My Open-baffle Hi-fi Speaker System, "the Aurium Waveguide" 2

The Aurium Waveguide

Open Baffle Speaker System

by Robert B. Richards, 2014

[ 2 ]

Most listening rooms will butcher the frequency response of any speaker. Especially smaller rooms.

There are both the comb filter effects, and room resonances, only the latter rings.

I found that putting acoustically absorptive material (2-inch cotton rope or foam rubber) in the corners of the room reduced room ringing substantially.

I used the hand clap test for this, and the difference was obvious and big.

----------------------------------------------------------------------------------------------

Comb filter cancellations average out better (get filled in) in "live" rooms (rooms with lots of reflections). This is typically true for frequencies above about 400HZ.

From about 80HZ - 400HZ, depending on the room, there will usually be so few effective reflections, due to the size of the wavelengths and room dimensions,

that there is likely to be some bad frequency response issues in the lower midrange/upper bass frequencies that typically cause "boominess".

"Boominess" is usually more because of the room acoustics, than the speaker itself. Below 80HZ, my room had no problems of any significance.

If you decide to use a graphic or parametric active EQ to even out the response (only recommended for below about 300HZ),

you can attenuate peaks, but trying to pull up cancellations doesn't really work and causes problems. You would create peaks elsewhere in the room.

Moving the woofers to different locations can be the best way to even out the lower mid/upper bass issues, which is why I prefer the Satellite/Subwoofer arrangement.

I don't recommend putting woofers in a 3 surface corner. You'd get more SPL per watt, but it stimulates room acoustics issues more.

----------------------------------------------------------------------------------------------

Things I learned from this system:

Although I thought they sounded quite good when seated in just the right place, especially with the Hologram circuit enabled, I realized that the lower midrange rolls off when you're off-axis,

which means anyone not sitting in the right place (centered), will hear a colder sound. My friends who sat off-axis were not impressed.

Also, the midrange to tweeter integration could have been better. In a larger room these speakers might have been great but in my apartment, not the best.

I eventually parted them out and used the drivers in other systems, which worked much better in this room.