June 2001 Reviewed by Doug Blackburn	Parasound CSE 6.1 Center Surround Expander

Description Price: $400 USD Dimensions: 9.5"W x 2.25"H x 7"D Weight: 3.5 pounds Warranty: Ten years parts and five years labor on non-moving parts, two years parts and labor on moving parts Features Circle Surround Matrix processing compatible with THX Surround EX, DTS-ES Matrix and non-center-surround encoded soundtracks and music

Features (cont'd) Gold-plated RCA inputs and outputs Two center-surround outputs One rear-subwoofer output Adjustable subwoofer low-pass filter (full range, 120Hz, 80Hz) Remote control for level, defeat/enable, setup tone Center-surround-information-present LED Two outputs for overhead effects (requires ceiling-mounted speakers) Hardwired infrared receiver connection (for custom installation) External power supply

The Parasound CSE 6.1 doesn’t replace anything in your home-theater system, but it may extend the useful life of the equipment you are using today. If your receiver or processor doesn’t have THX Surround EX or DTS-ES Matrix decoding and you were thinking about upgrading to a newer receiver or processor to add this capability to your system, the CSE 6.1 will do this and not require that you replace a component. All you need are outputs (RCA connections) for the rear-surround channels; connect these to the inputs of the CSE 6.1 and connect the left and right rear outputs of the CSE 6.1 to your left- and right-rear speakers. You then connect the center-surround outputs of the CSE 6.1 to an amplifier, which drives one or two center-surround loudspeakers. Lastly, set the levels, and then you are running 6.1. The CSE 6.1 has no internal amplifiers, so you do need one or two amplifier channels for the center-surround speakers you add.

One thing you learn very quickly when you review audio and home-theater equipment is that there’s nothing like experiencing a product in your own room to help you learn about it. I’ve heard plenty of center-surround demonstrations at shows, but none of them meant much to me. Most of the time they sounded like normal 5.1. The times when I did hear things in the center-surround channel, they were too obvious, too mono and too localized to be realistic.

The CSE 6.1 really changed my mind about the value of 6.1. But there is another feature of the CSE 6.1 that turned out to be at least as significant as the addition of a center-surround channel. Not only is this feature useful, you won’t get it on some receivers and processors that offer THX Surround EX or DTS-ES decoding. So adding the CSE 6.1 may be more preferable for adding center-surround capabilities than buying a new receiver or processor. I’ll let the suspense build for a few paragraphs over what this additional feature is.

New insights on center surround

When you hear all your old favorites like The Fifth Element, Contact and The Iron Giant with the center-surround channel added, you really understand what the center surround is doing. None of these movies is specifically encoded for 6.1 (THX Surround EX or DTS-ES), but the CSE 6.1’s licensed Circle Surround Matrix processing worked extremely well nonetheless. Never was there anything inappropriate in the center-surround channel. The center surround adds an uncanny sense of reality in airport (or spaceport) scenes, with announcements filtering through the large reverberant spaces from many sources. While 5.1 does do this acceptably well, I never got the willies caused by uncanny reproduction of this unmistakable ambient effect until using the CSE 6.1. Ambience of all sorts, especially when present in all channels, is significantly more realistic when the hole in the middle behind you is filled.

Another obvious improvement from having the center-surround channel came during the few times mixes contained center information in the front and surround channels at the same time, like a voice. You could have all hell breaking loose around you and in the middle of it this voice just appears so close to your head that you’re completely surprised by it. This happens several times in DTS-ES version of the The Haunting. The front-center and center-surround channels are used together to produce a phantom image that is much more convincing than the phantom image you get when a 5.1 system must use the front center and surrounds to try to produce the same effect.

The direct-radiating, point-source, on-wall surround speakers I use produce a very convincing center image -- a much more convincing center image than surrounds that fire forward and backward but not at the listener. In spite of the excellent center image I get in the back of the room with 5.1 processing, the addition of a center-surround channel filled in a hole in the back I wasn’t really aware was there until it was filled. Now the surround effect is seamless in the front and back of the room. I’m converted. You probably will be too.

But, to be accurate about the degree to which the center surround is noticeable, it isn’t a huge difference. It won’t blow your friends away. It’s more of a subtle improvement with occasional startlingly entertaining moments when the sound engineers do something unexpected with it. The CSE 6.1 remote control allows you to defeat the center surround and return to 5.1 at the touch of a button. This is useful for reminding yourself just what the center surround is doing for the presentation. Once you get to the point where you are convinced center surround is a benefit, you stop playing with the defeat button and never look back. The CSE 6.1 does its job unobtrusively -- if you set the level properly.

Terminator 2: The Ultimate Edition has THX Surround EX and DTS-ES encoding. The soundtrack of this flick is etched into my memory from years of it being a reference laserdisc and numerous viewings since the DVD version was released. As well done as the 5.1 soundtrack was, hearing it in 6.1 for the first time was a revelation. When the Harley wheels into the alley behind the apartment, the echo goes from cool in 5.1 to incredible in 6.1. The ambience that follows when the Harley is turned off is raised a notch, with sounds having much more of an all-around-you feel to them. There aren’t too many sounds directed specifically at the center-surround channel in this soundtrack, but it is used well to re-create spaces like the parking deck, the mental-hospital corridors, Dyson’s office and labs, and the foundry.

But wait! There’s more!

