Q I store my music collection on an iMac and use iTunes for playback. I have a plan to use two JBL powered studio monitors and an old Sunfire MKII subwoofer for a desktop speaker system. Here’s my question: How do I set the system up for optimal sound quality? Should I buy a USB DAC? If I did, how would I integrate it with the speakers and sub? Is there a DAC with three RCA outputs and a built-in subwoofer crossover? —Rick Martinez
Q My system consists of a Sony XBR-X900E TV, a PlayStation 4Pro console, and a Yamaha YAS-207 soundbar. The PS4 Pro does not play Ultra HD Blu-ray Discs, so I’m planning to buy an Ultra HD Blu-ray player. Here’s my problem: I want to connect both the PS4 Pro and the disc player to the Yamaha, but the soundbar only has one HDMI input. I’ve looked around for an HDMI switcher that’s compatible with both 4K/60-Hz video signals and high dynamic range but haven’t been able to find one. Will I have to switch the cable connected to the soundbar from my sources on an as-needed basis to maintain best picture and sound quality? —Paul Trava / via e-mail
Q What’s the best way to connect a subwoofer used mainly for music listening? I’ve been trying both the stereo RCA and mono LFE input connections on my Klipsch R 120SW subwoofer, but am not sure which works best, and also where I should set the low-pass/LFE filter on my Onkyo TX-NR717 receiver. My front speakers are Klipsch R-28F towers. I would appreciate any recommendations on crossover settings for the receiver and the subwoofer itself. —Ken Zarubi, via email
Q I own an Audio-Technica AT-LP120-USB turntable that I’ve modded. I’ve also purchased a Cambridge Audio CP1 phono preamp to connect the Audio-Technica to my Denon AVR-X6200W receiver. Can you help me understand how to hook the CP1 up to the Denon? I’ve tried many options but still fail to get sound. The turntable plays when plugged into another amp so I know it’s working correctly —Rodger Benson
Q Is there any way to connect my old Technics SH-GE90 Equalizer/Digital Sound Processor to my new Onkyo TX- NR838 receiver? The Technics is capable of signal manipulation, but what I really miss is the graphic display of audio waveforms on its front panel. If this is not possible, are there any similar devices that connect via HDMI?—Mark Goldberg, Rochester, NY
Q I have an old Yamaha RX-V1900 7.1 receiver that is still going strong. I know I should upgrade to a newer unit, but I spent around $2,000 on it back in 2008. Here’s my question. I have two powerful subwoofers and would like to connect both using a Y-adapter since the receiver only has a single subwoofer output. Will that function properly, or is it not even an option? —Jarrod Agesen
Q I just bought an Apple TV 4K streaming box and was wondering if I can use it with my surround sound system. If so, how do I connect it? —Mario Caballero
Q I own an Integra receiver, Polk Audio speakers, and an Oppo BDP-105D Blu-ray player with a high-end DAC. I recently bought an iMac and am using it to download and store high-res audio files. What’s the best way to connect my iMac to the Oppo player? Both are set up in the same room about 20 feet apart. —Neil Levy