There are those HVAC experts that have specialization in engineering; these exerts basically focus on the specialized side of the HVAC system. There are in like way the specialists alluded to as service professionals; their key part is to install belts and also accessorize the HVAC system. These professionals will regularly tackle the issues in your system inside a brief time frame but they ordinarily shun doing the major repairs.
In a case where you are to operate the music equipment, you would need to make sure that you focus on taking time to learn about the equipment especially where you are not the one to operate the equipment in question. You may also need to make sure that you take the pictures of the equipment just to be sure that any blame pushed on you is justified. However, one would need to have a music rental equipment that comes with a DJ. In such a case, one would not be liable of any damage just in a case where anything went wrong. One would also be sure that the connections and the equipment positioning will be done by an expert and hence reducing chances of possible hitches.