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
Hi again,

It's hard to describe some of the things I'm hearing since I don't share the audio vocabulary (yet) that you folks have. Not quite accurate, but the closest description is that the harshness is somewhat like humming and then patting your chest -- what should be a smooth sound is disrupted by unnatural vibrations.

I bought the Auvio RCA cable and the ferrite clamps that I installed, 2 per channel, on the CD-pre-amp and pre-amp to amp interconnects. I installed the new Auvio cable between the pre-amp and amp. The remaining non-brand RCA cable seems to be pretty good as generic goes (a little thicker than normal and w/ gold plated leads).

Again, re-configuring the room layout and adding some fabric to minimize reflections (still get some echo from clapping but not as bad as before), seemed to have a dramatic impact. I could turn up the volume louder before the harshness kicked in.

I also moved everything into a larger room (temporarily) that is asymmetrically shaped (no/minimal echoes from clapping). The sound really opened up then and harshness was moved to even louder volumes.

I'm guessing that:
1) room dynamics is having a large first order effect
2) the better(?) cables and the ferrite cores may be helping but not sure; hard to tell after changing the room config
3) the harshness also depends on what I'm listening too (Monheit singing louder and at higher frequencies can result in harshness; acoustics like Joe Pass seems less susceptible). Perhaps room dynamics affect certain frequencies more than others; or maybe just the selective sensitivity of my ears.
4) at some loud (uncomfortable but not painful) volume level, I think I'm approaching the limits of either the amp and/or the speakers (starts at about -5db) -- harshness that is maybe distinct from the symptoms I hear with Monheit at lower volumes.

I think now I can listen to things like Monheit at volumes I desire (around -15db to -20db) w/ acceptable levels of harshness (perceptible but perhaps not enough to drive changes to components with their associated costs) whereas before the harshness was unbearable and tiring.

I'll continue to experiment with room dynamics and look into getting a better (24/192?) CD player (my 20 year old Sony has had a good run). But the sound is much more enjoyable than 24 hours ago. :)

Thanks much to all for the help and suggestions!
Saru - I read through the manual for your pre-amp and didn't see anything like what I was referring to. On my truck subwoofer amp and also some of the amps in the audio system at my church have adjustments for the input sensitivity that can really change the way things sound. I think some seperates have this type of adjustments, but not all. I was thinking that you might have things oversensitive and amplifying something in the digital recordings.

You might actually try allowing your pre-amp to do some processing rather than bypassinge everything. On my Integra 50.1 receiver I generally listen in direct mode when I'm in audiophile mode, but for some recordings it simply sounds better in stereo mode where the signal gets processed a bit. It may be similar for your system but for different reasons.

I highly doubt that you'll hear much if any difference from any cable swaps you make unless you are currently using a damaged cable currently or you're getting a lot of interference in an unshielded cable.
1) CDs. Some are mastered horribly bright
2) Room. Too much reverberation at high frequencies
3) Speakers.
Glad some small tweaks could elp out.
you could experiment with the Ferrite, try taking a pair off an interconnect (a tiny screwdriver can pop up the clips if they are like the old ones I still use, bought them 20 years ago.. and have moved them around and around an all sorts of stuff. I must own two dozen of them))
And try one on the CD powercord.(or if new Radio Shack anytime soon, get one for the CD powercord.
If i was you, i would look foor a cheap used Adcom 315 power conditioner here . Or some other small conditioner, to use just for the CD player and preamp.
Not more than $100 used.
Given that your preamp has a headphone jack, my suggestion is that before going much further you invest in a pair of headphones. Considering the number of variables and possibilities that have been cited, I think that comparing results between headphones and speakers would be very useful in distinguishing between source material or front-end issues, and room/speaker/amplifier issues (despite the fact that headphone listening is a fundamentally different experience than listening via speakers).

A good fairly low priced choice would be the $84 Sony MDR-7506, which is widely respected within its price range. I have a pair that I use for non-critical purposes, primarily for monitoring while doing amateur videography and voice recording, and I've been pleased with it, especially considering the price. I haven't tried it in my main system, though.
04-22-11: Meiwan
At higher volumes you may be noticing harshness in your system that you don't at lower volumes (even though it's there).
This is an important point to keep in mind. As volume increases, the sensitivity of our ears to high and low frequencies increases, relative to their sensitivity to mid-frequencies. That is known as the Fletcher-Munson Effect.

Regards,
-- Al