If you have read audio and home-theater reviews for a while, you’ve probably read many times that bass below 100Hz is omnidirectional; it seems to come from all directions, and you can’t localize where it originates. This may be true for bass below 100Hz in an anechoic chamber, which is free of resonance (the walls, floor and ceiling are inert), but in my room it is easy to tell whether bass is coming from in front or behind. I feel front-of-the-room bass in my legs, stomach and chest, and I feel back-of-the-room bass in my back and shoulders. When you have front and rear subwoofers, you can feel the front of the room or the rear of the room get energized. You may not hear where the bass is coming from, but you sure feel it.

I connected an additional powered subwoofer to the subwoofer output of the CSE 6.1, and I got a major kick in the pants hearing all the old favorites again, with full-range bass being reproduced in the back of the room. My on-wall surround speakers are flat to about 60Hz in my room with useful bass though the 50Hz range. It was quite a surprise to hear how much bass I was missing in the back after connecting the powered subwoofer to the CSE 6.1. I set the CSE 6.1 to send a full-range signal to the powered subwoofer since it has internal high-pass filtering. This avoids sound-degrading double filtering.

The CSE 6.1 is almost worth the retail price just to get the subwoofer output for the rear channels without having to use less effective connection methods. The CSE 6.1 puts the bass from all the rear channels into the subwoofer output, so you get full-range bass to go along with all the rear channels.

A sound of its own

I’ve had no product like the CSE 6.1 (or any like-functioning center-surround receivers or processors) in for review until now, but it was still possible to draw sonic conclusions based on careful observation. When the CSE 6.1 is engaged, the rear sound becomes slightly softer on the top end and slightly more diffuse. The change is extremely subtle, but it is there. Sounds still have sparkle and detail; they are just smoothed a bit. Defeating the CSE 6.1 produced a sound virtually identical to not having the CSE 6.1 in the system. Thus, I would have to say that in Defeat mode, the CSE 6.1 is about as transparent as it can be. I was lucky to have multiple pairs of JPS Labs Superconductor2 interconnects to use for both inputs and outputs, so there were no sonic-signature changes due to dissimilar interconnect cables. Overall, I’d call the CSE 6.1’s sound relaxed, yet still with plenty of detail and dynamics. It actually seemed to make movies a bit easier to listen to at my customary volume level -- just a bit below reference level. The reference level strikes me as being just a bit too loud for a two-hour movie.

Having the left- and right-surround channels augmented by a center-surround channel took some acclimation. You are essentially moving the energy from two sources and spreading it over three, so each speaker could be down in output by as much as one-third from what you are used to hearing. There is a tendency to want to run the level of the rear channels and CSE 6.1 center-surround channel a bit higher to maintain the energy levels you are used to hearing at the left and right surrounds. You really need to use your SPL meter and spend some time dialing in the center-surround level properly and resisting raising the level of the rear surrounds via the receiver or processor setup menu.

Your mileage may vary

Center surround is not for everybody. You need space behind your viewing position. Preferably the distance from the center-surround speaker(s) to the listeners would be the same as the distance from the left and right surround speakers to the listeners. The CSE 6.1 does not have time-delay adjustments to compensate for disparate speaker distances. I have about 11 feet from the surrounds to the listeners, but only about eight feet from the center surround to the listeners. The center surrounds are mounted on top of 7'-high bookshelves and angled downward to ensure that the listeners are in the sweet spot. I can’t quite get the space I need to equalize the distance of my on-wall (not in-wall) surrounds with the center-surround speakers. If you have a medium-to-small home-theater room, you may find you just can’t physically squeeze center surround into your setup.

One thing to be careful about: the larger a loudspeaker is, the more space it needs for all the drivers to integrate. If you sit too close to the center-surround speakers, you may hear the drivers separately rather than as an integrated whole. Small two-way bookshelf or floorstanding loudspeakers will need at least four feet of space. Larger two-way bookshelf or floorstanding loudspeakers will need five to six feet of space. Most three-way loudspeakers will need a good six feet or more before their sound is completely integrated.

What’s that up in the sky? Ceiling-mounted surround speakers?

Because Circle Surround is a matrix technique, additional information can be extracted and redirected to an additional channel that essentially contains "ambience of the ambience" information. Parasound apparently believes that speakers mounted on the ceiling over the listeners and aimed down at the listening positions produce an interesting enough home-theater effect to include two outputs for this capability on the CSE 6.1. My 10.5' ceiling height made the positioning of two speakers over the listening couch more work than I was able to attempt during the review period. But I have to admit to being curious about what I’d hear. Perhaps at some future date there will be some way of positioning loudspeakers to try this out.

Summing up

I found Parasound’s CSE 6.1 to be a surprisingly addictive addition to my home-theater setup. Being able to easily add another LFE-type rear subwoofer was the real deal-sealer for me. I’m now convinced that both a center-surround channel and rear subwoofer will be permanent additions to my home-theater setup. The sonic performance of the CSE 6.1 was commensurate with the sonic performance of good surround-processing circuits. The center-surround channel introduces a superior all-around-you effect in the rear half of the room and makes startlingly real phantom images from the center-front and center-surround channels when they are used together. The CSE 6.1 would be less desirable if it only provided center-surround-channel information for THX Surround EX or DTS-ES soundtracks. But using the CSE 6.1 enhanced even ordinary 5.1 soundtracks. The CSE 6.1 is more feature-packed than some other center-surround adapters that don’t include remote control, subwoofer output or ceiling outputs. The CSE 6.1 isn’t the least expensive center-surround adapter, but this is a case where you get what you pay for. The CSE 6.1 is highly recommended if you have the space for adding center-surround decoding to your system.

Manufacturer contact information:

Parasound Products, Inc.
950 Battery St.
San Francisco, CA 94111
Phone: (415) 397-7100

E-mail: sales@parasound.com
Website: www.parasound.com

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