My SVS CS Ultra arrived yesterday. I just sat down this evening for a listening session. I wanted to see if it was worth all the good press its been getting.
However, The Adcom GFA-555MkII/CS Ultra package retails for almost two and a half times the price of the PSW650 I currently own. Is it 2.5 times as good as the PSW650? Depends on what's important to you. If you value accuracy and true to life sound, go for the SVS. If you value loudness, and brute force, go with the Polk.
You must also keep in mind that I am running the GFA-555MkII in bridged mono mode, which delivers 800 watts max into 4 ohms. The PSW650 is 250 watts into 8 ohms.
Listening Session 1:
My first listening session was done with the amps for the center, front, and rear speakers turned off. So, all I was listening to was the subwoofers through the LFE channel. I knew the PSW650 was sort of crude and unrefined, but listening to it by itself was a revelation. I could hear the woofers rattling (bottoming out) on some loud passages (Matrix, Star Wars Phantom Menance). I never realized that was happening. The PSW650 was apparently much louder than the CS Ultra, but that was just distortion. My sound level meter only read .5 to 1 dB higher for the Polk compared to the SVS on the same passages.
The SVS supposedly cleanly goes down to 20Hz. I do know that the china in my kitchen cabinets (next to the A/V room) rattled loudly on some bass heavy passages. I had never heard that with the PSW650. The SVS bass was much better defined. Low level definition (like, for instance, the difference between a growl and a rumble) was clear, articulate and lifelike. Low level definition is nonexistant on the PSW650. On first listening, it seemed like the CS Ultra lacked the visceral, in-your-face impact of the PSW650. However, the CS Ultra has a different kind of impact: the kind that moves through you rather that just socking you in the face.
The CS Ultra certainly integrates much better with my SDA 1C's for movies and especially music. I can't use the PSW650 for music. They make my ears hurt.
Listening Session 2:
This time I am listening with all the speakers running. Surprisingly, the differences aren't as great now. For explosion scenes, the PSW650's upper harmonic distortion adds more apparent impact. This is because the PSW650 is louder in the frequency ranges where your ears are more sensitive.
Little Technical Details:
My home theater system is in a dedicated video room measuring 18 feet wide by 20.5 feet long with a 10 foot ceiling (3690 cu. ft.). The CS Ultra and the PSW650 were placed in the corner behind the right SDA 1C (see pics in System Showcase). I was seated 15 feet from the TV and 17 feet from the subwoofer.
If you are considering the CS Ultra, be mindful of the fact that it takes gobs of power. The optional amp that SVS sells with the CS Ultra is rated at 500 watts. I tried running the Ultra with one channel of the GFA 555MkII in regular stereo mode (325 watts into 4 ohms) and it virtually vanished right before my ears. Reconfiguring the GFA-555MkII back to mono bridged mode (800 watt into 4 ohms) made the Ultra come back to life.
I'm impressed, but not overwhelmed. I really can't say whether I'll keep the CS Ultra. It certainly is a great match for my SDA's, it will have to grow on me some more. Maybe after I live with it for a couple of weeks, and I've watched the Star Wars: TPM pod race sequence a few more times, my ears will readjust to this kind of low frequency accuracy.