Wilson Benesch Torus and Thiel SS2 subwoofers

I know this is an old thread, but I came across it while I was having noise problems with a Thiel sub and thought I'd post this for the benefit of any future visitors.

I have an original Thiel SW1 (later renamed SS2 when more models were added to the subwoofer line). There have been three different amplifier modules used over time. I have the first/oldest version, with analog adjustment knobs and grab handles.

I bought my sub second-hand, and originally had a lot of digital-sounding noise coming from it, which was loud enough to be annoying and distracting. The electronics in these subs seem sensitive to interference and ground loops. The amp itself turned out to be fairly quiet once I eliminated outside problems.

The worst of my original noise turned out to be caused by my wireless router, which is in the same room. By moving the router farther away, I was able to eliminate the worst noise (which was a nasty digital sputtering or chugging sound). If you have any components with wireless network connections near your sub, these are another potential source of interference. Consider either moving them as far away as possible, or running wired ethernet connections to them and shutting off their wireless transmitters.

I also made sure to plug my router into a different circuit, just to further isolate it.

Eliminating wireless interference eliminated about 80% of the noise I was experiencing.

I was able to discover the source of most of the rest of the noise. To explain, I'll also review how these subs can be hooked up.

Thiel's subs can be set up in various configurations. I have one of Thiel's passive crossover boxes that takes the output from the power amp via speaker cables and sends a low-pass signal to the sub via an XLR cable - but does not touch the signal going to the mains. This configuration is all that's needed for stereo, and I think it's a very elegant solution.

My mains are a pair of Thiel CS3.6s. They play full range (using the untouched output from the power amp) and the passive crossover feeds the sub a low-pass signal that exactly compliments the CS3.6's natural rolloff. This is the most seamless sub integration that I've personally heard.

To use the XLR connector, your speakers need to be a Thiel model that the company makes a dedicated passive crossover for, or you need to find the very expensive (and I think now discontinued) Thiel Integrator, which is an adjustable active crossover that can be used with any speakers.

Additionally, the sub has an RCA input for home theater LFE and bass management. Since I also use the sub for SACDs and movies, I have an RCA to this input from the LFE out on my home theater preamp. This is a normal configuration - the sub can be connected with either the LFE RCA or the crossover XLR alone, or with both at the same time.

Via the RCA connector, the sub will function as a completely-normal sub in an HT system You can let the HT preamp manage bass for your mains or run the mains full-range (the preamp is not aware that the sub augments the mains in this case - all it knows is that its sending a full-range signal to the mains, and when it analyzes test tones it sees full range output - it's not aware that the sub is helping out).

In stereo you can entirely bypass the HT preamp and its bass management and let the passive crossover fill in the low end.

For me, if only the passive crossover/XLR connection is used, the amp is very quiet - still a little hiss, but with the wireless interference gone, no noise is audible at my listening position.

There is a louder hiss when the LFE RCA is connected - just barely audible at my listening position, but annoying because I'm so aware of it. This seems to be a pesky ground loop that I have not been able to eliminate. When listening to records I sometimes unplug the RCA, but this hiss is obviously a ground loop and not an inherent defect in the sub's electronics. I will keep messing with it.

Like other posters on this thread, I had wondered why no reviewers ever commented on how noisy this sub's amp was. I also wondered how it was possible for me not to have noticed this when auditioning Thiel's subs in the past.

Now I know that, while they may be overly sensitive to the environment, these subs can be made to run quietly, and probably are quite for most people.

Phamble

My guess is the problem is not with the setting of the Torus but rather your Discovery's (how do you like them by the way). So much nicer to get the speakers away from the back and side walls. Is that possible or is that the reason you have monitors in the first place, small room and not many possibilities for placement.

Try setting the Torus to come in at about 40 hz with the low filter at 20hz. At that setting even with the volume up on the Torus you should still have pretty tight and not over the top bass.

let me know how that goes.

Jim

Sounds Real Audio

I have a pair of discoveries with the Torus. Im having difficulty balancing the two. I get way too much bass but if i turn down the volume on the Torus, i lose the benefits of imaging etc. Can you suggest a setting for the low filter and ideal crossover for the discoveries? The discoveries are about 18 inches from the rear wall and 12 inches from the side wall, toed in. Thanks

Milimetr

Try placing the Torus directly in between the two main speakers. I know this is a bit of a shocker but in that location you will actually improve the sound stage, imaging and sense of air. It works almost like a center fill loudspeaker.

