yep, you're right. found it after i assembled it all and it accidentally disconnected because of the weight of the plate amp...

Just follow the steps in the service manual.

I found it quite easy. Just take out the screws and you should be able to place the PCB in some workable fashion.

Thanks. It's been a while since i even looked at a circuit board but i opened one to see what might be involved and my basic training came flooding back.

I did the limiter bypass on one anyway. It's harder to hear the difference with the forward mids but with arc and the full range bass correction the effect is more obvious, especially on stuff below 50hz. In particular i can hear where the limiter is kicking in on bass drums with lots of low end content on the right channel.

I'm considering upgrading the caps and opamps next but i think the improvements would be similar to what Arc is already doing. Could be a bit of a side project though but the limiter bypass is worth it imo.

Has anyone done these mods themselves?

It would be great to have a parts list and a guide for people who already have the HS80m's and can't get the mod done because they are not in the U.S.

I have the Hs80m and just recently got the subwoofer that goes with them..it was a HUGE improvement. I'm rolling off the low end that goes up to my hs80s at 110hrz and it has really improved the accuracy of tha hs80s (at least to my ears anyway). just curious if the mod still seems like money well spent or not, or if i should at least snip the limiter...warren..?

If our description of the changes we describe fits your desires, go for it...!

Also, we now have some preliminary reviews on both our mail-in mod product pages, as well as the mod speaker product pages on the ZenPro site. We are starting to get the feedback, and people are hearing what we hear.

The second pair we sold was to a guy who already owned the originals, and wanted to buy a new mod pair to use side by side, before making up his mind.

His other pair is now on the way to us for mod, also.

I know of at least one other guy who also just went ahead and bought a new pair to compare to his existing pair, and is blown away.

War

Have you tried modding KRK Rokits at Zen Pro? Im sure that would be a more bang for the buck mod.

That's what i've been trying to get to but noone seems to want to share.

Nah, a few people have posted, check posts in this thread. The service manual shows you how to get in and where the components are located with schematics.

No, and I disagree the Rokit series would surpass it in any way, modified or not.

RP8's and 6's are muddy!!!!

Hi, i'm doing the mod with the chips i have on my stash. I the first to chips in each monitor with lme49722 and a opa1642 on mid eq and room control section.
I did the limiter snip and signal path caps with Pana FM's.
So much better sounding now, the bass is more extensive and natural and highs begin to became liquid instead of rough.

Loving so mucha that i'm thinking of swapping all opamps. In order to finish the mod in both speakers i only have 8 of the opa1612 type or ne5532 type.

Are 1612's less stable than 1642's? Worse sounding?
Same question for the NE5532.

thanks.

Bump! Anyone got any updates on this?

how many opamps needed in total to finish both speakers?
can you explain details component for this mod..
cheers

There are 6x op amps per speaker so you'll need 12x replacement op amps all up.

Here's what I have so far. I haven't checked which poly caps should need replacing though.

Electrolytic caps (Panasonic or Ni****** low esr, 2x speakers):

- 1uF/50V x6
- 10uF/50V x22
- 47uF/16V x2
- 47uF/35V x2
- 47uF/50V x4
- 220uF/10V x2
- 4700uF/50V x4

Op amps (Burr Brown, 2x speakers, direct replacement)
- OPA2134 x12

Hope this helps..

Warren: sounds like an interesting further mod while you have these open is to convert these to a sealed cabinet (as an option). What do you think? It's hard to find good sealed-cabinet active monitors with a driver this size anywhere near the price of one of your modded speakers.

Damn you Gearslutz! I was happy before I read this thread and now I NEED something that doesn't even exist yet. Sigh...

Couldn't we just stuff a sock in the port!!! I think we can. I've done it in the past...!

We could stuff a sock in the port with uncertain results and hope we are doing more good than harm. But I don't have access to an anechoic chamber or the right equipment to measure the impact on the frequency response, do you? (Yea I have a Behringer measurement mic and room EQ wizard, but I can't separate my room from the speaker.). Also it was said earlier on this thread that you may need to provide different treatment inside the speaker cabinet for a sealed cabinet to work well.

A premodded sealed cabinet speaker would be a known quantity and be truly sealed. Not just sock-sealed.

No I don't trust my ears

It's not that complicated.. You just have to do homework on what frequency it's the port is centered around. I think it's 80 on the HS80 no pun intended.
Maybe a cork works best. It's inexpensive and you could remove it if it's not working.
I've read a few great mixing books, they recommended covering the ports yes even with socks. Just try it.

I think there are two questions.

1. If you already own a pair of ported speakers and wish to heed the advice of 'Mixing Secrets' and others, which states that owning a ported speaker is a bad choice because of port resonances, what do you do?

