Taming the Harness of My QSC K12

    Early this year I wrote in this forum about the harness of my QSC K12 and what others were doing to reduce it. I realized other users have similar problem with QSC K12 and I think with that the interest for QSC K12 as KPA monitor have died down. The mostly discussed monitors now are Yamaha DXR10 and the Atomic. However I did not give up on my K12 because it is a good acoustic guitar monitor together with KPA using the Acoustic A-E profiles that I downloaded from the Rig Exchange ( many thanks to the uploader of that profile). I can say it was a better compared against my AER Cube 60 Bingo. Another reason for sticking with K12 is that I bought it at great discount and I don't want to spend anymore for another.


    I asked my best friend Google for a workaround and found out that the famous sound engineer Bob Clearmountain used tissue paper to tame the harshness of his Yamaha NS10 monitor during his time. However realizing that this was not a robust solution I googled again and found that the same principle was used by Weber Beam Blocker (Although some would say that they are different principle but for me they are the same). I was thinking then how to use the principle with my K12 and while searching, the lowly mouse pad got me very curious and as a result this is my QSC K12. I'm no longer eyeing at any monitor since.


    What I did was attach two mouse pads using mounting tape and adjust the KPA EQ to fine tune. You may ask why not just adjust the EQ to tame the harshness, however I found out that I cannot duplicate the mousepad effect on reducing the harshness with EQ adjustment alone. The have different effects the way I hear it. However if I want to use it as acoustic guitar amp I need to remove the mouse pad and switch KPA to acoustic profile. I was tempted before to adjust the area of the mouse pad to get variation in the harsh reduction but I think I hit it the first time so I don't want to experiment further.


    A word of caution though and a disclaimer. This method may have the potential to damage your speaker. I only play music at home so I don't need that much volume compared to live gig. However I have used this for quite sometime and still I haven't found any adverse effect with my K12. To those who wanted to try kindly share your observations, maybe I'm just having a placebo effect, well I don't know :)


    My current predicament is how to get my K12 to be used as electric and acoustic amp without too much hassle of removing the pad from the mounting tape and back again. Maybe you have a better idea :)

    WIth all due respect, that's kind of bizarre... I know it works for you, but still... :S


    What do you do when you record? Or when you play through someone's PA?


    OK, let's break this down... The K12's crossover frequency (the split between the LF and HF drivers) is at 2KHz. You're effectively muting the HF driver. So what you're doing, in practice, is cutting all the frequencies from 2KHz up.


    How have you attempted to duplicate this effect using EQ?


    Clearly, the Kemper's output EQ won't get you there...


    However, the Studio Equalizer should work. You can drop it into the X slot. Start with the Studio Default preset (the gain on all bands is set to zero), then set the High Freq to approximately 2000 Hz and the High Gain as low as it'll go (-18 dB). That should give you the same effect as covering your K12's HF driver.



    That should at least let you get the mouse pad off of your K12, allowing you to use the speaker for your Kemper and other program sources.



    But... Your approach seems a bit extreme from a tonal perspective. I'm certainly not going to tell you that the K-series speakers are flawless. But corrective EQ for the speaker is not of the "cut everything above 2K" variety. I suspect that you may want to rethink your rigs. Or just go with the Studio Equalizer hack that I outlined above.

    why would someone keep the k12 and try this instead of selling it and going for a different monitor?


    the studio eq approach sounds interesting but see above.


    I would always want my reference system to be a sonic foundation I am in sync with (meaning: buy something you like better)

    90% of the game is half-mental.

    Quote from bigHF

    why would someone keep the k12 and try this instead of selling it and going for a different monitor?


    Briefly, because finding a need to suppress all energy above 2KHz using an acoustically-opaque blocker suggests a problem with the program source, particularly when other program sources don't require this modification to the speaker.