I would like to report effects of Thiel SS2 and Torus comparison. After few days Torus improved their performance and now is quite pleasure to listen. I made direct comparison between subs by connecting Thiel with passive crossover to the left channel and Torus amplifier at high level signal to the right main amplifier channel. Using balance I have quick comparison between two subs.

However I am sure that both subwoofers received different signal. Torus was rolled off by their amplifier filter at given frequency, Thiel received signal from passive crossover and the roll off point seemed to be considerably higher than with Torus. Thiel received not only bass signal but also some part of middle frequency signal and this probably caused the impression of more punchy bass.

Torus is indeed great subwoofer. Is has rock solid and dead quiet cabinet, so there in not boxy sound from that. The only feature is missing is Room boundary compensation feature available in Thiel subwoofers. Without this feature Torus positioned near the walls can sound a little boomy, but there are laws of physics. I can agree that it produce bass so different than typical subwoofer that it can be hard with proper interpretation at the beginning.

Milimetr

Your comments
"Thiel sub in comparison with Torus can go audibly lower in bass, but the most important difference is that Thiel subwoofer is capable of output very resolved sound and definitely more punchy bass. Thiel bass is short, deep and punchy."

beg for a response. I have never been to any live performance were I could honestly say the band/orchestra had a "punchy" bass. Punchy is just not a musical term, at least in my mind. No the Torus does not have a punchy bass it will however reproduce the actual music. The Torus amplifier has a set of switches on the bottom that allow you to adjust the low frequency roll off. If you would like to go lower you might want to adjust those to the lowest possible output. I roll mine off at 20hz. (not into organs).

I think some users who are not used to such a clean and tight bass might be surprised by the sound of the Torus. Unlike everyother sub I have heard it will complete disappear. An unlike every other sub I have heard it does not double up.

Spend some time with the upper lead in frequency. That also makes a large difference in the overall sound. I bring in the Torus at about 60 hz with the Wilson benesch Curves and about 40 hz with the Wilson benesch A.C.T.'s.

Every speaker is going to be different.

As I mentioned, Thiel developed completely new amplifier for their SS2, SS3 and SS4 subwoofers. New amplifier design is similar to the amplifier used in SS1 subwoofer but with double power output. Probably the new design was necessary because older design in SS2-SS4 subs have had unfixable high residual digital noise which was quite loud and disturbing during listening and at idle. For me such high level of noise in such expensive subwoofer is really a shame for such manufacturer like Thiel. I can’t understand why this obviously necessary improvement took few years since subwoofer line introduction.

I received my SS2 at the end of 2008 with old amplifier and level of noise was not to be accepted. I was ready to return the sub and find something else, but instead I received new amplifier. Their started to supply subs with new amp since beginning of 2009.

With new amplifier the residual noise is significantly lower, however not gone completely.
I am very sensitive on that but now it is non an issue here.

The main differences:

-new amplifier has completely new construction. It is dual mono of SS1 amplifiers.

-new amps is much lighter because instead of big and heavy toroidal transformer in power supply it has switching power supply. The whole sub is much lighter than manual stays and it is not good for the sub, because it is more sensitive for rattling. Thiel claims that new switching power supply allows the sub to work faster witch more punch. I did not compared old and new side by side so can’t confirm.

- new amp does not have handles on the panel and do not have LED display.

- room boundary compensation circuit was preserved but now you do not setting the distances from the wall by pushing the three buttons, but you have three rotary potentiometers. For me it is downgrade, because you do not see on the display precise setting, but Thiel claims that it is upgrade because potentiometers allow continuous regulation instead old one in steps.

- with old design you could switch off green LED on front panel by pushing and holding one of the switches at the back. In new design you can’t do this and green LED still glow during operation. In completely darkened room during movie projection it is disturbing. The only solution is to disconnect wires internally.

- I am not sure if that feature was in old amp, but new one has trigger input allowing to switch on with other components in system.

All changes mentioned above does not matter for me. The only think that matters is lower noise floor. Regardless Thiel subs are fantastic performer, however a bit overpriced.

