It's November 2025 and Steinmusic has introduced a flurry of new products in the last few months, and I am happy to report they are at the top of their game. I want to talk about the Acoustic Discs. They are a room treatment whose claim is to open up the soundstage, give the illusion of the walls "disappearing" while being small and discrete enough not to arouse the ire (or suspicion)  of significant others who may have a say in your listening room's decor.

Description

The Acoustic Discs. are a little over 2 inches in diameter, and not quite 3/8" high. They appear to be made of 3D printing resin (plastic), and come in black or white. Stein claims that they are also paintable, to that I would add they are plastic, so use a spray enamel paint and paint like you would any other plastic object.

You can buy just a single unit for $149, or buy 3 for $438.

Recommended Use

Stein suggests placing them on the walls, and offers an example diagram of how to implement them. See below.

For the full treatment, 11 discs are recommended. 

• 3 each on the left and right side walls, 12 to 15 inches below the ceiling
• One disc centered on the wall behind the listening position, about 12 to 15 inches below the ceiling
• One disc on the ceiling, in line with the centerline between the speakers, mid way between the speakers themselves and the listener (this one I have found to be the most flexible in placement in terms of preference.
• 3 discs at ear level
  • One centered between the speakers
  • One each on the left and right side walls directly to the sides of the speakers (experiment with moving them forward and backwards as well)

In addition, placing one disc on top of (or as I prefer, on the back of) each speaker also produces excellent results.

Listening

I started my listening with just 3 discs placed at ear level. One centered between the speakers on the wall behind them, and one on each side wall flanking the left and right speakers just slightly in front of the imaginary plane their front baffles create.

The effect was fairly immediate and far more powerful than I expected. The soundstage opened up to the sides, beyond, above the speakers and also increased in depth. I noticed an increase in the audibility of low level sonic information. Reverb, space, small sounds made by the recording artists as they moved breathed or made sounds with their mouths when close to a mic.

I then added one Disc to each speaker. They continued to exceed my expectations 

Very subtle background sounds in the recording, intentional and unintentional, became more evident and added a stronger sense of realism to the recorded event. Dialogue and harmonies become more distinguishable/intelligible. The amount of low level information now audible was incredible and kept me listening for hours into the night. There was no tonal shift, like an increase in midrange or treble that would easily explain how the discs were pulling off this sonic stunt. There was no listening fatigue as my system maintained is balanced presentation. There was simply more going on in the music, and it was being projected all around the room and my listening position.

As per Holger's advice, I placed an Acoustic Disc on top of each speaker, towards the rear of the enclosure. The Discs on the speakers brought forth more air and space immediately around the speakers,  with the sonic projection all around creating a more emotional listening experience. I could hear vocal and instrumental intonations, textures and emotive elements of the entire recording far more clearly.

Final Addition of Discs

As I added the final number of Acoustic Discs to the sidewalls and behind the listening seat, the sense of pressure one experiences, I suspect as soundwaves and air hit the walls and move through the room, seemed to be reduced. It created this illusion of a bigger room if I closed my eyes. The sound enveloped me on all sides. It awakened my sense of hearing, but my body and mind remained relaxed. There was no listening fatigue, just music and peace.

Every night it was difficult to stop listening to music, and every morning I was excited to fire up the system and do it all over again. 

Additionally as I kept listening over the next few days and weeks, I started noticing that the dynamic and transient attack of the music had more energy and liveliness to it.

Nothing New, And Nothing Better

Okay, Acoustic room gizmos have been around for some time. We've had devices from Bybee, Synergistic Research, LessLoss, and many others. Some large, some small, some powered and some needing no power at all. Some do really nice things when used sparingly, but they give their secrets away when one applies too many. By that I mean they their "wow" factor is tied to the exaggeration the highs or mids in order to produce their magic, but it becomes evident when you reach a certain number of devices within the room.  So one has to be sparing in their use, otherwise one risks a tonal imbalance at the expense of the walls disappearing and rendering of a huge soundstage.

They all do something, but the Steinmusic acoustic discs are the best in my experience. Why? 

1.  They are small and visually unobtrusive.
2. There are no tonal shifts when more are added. 
3. They are the most powerful of any room acoustic tweak I have tried, 
4. They are reasonably priced, and one can invest incrementally to get the full system and more.

Compatibility

I used the Acoustic Discs with Stein Harmonizers, Bybee V2+, QSA fuses and AC receptacles. After placing 12 of the Discs I removed the Stein Harmonizers, and the Bybee V2+. I lost a little something when I did this, so I added the V2+ back, spreading 3 across the floor against the wall behind the speakers. One in each corner and one centered on the wall. This gave me back a richer, fuller, larger more convincing soundstage. The Harmonizers ended up being a little too much of a good thing and I ended up leaving them out. My guess is one could turn down the effect of the Harmonizers, and use fewer discs if they wanted to. But frankly the Discs are so much less expensive that using them without Harmonizers is the better value proposition. That is great news for those who have always been curious about treatments like the Harmonizers, but had a hard time justifying the price. For a little more than half the price of 4 Harmonizers one can treat their whole listening room with the Acoustic Discs and have an equally engaging result.

Conclusion

Not only to the Steinmusic Acoustic discs "make the walls disappear" when judiciously placed within one's listening room, they do so without shifting the tonal balance, and do so without being a visual distraction. That would be good enough, but they also sharpen transient attacks, and add a jump factor to dynamics. Last, but by no means least is the improvement in resolution, especially if placed on the speakers directly. They bring down the price of admission for this type of room tweak, as well as allow one to gradually build up to the full recommended system.

I want to make a special point here. Some of you might think the acoustic discs can be used in place of conventional room acoustic treatments. No, they are not a replacement. They cannot fix reverb times in your room due to the abundance of sonically reflective surfaces in your room. These are a finishing touch to be implemented only after you have adequately treated your room with proper purpose made acoustic absorption, diffusion, and bass treatment. Please get your room acoustics in order, then try the Acoustic Discs.

Follow those orders and you will be rewarded with sound that is enveloping and engaging. Natural in tone, dynamics, and timbre. With haunting resolution that leaves you exhilarated instead of fatigued. Yeah they are that good.

Tinfoil Hat Award

SteinMusic Acoustic Discs