New Old Thiel CS6 Speakers--Too Harsh

Hi All,

New pair of Thiel CS6 Speakers. First true pair of 'audiophile' speakers (...still might go back to my Kappa 7's and 8's).

Imaging and that 'holographic' sound is pretty good on the Thiels but not as good as the JBL 4312a's.  But again I am plagued by harshness in my system. It seems detail and excellent spatial performance just equates to brittle, harsh and painful in my room. I like to listen at rather loud volumes.

Frequencies that appear to be the problem are between 2khz all the way up to 16khz. If I EQ the system is listenable. 

The other issue the Thiels seem to have is out of phase low bass due to the passive radiator. Can anyone confirm this?

Here is my setup right now:
Modwright Oppo 105d (physical media and streaming)
Sonic Frontiers Line 2 preamp
Conrad-Johnson Premier 350 
14x17 room, on concrete slab carpeted with additional thick throw rug, heavy velour drapes over windows, bare walls and cd/record shelves, nothing on the ceiling.

What is causing the tizzy sharpness in my system/room?

So far the Infinity Kappa Series with its ribbon tweeters has sounded best in my room. The 8's are very impactful and tonally very complete. The 7's are close, not quite as impactful but have better imaging due to lower tweeter height. 

....and I don't want truth. I want beauty.



I had the Thiel CS6 and it's hard to imagine someone's description being more opposite from what they sounded like at my place.

For me they were beautifully smooth, rich, easy to listen to, with some of the most dense, punchy, focused bass and among the most focused, holographic imaging I've heard.

So...I dunno what's going on with your pair.

(I had a good listening room and powered them with Conrad Johnson premier 12 amps, which helped, I'm sure).


Nice system!  Perusing over your gear- I cannot imagine the harsh factor reported? What cabling are you using? Double check all cabling connections.

The Thiel will reveal more imaging  presentation and sound than the Infinity Kappa series. Your ears can expect richer texture and timbre in comparison. Often, audiophiles lay claim that equates to bright, forward and harsh.

Happy Listening!

Obviously, I’ve not been in your room, but let me suggest a few things.

(1) with bare walls and ceiling, you have a lot of reflections. If there is slap echo anywhere, you need to kill it, preferably with a combination of diffusion and absorption. Same with 1st reflections from sidewalls. Both cause irritation.

(2) I owned a pair of Thiels -- maybe CS 2 or CS 3 -- about 30 yr ago. I found them so tipped up that I built a high-cut filter to go between my pre and power amp. That was a different speaker, of course, but I don’t know of any Thiels that have been described as "mellow."

You probably need to treat the room, at least a little. You may need different speakers, as well, or a good EQ, or both. (What kind of music do you listen to? If it's violin sonatas, you DEFINITELY need to do both 1 and 2. ;-) )

Good luck! Have fun!
Not sure about the Kappa's and how they sound but I can tell you having owned Thiels for 20 years they are great speakers.  I am using CS6 in my system and also own a pair of 3.6's.  You have some great speakers and to get the most out of them, like any great component, you have to build a synergistic system including cables, around them.

I think your source could be an issue, not sure because I don't listen to streaming or rarely digital.  Your Thiels will let you know right away if the tone leads towards brightness which can be a symptom of digital or even some vinyl.

I am familiar with your amp.  I love CJ and considered this amp for my system.  Around this time CJ began using Teflon caps.  The teflon caps are definitely more revealing especially on the top end.  I have a CJ ET5 which also uses teflon caps and is a departure from the warm romantic golden glow of CJ past.  This also takes careful system matching.

What cables are you using?  

Finally, good advice with your room above.  It is on the small side for the 6's but can still work with some placement experimentation and first reflection absorption or diffusion .  Thiels do not like walls, front or sidewalls.

You bought great speakers but they are definitely not plug and play.  They are speakers you build around not finish off.  Good luck and have fun with it!

Your source is causing the sharpness period.  I just went though this with an owner of the 2.4s and the newer versions of the larger speakers. He was amazed when we swapped out the source with a better one.

Happy Listening.


I can't make sense of your claim.

