I don't have any subs yet. Other forums recommended a powered sub(s). I'm not sure what type of speaker inputs I have, I have to look at my manual. I bought a preamp because it has a Midrange control which I really love. And there's something wrong with the Integrated amp: It has "Pure Direct" and "CD/DVD Direct" buttons. When they are on they are supposed to bypass the circuitry to give a better direct sound and the bass/treble/loudness are bypassed, too (so I can't use them). For some reason, when I turn both Direct buttons off I get no signal at all! So I can't get the bass/treble to work on my Integrated amp, period. I contacted Yamaha Support and they told me something's wrong internally with the amp if this is happening.
L110's are by far the best speakers I've owned and I've tried a lot of speakers (Polk, Infinity, Klipsch, B&W, ADS, JBL L100). L110's give the most realistic vocals and highs I've heard but the bass is not as well-defined as I would like which is why I want to add a sub(s). I'm on a really tight budget because I'm on disability and in debt and I can't put money into other expensive speakers. The Infinity and B&W cost me a lot of money and they were really disappointing. Infinity's were harsh and B&W had lousy bass definition. So I thought adding sub(s) would be the solution for my system. I listen to a lot of Sabbath, Priest, Robin Trower, ZZ Top, Cream, Joe Satriani, Van Halen at high volume and the L110's hit really hard and are balanced and sound very realistic.