>> in this case I'm all for you plugging up the ports as you have nothing to lose.

2. If you are considering a new pair of monitors and wish to heed the same advice, what should you do?

>> in this case, I contend buying a ported speaker with the intention of plugging the port is foolish. The speaker was designed and tested with the port and your money is likely better of spent on a speaker that was designed and properly tested and tuned as a sealed-cabinet speaker.

If War, or anyone else, chooses to sell a sealed version of the HS80, along with frequency response charts and a properly treated cabinet, you are buying a known quantity and not taking a gamble by buying a pair of ported speakers you HOPE will perform more accurately when you shove a sock in the back.

I read 'Mixing Secrets' and saw what ported speakers look like on anechoic waterfalls and it's scary-bad. I will never purchase a pair of ported monitors after reading that book. But I am certainly open to trusting talented people to build a modded speaker that once was ported as long as it still has a better price-performance value than similarly-priced sealed cabinets.

I could tell the difference after I mod them with a sock.
lol!!!
Using Avantone MixCubes as a reference monitor now instead of Ns10's. But TONS of mixers use ported designs! Makes me wonder. I see tons of Mackie HR series too which is a semi close monitor, right?The room most def makes a difference. In my room I use AcstTrtmt and the new ARC2, for now, until I build a 20x25 room. I'm 10 years out! Til then, I'll sock it up! Hahahaha!
What ever gets you to better mix is the best for us!!!

Not to mention the modern sealed monitors are the price of a used car!! one day! For now my Event 20/30's and Mixcubes will have to do.
I do have the Pelonis 3ways on my wish list!!! Heard nothing but great things about those!

As I said, if you already have the HS80, by all means sock them

However, based on what I saw in the waterfall graphs regarding ported speakers (and speakers with passive resonators like the HR824), I wouldn't recommend buying a pair. Especially for someone with a small room.

And as you say, good sealed speakers of the size of the HS80 are incredibly expensive. Which leads me to believe that Warren and Zenpro would have a real winner on their hands if they added a case mode to their HS80M product. Take that speaker to an anechoic chamber and do a head-to-head shootout against the original HS80 (and maybe some other much more expensive monitors or even an HS80 with a sock in it!). I actually lied... where I work there is an anechoic chamber specifically for audio applications. I would have to pull some strings to get in... and I'm all the way across the country from South Carolina, where Warren is based, but I would be happy to test any design he comes up with if it's less expensive to ship them back and forth than to book time in a chamber where he is

An aisde: I am dubious that ARC2 can solve bass nodes in a room. I would love to see a waterfall plot of your room with and without ARC2 engaged and see how it looks.

I Absoulutly should do that!!

It solves my problem (treatment and ARC2), for now.. The good thing is thy it works great for me. My opinion, my mixes sounds a lot better when I use ARC2. Once again when I have the proper funds I'll make the BIG jump and built a larger room! Moving into a new house soon, with a build in mind.

I test in my room and make my own opinion(s) on gear. Socking the ports on the HS80 I liked, when I owned them,but those are gone!!! NS10's and Avantone is where I rely to reference my mixes.

Lol. +1 me too

I SHOULD be just writing music!!

I disagree ... Our ears are our best measurement tools (provided they still work ... and they determine the music everyone else likes too. If you stuff a sock and it sounds good to you in your room and your mixes travels better then you've done some good make-shift engineering.

+2
Like a pair of socks..

I liked a pair of socks in my KRK in my old room, in my new room though they weren't necessary as I needed more bass and not as much mid bump

Finally ordered a new pair of HS-50m's today. I decided for sure I will do 2 mods - disable the limiter and also replace the opamps.

Is only replacing the opamps and not replacing the Electrolytic or polypropylene capacitors advisable/doable? I only want to replace the opamps, mainly because they're easily identifiable by their shape, since I am a n00b at electrical work.. so I don't know how many, which exact type nor too good at reading schematics to properly replace certain/diff caps (tho I've soldered a couple times on my synths; but don't know much about caps, electrical, etc).

So my question are:
-Can i just replace the opamps, and not the Electrolytic/polypropylene caps?
-How many opamps should I buy total per monitor?
-Any other parts I should get to put on my mod list? If yes, quantity of them also please?

I'm just going to just get all Burr Brown OPA2134 opamps, since they've already been known and tried in the Yammies to work good (unless someone wants to convince me other wise to use diff opamps, such as the 2132, 1642, 5532, etc (tho I've read the 2134 work much better than the 1642's in the Yammies; though I am unsure of the 2132's nor 5532's (first and last circuits? - IC101 IC 104)).

Selling my pair now. Anyone interested PM me. The mod is DEFINITELY worth it and these speakers are amazing for the price. I just upgraded to much higher end ones. Thanks!