Likely culprit for harshness at higher volumes?


Hi,

I'm a newbie to higher end audio. I have a very modest system:
1) Pre-amp: Anthem AVM2
2) Amp: Adcom GFA-5400
3) Source: Sony CDP-X111ES CD player
4) Speakers: KEF C75
5) Toslink between source and pre-amp; cheap RCA cables from pre-amp to amp; 16 or 18 gauge speaker wire (Radio Shack?)

Room setup (10-ish feet x 20-ish feet rectangle):
1) 2 foot deep cabinets along one wall (20-ish foot)
2) Components stacked on top of small end table against rear wall (10 foot); centered between cabinets and opposite wall.
3) Speakers slightly in front of end table and about 2 feet from side walls and 4 feet from rear wall

Sounds good at about -45 to -25db; but higher frequencies get harsh at higher than -25db.

Appreciate your thoughts.
saru
Tsk, tsk, tsk. Twenty one posts to this thread and no one has suggested upgraded power cables? :O
Seriously though, sounds to me like speakers or room reflections are the most likely cause of your problem. You are on the right track with your 4-step program. Although I would move number 4 up to 2 and scrap number 3. Good luck and keep us informed.
Saru, why don't you at least post the city or vicinity you are located. I am sure others may be willing to stop by and listen, diagnose, and even help you ID the problem with bringing some stuff (equip, cables, deflectors, etc. . . ) over.

Any component can create congestion, HF glare, etc. . . as part of a combination with other components (or alone).

I once owned an amp (Theta Dreadnaught II) that was literally unlistenable for me. Nora Jones sounded like the worst singer in the world with that amp, any time her voice reached up it sound like she had a horrible scratchy, distorted voice. This sound only revealed itself when the amp was installed. I replaced the amp and everything went away. I once had the same issue with a DAC and another time with a CDP (but with the CDP it was only at higher volumes where it became apparent - and much less so than with the Dreadnaught).

Your steps seems to be in good order, but try to find people in your area before you start replacing components on a guessing basis. You may replace half your components before you find the real culprit if it really is even component related???
Its probably a combined effect of everything together more than due to any one thing.

I'd get some decent ICs as an easy and cheap thing to try as a first step.

I'd recommend a used pair of MIT Terminator 2 or 4 ICs for < $50 used as a first step to help tame things down a bit and get more out of what you have before changing anything else.

Next I'd look at some decent but not expensive speaker wires also for an upgrade. DNM Reson would be my first choice.

From there, perhaps a tube DAC upgrade to use with the CD player or a tube pre-amp if the harshness exists in multiple sources, not just digital.

For a tube DAC to help tame things further, I'd recommend an mhdt Paradisea or even better a mhdt Havana if you can squeeze it.
Is there any adjustments on the pre-amp or amp that might be turned up too much. Isn't it possible to have the inputs too sensitive?

Hi folks,

Again, thanks for the continued expertise and help. BTW, I should mention I'm on a pretty tight budget which explains my rather dated and very modest system as well. :)

Started the experimentation this morning with room dynamics while waiting for Radio Shack to open.

I'm still testing but it seems that room dynamics is having a strong first order effect.

I changed the configuration of the room such that the listening direction is across the narrow of the rectangular room. So, the listening distance may be slightly shorter (not by much -- maybe a few feet at the most) but it allowed wider separation of the speakers. I also put up some fabric to try to minimize reflections.

This change allowed me to increase volume levels from about -20db (when I would start to hear harshness) to about -5db (where it starts to get uncomfortably loud); at this point, I hear a little harshness but it's not nearly as much as before. The harshness is almost (but not quite) acceptable.

Wow!! Just a little grunt work and things seem to be improving. Either that or I need coffee and my ears haven't woken up yet.

I'm still working my way through the 4 steps but so far things seem promising. I'm hoping to make what I have work -- basically have a zero sum budget. If I buy something, I need to sell something else. :)

BTW, a lot of terms, brands, parts (ie - HF glare, congestion, ferrite clamps, etc) you folks mention are new to me. I've been spending a lot of time looking things up on the internet. Thanks -- I'm learning a lot. This has been a good experience -- you've all been very helpful.