Re: my new doors (BL4CK-VR6)
SPL is short form for Sound Pressure Level, it is measured in Decibels or dB's. We use a machine to measure the sound pressure (know as bass competitions)
Sound Quality is judges though objective and subjective judging with the use of judges and machines (called RTA, real time analyzers)
I can go on and on, but I don;t wanna ramble