I have a Williams allegro 2 digital keyboard i don't ever play it loudly however the left side speaker goes in and out, making it not sound great at all. Any tips into finding the problem?

The contact strips under the keys need to be cleaned or replaced.

Hi Kyle:
Have a look at your manual.
Sometimes you'll find that there will be an "input" setting required.
You might also try google with his link.
https://www.google.ca/#q=Williams+Allegro+88-Key+Digital+Piano
Hope this helps.
Cheers.

Sounds like either there is a problem with a low frequency driver or perhaps an eq setting.
If you have an external (line) output, you can try sending the signl through another amp. If you have headphones, then try them also. If the headphones sound distorted as well,then see if you have the eq to high on the bass.
Other than that, it could be a filter capacitor in the power supply. You would need some experience fixing that.

You probably want to connect to an audio input.

As you didn't tell us the make and model, we can't be much help. You should conytact the Customer Service Department of whoever manufactured the instrument.

Take it back to the store (send it back to the store but call first to get a return authorization if you got it online). This sounds like a manufactures defect. It shouldn't work that way.

You can also try calling Yamaha (good customer service historically). Check your packaging for their number. They usually prefer that you call them to get things fixed instead of returning it.

I would not recommend trying any quick fixes anyone else recommends because they can invalidate your warranty from Yamaha

Good luck.

Assuming this has worked in the past (otherwise if you have changed to different pedal that is the problem) the usual thing is the machine samples the state of the pedal at power up and assumes the polarity of the pedal is at rest. Make sure you are not pressing it as you power up. Also verify the pedal is COMPLETELY plugged in... sometimes they are not quite fully in and that causes a problem, especially with the two stage versions that are sometimes used.

http://www.williamspianos.com/products/Williams%20Allegro%20manual_LR.pdf

If this is a brand new unit, exercise your warranty!

BUT FIRST see if packing material worked through the speaker grill... you know littel pieces of the packing peanuts or otherr contamination that sits in the speaker cone and rattles.

Check if front of key is hitting the case. If it is, analyze why it is happening. If unit has been dropped this can happen. One can sometimes move the whole key assembly back slightly if this is the problem.