NakamichiUltimate Series 24k Gold Plated Beryllium Red Copper Banana Plug 12 AWG - 18 AWG Gauge Size 4mm for Speakers Amplifier Hi-Fi Stereo Receiver Audio Wire Cable Connector 36 Pcs (18-Pairs)

Very good product.

I bought these hoping for an upgrade after one my old banana plugs - also Nakamichis, but the regular gold-plated ones, so cheaper than these - came apart. I use banana plugs at both ends - speakers and amp.These fancy berillium ones look the part and weigh quite a bit so they feel like quality banana plugs, but that's about all they get right. They're very fiddly to fit - once you've got the cable end in place and clamped it in place by tightening both screws, it's then really difficult to screw the jacket/cover on. Maybe my cable was a bit too thick for these, but I never had that issue with my old Nakamichi plugs.With a pair of pliers, a bit of persistence and some choice language, I eventually got them on, so I plugged them into the amp and speakers, sat back and played some mucis, expecting to enjoy the rewards of my efforts. But no, things went from bad to worse: the sound was very noticably impaired compared to how it had been with the old plugs; the frequency extremese were rolled off, so really deep bass and top-end (hi-hats, cymbals, etc) were muted, and the whole presentation just seemed a bit veiled, a bit less clear and sharp than it had been.I gave them a chance, stuck with them for a week or so, then decided I'd had enough. I took them off and went right back to basics, did away with plugs altogether and just went bare-cable-ends to amp/speaker terminals. And voila, clarity and presence were back in abundance.If you've got a system that needs taming - maybe too bright in the treble, or too boomy in the low bass - then these might be just what you need. But you will also lose some clarity and detail too.