What the Resolut BT-IN Bluetooth module offers, why aptX Lossless depends on your phone, what Resolut doesn't publish, and cheaper ways to add Bluetooth to a Resolut processor.

What the Resolut USB-IN HQ module does, which processors take it, what Resolut does and doesn't publish about formats, the cables you'll need and the alternatives.

The Resolut X12-DSP BT adds USB and Bluetooth to the X12-DSP for ₹50,000 more. What Resolut publishes, what it leaves out, the external-player alternative, and who should buy it.

The Alpine iLX-F509E 9-inch floating-screen receiver explained: wireless CarPlay and wired Android Auto, cameras, steering controls, sound tuning and pre-outs, fitting it to Indian dashboards, and its India MRP.

The Alpine UTS-A100 takes music from your phone over USB-C or LDAC Bluetooth and passes it to a DSP amplifier's optical or coaxial input. Here's exactly what it connects to, what it needs, and who should buy one.

What the JL Audio MBT-RXv2 weatherproof Bluetooth receiver does, which systems it suits in Indian cars, how to wire it to an amplifier, and what we could and couldn't verify.

What the Zapco Z-OTG-RCA's built-in DAC does, which Zapco amplifiers and processors it can feed, volume and noise caveats, the length Zapco lists, and how it compares with Zapco's other OTG products.

How the Zapco Z-OTG-OPT turns a phone's USB-C output into an optical feed for a DSP, which Zapco processors have a matching input, the cable length Zapco lists, and when another OTG product suits better.

What the Zapco Z-OTG-BT C does, which Zapco processors and amplifiers its outputs may suit, wired OTG versus Bluetooth, how it compares with Zapco's OTG cables, and when you don't need it.

What Zapco's optional HD-BT II-D Bluetooth module adds to an HDSP or DSP-IV processor, which units it fits, what Zapco doesn't publish, and how to get one in India.

The JL Audio VXi-BTC links a phone to JL's VXi DSP amplifiers over Bluetooth for tuning and control, not music. We explain what it works with, how it compares with the DRC-205 remote and whether you need one.