plus there's the little matter of it not getting anywhere near enough voltage to work anyway.



And I see the stupid little thumbs-down **** is still at large.

Ooohh - 4 of you now.

No - make that 6.

9 now.

9 people incapable of joined-up thinking.

9 people incapable of rational debate.

Has the GD forum shut down for some reason, leaving the knuckle-draggers looking for somewhere else to play?

 

[timtheenchanter]

what make/model if the amp, what make/model are the speakers?
is the source plugged dirtectly into the amp??

at the very least you will need somthing like this
http://tinyurl.com/speakercontrol
(not a reccomendation, but somthing like you will need)

personally, if you only need an overall control of the volume, and not in specific areas, I would buy a small mixer to place low down and between the source and the amp. you can get a small mixer with 2 stereo inputs and a mic input for around £45

until we know the amp/speaker info, cant help past this.

 

[Bill Stickers]

And I see the stupid little thumbs-down **** is still at large.

Ooohh - 4 of you now.

Cretins.

Are you really so arrogant that you can't accept that maybe, just maybe people don't actually like your down right rude posting style?

 

[ban-all-sheds]

Everything I said about the ignorance, incompetence and lack of judgement of someone who could think that a mains dimmer switch would work as a volume control on the output of a power amp deciding to install a sound system for a 3rd party was absolutely true.

It may have been an uncomfortable truth, but it was factual, non-insulting and not rude in any way.

Tell me - do you honestly think that trying to use a mains dimmer switch on the speaker output of an amp does not display monumental ignorance of how they work? Yes or no?

Do you honestly think that the person described by the OP is not incompetent? Yes or no?


Do you honestly think that such a person did not display poor judgement when agreeing to install a PA system, in a public place, for someone else? Yes or no?


If you do think any or all of those things I would be very interested to see a reasoned argument from you explaining just how and why using a mains dimmer switch on the speaker output of an amp shows an understanding of how they work, competence at installing audio systems and good judgement when agreeing to do it for a 3rd party in a public place.

 

[matt1e]

Amp is on half with left in the 8ohm screw-in output and the other is in the 0 output (I assume this is the common! When i take the 2 wires out of the dimmer and put the wires together sound comes out load and clear! The dimmers are 1 pole! What am i doing wrong?
There is other out puts ladled 70v 100v ect.
Thanks, Richard

as already explained you cant use lighting dimmers on speakers
How many speakers are you installing?
if there are a good few then you will be better off using 100v line
which would require a different type of volume control again then the one you would use to control speakers connected directly to the 8ohm outputs
what make/model of amp is it?

Matt

 

[joinerjohn]

Ideally, you need a volume control that would work on the Pre-Amp stage of the amplifier. does the amplifier have an effects out and back in loop?
Could possibly be set up that way.
Alternatively, some sort of mixer wired in at low level, then up to the amplifier would be better.
EDIT, Sorry Timthenchanter, Just read your post.

Great minds think alike ehh.

 

[ban-all-sheds]

Are you really so arrogant that you can't accept that maybe, just maybe people don't actually like your down right rude posting style?

People have all sorts of irrational views, and with every negative vote, with every positive one for you, with every thanks for your post, I just become more and more convinced that I am right, and that you're all a bunch of pathetic, inadequate, mewling children without a single worthwhile idea between you.

 

[Bill Stickers]

Are you really so arrogant that you can't accept that maybe, just maybe people don't actually like your down right rude posting style?

yes

 

[bernardgreen]

There are times when I totally agree with Ban All Sheds in his comments about un-informed DIY people who, based in their in-adequate knowledge and in-adequate thought processes, ignore and often abusively reject sensible sound advice. The advice has been given with the intention to prevent the ignorant DIY person causing harm to themselves and / or other people.

That said sometimes Ban All Sheds approach can be a bit heavy handed.

But sometimes the arrogance of the DIY person in rejecting the sound sensible and profession advice is enough to make a saint swear or drive a vegetarian to cannabalism. Barbequed DIY persons can sometimes be found in close contact with their own incorrectly installed electrical systems.