What is the cause of my sibilance problem?

I have been fighting a sibilance problem for about a year. I thought I had it beat but it is back. I've tried cleaning and treating all connections, acoustic foam treatment at first reflection points on side and front walls and ceiling, different interconnects, speaker position, and even a different digital front-end. The problem manifests itself as extremely harsh 's' sounds in both male and female voice. I am beginning to wonder if I need to have my hearing checked - I tried headphones and hear the same problem. Well, here is my system:

Aiwa XC-37M CD-changer
MSB Link DAC III with 24/96 upsampling board
B&K Ref. 10 preamp
B&K AV6000 poweramp
Paradigm Reference Studio 60 Loudspeakers
Hsu Research VTF-2 powered subwoofer
Signet center channel
Atlantic Technology surrounds
Sennheiser HD580 Headphones
Home Grown Audio Super Silver interconnects
Monster Cable subwoofer cable
Ted's Excellent Cable speaker wire (mains)
Kimber 4TC speaker wire (surrounds)
Mapleshade Brass cones, weights, and cork/rubber feet
Michael Green 5-shelf Audio Rack.

A Television, the subwoofer, and the Audio Rack sit between the louspeakers; which are approximately 7' apart and 7' from the listening position. My room is highly irregular and ASC claims that $1200 in acoustic treatment is the answer to my problem. I'm not saying they are wrong. But, having experienced the same problem with headphones (and acoustic foam not alleviating the problem one iota) I am beginning to wonder...
I would first forget about anything that was eliminated by using the headphones, such as speakers, cables, room and room treatments. Then, if possible start swapping with other gear one-by-one with the ones that were not eliminated. It shouldn't take long to narrow it down to the guilty "party".
Good luck and keep calm.
If you have a cable feed into your home, try going to where it comes into your home and disconnecting the 75 ohm coax and the green ground wire that the "cable guy" had connected and re-listen.

If this solves the problem, then you have a DC voltage that is getting into you audio system via the cable ground. If it doesn't...post again, please.
What do you use as a headphone source? As Drr noted, you have already eliminated everything downstream of your headphone source. Good Luck. Craig
gallaine: you say that you thought you had solved your sibilance problem but then it returned. what did you do, or perceive that you had done, to "solve" your problem? you have a complex system comprised of many parts. each of those parts "reacts" to every other in the chain. finding the weak link is no easy task, as well you know. i suspect the annoying sibilance emanates from the match or mismatch between your transport and dac. i would also suggest you have overly bright interconnects for your component, although you say you've tried changing them out. did you substitute copper interconnect between EVERY component, SIMULTANEOUSLY? if you didn't, i'd suggest you somehow arrange to do so. i empathize with you. sooner or later, we each hear a mouse in the works we can neither see nor capture. have patience and continue your quest. i'm sure you will eventually capture and tame the little beast. -kelly
The way to solve problems is to look at them logically.

Since you have this problem with either headphones or speakers, it is obviously something in the components and NOT the room. While the room acoustics may not be the greatest, the use of headphones remove that part of the problem from the equation.

While you did say that you tried different interconnects, you never specified what you tried. You might have made a lateral or backwards step that showed no difference. My first guess would be to rid yourself of the "super silver" interconnects. While MOST silver tends to highlight upper frequencies, these specfic cables might not. I'm not familiar with them, but it seems a good place to start. If they are "peaky" in the top end, this would give you the problem on either the speakers OR headphones.

The MSB is also not known for producing the smoothest of highs. That piece has always come across as sounding very "transistor" to me. Combine this with a "bright" cable and you might have "ear bleeds" on some particular recordings. This would also give you problems on both the speakers and headphones.

While the next comment does not affect both aspects of your problem, it is something to think about. While i'm not familiar with the model Paradigm's that you have, do you know if they use a metal dome tweeter ? Some metal domes just can't be "tamed" other than to use components and cables with a VERY soft top end. Some tube gear benefits from using metal domes as it adds the "brilliance" that the otherwise "smooth" tubes lack.

Other than those basic suggestions, i am at a loss of where else to go. Sean

no offense but your b&k is dark and cold sounding and when you turn it up is when you will hear your problem. Pick warmer gear than the b&k I used to own it and went through the same problem. Also get a center that matches your front speakers your center is not voiced the same as your fronts. I would buy a classe ssp30 pre and a classe cav 150 that will fix everything. Good luck
If the DAC is the problem, direct feed your CD output to your preamp. If the sibilance goes away there you have your answer.
Kelly's question about what happened that made it return is very worth to think about....

Do you have your gear (specially transport and DAC) on their standard feet? Cones?
What is your audio rack shelves made of?
Do you have any power treatment in place? It is not listed in your system description.
Please some more info that could provide more hints on this. Luis
Sounds like RF interference and/or dirty AC power.
Try a PS Audio P300 on front end or at least a Monster HTS-2000 power conditioner. Make sure you're using shielded interconnects and Speaker cables. -Ed
I appreciate all of your responses and apologize for not posting earlier - my ISP was down for two days.

