Recommended Components Fall 2021 Edition Room Acoustics Treatments

Room Acoustics Treatments

Acoustic Geometry Small Curve: $399.99 ★
Medium Curve: $449.99 ★
Deluxe Curve, Walnut Frame: $549.99 ★
Deluxe Curve, Red Oak, Stained Black Frame: $549.99 ★
Acoustic Geometry's Curve System comprises Diffusors, Absorbers, and Corner Traps, each 42" high and available in a number of fabric choices. Each model is built on a wooden frame with a wedge-shaped cleat for hanging the product from a matching piece attached to the wall. Diffusors include a Mass-Loaded-Vinyl (MLV) membrane and are intended to control low- and midbass frequencies; Absorbers are essentially the same design as the Diffusors, but have an acoustically transparent front and don't include the MLV membrane; Corner Traps are triangular wooden frames filled with recycled cotton. In EL's listening room, the Curve System created a wider soundstage and greater clarity. Diffusors: $339.98$639.98, depending on width. Absorbers: $320.98$395.98, depending on width. Corner Traps: $697.98. Prices based on Guilford fr701, Anchorage and Acoustic Suede. All other sizes and fabric options quoted on individual basis. (Vol.35 No.2 WWW)

ASC StudioTrap: $589 ★
Adjustable tripod-mounted room-tuning device that represents the "latest in TrapThink from ASC," according to J-10, who uses an array of StudioTraps to great effect in his Manhattan loft. The front half is treble-reflective for a brighter sound, while the back side is treble-absorptive for a drier acoustic. He highly recommended the Traps for "anyone whose family will allow them to populate the listening room with gobos." (Gobos are "sound-absorbing panels used to surround performers in recording studios.") Stereophile's "Accessory of 1999." (Vol.21 No.12 WWW)

ASC SubTrap: $659-$839 ★
This "big, chunky black box" sits under a subwoofer to attack acoustic problems caused by the interactions of a subwoofer's output and the room's modes. Improvements in room acoustics were immediate, thought KR, even with the subwoofer disconnected: "There was less apparent energy from clapping, loud conversation, or just stomping around." With the system turned on, there was "less apparent bass energy from all wide range signals." With a Paradigm Servo-15 sub sitting atop a SubTrap, bass was deeper and more detailed: "Ah, yes—glorious bass without the boom!" Available in three sizes: 15", 18", and the 22" square model reviewed. (Vol.27 No.9 WWW)

ASC TowerTrap: $411-$1096 ★
Originally called the Cube Tower, the TowerTrap is a "smaller, more cosmetically acceptable, more affordable version of the classic TubeTrap," writes BJR. "Very effective at taming mid- and upper-bass room anomalies. Looks like an attractive Vandersteen speaker sitting there in the corner." (NR)

ASC TubeTraps: $459-$1046 ★
Relatively inexpensive but remarkably effective room-acoustics treatment. TubeTraps soak up low-to-high bass standing-wave resonances like sponges. WP agrees, using Traps to optimize the acoustics of his room for MartinLogan SL3 electrostatics, while BD used them to optimize his room while auditioning the Thiel CS7.2s. Using the Music Articulation Test Tone (MATT) from Stereophile's Test CD 2 (STPH004-2), he first positioned them for smoothest overall response and articulation, then "dialed-in depth, dimensionality, and ambience." A chart recorder graphically showed the changes. In the end, "The sound was fantastic," quoth BD, who recommends them unconditionally. (Vol.9 No.3, Vol.15 No.2, Vol.16 No.12, Vol.19 No.1, Vol.20 No.5, Vol.23 No.2 WWW)

Auralex SubDude II: $70.99 ★
An MDF platform 23" long × 15" wide, covered with a carpet of thick felt and supported by two risers of high-density isolation pad, the SubDude has a rated load capacity of 300lb. KR found that the SubDude significantly isolated his Paradigm Servo-15 subwoofer from the live wooden floor and made the sound "tighter and fuller, but, conversely, less obtrusive." When used under full-range speakers, the SubDudes offered similar bass results while affecting high-frequency performance. Current SubDude II has a lower profile than the original sample reviewed. (Vol.27 No.12 WWW)

