In-Room Frequency Response

The Thiel PP1.2 requires boundary mounting for proper acoustic loading and mid-bass response. According to designer Jim Thiel, it is perfectly acceptable to floor mount these speakers for evaluation and review purposes.

I floor mounted the PP1.2 in my acoustically treated evaluation room, placing them about 8 feet apart and toeing them in toward the listening position (about 8 feet away), thus creating the "acoustic triangle" preferred by many enthusiasts for critical listening applications. I also placed an SVS PB10-ISD subwoofer between and slightly behind the PP1.2s, to provide a coherent and seamless transition to the subwoofer.

For digital bass management, the main speakers were set to Small in the SSP menu, with a crossover frequency of 80 Hz. The digital bass management circuit imposes a 2nd order high pass filter on the speakers, and a 4th order low pass filter on the subwoofer.

I first adjusted the speaker and subwoofer distances in the pre/pro according to their physical distance. I then fine-tuned the set-up by measuring the phase response curves of both the speaker and the subwoofer, and adjusting the variable phase control of the subwoofer until the phase responses overlapped at/near the crossover bandwidth.

The in-room FR at the listening position measured a remarkable 18 Hz - 20 kHz ± 2.5 dB. This is due to the inherently accurate anechoic FR of the PP1.2, the near-field location of the speakers and subwoofer, the acoustic treatments and bass traps in the room, and the aforementioned optimal match of the PP1.2 and the SSP digital bass management circuit.

The Sound

I evaluated the PP1.2 on several music selections for balance, definition, pitch and timbre, coherence, sibilance, and soundstage imaging (both lateral and depth). My overall subjective music ratings are provided in the table below.

Evaluation Criteria	Rating (1-5)	Summary Comments
Balance	4.50	Excellent octave-octave balance.
Definition	4.50	Very good detail across the pass band.
Pitch and Timbre	4.50	All musical instruments rendered with accurate pitch and realistic timbre.
Coherence	5.00	Fabulous coherence – sounds like a single full range driver.
Sibilance	4.00	Flawless on high quality recordings, but slightly sibilant on poor quality recordings.
Imaging (lateral)	4.75	Sound stage is rock solid, almost sounds like the listener is wearing headphones.
Imaging (depth)	4.75	Great sense of depth, especially with well recorded orchestral passages.

Provided below are some listening notes from a few CDs. I assessed the PP1.2’s abilities on a variety of recordings, including chamber music, piano, full orchestral, male solo with acoustic guitar, and classic jazz.

Since I only had two PP1.2s, I was unable to assess their full capabilities for home theater, but given their excellent performance with all types of music in a two channel application, I have absolutely no reservations recommending these speakers for a full blown 5.1 or 6.1 home theater environment.

1) The Four Seasons (Vivaldi)- English Chamber Orchestra (Nigel Kennedy violinist), EMI Recordings, 1989.

All instruments were in their proper location in the soundstage, with excellent lateral imaging and depth of soundstage. Hall size was convincing, and the violins had natural silky pitch, never sounding strident.

2) Piano Sonatas Nos. 2 & 3, Fantasie, Barcarolle (Chopin) – Daniel Barenboim, EMI Records, 1974 (2004).

Barenboim was engaging, and chamber ambience was well-conveyed. The piano is a difficult instrument to reproduce properly, but the PP1.2’s sailed through this recording with nary a sour note.

3) Giant Steps – John Coltrane, Atlantic Records 1960 (1990)

The PP1.2 showed off its bass chops on the title track, preserving the "ba bum bum" sonic signature of the upright bass, and blending seamlessly with the subwoofer. Coltrane sounded suitably rich and resonant on the sax, with just the right amount of brass and honk. The drum solo in Countdown had good tympanic impact and skin, and high hat and brushed cymbals were spot-on. All instruments and musicians had their proper location on the sound stage and never wandered.

4) Soul’s Core – Shawn Mullins, Warner Brothers, 1982 (2002) DVD-A.

Shawn Mullins sounded like he was in the room on "Twin Rocks Oregon", with just the right amount of warmth and richness in his voice. Acoustic guitar was well rendered, with excellent attack and transients, perfect pitch, and great detail on the finger slides and fret work.

Conclusions

The Thiel PowerPoint 1.2 requires a fairly conventional room lay-out to work well, as typical mounting locations would be upper walls and the ceiling. Unless these speakers are being installed as part of new home construction, some handy-man skills will be needed, such as fishing speaker wire through the walls and ceiling, and also attaching the PP1.2s securely (I recommend stud mounting). Once installed and painted, though, the PP1.2 will virtually disappear in any décor, and yet still fill the room with audiophile grade sound quality.

The PP1.2 has several unique engineering and design attributes which give it a measurable and audible advantage over more traditional on-wall or in-wall designs. Its 2nd order acoustic roll-off at 80 Hz is a perfect complement to nearly all pre/pro and A/V receiver digital bass management circuits, so it will blend seamlessly with the subwoofer.

Due to its unique design features, the PP1.2 displays outstanding imaging, detail, and coherence on all types of music. While it was designed primarily for home theater applications, this loudspeaker has genuine Thiel pedigree and will please the most discriminating of listeners.

For the enthusiast who craves the convenience and aesthetic appeal of on-wall or in-wall designs, but wants to retain the superior sound quality of conventional speakers, the Thiel PowerPoint 1.2 is the perfect solution.


- Ed Mullen -