- Lab-tested, cost-effective
- Simple to Install
- Use on walls, ceiling or behind stretch-fabric systems
- Can offer either horizontal or vertical scattering
- Improve tonality and clarity
- Improve soundstage, air and spatial imaging
- Improve surround sound envelopment
- Control first order reflections
- Eliminate flutter echo
PolyFlex balloon dispersion results at 1 kHz.
What is unique about the acoustic performance of the PolyFlex compared to other diffusers?
- Adjustable 2”-4” depth for randomization (no frequency lobing), or fine-tuning
- Minimum uniform dispersion of 150° of horizontal or vertical scattering (wider than any other type)
- Effective from about 630 Hz. and up (broad frequency bandwidth and no high frequency limit)
- No high frequency limit, even when off-axis (never casts a shadow upon itself)
- Effective even at 90 degrees off axis
- Remains phase coherent, unlike number-theory diffusers.
- Though the PolyFlex is a pure diffuser on its own, the open sides can be loosely filled with insulation to add absorption properties
NWAA Acoustics Lab 1 kHz. Side or X view Polar Plot Results
NWAA Acoustics Lab 1 kHz. Plan or Z view Polar Plot Results
NWAA Acoustics Lab 1 kHz. Top or Y view Polar Plot Results
NWAA Acoustics Lab 1 kHz. 3D View Polar Plot Results
Number theory diffusers are expensive and difficult to build. They are also very limited in performance. For example; common QRD or skyline-type diffusers are diffractive diffusers. The different length wells or blocks reflect at different phase points. This phase scrambling removes localization. They are also typically limited to 4kHz. – 16kHz.
If a skyline-type diffuser uses blocks that have a 2″ reflective face, it can only reflect wavelengths that are smaller than that dimension, meaning it is only effective down to about 6.7kHz. It will also block itself to sound sources and receivers that are off-axis, is ineffective when too close to a receiver, and if one dimension is slightly off in build or calculation, it doesn’t work at all!
The PolyFlex Diffusers are very effective at dispersing sound and remains phase coherent. They offer wider frequency bandwidth, and smoother and wider off axis scattering than any other type of diffuser. They also have no minimum seating distance (convergence point), as do grating number-theory (well or skyline) type diffusers.
A single PolyFlex Diffuser can be used at a single listener reflection point, or multiple diffusers can be used to cover larger listening areas.
Multiple PolyFlex Diffusers- It is good practice, when using polycylindrical diffusers, to avoid mounting four or more together with the same orientation, depth and spacing. Doing so can create repeated constructive and destructive energies at particular frequencies (lobing). Changing the spacing, depths and/or orientations will prevent such conditions.
The above configuration of four PolyFlex Diffusers can offer 2-D hemispheric scattering. This job shows them primer-painted to be concealed with our FRP stretch-fabric panel system.
Painted PolyFlex Diffusers mounted near corner and behind
floor standing loudspeakers
The PolyFlex Diffuser can easily be fastened on walls and ceilings using drywall screws. They can also be concealed under stretch-fabric systems. They are typically used to control first order reflections, enhance surround sound envelopment, control flutter echoes, and/or to add more aural openness and sparkle to the space.
PolyFlex Diffusers can add sonic spaciousness to the room, air around the instruments, timbre accuracy and/or widen the soundstage. They also improve clarity in speech and spatial focus without making the room sound dead and/or small. PolyFlex diffusers can also be used at reflection points in place of typical absorbers when room reverberation times are already low. Once the reverberation times of the room are under control, it would be very difficult to have too much diffusion added to the room.
Finding First Order Reflection Points
You will need an assistant, a flat hand-mirror, and masking tape.
First order reflections are geometric relations that can be drawn between the source drivers, the room boundaries, and the listener. There is a first order reflection for each speaker, on all six surfaces of the room. With one person seated in the listening position and the other person at the boundary surface of interest holding the mirror flat against the surface at about tweeter height, run the mirror around until the listener sees the tweeter centered on the mirror. Mark this spot with tape. That is the first reflection point on that surface, for that speaker. Repeat this process for the other speaker on the same surface. Repeat for the other surfaces of interest. Typically, you want to orient the diffuser to scatter sound horizontally in the room, but when using at a wall/ceiling or wall/floor junction, you may want to scatter up and down. On the ceiling, you typically scatter front and back.
Norman Varney at the NWAA Diffusion Test Lab
Multiple PolyFlex Diffusers for Surround Sound speakers in an FRP installation. Stretch fabric will conceal the acoustic treatments.
PolyFlex Diffusers for the right/rear surround sound speaker.
PolyFlex diffusers installed before stretch fabric
PolyFlex diffusers installed with and w/o stretch fabric
Photos of PolyFlex diffusers at the rear of a home cinema. These are part of the FRP acoustic treatments and will be covered with stretch-fabric.