What could the Oppo 105d possibly be doing to the signal, either playing media or streaming, that could cause "sharpening" of the sound?

I had a similar experience after purchasing a pair of Thiel CS 3.6's.  I thought they'd be a good match for my CJ MF2300A.. Turns out the CJ wasn't capable in this matchup.  Replaced the CO with a Sunfire 300 and was instantly in business.
You'll find plenty posts on Thiels and amp capabilities.  Once you get it right you'll be smiling.  

To test the room-acoustics hypothesis, you could hang quilts or blankets on the walls temporarily to see if tizziness is reduced. I would put them on the sidewalls 1/2 way between speakers and listener.

To test the "source is the problem" hypothesis, you could borrow a good CD player from a friend and see if that improves things.

Likewise with the "amp is the problem" hypothesis, though I doubt that a CJ Premier amp will be causing tizziness. The CJ stuff tends towards the mellow side, in my experience. And your SF Line 2 got a review from Tom Norton saying it doesn’t emphasize or hype things, which to me means it’s not likely the culprit, either.

To test the cables hypothesis, you could buy some returnable cables by mail order. (That would be my last thing to try, but it’s your choice.)

Years and years ago I had Thiel 3.6's driven by Muse 175 high-current monoblocks.  Eventually the hardness of the sound drove me into the arms of 300B SET amp + ProAcs.

Obviously, lots of people love Thiels, so YMMV.  BTW, I had 2.3's before, and while they weren't as hard, I found them lacking in bass.

My room is 14x17 and I have things setup lengthwise—speakers and gear are on the 14’ wall. Heavy, wall sized bookshelf full of vinyl and reel to reel tapes along the opposite wall. 
It’s got to be the room. I have been fighting this ‘listening fatigue’ hard harshness for like 5 years now. 
Two things I really have not changed are the room and the cabling. I would assume that room and room treatments will have a much bigger impact than cables so I should probably address that first.

I have been selecting gear that is all about ‘detail’ and that holographic reproduction—darker and colder. Maybe I have gone too far?

i also need to test the tubes in my Oppo and it’s power supply. Wish this were easier.

i have a BAT VK-500 with BatPak and a Caver Signature Sunfire 600 (I think it’s a 600?) that I am going to try with the CS6s.

Does anyone know if a Berning ZH-270 can adequately drive the Thiels? 
I suggest you not change gear before you try some acoustic treatment. You might find your existing gear is fine.
brettmcee OP
Old Thiel CS6 Speakers--Too Harsh

Brett it may almost surely just be the age they are now "if" that tweeter is ferro fluid cooled. It goes hard and make the tweeter nonlinear/distort and need to be changed. See here what I posted.

Cheers George
@brettmcee OP

Btw your Bat is a fine amp for these CS6, and should be a great match with that load if working well, and not be the problem of your hard highs, unless there is a problem with it like the bias is out or caps need changing. (Is it equally nice and warm on both sides after an hour) this will tell you if the bias is OK.
But it’s probably the "ferro fluid" as I stated above if it has it and gone hard, go onto the Thiel forums and find out from the "experts" if they had "ferro fluid" in the tweeters many do and don't say it.

Cheers George

I think I can be of some assistance here. I have Thiel CS 3.6's and experienced both of the issues that you described, 1) the harshness and 2) the strange "out of phase" bass quality.

I would first of all say that while I have not listened to the Modright Oppo 105d, my gut tells me that your front end is NOT the cause of the harshness. I would say it is, with very high probability the AMP. I don't know the specific specs for a Conrad Johnson Premier 350 but it sounds like "parkhurst" above identified a mis-match with his CJ amp and the 3.6's. My previous power amp, an NAD 2200pe sounded very harsh and fatiguing with the 3.6's. The layering and detail in my digital recordings was all congealed and compressed in a very fatiguing way. I hated it. o I set out to do something about it. I ended up purchasing a Bryston 4B2 solid state amp. Apparently the 3.6's are present a very difficult low impedence load to the amp. I almost bought one of the hot rodded McCormack amps (used) that I had read quite a bit about. Instead I went with Bryston (new) for their 20 year warranty. The Bryston 4B2 (now replaced by the 4B3 which is even clearer sounding) really has the power that these 3.6's need. My Bryston is also hooked up to a Bryston BIT15 power conditioner which I believes helps as well. With a proper power amp that can handle the lower impedence loads your 3.6's will be much happier.

