Will a voltage regulator improve sound?

I have a cheaper system. Pioneer VSX-1014TX receiver, Sony SCD-C333ES cd player, BESL 5MT speakers, and a homemade 12" Peerless XLS sub. Here in San Diego I notice we have lots of power sags (the lights dim in my house). I have considered adding a 1200w voltage regulator. I see the APC LE1200 available for $45 and the TrippLite LC1200 for $100. Will this just help protect my equipment or will it actually improve the sound? Will it color the sound? Any guesses about the difference in price?
Go with TrippLite. It's a great product that will NOT color or alter the sound but WILL protect your equipment.
The purpose of any surge-protector and voltage regulator for audio applications is not to alter any equipment performance.
If you live in a home built in the 50's or older, the problem is probably due to wiring.

I used to live in San Rafael in a home built in the 50's. It had a 100 amp service panel (as most older homes do) and there were only 4 circuits for the entire house.

To make a long story short, every time the dishwasher and/or microwave and/or washing machine and/or refrig motor were running all the lights in the house would start to flicker for the duration.

I know CA has it's electrical issues for everybody, but I'll bet it's the overloading of circuits that you are experiencing.

If you do not have dedicated lines (or at least one) from your service panel to your equipment, if you had an electrician install one or more, it may help. And while he's there, (assuming your home is an older home) you could inquire about moving appliances around on the service panel, dedicating the lighting to their own circuits, etc. which may resolve some or most of your problems.

Most surge protectors will give a blacker background, but at the expense of dynamic range.
This is especially true of the cheaper ones(under $1k)

Make sure you can return it for a refund if it doesn't perform to your liking, whatever you decide to buy.

John C.
I Live in the middle east, the voltage is very unstable. I purchased a tripplite LR2000 (220-240V) line conditioner/voltage regulator. I purchased this product for the reason of voltage protection only and was suprised that it also improved the sound. I consider this a good buy, I paid approx $160. I've had the unit for about 6 months, my system is on for an average 4 to 5 hr's a day and I've had no problems. I was always a bit of a sceptic when it comes to mains conditioning, I'm now convinced and will probably buy a better unit when I return to the UK. It would be good to hear if anybody else has had good experiance with Tripplite products.