hi anyone interested in modding hs80m, wanted to give my experiences / thoughts
after doing the mod, i highly recommend. it makes the midrange waaay less harsh. for me this has allowed to mix more detail in the sensitive 3/4k etc range. previously, when i had mixed on hs80m, things often sounded dull because i overcompensated for the shrill sound of these frequencies. now, it's much easier to mix them accurately.
prior to mod, i found the monitors to be too clinical, very quick to bark and snarl. i think the circuit mod is enough to make these monitors sound much sweeter. maybe on par with something in the $2000+ range, but costs nowhere as much - like maybe $100ish in parts.
as others have said, the bass is also able to breathe a bit more due to disabling the limiter circuit. bearing in mind that you should be careful with the volume after removing the lim, i've cranked it a few times (obviously never close to full volume) and it's still more than loud enough. i still don't think they're super accurate in the bass - i would much prefer a sub tbh. there is def is an improvement in the bass, but the main improvement is in the midrange. fundamentally, mixing is quicker and easier.
i did the following:
- replace 4558 with BB2134
- replace electrolytic through-hole caps with low-ESR equivalents
- remove limiter circuit (snipping the wire)
in the first stage, i only removed the limiter circuit. there was noticeable difference. this step is relatively easy for anyone curious but not wishing to commit to arduous desoldering/soldering overhaul. i then used the monitors for a few months to see if there was any point continuing.
given the improvement i noticed, i then in the second stage replaced caps and opamps. in my opinion this produced a wonderful improvement, much more so than just removing limiter. it is tricky to desolder the SMD 4558s - unless you have a rework station or skills, it might be too hard. i think i used lelon caps from memory. some might have been rubicon/nichicon/panasonic fm. i'm sure any ESR / audio-grade cap would work well. it wasn't super difficult to unscrew everything.
i've seen some ppl mention replacing the power transformer or putting in WIMAs or other things like replacing the tweeters. maybe this would yield further improvements - not sure. i think the results are more than satisfactory with the minimal mod that i've followed. it's not super expensive, and i have no interest in further modifying them.
finally, i doubt it's worth replacing caps/opamps WITHOUT removing the limiter. not sure as i haven't tried it.
keen to hear others' experiences / any tips etc - cheers