As to your issue with the bass. First of all see if a proper (solid state or tube) amp that can handle this speaker's low impedence needs helps the bass. Do much auditioning of your music as you make these changes. But my bass had been in focus in my rectangular listening room with the speakers arranged along the long wall. Then my girlfriend re-organized the room while I was at work and decided (on her own) that it made more sense to position the speakers along the short wall. Mistake! I noticed the bass being cancelled out right away. Turns out it was a sonic room node causing some cancelling of the bass energy. We put the speakers back where they originally were and like magic, the bass is back to being tight, and focused again!

I didn’t have Thiels nearly that size (2.2’s) but still know exactly what you’re talking about. I originally demoed them with Spectral and McIntosh. My original environment was less than optimal, but a few years later I was able to build a dedicated listening room. Since I had Maggies previously, I thought I was ok as far as power went. I went from 2 Adcom 555’s to one, to NAD to Bryston (close but..?), not to mention whatever friends hauled over. I finally nailed it with BAT and the bat-pak. VK-220 and VK-3iX.

Something about having that current on reserve with the bat-paks totally solved the bass sluggishness (something about that passive radiator being slightly out of sync with the bass driver?) and the top was unbelievably sweet and tame. PS audio cable Xstream Statement throughout and the XLR I think made a heck of a difference as well (from MIT/Cardas/Nordost combos). I didn’t need nearly as much power as I always assumed, but just that added reserve. I guess like torque on a V8, the bat paks add instant current. Most impressive was the low volume performance. Before the things used to have to start getting loud to get the drivers moving. They sounded amazing at whisper levels.

Recordings I had hated were suddenly lush. For instance, I had an "audiophile" Japanese pressing of XTC’s Nonsuch that made my ears bleed. I literally almost tossed it. Suddenly it was so much better than the original redbook, articulate, subtle - a totally different beast. It certainly didn’t romanticize bad recordings, but good ones got better, and some that were etched before were obviously being emphasized by the amp/cable combos.
I am a bit surprised that the CJ isn’t doing it, and as others have suggested double check the room treatments. Mine were in a 12x18 room, about 7’ out into the room, and about 30" away from side walls with listening position about 10’ away and LP rack taking the rear wall. Room was pretty inert overall.
Thanks much for your post!

I love CJ amps for their 'holographic' sound, but in my room i am always ending up with harshness.

The last setup that worked great in my room were Infinty Kappa 8's powered by BAT VK 500 with batpak on lows and ZH-270 on highs. Sounded amazing! Nothing can beat those huge cones on the Kappas. They totally pressurize the room. And the ribbon tweeters are nice and airy...

But the Kappa 8's keep shorting out different amps. I will never hook my CJ up to them.

I am sending my BAT VK-500 for full maintenance shortly...once it's back I'll give it a shot.

The Thiels are much clearer and cleaner but yes a passive radiator design means that something is out of phase in the lows...and you can hear it compared to the Kappas. But the Thiels never lose composure no matter how hard you drive them.  But so far they make some of my favorite albums sound horrible if not EQ'ed (anything by peter gabriel and genesis). Very consistent at any volume. 

I have been eqing with a Venu360.  Sadly it redigitizes the signal just before the amplifier.  Any adjustments seem to step all over the spatial qualities of the sound but can tame the harshness.  I realize sadly this is not a solution to the problem.  The more I listen the more it sounds like a ratty band-aid.  

My room is 14x20 but it's a multipurpose space. So my Thiels are 1.5 to 2 feet from the back wall. The speakers can only be setup on a short wall in this room. The Kappa 8's were great for how not deep physically the cabinets are and how little they relied on their cabinets to fill out the bass. And you can easily get them 1-3 feet from the back wall.

Please send more thoughts.
HI All,

When it comes to driving my new old CS6's, a Carver Signature Sunfire Load Invariant Amp (600w) is trouncing my CJ Premier 350.

