My brakes are quite loud after they warm up. I understand this is caused by the semi-metallic pads. Does anyone have a solution?

Thanks.

 

The squeal is generally caused by the pad vibrating against the caliper. It can usually be cured fairly easily using a can of brake cleaner and anti-squeal paste from the local auto parts store.
Take the brake pads out of the caliper and take a can of brake cleaner to caliper as well as the pads. Rest assured that it's going to be dirty. Apply the brake paste to the back of the pads and reassemble the brakes.
That will take care of it most of the time. Should the noise continue, get a small bottle of a product called Stop Squeal. It's in a small white bottle hardly bigger than a bottle of fingernail polish. This is the ONLY product that can be applied to the friction surface of the pads. You rub a little of it on the pad surface and allow it to soak in. After the pads are dry, reassemble the brakes (using the brake paste again) and go on down the road.

If you use an aggressive high performance brake pad, expect more noise than factory brake pads.