Likely culprit for harshness at higher volumes?

Thanks guys.

The KEF C75 (4ohm) is rated for at least 150W I think. I think the Adcom GFA-5400 is rated for 150W/ch for 8ohm, 200W/ch for 4ohm.

I'm waiting for Monster MC 200I-2M interconnect cables (for pre-amp to amp) to arrive; hope these are okay. :) I didn't plan to change the Toslink yet. I am also planning to get some (better?) 16 gauge speaker wire from Radio Shack (I was thinking about Monster XPMS but it's 3x the price and not sure if it's any better).

The typical CD's include Jane Monheit "Never Never Land", Joe Pass "Virtuoso" and various Diane Krall; also some Burrell, Coltrane -- usual vocal/jazz stuff I guess.

I was wondering if it was the KEF's since the AVM2 and GFA-5400 seems to have good reviews. I only have KEF Q10's to try but I can see what happens. I'll also try using analog from CD to pre-amp. I was only using the digital connection because I was assuming that the AVM2 DAC's are better than the Sony's.

2 easy things to try and I'll report back later. Thanks for the help. Open for any other thoughts as well.

Hi guys,

Thanks for the good info. I connected the CD player to the pre-amp using non-brand but what seems like otherwise decent, gold plated RCA cables using the analog output/inputs. To my surprise, while the harness is still there at higher volumes, since I was listening somewhat critically, the analog actually sounded a noticeable crisper and brighter than using the toslink. The toslink sounded slightly muffled in comparison. I'll get better cables next week to connect the pre-amp to the amp; maybe the combination of using CD analog outs and better pre-amp/amp cables will help.

Anyway, the harshness is still there regardless of toslink or analog.

So, based on the comments so far, that leads to speakers and/or the room (ignoring the cables for now). I'll try using the Q10's I have and see if that makes any difference. Will report back again later.

The room is fully carpeted but the drywall walls are bare and the cabinets are either dense wood or glass so reflections are probably possible.

Using the KEF Q10's didn't seem to make much difference; noticeable less bass but the harshness is still there, especially when a singer hits loud, high notes. Perhaps the KEF Q10's are too similar to the C75's?

I hope the Monster MC 200I-2M I'm getting next week to connect the pre-amp to the amp will make a difference.

I'll need to research what ferrite claps are -- I've never heard the term before. But sounds easy enough. I can try it w/ the current interconnects and when the Monster MC 200I-2M arrive.

Thanks for all the comments. Still open to any suggestions until the issue is solved. :)

I'll try the ferrite claps and report back later.

I am turning up the volume a bit; not necessarily to get more bass but to hear some of the other instruments that may be in the background and/or a little quieter.

I found that on some CDs, at background listening levels, sound seemed to come mostly from one side or the other. When turning up the volume a bit, I'd then notice additional instruments coming from the other side (mostly some sort of percussive instrument). Since then, I've gotten used to playing CDs at a certain volume levels.

So, the 'desired' listening levels may be a little loud but I don't think they are overly so -- I'm not concerned about damaging my hearing at these levels (but perhaps my ears are already bad :)).

But if certain frequencies are being overdriven, what's the solution? Get different speakers? If so, any specific speaker attributes I should be considering? Larger tweeter / mids? Bi-wire capable? Capable of higher power inputs?

Or is this an amp issue? Need a more powerful amp?

Hi folks, thanks for the continued comments.

So, if I summarize correctly, the primary suspects include:
1) speakers (distortion)
2) amplifier (insufficient to drive the KEF 4ohm load)
3) RF noise entering the lines (will get the ferrite clamps to check this out)
4) room dynamics (reflections); I walked around the room quickly and clapped in various locations. It was interesting -- even though the room is fully carpeted, I could hear reflections and a kind of pinging after each clap (I don't really know how to describe it -- a kind of reverb echo).

Oh, yea I know that the volume level reference I made above is a little abstract but I assumed that you experts would have an order of magnitude sense given the components I'm using. :) Not extremely loud but louder than conversation levels.

I'm going to try some of the easy suggestions next (this weekend):
1) using the KEF Q10's again; do a larger sample to see if perhaps my C75's are blown (but by nature, the KEFs may be subject to the distortion I'm observing in which case I may hear no difference; in this case, may need to borrow some speakers)
2) use some blankets to minimize reflectivity
3) use the ferrite clamps
4) Not sure what I can do to check if for amp insufficiency; I can try using my Nakamichi AV8 receiver but I'm assuming that the Adcom is a better amp.

Anyway, I'll start w/ #1,2,3 and go from there. I'll report back later.

Quick question on the ferrite clamps -- do I need two per channel (one at each end of the cable, so 4 altogether for a left / right pair)?

Or do I just need two for each cable pair (one at each end that wraps around both channels)?

Or do I just need one for each cable pair (one that wraps around both channels, placed either near the source or near the sink)?

I'm not sure how to use these clamps..... Thanks.

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.

