davekayc:
"Most every frequency had a standing wave in a slightly different location from each other . But most landed where i had each of the rear subs. (Rear subs off ) sound right to you tim ? Felt like i should be putting them in the obviously quiet spots . A couple spots would almost cancel out."
Hello davekayc,
Yes, it sounds exactly right to me. The reason there were bass standing waves, and noticeably poor bass performance at the rear of your room, was because you only had the 2 front subs launching bass soundwaves into the room if you turn off the rear 2 subs. But this makes perfect sense to me given my understanding of the 4-sub DBA concept.
It's important to understand that having 4 subs well distributed throughout your room and launching bass soundwaves is the key ingredient of the 4-sub DBA concept and the main reason it works so well in virtually any room. Reaching the threshold of having 4 subs launching bass soundwaves into the room is not an option but a requirement.
The way it really functions is a bit counter-intuitive and involves psychoacoustics. The 4 subs actually significantly increases the number of bass modes ( spots in the room where both directed and reflected bass soundwaves meet at various angles and cause spots of bass exaggeration, attenuation and even cancellation) existing throughout the room. However, our brains process the presence of these numerous bass modes by summing and averaging the bass information by frequency and this rather unexpectedly creates the perception that the bass is very smooth, fast, detailed and natural. This process is referred to as psychoacoustics.
By turning off your 2 rear subs, the overall quantity of bass modes existing in your room is significantly reduced and your brain is only summing and averaging the smaller number of bass modes existing in your room which is not sufficient to create the perception of smooth, fast, detailed and natural bass.
You're stating you mainly detect poor bass performance at the rear of your room with your 2 rear subs turned off. I believe if you made a more thorough sound quality canvassing of your entire room, however, you'd likely detect poor bass performance at other specific spots in your room.
Overall, I think you've done an excellent job of creating a high quality custom 4-sub DBA system in your very large room with seemingly little assistance. Congratulations and enjoy.
I'm achieving the same excellent bass quality and soundstage imaging results you described in my 23' x16' x8' room and have been enjoying it daily on both music and HT. I think it's important that readers of this thread realize that the 4-sub DBA concept is capable of providing these excellent results in virtually any size room.
I feel it's also important for all to know that buying a complete Audio Kinesis Swarm or Debra 4-sub DBA system for $3,000 is convenient but not the only option, custom 4-sub DBA systems can be created using any 4 subs properly positioned and configured. The 4 subs don't even need to be the same brand or model and individuals can buy the same 1K watt Dayton amp from Parts Express (usually for about $300-$500) and build 4 DIY subs if they'd like.
Later,
"Most every frequency had a standing wave in a slightly different location from each other . But most landed where i had each of the rear subs. (Rear subs off ) sound right to you tim ? Felt like i should be putting them in the obviously quiet spots . A couple spots would almost cancel out."
Hello davekayc,
Yes, it sounds exactly right to me. The reason there were bass standing waves, and noticeably poor bass performance at the rear of your room, was because you only had the 2 front subs launching bass soundwaves into the room if you turn off the rear 2 subs. But this makes perfect sense to me given my understanding of the 4-sub DBA concept.
It's important to understand that having 4 subs well distributed throughout your room and launching bass soundwaves is the key ingredient of the 4-sub DBA concept and the main reason it works so well in virtually any room. Reaching the threshold of having 4 subs launching bass soundwaves into the room is not an option but a requirement.
The way it really functions is a bit counter-intuitive and involves psychoacoustics. The 4 subs actually significantly increases the number of bass modes ( spots in the room where both directed and reflected bass soundwaves meet at various angles and cause spots of bass exaggeration, attenuation and even cancellation) existing throughout the room. However, our brains process the presence of these numerous bass modes by summing and averaging the bass information by frequency and this rather unexpectedly creates the perception that the bass is very smooth, fast, detailed and natural. This process is referred to as psychoacoustics.
By turning off your 2 rear subs, the overall quantity of bass modes existing in your room is significantly reduced and your brain is only summing and averaging the smaller number of bass modes existing in your room which is not sufficient to create the perception of smooth, fast, detailed and natural bass.
You're stating you mainly detect poor bass performance at the rear of your room with your 2 rear subs turned off. I believe if you made a more thorough sound quality canvassing of your entire room, however, you'd likely detect poor bass performance at other specific spots in your room.
Overall, I think you've done an excellent job of creating a high quality custom 4-sub DBA system in your very large room with seemingly little assistance. Congratulations and enjoy.
I'm achieving the same excellent bass quality and soundstage imaging results you described in my 23' x16' x8' room and have been enjoying it daily on both music and HT. I think it's important that readers of this thread realize that the 4-sub DBA concept is capable of providing these excellent results in virtually any size room.
I feel it's also important for all to know that buying a complete Audio Kinesis Swarm or Debra 4-sub DBA system for $3,000 is convenient but not the only option, custom 4-sub DBA systems can be created using any 4 subs properly positioned and configured. The 4 subs don't even need to be the same brand or model and individuals can buy the same 1K watt Dayton amp from Parts Express (usually for about $300-$500) and build 4 DIY subs if they'd like.
Later,