When I originally auditioned the Super Silver interconnects I liked everything I heard except for the top-end. At the time I owned a Roksan Caspian CD Player. Adding vibration control to the system seemed to smooth things out to acceptable levels. Perhaps it was just wishful thinking.

What have I auditioned in the way of interconnects in addition to the Super Sivlers? I tried Wireworld Equinox III+, Harmonic Tech Truthlink, and AudioQuest Viper. Of those the Wireworld was the best. But all of them had the same sibilance problem. I only audtioned a single pair of each. Perhaps the suggestion to audition multiple pairs of each is a good one.

I forget to list my PS Audio P300 power plant and Quiet Lines in the list of equipment. The only components without conditioning are my power amp and subwoofer.

I usually listen with the cable TV unplugged. Maybe this isn't enough. I'll look into it. However, I live in an apartment it may not be feasible to disconnect anything.

All components except the power amp are sitting on brass cones. My digital front-end ( DAC and transport ) are also on shelves supported by cork/rubber feet. In addition, brass weights sit atop everything except the power amp. All of these vibration control devices are form Mapleshade.

At first, I thought my power amp needed servicing. I sent it B&K in New York and a few weeks later put it back in my system. After 200 hrs of burn-in the problem hadn't been solved. A call to B&K revealed that they hadn't found anything wrong. As a side-note, B&K technical support was outstanding. They only charged shipping and replace the top cover with one with better ventilation.

I plan to try the new Antique Sound Labs AV-8 tube monoblocks. They may not be the best, but it fits my budget right now. I want to hear the tube sound everyone talks about and see if it might get me a step closer to eliminating this problem.

Again, I appreciate everyones comments and plan to try them.
Gallaine, is it possible that your source material is the problem? Performances of close miked female vocalist, if not processed fully, will tend to be somewhat sibilant. This can also be the case if the singer is not familiar with the recording process. Is this problem on all your music, or only on a select few discs? It's unfortunate, but as you system gets better and more resolving, the quality of the disc becomes an issue.
Onhwy61 - it is certainly possible that it is the source material. I don't have that many CDs with female vocals, but the problem occurs on all of the them.
My question regarding the use of cones is a key one.
Please advise which brass cones from Mapleshade are you using and how specifically you have them set in your CD player and DAC. Where and how are the cones positioned?
Do you have one of the cones at the rotation axis of the disc? Are they point up or point down?
This cone detail has a great doing with overly enhanced highs in my experience.
Gallaine, I've made a different experience. I listen to a lot of vocals, male and female and I've got the problem of sibilants perfectly licked, inspite of having very resolving tweeters,( plasma) which go up to where the bats hear. With me it was the front end and I suggest, that Gallaine experiment with that.
I guess that it is high frequency oscillation and/or ringing riding on the music waveform caused by RFI being picked up/reflected back into components by too many cables and wires. Also, so many connections to component input and output stages with so many series and parallel input and output stage circuits terminated could be setting up a "tuned circuit", ringing like mad or even picking up RFI at frequencies all over the spectrum. I would simplify the wiring and connection paths and pay close attention to a true single point grounding as well as common shielding and shield current direction.
Sol322 - The cones I use on the transport are the Mapleshade Triplepoints and on the DAC and preamp I use Mapleshade Surefoot cones. The Triplepoints have three small points instead of a flat surface where the components comes in contact with it. For each component the cones are arrayed in a triangular pattern with the "points" "down" (one cone along the rear and two along the front). It certainly is easy enough to try different configurations and I think I'll experiment tonight (provided I get home early enough). Incidently, the problem occurs with or without the cones installed.

Detlof - While I'm not ruling out the front-end I had a Roksan Caspian CD Player that only started exhibiting the problem after several changes to my system. There-in lies the problem. I don't know if it was something I did or if the problem was always there just hidden.

Nightdoggy - I must admit to some confusion. While I think I understand the gist of your post you lost me in the details. My system does in deed have alot of wires. But I don't think there is any possibility of simplifying without removing components. Perhaps one day I'll have the room and budget for separate HT and two-channel.

There is a possibility that the culprit is the preamp. It is the one component that I haven't experimented with. And given that the problem is experienced both with headphones and loudspeakers it seems to me that eliminates the power amp (though certainly has other failings). Another interesting thing is that the sibilance is present at all volume levels - well, I haven't actually tried all since I live in an apartment and don't want to upset the neighbors. And, the sibilance is greatly reduced to non-existent with movie playback - maybe a good experiment would be to play a movie in direct stereo mode and see if the sibilance is worse or better than Dolby Digital mode.
Gallaine, after what you say now, I doubt that the front end could be the culprit. Nightdoggy might indeed have a point, with RFI being the culprit. Then also a bad solder joint or a loose connection somewhere comes to mind, but then I think you said that you had switched and experimented with cables. Experimenting with your preamp is probably your next best bet. I wish you the best of luck. The fight against this kind of nasties can be very exasperating. Please let us know of your progress!
Check to see if the problem persists w/o DAC. If it does not then you have jitter. See Sonic Frontiers for a solution.
Sorry about the silence. I haven't had much opportunity of late to try some of the suggestions posted. My deadline at work is the end of week - hopefully I can take off this weekend.