@Mceljo: I set the Front Speakers as Large. I don't have center, surround or subwoofer (probably meaningless, but I set the sub x-over frequency at 160Hz from 80Hz; I feel my speakers put too much weight on bass). Other than that, I set the effects to Stereo (no processing) and have bypassed Tone controls.

Using analog inputs now --- I have them going into the Direct Analog inputs which is supposed to bypass everything except volume and tone (which I've set to bypassed).

Other than that, I'm not sure what to check. Is there something else I should look at in the config that I've missed? Nothing else seems to be mentioned in the manual (that I recall).

@Mapman: I have Monster MC 200I-1M being delivered next week for the pre-amp to amp connection. While picking up the ferrite clamps from Radio Shack when they open, I was thinking about picking up their AUVIO® 3-Ft. Stereo Audio RCA Cable for the CD to pre-amp connection.

Is this better than the non-branded red/white RCA cables (that might come with cheap consumer electronics)? Or are you thinking about something even better? I'm not really sure what to look for in a IC cable.

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!

Hi -- thanks for continuing to check in on this topic and offering your suggestions. I am continuing to experiment, mostly with fabric (types and locations) for reflections, speaker location (separation and proximity), analog vs digital interconnections and various types of music (classical, jazz, vocal; low (ie - bass, sax), mid (vocals / guitar) and high (some vocal and violin) pitch sounds across various volume ranges.

I've been spending a lot of time listening, moving stuff around (including using a different room and moving components between rooms) and characterizing. :) This seems really more of an art than a science.

I've tried a lot of things and I think I'm reaching the limit of room dynamics and my components without buying stuff (dampeners, drapes, different components, etc).

While it's not perfect and some harshness is still there, it's definitely better than a few days ago and I'm actually able to turn up the volume quite a bit more before the harshness becomes unbearable. Again, before, I would get unbearable harshness before the sound was uncomfortably loud. Now, I can get the sound to be uncomfortably loud before the harshness is really unsettling (and perhaps I'm also now reaching the limits of my speakers and/or amp). The clapping / pinging test is much better now, especially in corners where it was the worst.

I appreciate the suggestions and understand the reasoning for a power conditioner and the headphones (actually, I really want to buy some nice headphones and using them for additional testing here is an additional reason). And I keep learning new things: I had to look up the Fletcher-Munson Effect (never heard of it before). BTW, what is BPC (as in, my Adcom amp are not much more than BPC)? Not that I disagree but just not sure what it stands for. :) I think my GFA-5400 is rev 1 of 2 versions (I have the rev made in Japan, not China).

But, given my budget, I can almost buy a used CD player that may help improve a weak link in my system (access to additional bits and higher sampling rates); I think my current DACs (in both my AVM2 and X111ES are 8 or 16 bit and 48 or 96 KHz). Perhaps getting something like a used Cambridge Audio CD player in the $200 price range would be the best use of any budget I might have.

Or maybe I should just be happy with what I have. It doesn't actually sound too bad now after trying some of the inexpensive suggestions received; it's not perfect but better. But I can see how a budget could very quickly spin wildly out of control here. :)

@Csontos: Thanks for the suggestion. I want to make sure I understand the methodology. The presumption is that a well recorded CD (ie - something that is well mastered using larger word sizes (24bit?) and higher sampling rates (ie - 96 or 192KHz?) and well done (ie - good recording studio, good equipment, etc) should play well on any system (up to the limits of said system).

The assumption here is that the pre-amp and speakers are not the weak link at the volumes I'm using. And even a source that is 8 or 16 bit at 48 or 96 KHz should be sufficient for a good recording to highlight deficiencies in an amp.

So, by playing a known good recording (like ones suggested), I can determine if the amp is limiting if there is harshness detected.

Whereas, if harshness isn't detected, then it's just poor recordings I'm listening to (in addition to other things like room acoustics)?

Actually, I've been wondering if there is a way to challenge each component in some way. But I've just learned that this way of thinking may not be useful -- that components play off each others strengths and weaknesses so you need to measure the system as whole in the room you are targeting. Must drive audio component retailers crazy - a component that sounds good in the store may sound lacking at home :)

So, if I learn that the Adcom is lacking, I guess that's what the amp forum is for. :)

Hi all,

If anyone is still reading this, I was wondering if I might ask one closing question.

I've been reading up on jitter (who knew moving to digital wasn't going to be perfect?). I don't have a detailed understanding but I do have some questions about how it manifests itself:

1) when it happens, I assume it's not modulated by volume levels. I should observe equally at low and high volumes although it might be more obvious at higher volumes. Correct?

2) when it happens, does it happen just for a brief period (milliseconds? seconds?)? Or does it happen almost continuously? If it happens, does it just happen once and go away for awhile? Or will it happen frequently?

3) is coax and optical equally susceptible? or is one better than the other? In any case, it sounds like analog between the source and pre-amp is the way to go. So, this suggests I should focus on having a good DAC and electronics in the source and should not care what is inside the pre-amp / processor. Correct?

Thanks again to all for your help. My modest system is not perfect but it's much more enjoyable now than before.

