Using a voltage regulator

Background: I live in Mexico. We suffer from a highly fluctuating voltage system. I have put voltage regulators on all sensitive electronic equipment (refrigerator, microwave, washer, dryer, computers, modems, routers, etc.) but use an S 15 APC surge protector on the stereo system.

Question: Since the APC a surge protector but NOT a voltage regulator would it be wise to put a voltage regulator between the wall outlet and the APC? Currently I have to set the high end of the APC to 135 volts to prevent it from constantly sounding the alarm and going to battery back-up.

We also suffer from brownouts which can be just as deadly to equipment.

Is this not what you have? If not, it might be an option to consider. I looked up APC S15 and it's a Power Conditioner with battery backup and it does voltage regulation. I have the APC H15 that doesn't include battery backup.

I'll keep looking for an S15 surge protector.
Mceljo: Yes, that is what I have but in order to regulate the voltage you set low and high voltage parameters. When the voltage crosses those parameters the alarm sounds, the power is shut off and the battery back-up activates. So by definition the S-15 is really a surge protector. My other regulators on the computers, etc. actually do reduce the high voltage to an acceptable level before passing in on to my equipment. This is different than the APC which simply shuts itself off when the voltage is higher than what you set it for. . Thanks for joining in.
Gotcha - My APC H15 has voltage regulation but doesn't switch to battery power so it much function differently than the S15. Mine simply turns on a warning light to let me know if it boosting or trimming.

If you don't need the battery backup you could try an H15 or even double down?
Puerto - What specifically are you concerned about for your equipment? The APC S15 is, in a sense, performing a voltage regulation function because it isn't allowing voltages outside of a certain range to reach your equipment. It almost sounds like you're looking for something that will avoid "sounding the alarm" more than you're in need of better protection.

I'm almost thinking that a power regenerator might be what you're looking for, but not sure how they would perform under the power conditions you describe.
I guess what I am looking for is the ability to energize my equipment at a reasonable voltage level without having the APC constantly reverting to battery back-up. It wouldn't take long to run out of battery if the monos, et al were in full swing. As it is, the system is operating on about 130-135 volts most of the time. I think that is too high. I don't mind the alarm per se, glad to have it but prefer that the voltage remain steady throughout at 110V. That is what has prompted my question about the feasibility of installing a voltage regulator between the wall outlet and the APC. I'm just not knowledgeable enough to know if that would be a harmful set-up in any way.
Mceljo: What you have is what I need. That is exactly how my other regulators work on the computers, etc. Going back to my original thought - if a voltage regulator reduced the high voltage spikes back to 110V BEFORE sending the power on to the APC would this in some way be harmful to the APC or SQ?
I can't imagine how. It might limit current and that can have a negative effect on sound quality, but it won't damage anything.
OK! The verdict is in! I hooked up one of my voltage regulators in between the wall and the APC. According to the APC it is putting out a steady 118-119V to the APC. SQ you ask? Can't tell the difference. My peace of mind? Much better.

I have left the APC alarm setting at 134V as a "just in case".

Thanks for your input.
One last thought for those that are wondering - the monoblock amps are NOT running through the APC (hence the voltage regulator). I think they can handle the higher voltages - to a point.

Any further thoughts are welcome.
and finally . . .I wrote to Krell to ask about putting voltage regulators on the FBP 350 monos. Their reply - don't do it. The amps can handle the higher voltage, in fact the VR would have a current limiting effect on the amps which could hinder their performance, Mceljo had mentioned that earlier - a good observation.