Glad to hear you like! I was amazed by these little things. We use them in most of our BMW OEM HU interfaces. Specs say flat to 0.5 Hz! (20 Hz with 7V of signal).

I'm pretty sure you could put one of these next to a piece of Romex inside a wall and be OK...

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musicar northwest, portland oregon

musicarnw.com

The West Coast BMW audio experts