@Csontos: Thanks for the explanation. I think I get the high level gist although I'll have to research more about the 3 attributes: fast, flat, linear. Not sure what the standard metrics are for these attributes, what range of values is considered acceptable, and make/model/costs associated with various ranges. I'll try to research my unit to form a baseline.

I measured, using an infrared meter, the top cover vents of the amp and left and right seem to be fairly close (91 degrees +- a couple degrees) while playing Monheit). I don't know what offset is and how to check / adjust it. Is that something available on all amps (nothing mentioned in my manual that I recall). Or only 'good' ones?

Left: 7.2mV; Right 13.2mV. Same reading with volume at -95db (minimum) and 0db (wasn't sure what you meant by 'volume at 0'). So, I'm assuming that the DC offset on my amp is acceptable, even though left and right are a little different?

I don't really have any idea how to measure fast and linear but I assume that's not something adjustable (w/out changing internal components?) so I have what I have. I'm not even sure how to adjust for DC offset so it's a good thing it's within the range you suggested. :)

Planning to order the Sony headphones recommended by almarg when I get the money.....

Hi folks,

I tried hooking up on iPod Touch -- it sounded terrible pretty quickly. Both my pre-amp and CD player have headphone outputs. I'm going to order the headphones recommended by almarg -- I wanted some headphones for watching videos on my iPod Touch anyway. I also need to buy some known good source material as well.

It does seem that overdriving the room is having a first order effect. I can add/remove much of the harshness I've been hearing just with fabric, although there is still some at louder volumes (loud but not uncomfortable) that I haven't been able to remove yet. I had changed out my KEF C75 (floor standing) with KEF Q10 (bookshelf) - this seems to have helped a bit but still experimenting. I think the Q10s are less efficient than the C75's -- it seems I need to increase the volume setting on the pre-amp to get similar volumes levels as the C75. I'm also playing around with fabric (sheets, towels) placement.

I'm also trying different speaker placements to get the imaging right. I'm beginning to think that even if I had the best stereo equipment in the world, it would still sound lacking unless I know the art of speaker placement and room acoustics.

Hi there,

Sorry, I missed that. I'm in northern CA in the outskirts of the Bay Area. It's relatively inconvenient except for the neighboring cows. :) Folks have been more than kind offering suggestions here on the forum, especially given my very modest system (My AVM2 may be the only unit worth mentioning and that's more than 10 years old).

The sound has actually improved dramatically since the thread started. I've actually to the point of indifference to the original issue that prompted me to start this thread (is not completely gone but it's approaching acceptance).

My I've noticed that the onion peeling has started. With relief of the original problem has come new 'concerns.' For example:

1) I'm now able to notice noise / hiss in what I believe is the content (for example, a track may start fine with just vocal and no instruments, but when the instruments start to kick in, I hear some background hiss / white noise).

2) I now realize that, whatever the musical merits of Miles Davis' Kind of Blue (Columbia 20-bit remastered version), I now notice what seems to be distortions at points in several tracks -- especially noticeable in the first few minutes of the first track. At least the sounds are not recognizable as any instrument I've heard before.

3) Something in my system / room is causing the low end to seem muffled (using the KEF C75) and poorly imaged. It's like basses span the soundstage are played behind a thick curtain. Still playing around with this. Here is one area where it would really help to have some known good content - I need to follow-up on some of the suggestions above, including getting the headphones that almarg recommended.

Sorry about my volume references -- this is still new to me and not sure how to describe stuff quickly.

I'm not trying to listen at painful volume levels -- I think I was just noting that the earlier harshness has seemed to move to these louder levels (at which I'm also noticing some additional non-musical sounds). Whereas the harshness that prompted this thread was at listening volume levels (where I can hear background instruments and where I start to feel enveloped in the music -- really hard to describe this -- it's as though music is a point source in the room at lower volumes, while at 'listening' volumes the music seems to fill the room and you feel like you're a part of it.

So, at this point, I think I've reached a point of acceptable resolution for the initial problem (still will continue to tweak) but and somewhat shifting focus to cheap, significant improvements to sound quality.

The sound quality seems to be the same between using toslink to my ARM2 (Burr Brown 24/96 DAC per the manual) and using analog (switching from 'digital' in Disc 1 to 'analog' on Disk 2 is seamless). So, based on what I've been learning so far, unless the AVM2 is generally considered a poor DAC/pre, this seems to suggest I should be looking at my amp or speakers (discounting the room once I get the headphones).

It's mostly academic at this point as I probably couldn't afford to replacing anything with something better. But, I'd like to isolate the issue so that I can keep an eye out for a bargain with the right attributes to make significant improvements to the listening experience. As I don't think I'm in the realm of diminishing returns yet, I think I can viably improve the quality w/out large net expenditures. At least I hope this is the case. :)

Thanks -- yes, I'm finding that small changes in speaker placement can dramatically change the experience. I'm overwhelmed by the number of degrees of freedom here: x,y,z,separation, toe-in, etc.

Seems like there should be a computer model that incorporates room dynamics via camera and microphone. Too complicate for us mere mortals. :)