Recommended Components 2021 Edition Room Acoustics Treatment

Room Acoustics Treatment

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 by 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 by 13" W by 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: $385 ★

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" by 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" by 40" by 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: $2580 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 by 24" wide by 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 by 24" W by 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 by 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
grymiephone's picture

The Linton Heritage is not an audiophile speaker, and I will stop there, it's hard to find music it plays well

Glotz's picture

And it sounded fantastic with 'entry'-level Hegel components.

Everyone is different, and especially when one levels generalist comments.

grymiephone's picture

I had a response with more details but it was deleted.

Glotz's picture

Sorry man. I think the site had some issues a week back as well. Anything that was edited sometimes got deleted.

grymiephone's picture

Oh, well. for what's it's worth:
I tested the Linton with 5 other speakers. When I ordered it, the sales person said: be warned, it's NOT an audiophile speaker. And it didn't compare well. I wanted to love them but my 23 year old Celestions had more image and punch than the Lintons. I am sure they can sound good in a different system

MatthewT's picture

I agree with the "not an audiophile speaker" remark. I wish we could know what Art Dudley thought of them. I love them, FWIW.

Glotz's picture

I appreciate both of your insights here.

It helps me come closer to the truth. Or that's not right- The perceptions of each person lend us insights into how each person feels in their system.

I know a lot of times it's hard to speak to one's system for fear of others being critical.

Nonetheless, it does tell me what possible variances there are. I thought the double Linton's were impressive, if expensive. The dealer had them in a pseudo-d'appolito configuration, with the top speakers upside down and on top of the bottom pair.

liguorid42's picture

I agree everyone's opinion of what he or she likes is valid, and an opinion that you shouldn't like something because it's not an audiophile product is invalid. That being said, if you're a wine connoisseur you wouldn't necessarily make a buying decision on a pricey Cabernet based on the opinion of someone whose beverage of choice is Mountain Dew. And "not an audiophile speaker" can just mean your favorite reviewer has not made the sign of the cross before it, and is pretty useless without some description of what you perceive its sonic flaws to be.

Glotz's picture

I think all stereo products can have a home, but you are right it's all about context.

I was impressed with the Denton's midrange, but perhaps that's not fair given I was listening to the collective output of 2 pairs of speakers working in tandem.

mememe2's picture

PLease put this in the "useless phrases" section of your mag. Can we have good pace but lack timing -no. can we have good rhythm but lack pace - no. Can we have good timing but lack rhythm - no. This description seems to be aimed at audio prats (in the original meaning of the word).

Charles E Flynn's picture

"captures the emotion"

liguorid42's picture

Back when founding father Gordon Holt started Stereophile he tried to develop a lexicon to describe how things actually sounded--things like "liquid", "transparent", "grainy", "warm"--as opposed to how things emotionally affected him personally. Theoretically you could go to a hi fi emporium, listen to KLH Nines driven by Audio Research electronics and hear for yourself what he meant. Though he did open the door with his "goosebump test". These days terms such as you describe have made subjective audio reviewing so subjective as not to be very useful to anyone else.

Charles E Flynn's picture

Thanks for your reply.

I have always wondered how one could determine that a playback chain captured the emotion of the performers when the only evidence we have about their emotions is what is provided by the playback chain.

The reproduced sound may convey or provoke emotion, but whether what it conveys is what the performer felt is something we can never determine on the basis of only the reproduced sound.

liguorid42's picture

..in the Firesign Theater album said, "That's metapheesically absurd, mun, how can I know what you hear?"

Heck, you can't know if what you're feeling is the same as what the performer is feeling even at a live performance. Not even close would be my guess. What I'm feeling when I play the piano in private is very different from when I get conned into playing for someone. What the composer felt when setting the notes to the page, different still. I doubt a loudspeaker, let alone a piece of loudspeaker cable, has anything to do with any of this.

George Tn's picture

the Schiit Sol made it on to the list in such a high spot for its price. I've been rooting for that product and it's finally being seen for how great it is.

PTG's picture

Yup.. So happy to see Sol finally get some recognition. SOL had a very rough launch but they owned up to it and made it right ! I would love to get one but am worried about how much tinkering is needed to make it right.. Still thinking about it.... It LOOKS amazing !!!

georgehifi's picture

Same for the Aegir, a A20w Class-A stereo in Class-A Stereophile. I can only think of one similar that could/would do that, and that's the mighty 20w Mark Levison ML2 monoblocks.
https://i.pinimg.com/736x/d6/6a/cc/d66acc2c1d4fa7ea17f5a9bb9345e912.jpg

Cheers George

Glotz's picture

Yes, these components are great to see classified, but it's one person's ranking for a component. The classes also cut a large swath in performance of any one category- and within each class.

That being said, I do think the Sol is pretty-well-reviewed for the money and if my rig broke suddenly... I'd get this one to tie me over.

PTG's picture

Did I miss it or was Bluesound family of products (Node2i, Vault2i ??) totally dropped off the RC2021 list ? If yes, I wonder why...

Jim Austin's picture

On previous lists, when several Bluesound products were listed together, we put them under "Complete Audio Systems." We dropped most of them simply because they haven't been auditioned in years--indeed, no Stereophile reviewer ever tried a gen-2 version of any of the products except the Node2i, which I bought a few months back and use daily. Dropping products that haven't been auditioned in a long time is longstanding RecComp policy.

With only the Node2i on the list, it no longer makes sense to list it under Complete Audio Systems; it should be moved to Digital Processors. But I overlooked that fact when preparing the 2021 edition.

Jim Austin, Editor
Stereophile

C_Hoefer's picture

I just navigated to this page intending to point out the error in location of the Bluesound Node 2i - glad to see you already caught it! It belongs in digital players.
--CH

prerich45's picture

I'd like to see some of the other offerings tested by Stereophile. The Gustard dacs have measured well by another site. I've actually purchased one to see how it fairs to my ears - as I've already seen its numbers. SMSL,Gustard, and Topping are making some possible world beaters, it would be interesting to see this publication put them on the bench.

Fstein's picture

Lirpasound announces $79 amplifier, states previous price of $159,000 a joke no reasonable person would believe

Tweak48's picture

I'm confused by the Editor's Note: "There are no Class D integrated amplifiers listed". It looks like the Marantz 30, the NAD, and the Rogue Sphinx are using Class D output sections, among others. What am I missing here??

John Atkinson's picture
Tweak48 wrote:
I'm confused by the Editor's Note: "There are no Class D integrated amplifiers listed". It looks like the Marantz 30, the NAD, and the Rogue Sphinx are using Class D output sections, among others. What am I missing here??

Not amplifiers that have class-D output stage stages but amplifiers that are rated in Class D in this Recommended Components category.

John Atkinson
Technical Editor, Stereophile

Ron Lel's picture

Is there any reason no class D amplifiers are listed? Surely the Mola Molas should be mentioned.
Also I am surprised at the omission of the Audionet Humbolt.

John Atkinson's picture
Ron Lel wrote:
Is there any reason no class D amplifiers are listed?

There are several amplifiers with class-D output stages listed, but none in the Class D category/

Ron Lel wrote:
Surely the Mola Molas should be mentioned. Also I am surprised at the omission of the Audionet Humbolt.

As it says in the introduction, Recommended Components is reserved for products that have been reviewed in Stereophile. Neither the Mola Mola nor Audionet amplifiers have been reviewed yet.

John Atkinson
Technical Editor, Stereophile

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