Bag End E-Trap: $1760 ★
Uses active electronics to control an acoustic device that acts directly on room acoustics rather than imposing anything on the electronic signal path. With its 10" driver, controls, and power amplifier in a box measuring 18" H × 13" W × 9.5" D, the E-Trap looks like a small subwoofer without input terminals. "While the appearance of the E-Trap is generally not noted, its effect on room acoustics is substantial," praised KR. It canceled out the superimposition of room modes, providing tight, clean bass while reducing the effects of ambient noise. (Vol.31 No.7 WWW)

DHDI ZR Micro Twin Mk3: $888 ★
ZR Sample Rate 8 Bit Mk3: $387 ★
Delta H Design, Inc., or DHDI, is an acoustics and architecture firm in Los Angeles County that manufactures room-treatment products for the professional and domestic markets. Two of the latter are from DHDI's Zero Reflection line: the ZR Micro Micro Twin, which measures 24" × 48" x 1.25" and is covered with fabric, is intended for placement directly behind one's speakers, while the curiously and clunkily named ZR Sample Rate 8 Bit ($383) is a 20" × 40" × 0.75" sheet of MDF into which has been CNC-carved an intricate pattern of ridges. After treating his room with two ZR Micros and three ZR Sample Rate 8 Bits, JM noted an appreciable improvement in sound: "I loved it. Indeed, I was taken aback at how much of an improvement I heard." (Vol.38 No.4 WWW)

PSI AVAA C20 electronic bass trap: $2769 each ★
In a field dominated by DSP products, the AVAA C20 stands out: this response-correction device uses pure analog technology. Inside the AVAA C20—its name stands for Active Velocity Acoustic Absorber—is a microphone, a perforated membrane, a velocity transducer, and an amplifier with feedforward and feedback. In principle, the C20 converts incoming pressure waves into velocity waves, thus absorbing them. It is said to work on pressure waves between 15 and 150Hz without affecting other frequencies—and more than one C20 can be used in a given room. In a guest review for Stereophile, acclaimed mastering engineer Bob Katz described the AVAA effect as more of polishing than "fixing" per se and praised the active C20 for working well in tandem with his more traditional (and sizable) passive trapping products. (Vol.39 No.6 WWW)

Ready Acoustics Chameleon Super Sub Bass Traps: $309.99 ★
The Chameleon Super Sub Bass Trap measures 48" high × 24" wide × 6" thick, and is available in eight fabric covers and four frame colors, allowing it to be employed without dominating the view. Assembly and installation were simple. The Chameleons were "audibly and measurably more effective" than KR's Echo Busters corner traps, and produced "undeniable" improvements in the midbass and bass. (Vol.32 No.9 WWW)

RealTraps MondoTraps: $330 ★
Corner MondoTraps: $370 ★
The MondoTrap is a large (57" H × 24" W × 4.25" D) acoustic absorber built from "double-density" rigid fiberglass and covered in a sound-transparent fabric. In addition to imparting to bass instruments a "fuller, clearer, more palpable" sound, the MondoTraps seemed to reduce a "glaze," allowing Jim Austin to hear deeper into the music. "Far from deadening the room," he said, "the MondoTraps made the music more involving." "I really liked what the Mondo Traps did in my room," adds KR, "although I have to agree with Jim (and my wife) that their appearance better suits a studio or dedicated audio room than a regular person's lifestyle." Adding four MondoTraps to WP's small listening room resulted in punchier, more coherent bass. Corner MondoTrap, designed to fit unobtrusively into a corner of a room, costs $350. (Vol.30 No.8, Vol.33 No.2 WWW)

RealTraps: $150-$600, depending on size and type ★
With these fiberglass panels set up across the junction of room boundaries and in corners, KR heard major improvements in imaging, detail, and soundstage width: "Every sound in the room, real or reproduced, is more defined in character and location." While KR was greatly satisfied with the results, he admitted that the panels were visually imposing: "The stand-mounted HF MiniTraps are in the way all the time." MiniTrap, $200; HF MiniTrap, $200; MondoTraps, $300; stands, $80. (Vol.28 No.1, Vol.29 No.11, Vol.33 No.2 WWW)

Stillpoints Aperture II acoustic panel: $800 (any color)
A refinement of the original Stillpoints Aperture—a 22" square wall-mounted room-treatment panel said to act as a diffuser, an absorber, and a resonator—the Aperture II is lighter in weight and easier to mount. According to MF, it's also better looking—and even more effective: "The illusion of my room's sidewall boundaries disappearing became even more convincing." (Vol.42 No.6 WWW)