One thing I did try was to change the "mode" from direct stereo to several others. Interestingly, the problem was significantly less in surround. I am beginning to wonder if the problem is my loudpseakers. When voice is routed to the center channel the sibilance goes away - or seems to.

I disconnected the Aiwa from the MSB Link III and connected my Sony DVD player to it. After trying both coax and optical connections the problem wasn't solved. I am, however, better able to characterize it. The sibilance is most noticeable in words that begin or end with "s" as opposed to having an "s" in the middle.

I also opened up the MSB Link III to ensure that the upsampling board hadn't been knocked loose. It wasn't. But I did discover something that was a little disappointing. The upsampling board plugs into two rows of pins in the middle of the "main" board. There is a tall capacitor under one corner of the board that prevents the sockets from sitting flush i.e. it isn't completely seated.
Have you tried different IC´s?
Might not be the case but worth trying... I recall a friend of mine who had this situaton with silver IC´s I´m not familiar with your brand though.....
After you solve this or if you want to take a break I can give you some interesting tweaks for your amp. Just for kicks why not you change or swap power cords with your amp to see if this lessens the problem, it might provide you a pointer....
Don´t give up!!
Sol322 thanks for the encouragement. I have indeed tried different interconnects and powercords. I spoke with Steven at The Cable Company and I have one or two more things to try before going back to interconnects. Steve was, in fact, the person who recommended reseating the upsampling board and changing transports from the Aiwa to the Sony DVD Player.
I once had sibilance issues that turned out to be AC power related. The PSAudio should have helped, but maybe you need to try something else? The right combination of AC cords should also help, & a dedicated AC line if possible.
Room treatments normally are worthwhile too, but considering that you even have sibilance in headphones, this points toward the front end, those interconnects, or the preamp itself. Brass cones could also be complicating things; they can add brightness & may not be best for your rig. Try removing them altogether, or repositioning them closer together 1" at a time to add some warmth. Black Diamond cones may be better for you than brass, they are for me. Try the #3's first before the #4's, considering the sibilance. Try to borrow another preamp & be sure it's warmed up?
That brings up another issue, are you leaving at least your front end components on all the time for best sound? Cold transistors sound can be pretty harsh.

Bob_Bundus mentioned the sibilance issue might be related to power. So, I contacted PS Audio and who should respond but Paul McGowan himself. He was honest and showed genuine interest in the problem. Unfortunately, he didn't think it was related to power. Considering how busy he must be I was very thankful that he took the time to try and help.

While visiting the HeadWize (headphone forum) site I found a device called the Corda Analoguer. It is essentially a high frequency filter. This device was advertised as reducing the digital glare associated with CDs. I gave it try. It certainly took off some of the edge but didn't cure the sibilance enough to warrant ending my search. If you are interested in my review of the device check out www.headwize.com.

I also decided to try the Sony 333ES SACD player. Well, I am happy to say that it reduced the sibilance to a nearly tolerable level. And, the music sounds more natural and relaxed than the Aiwa/MSB/Analoquer combo. My next step is to try the Analoguer with the SACD player. After that I will probably concentrate on the preamp.

It seems from my experiences to date that the problem is mismatched equipment. Cables and filters are only poor substitutes for proper equipment matching. It is now my belief that they are, or should be, icing on the cake. But you can't match equipment without cables. So, maybe there is something of the chicken-and-the-egg problem here :)
Gallaine: let's revive the basic assumptions. If mismatch, there can only be two points producing the sibilance if we rule out equipment per se: trans->dac, dac->pre. If you switch off the rest of the system and listen to headphones alone: is there a difference? Pls note the difference (or lack of it), then try the Kimbers as an IC on the two points. Note the difference (if any). Try another trans & note the sonic character (w the Kimber). Go back to the trans & change the dac (if possible). Finally, compare with the Sony. (ofcourse, listen to a cut of the same female vocals throughout).

A tedious undertaking, true. But you must be able to identify the source of the problem. In my experience sibilance is often the result of cable/equipment mismatch, then equipment mismatch. Unfortunately, it's also a result of many other causes, as suggested above.

Best of luck -- and hold on there!
i once had a sibilance problem - think tubes! since you feel that the cd unit may be a source of your problems, and i agree that it could, audition a tube cd player, if not for purchase, just for the experience. if you like that then you can take the idea forward down the chain of electronics as far as you wish.