Just to revise my last post - one thing I didn't take into account was that subwoofers are likely to be higher sensitivity than normal speakers, and you will get back some or all of the necessary level difference there, rather than in amplifier gain.
Normal speakers are often in the 85-90dB range. Subwoofers are generally 90dB or higher.
The Dynaudio Sub RCC mentioned above is 92dB. So the combination of a 36dB power amp with the higher sensitivity would provide the required overall +15dB level increase over typical 87dB main speakers with a 26dB power amp.
Normal speakers are often in the 85-90dB range. Subwoofers are generally 90dB or higher.
The Dynaudio Sub RCC mentioned above is 92dB. So the combination of a 36dB power amp with the higher sensitivity would provide the required overall +15dB level increase over typical 87dB main speakers with a 26dB power amp.