Totem Acoustic Tuning Pods: $130/pair ★
The Beak is a precision-machined, bullet-shaped device, about 2" high × 1.5" in diameter, that's intended to be placed atop a speaker to control parasitic resonances. When the Beaks were used with the GoldenEar Triton Two loudspeakers, highs gained clarity and extension, percussion instruments had greater presence, and voices became more tightly focused, said RD. "The improvement wrought by the Beaks was such that I wouldn't want to be without them," he said. See also EL's Totem Forest review in Vol.33 No.1. (Vol.35 No.2 WWW)

COMMENTS
MatthewT's picture

Not much for me here, being a vintage gear fan first. Please bring back the entry-level column, there is a lot of gear at that price-point worth getting reviewed.

Anton's picture

Budgetwise, I think I would be most like a "Double A" audiophile.

Same with me and wine.

I do admit to seeing some of the top end prices for either wine or Hi Fi and thinking that there are people who have checkbooks that are 'better' than their palates/ears.

Like JA1 described in the past...there are already parts of my own hobby that are beyond my budgetary event horizon.

_

If we did have audiophile classes, from minor leagues to major league, I wonder what the price points for each step would be.

MatthewT's picture

Lets me play every now and then in the Majors. Nothing depreciates faster than audio gear. I have to admit being somewhat happy at seeing a dartZeel break while listening to it, while my beloved Sansui keeps making music.

Anton's picture

I like showing gear in the reviews to my wife and asking her to guess the price.

When I saw the OMA turntable in the latest issue, I guessed 15,000 dollars. When she saw it, she guessed 12,000 dollars, and we've been playing this game for 25 years!

Next, I asked her if I were able to purchase it for 90% off retail, would she let me. She said, "Only I promised to flip it immediately."

Then, she threw me a bone and said, "You could buy it and keep it for the 12,000 dollars that I guessed."

I'd need a 97.5% discount to have a chance at it. And even that would be wildly extravagant. I'm happy with life, this is just for scale.

tonykaz's picture

Above the PS Audio level is the world of Status & Ego. !

Which has me wondering if Stereophile is a Status & Ego type publication ? Is this a Robb Report mag that belongs on the coffee tables of private Jet Airports ? ( I've never seen it there )

Does an Anodized Red $200,000 Amplifier belong on the Front Cover of a magazine like ours ? None of us will ever have any chance to experience Velvet Rope Gear so why are we bothering with it? It being better is probably one person's opinion ( and that person probably doesn't have to buy it or own it ).

Reviews of these $100,000 +++++ pieces are man-speaking to us how our gear is deficient and unworthy, we are reading Hubris & gas lighting.

There is a World of $1,000 bottles of Wine, $25,000 Rolex Watches, Super pricy First Class Seats on UAL Flights and Political Leaders that are wealthy from insider trading. We shouldn't be reading about those things here.

Ours is like the world of our modest Canadian, revealing a new form of music discovery and writing one of Stereophile's most insightful pieces of literature about it. ( nice writing Mr. Robert S.)( is that the door bell? )

Tony in Venice Florida

rschryer's picture

Thanks, Tony

tonykaz's picture

Annnnndddd :

Thank You to the Editor that gave you the Word Budget and turned you loose.

Stereophile keeps raising the Bar !!!

Tony in Venice Florida

Anton's picture

Where on Maslow's Pryamid is a half million dollar record player?

I'm curious to see....misguided 'esteem?'

I prefer to use Swanson's Pyramid....

https://external-preview.redd.it/5cDe4MZ9E0ZfvcS10kmAUd2ynTkp6b3wfU-fYsxyNfg.png?width=960&crop=smart&auto=webp&s=be478d54ccedc0bd3a8ea8428e368fe10ed78c60

(Second from bottom left.)

tonykaz's picture

A most expensive record player would service the Ego needs of someone needing to establish themselves as the very Top of Analog Audio's Caste System.

The widely recognised Top Level Analog Format has been Tape.

I grew up in a Performing Arts household, my mother was an Operatic Performer and one of my older brothers was a Horn Player for our local Detroit Symphony Orchestra.

