Can you upload a short video showing how solid they are? For me the bt-77 arm itself was rather solid, but the plate on which the speaker rests, when placing the entire weight of the speaker, allows the speaker to wobble (it seems to wobble with the plate, possibly the plate itself is bending a bit for me). Although I did place them slightly more forward on the plate (as forward as I could without the clamp failing to hold the speaker and allowing it to tip forward).