The other thing worth to mention. Thiel subs were reviewed many times – NO ONE reviewer mentioned about this noise! Are they deaf? Think about it…

yes, i do have allot of noise from the sub. i am dealing with a hiss issue throughout my system (thread going in amps forum) so i attributed some of the sub noise to my system trouble. it is a large amp and i was expecting some but it does seem excessive. maybe i should look into the changes to see if there may not be some fix for this original design.

--> Richard,
rattling could be from not property tighten spikes.
I still thing that such large and resonant cabinets should be positioned on three spikes in triangular configuration.
Could you kindly let me know if you hear any residual noise from the Thiel subwoofer amp when the amp is in idle (no signal feed). I found that my SS2 had level of noise to high to be accepted. During low music passages it was annoying. I had the sub amp replaced with new one construction. Whole line of Thiel subs has new amplifier design. There many changes compared to original design, but noise is significantly lower with new amp.
I am still auditioning Torus and it becomes improve during break-in. Definitely the bass has different character that bass from Thiel sub.

thanks for the comparison post milimetr.

i am wondering if you may not have a problem with your thiel. i can say i have never heard any ratttle from mine and have played often at concert (and beyond!) levels. my sub test song is from laurie anderson's life on a string, trach #6, "my compensation" which has tremendous electronic lows. this really displays the depth and power and it does not give any noise from the cabinet. i also use diana krall, girl in the other room for stand up bass demo...tightness and accuracy...no noise.

Hello guys,
thank you for the inputs.

I asked those question, because I have both Thiel SS2 and WB Torus at audition at home. The Thiel is mine and Torus is at a loan. I was almost sure that I will replace Thiel with Trous after reading so much enthusiastic opinions.

I would like to replace my Thiel with sub at the same level of performance, but more room friendly and easier to hide.

Now after audition the Torus I am not sure about those replacement.

From technical stand point Torus is quite original approach to sub design – no doubt on that. But what I heard is a little disappointment. However Torus is a brand new and out of the box, so maybe requires some break-in period, but I am not sure if break-in may change the sonic signature.

Technical parameters comparison is better for Thiel:
Thiel has 1000W RMS amplifier, Torus only 200W,
Thiel is capable of 105 dB output at 20Hz and 112dB output at 30 Hz. Torus does not go over 100 dB.

Thiel sub in comparison with Torus can go audibly lower in bass, but the most important difference is that Thiel subwoofer is capable of output very resolved sound and definitely more punchy bass. Thiel bass is short, deep and punchy. Torus blends notes together. It is harder to follow music rhythm. There is also tonal differences between notes with Thiel. With Torus all notes seems to sound similar in their character.

I really can’t understand why Torus sounds this way, but if it does not improve after few days of working it will be disappointing.

However Thiel also has their own flaws. Their speakers are front firing and sub has four speakers instead of three and sometimes it starts to rattle.
At high volumes there is also rattling sound coming from inside, probably from the board with amp.

In my opinion if Thiel will designe subwoofer with outboard amplifier it would be great improvement.

Also the Thiel has room boundaries compensation circuit, which really works especially when sub is near to walls. With Torus there is no compensation for close to wall placement and it is really audible as the bass is not as clear and linear in room.

Any thoughts?

i have a pair of Torus's with magico Mini 2's...
Similar story to The first poster..EXTREMELY FAST AND WELL INTEGRATED!
Not the lowest but the most accurate and musical to date...
Comes with it's own outboard amp with full function capability for adjustment.

If booming airplane take offs and Thunderous passages are what you crave you can certainly buy cheaper but for sound, flexibility, build quality and the ability to work in ht and 2 channel this is the one!

i have been using the thiel sw1 for many years (which is the ss2 now). i am very pleased with it although it has been mostly used for movies. i do have a setting for music that i use now and again but my speakers do a very nice job on their own. as far as performance, i find it to be extremely fast, tight and detailed for a subwoofer. it does not provide as much boom and drama as allot of subs but will get as low as you need to go with great accuracy. i do not use the thiel crossover rather my theta for integration. it blends very very well with my watt puppy's. i have not heard the torus.

If you can afford the Torus Infrasonic Generator buy it, I think you will find it is the best piece of audio gear that you have ever had.