Product Review (May 2003)
Eighth Nerve - Response Controller
Acoustical Products

Room acoustics play an important role on the sound quality of any audio system. Windows, hardwood floors and other highly reflective surfaces cause secondary reflections and echoes that tend to defocus and blur the sonic image we try so hard to create. Surprisingly, simple room treatments help reduce these problems by absorbing sound which would otherwise be reflected back into the room. Sonic improvements can be made by treating the room at specific locations to reduce unwanted reflections. This not only applies to home theater sound, but also the more traditional two channel systems as well. A company called Eighth Nerve, located in Nashville, Tennessee, has introduced a series of Response Controller specifically addressing these problems.

Bill Laurent, President of Eighth Nerve, sent us a set of Ivory colored acoustic response controllers to try out in our listening space. They are available in Ivory or Black. They included Corners, Echoes and Seams. Corners are used where the two walls meet the ceiling, so four of them are needed in a typical room. Echoes are placed on flat surfaces to help reduce "Slap echo" locations caused by two parallel walls facing each other. A simple test to hear the effects of the echo is to clap your hands while standing between the two parallel surfaces. You should hear the slow decay of sound as a result of the sound bouncing back and forth. This is a common problem in most listening environments. The Echo controllers are usually mounted on the front and back walls as well as the side walls to reduce the echo problems. They are also used to reduce "mirror points" in the room where sound is reflected off the side wall and hits the listener slightly later than the direct sound from the speaker. Imagine the wall being a mirror and you look at it and see your speaker. This is the location of the "mirror point" that reflects the sound. This causes blurring and imaging problems in many setups. The Seams are used to control energy traveling along the wall surface. They are mounted equal distance from the floor and ceiling. All of the products we received use push-pin tacks to hold the controllers in place. This is a better approach than the double sided tape since adhesives tend to ultimately fail over time.

Using our Sencore SP295C Audio Analyzer, we measured RT60 times both before and after the installation of the Response Controllers and we saw a reduction in the reverberation time. Our listening room has a nasty reflection on the right side wall and the installation of two Echo panel helped reduce the level of the secondary reflections. We measured this using the SP295C, which sends out a pulse and looks at the incoming sound wave and converts it into a Time/Energy graph. We could clearly see the fundamental arrival of sound and the secondary reflections. This is a great way to tune a room. By attenuating the primary reflections and other mirror points in our room, we were able to improve the intelligibility and image coming from our speakers. Two channel audio as well as movie soundtracks were certainly more enjoyable once we added the controllers to specific locations.

Acoustic Response Controllers can make a significant difference in how your audio system performs. What we liked about the Eighth Nerve product was the great performance we got for the relatively low price. For under $270 you can pickup a Roompack that includes four Corners, four Seams and 2 Echo products. Additional controllers are available for your specific needs. Eighth Nerve also has framed response controllers designed for higher sound pressure levels, but we didn't have any for this review. If you take your room acoustics seriously, you should set aside part of your budget for some affordable Eighth Nerve Response Controller products. Depending on your room acoustics, you may be surprised at what a difference it can make.
- Kevin Nakano

Review System

Display - SharpVision™ XV-Z10000U High-Definition DLP™ Front Projector
Filmscreen - Stewart 100" 16:9 Luxus Deluxe FireHawk ScreenWall
Preamplifier/Processor: Parasound AVC-2500u THX-Ultra DTS/DD Preamp/Processor
Amplification: Parasound HCA-2205AT THX-Ultra Five Channel Amplifier
Bass Management - Miller & Kreisel BMC Mini 5.1 Bass Management Controller
Front Speakers - Miller & Kreisel S-150THX (L+R) and S-150AC (Center) Speakers
Rear Speakers - Miller & Kreisel SS-250 Tripole® Surround Speakers
Subwoofer - Two Miller & Kreisel MX-350THX MkII THX-Ultra Push-pull Subwoofers
Set-top Box #1 - Samsung SIR-T165 Terrestrial HDTV Receiver with DVI
Set-top Box #2 - RCA DTC100 HDTV/DSS Satellite Receiver
DVD/CD/SACD Player - Sony DVP-NS900V DVD/CD/SACD Player
DVD Audio/Video Player - Kenwood Sovereign DV-5900M 400-Disc DVD Changer
A/V Cables: Ultralink Platinum and Advanced Performance Series Cables
Audio Analyzer - Sencore SP295C Contractor Audio Analyzer

Review at a glance
Eighth Nerve - Response Controller
Acoustical Products


Corners should be installed in a room's upper corners, where two walls meet the ceiling. They control horn-loading effects and will make an immediate difference in the sound quality and harmonic structure of music. The Corners should elegantly straddle the corner area so that sound pressure can build behind the unit.

Size: 16" x 16"
MSRP $89.95 (Set of 4)

Echoes have many applications and installation possibilities. The first place they are usually installed is on the centers of the front and rear walls, either an inch under the ceiling or straddling the wall and ceiling edge. You can further balance your room by placing 2 additional Echoes on the remaining walls of your listening space.

Size: 16" x 10"
MSRP $49.95 (Set of 2)

Seams treat signal smearing due to laminar flow by controlling acoustic energy traveling along wall surfaces. In most cases, Seams will be applied vertically, halfway between the floor and ceiling in corners, or in mid-wall positions.

Size: 48" x 7"
MSRP $169.95 (Set of 4)

This set of ten passive products is the cornerstone of most home audio acoustic treatments. It is comprised of four (4) Corners, four (4) Seams, and two (2) Echos. Eighth Nerve has made it their goal to produce acoustic products at a price every music lover can afford.

MSRP $269.95 (4 - Corner, 4 - Seam, 2 - Echo)

Framed Response controllers are designed for spaces with very high sound pressure levels. These are recommended in place of Seams for large, live rooms. Framed Response controllers were originally designed to treat music rehearsal spaces. They offer a musical solution to sound problems in spaces where a great deal of sound control is necessary.

Size: 36" x 7" x 5"
MSRP $74.95 (Set of 1)

Response Floostanders are mobile. They can be used to treat problem areas inside a room or simulate room boundaries for a more cohesive sonic picture. We recommend using them when a listening room or home theater has irregular open spaces or openings into other rooms. For instance, Floorstanders can simulate a wall in an entryway between your listening room and other rooms or hallways. The presence of a Floorstander allows sound pressure to build in that gap, balancing your listening environment.

Size: 48" x 12" x 3.5"
MSRP $149.95 (Set of 1)

Company Information
Eighth Nerve
7 Music Square West
Nashville, TN 37203
Toll Free: 877-8TH-NERVE
Phone: 615-742-4283
Fax: 615-742-4617

Room Controller Instructions

Source: Manufacture loan


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