Thiel Owners

@prof 

Congratulations on your new gear. I think you'll like the improvements. You called yourself a sub newb in an earlier post, but IMO, your previous comments suggest you understand the principles just fine. So dive in and have fun.

My impression is that steeper is better for crossover slope, so probably 24 dB per octave is best on the CR-1. On the other hand, it might not matter all that much since your Thiel mains and JLA subs should both have good linear frequency response in the overlap region, even at 12 dB per octave. Easy enough to try both if you like.

As before, I recommend the Sound Doctor's sub setup instructions here (or see hardcopy with your CD): http://www.soundoctor.com/testcd/Soundoctor_Test_CD_v2-7-2.pdf.

As for crossover frequency, here's a range of opinions. Sound Doctor says,

I suggest never going below 80, even if you think your speakers go down to 40, or below. Even in a room where the existing "mains" have a pair of 12" drivers (each) you will get far better results if you ... correctly cross them over at 80, (or higher) ...

The Thiel SI-1 instructions state,

Unless the main speakers are very small, it is usually preferable that this setting not be higher than 80.

There's no explanation for Thiel's recommendation of 80 or below; it might be specific to some feature of the SI-1 or Thiel SmartSubs (probably not specific to Thiel mains because the SI-1 is intended to work with any make of main speakers). Alternatively, it might have something to do with staying well below the frequency at which the period equals the sub's group delay (about 120 Hz for JLA f112s). Above this point, the minimum timing error doubles to 720 degrees. 

Finally, a team of audio pros working with JLA f112's and Thiel CS3.7s chose 100 Hz in this example, http://www.soundoctor.com/studio/.

I decided to follow the Thiel recommendation (because I'm working with all Thiel components except for the subs). I selected 80 Hz as my reference but also stored preset configurations at 60 and 70 Hz for comparison. I can switch between these from my listening position with the SI-1 remote, but to my ears, they are indistinguishable. They all integrate seamlessly, and I couldn't reliably detect differences between these settings –– either in the highs or the frequencies surrounding the crossover setting. Still trying to test this.

I suggest you also consider settings somewhat above 80, e.g., 90 or 100 Hz. In fact, I spoke with a support person at JLA who helped an audio dealer install JLA subs, a CR-1 set to 100 Hz, and a pair of Thiel 3.7s. The dealer said it was the best sounding system he ever heard in his space. I would think your 2.7s should not be all that different from the 3.7s. Maybe I'll try up to 100 Hz, too. Can't hurt.

I found the Sound Doctor's Method B (p 4) for adjusting phase and level to be easy and effective. Rather than depend on my hearing, I used a sound-pressure-meter app, SPLnFFT (available for iOS and Android), to easily identify the settings for maximum cancellation.

Good luck!

Attn CS2.4 owners:
I’ve been thrilled with the performance of my "new" Thiels. One parameter lacking, however, was image density. My front wall is ~19’ wide altho’ confounded by a 4x4’ wall jutting in for the rear door exit in one corner. It is ~18’ on the sides. The ceiling is vaulted, 8’ on the front wall and ~12’ on the rear wall. There are two large openings on the rear wall, one just above my head; I sit within 2’ of the rear wall. I think the openings really "save my bacon" from unsatisfying sound with this room.

I did have the speakers about 10’ away from my ears to the tweeters and played with speaker spacing 7-8’. ~7’ sounds best but image density was not satisfying. I just spent most of the past hour experimenting with distance to the listening position, now have the speakers ~9’ from my ears and spaced at 7’ (7’ to the front wall!). Zero toe in. Image density is notably improved.

Anyhow, curious to read what other have for their placement. Thanks.

EDIT: Looks like my spacing is similar to what Shane Buettner used in his review: http://www.vandersteen.com/media/files/APJ%20Files/APJ13_Proof.pdf

@ish_mail

Wow, I couldn't have asked for a more helpful response!  What great information.  Thanks for sharing as it will come in very handy!

I'll let you know how things go.

beetlemania,

I'm always looking for the most immersive sound I can get, while not sacrificing image density.

For whatever reason, the 3.7s can be spread ridiculously wide and still have focused images.

The 2.7s, which are the next version of your 2.4s, are very good in that regard but don't take to be spread quite as wide.

Still, I've got my 2.7s at 8.4 inches apart, 6 1/2 feet from my listening position, and the image density (their hallmark) is superb.  I just demoed them to a musician friend and the first thing he raved about was the imaging and the "thereness" of the images between the speakers.

My room was designed with an acoustician - it does both home theater and 2 channel listening duty.  It's 13ft x 15ft deep, 9ft ceiling, with a large opening to one side of the room into the hallway.  That opening helps "save my bacon" too I think.  It's a well damped room.

My Left speaker is close to the side wall, near a fireplace with reflective tiles, so for years I have placed a thick velvet cover over those tiles when I'm listening.  It mellows out the sound, reduces hash, increases image focus.  But just recently I've tried leaving the cover off and I've really appreciated the added liveliness it brings to the sound.  The only issue is that tonality does take a little hit. 

So I'm going to order a curved diffusor and try that out, to see if I can keep some of the liveliness I'm enjoying, but restore a bit better tonality.

Thanks for the reply, prof
6.5' seems close for Thiels. Seems like most listeners prefer at least 8', so I'm surprised to read about your set-up. Sounstage's measurements of the CS2,4, however, were taken at 2 m (~6.5') and the frequency response was outstanding at that distance (as opposed to Stereophile's inadequate measurement at a mere 50"). I hope your diffusor gives that result you want!