I would certainly get the speakers serviced - it is a common issue for DSPs of this age to need replacement capacitors and load resistors. As the speakers get warm, the component values change, affecting the sound.

If you're not handy with a soldering iron, then there are a number of fellow HH's that offer re-capping services.

Feel free to drop either Tarik or me a PM - it is just a case of removing the back panels and sending them off...

Cheers,

Steve

Main: 861v6 (LPS), 808v6, UHD722, DSP8000SE Anniversaries, DSP5200.2HC, DSP7200.2, SW1600, Sky Q, Cambridge Audio BD, Roon, M80
Office: 861v4 (LPS), 818v3, 800v4, HD621, M&K S150P, DSP5500HC, M&K MPS2810 sub x2
Son's system: 861v4, HD621, DSP6000.2, DSP5200HC, DSP33
Spare: MCD, 100 Series, 200 Series, 500 Series, F80s, C15s.