So, from my point of view, no Analog Audio System has ever come close to performing like a Live Audio Performance from a listening distance position.

Super pricy Audio Gear is about Status & Ego !!! ( I hear that Bob Carver still laughs at this stuff )

Tony in Venice Florida

tonykaz's picture

Yes, Brilliant Observation! ,

of which, of-course, I completely agree .

Proving the old maxim: when two people agree on something - only one is doing the thinking.

Now that I'm living in the Deep South, Swansons Pyramid is where I'm slowly migrating to. Hmm.

Y'all have a Grate Day

Tony in Venice Florida

ravello's picture

The introduction to recommended loudspeakers states that "Candidates for inclusion in this class [i.e. Class A, limited LF extension] must still reach down to at least 40Hz, below the lowest notes of the four-string double-bass and bass guitar." The Falcon LS3/5a, for example, most certainly does not reach down to 40 Hz, unless you define "reach" to include a -10 or -15 or even lower dB point, which cannot be construed as useful bass etension. This is probably true for several other speakers listed in this category. So what is happening? What is the thinking behind this inconcistency?

smileday's picture

Perhaps about -7 dB at 40Hz in this room. Fig. 6, https://www.stereophile.com/content/bbc-ls35a-loudspeaker-harbeth-measurements

It might be -3 dB at 40Hz in a broadcast van, the intended usage at the design stage.

tonykaz's picture

...performance level for all Great Transducers?

It was the very loudspeaker that brought me and my English partner into the Audio Business. ( back in the early 1980s ) -- ( my business partner and I begged Raymond Cooke for this design to import to USA - he said NO! )

Isn't it still a "Reference" for comparison ? , doesn't any new design have to match or exceed it's super high levels of performance?

This little device and a well matched sub builds an outstanding Desert Island System.

But, it's still outstanding without the Sub.

It may not be Full Range but it well earned a Lifetime Class A+ transducer system rating. ( four Decades + )

Tony in Venice Florida

Ortofan's picture

... like antique furniture, but the KEF LS50 Meta is a much more highly evolved successor.

tonykaz's picture

I'm sure that I agree with you.

I seem to have a deeeeeeeep seated feeling that the LS3/5a is the grandfather of High End music Gear.

Even during the 1980s, my little shop : Esoteric Audio in Farmington Frills, Mi. stocked most of the small mini-monitors including the LS3/5a, Linn Kann, ProAc Tablette, Spica TC50, Quad ESL63 and the whole range of other hopefuls. Performance wise, the ProAc Tablettes were the musical leaders, the Quads were the Sales leaders, the Spica was the Reviewer Favourite . We had them all on permanant comparison using a VPI player, Koetsu Rosewood, Electrocompaniet Electronics and MIT Music Hose cable interfaces. It was an exciting adventure for any and all customers to take part in the ongoing comparisons. People bought scads of 'all' of those small speakers types.

With great or outstanding supporting gear, the LS3/5a can Scale up to amazing levels of music reproduction.

Tony in Venice Florida

ravello's picture

@ smileday: With due respect, the link you posted is not to the current Falcon "Gold Badge" reviewed in 2021, which I was talking about, and which is about 12 dB down at 40 Hz (ref. 1 KHz) in JA's listening room on the evidence of Fig. 6 and Fig. 8 (red trace). This, as I was saying, cannot and should not be construed as useful bass extension at 40 Hz, so listing this speaker as "Class A, limited LF extension" is misleading (to say the least) in light of Stereophile's own stated criteria for inclusion in this category. Perhaps Editor Mr. Austin would like to take the stand on this. Furthermore, most of us don't listen to music in a broadcast van. Mind you, I am not saying that these are not truly great speakers. Indeed, I used to own the Harbeth P3ESR, which I found as nearly flawless as I suspect is possible in a loudspeaker, except for bass extension and volume (SPL) capability -- admittedly an inevitable design constraint given the size of the midbass driver, the size of the cabinet, and the benign impedance. This is why I eventually replaced them with a pair of the Harbeth C7 (40th Anniversary), which turned out to be game-over speakers in my small, 12 sqm study. Perfectly solid bass to 40 Hz and possibly below.

TowerOfPower's picture

It's surprising to not see a single Soundsmith cartridge on this list. Would like to know why.

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