More bass, greater specificity in imaging, a bit more 'immediate' sounding and the harshness I was experiencing with the CJ amp is mostly gone.

I have to send my BAT VK-500 with BatPak in for servicing. I am hoping that it will best both the aforementioned amps when it comes to the Cs6's. 

I will be trying two Crown Class D XLS1500s in mono this weekend.  Should put out 1500w to really get that volume of air moving that moves the passive radiator. 

Is there a tube-based power amp that one could try to drive the CS6's?
Hi, sorry for the vanishing act - but I suddenly decided instead of downsizing into my townhome I’d sell it and move back to my big house. LOL! So, the Thiels might be coming out again. I’m facing however setting up on a floor plan that is NOT stereo friendly. It’s basically the same as my first place, only the dedicated room is half the size so you have a 20’ ceiling at the entry (stupid).

LOL, I had a friend who had Apogees, and I swear the gear stores loved seeing him walk in. I think the last I saw he’d hooked up some Spectrals, but had a graveyard of Thetas, Pass, McIntosh... Freaking vampires.

Why can you only run the speakers on the long wall? One thing I found at least in my last 2 setups (16 x 27 and dedicated 12 x 19) was they sounded better close together and far, far away from the backing wall. I don’t think I ever got closer than 3’ no matter which way I did it. Listening distance 9-12 feet. Then again, I seem to be in the minority on listening on the long end. My dedicated room they were almost 7’ from the back wall.

I’m wondering if there’s something else in the CJ pairing that’s not right. Because your experience is completely opposite of mine over the decades. Then again, I’ve always dealt with this gear when it was new - we are talking "vintage" on a lot of this. Maybe old amps get cranky or get dementia?

I’m willing to bet once the VK-500 is back to spec you’re going to be ecstatic. Did you say what preamp you’re running? I’d put an awful lot into that. The BAT’s were made for each other. What I can say is that the Thiels are the pickiest speakers I’ve had the pleasure of owning. The final spice was getting the cable correct, which is honestly something I wouldn’t have believed. But a small moving box full of cable says otherwise.

Are you having them upgrade the bat-pak as well? I know they’re on their second generation at this point. Does Victor still work there? I’ve been so out of touch - and BAT seems to have fallen out of favor a bit. But my dealings with BAT were always excellent, very responsive.

BTW, huge Genesis fan, but I'm old AF. Saw them several times, and Gabriel for every tour from his first solo up to So.
brettmcee OP
Is there a tube-based power amp that one could try to drive the CS6’s?

 Only if you can find one with at stable 2ohm transformer output tap that can output 100w from it.😉

Did you find out if the tweeter uses ferro fluid like a said way back, it WILL be your harshness problem if it does
As the ferro fluid will be almost turned to glue by now with age and the tweeter will be pushing **** up hill trying to move against it and giving non linear distortions.

Cheers George

Thank You for the update. I am looking forward to the B.A.T. / Sunfire comparison.  Have fun!

Happy Listening!

Should you decide to re-engage those Thiel speakers, join us, over on the Thiel Owners thread. I look forward in reading more about your musical tastes and system.

Happy Listening!

Should you decide to re-engage those Thiel speakers, join us, over on the Thiel Owners thread. I look forward in reading more about your musical tastes and system.

Happy Listening!
I did pop over there a few weeks back. I'm excited to see if they're up to snuff. But as I mentioned unfortunately I recall one of them was having an issue - buzzing midrange IIRC. I had written them off with the demise of Thiel several years ago, but apparently there's a market in rectifying these.

As I mentioned over there, I loved the speakers so much my chase ended right then and there, even passing on the (amazing) 2.4's when I had a chance. I only updated my electronics/peripherals until I found the perfect match.Of course at the time, it was for a very specific space. In my new house all bets are off.
In the pair of CS6 that I'm going to buy both midrange/tweeter speakers have no signature "THIEL" and "Coincident Array" oabove and under the speaker.  I guess they must have been replaced some time ago by previous owner. If there are no  those signatures I've mentionet above schould I assume that those are not original midrange/tweeter speakers or after some years Thiel produced the replacement speakers without this signature? They sound excellent.
I would be very grateful for help.