Please go to car accessories shop called "Lebanon Rock", near to Crazy signal. If you are going from Toyota signal, after reaching Crazy signal, take right turn. Almost after travelling 100 meter after passing first right, right side you can see this Lebanon Rock shop (before Nissan spare parts dealer)
Contact Numbers shown on their receipts: 77731223, 77714786
I took their service for two times for two different cars. So good sound installation and settings....I installed bass amplifier and bass woofer speaker. Excellent sound with boom...boom sound vibrations. This shop has good technician who can install car audio perfectly. Now i am enjoying good beat sound.
Please check with them.
But please note bass woofer speaker may be required for the good beats. This woofer you may get from Lulu or Carrefour.
Enjoy. Good luck.