Well, after months of lurking, research and construction, I am finally posting! I have completed our HT (Ha!) and now in the process of tweaking. The never-ending process. I have written a thesis here to enlist the best in the arena of HT set-up...the Shacksters. Please forgive the long post, but I wanted to cover as many HT factors as necessary for you guys to suggest a plausible solution.
Feel free to comment on any aspect of construction taht may need improvement, but my main complaint is the bass null in the front row seating. I have also reached out to GIK and RealTraps for possible solution.
First of all, thanks for everyone's posts in the spirit of DIY and product guidance. I have been a DIY guy to this point, but have reached an impasse and would like to know if anyone can suggest an improved configuration or product that can fix my problem.
The HT is a 2-row seating arrangement, and the front row has a HORRIBLE null at most practical bass frequencies in music and movies. This is due to the mid-placement of the front row, but cannot be changed due to room layout, screen distance, legroom etc. My room is dedicated HT 12’x17’x10’ with a sloped/flat reflective ceiling and absorptive carpet floor.
For EQ, I am using a RS SPL meter and a spreadsheet, 1/6 octaves test tones, 16-160Hz, played on the Okyo DPT-1. The Oppo BD83 had trouble with the track splits on the burned test tone CD.
I began EQ with a parametric sub-amp that allows one cut/boost, and the AVR which allows another at set frequencies (40Hz being the only usable one). I was trying to decide if a BFD would help and discovered that I have much bigger problems.
My brother proclaiming “it needs more bass!” from the front row during a movie, while I was being bass-massaged in the back, did not settle well with me either.
The sub is slightly off the screen wall and 1/3 from the corner. I tried lateral 2/7 with reduced front seating output; 3/7 is not feasible placement. 7” off the wall was better than 3”; 12” was worse. I also tried side-wall, fore of the front row, but that also reduced output. No other sub-placement is really feasible due to the small room layout.
-Sub-amp X-over is ~90Hz, mains are set "small" in the AVR
-AVR X-over is set at 80Hz
-Sub-amp is reduced -2dB at 18Hz, 1/6 octave BW to reduce clipping in bass intensive explosion scenes. Gain is at 0.5.
-AVR amp is set at -2 at 40Hz as a result of measurements in the back row, and +1 at 80Hz to help the X-over dip. Raising the 40Hz range helps mitigate the null attenuation in the front row, but causes overwhelming increases in the back row.
I may remove that 18Hz cut and reduce the amp gain to prevent clipping, but right now the front lacks so much that I was compelled to turn up the gain and cut the sub-sonic for the benefit of the “audible” frequencies.
Walls are ½” + 5/8” sheetrock with 60oz GG per sheet, on 16” centers. Ceiling is the same except on 24” centers. All are covered in very heavy “mud” texture.
Floors are second story wood sub-floor with 1/8” polyethylene underlayment beneath 1/8” MLV with padding and carpet.
There are curtains in the screen-wall corners behind the mains, and soon there will be parted curtains mid side-walls for appearance and some first reflection absorption. Back walls are empty for now, with good mix of reflection/diffraction due to the heavy texture.
I have a 8’x10’x8”riser along the back wall that has the top-back 9” of deck open, and filled with 50% ultra-touch for the purpose of adding some bass trapping. No additional holes or ports. Measurements open and covered show that this does not make a difference, concluding that a small riser-trap is ineffective (except to raise the back row. I did use GG between the deck ply and MDF layers, attached on 16” centers.
My trapping consists of front corner super-chunks of the R21 UltraTouch, 23” across the face, floor to ceiling, covered with 1mil plastic. No trapping exists in the back corners where the tremendous bass lives, and I am not undertaking any more construction in the room.
Bass Measurements in trouble:
20Hz: FrontRow 76dB; BackRow 78dB (OK)
25Hz: FrontRow 90dB; BackRow 95dB
28: 91; 100
31.5: 92; 106
36: 82; 104
40: 86; 102
45: 95; 96
50: 94; 91
56: 93; 100
63: 98; 101
71: 97; 100
80: 90; 88
89: 80;91
100: 88; 87
111: 92; 84
125: 81; 65
WTH??
So, how do I fix this? Will Monster Bass Traps or Mondo Traps in the one available back corner help the 25 to 56Hz range? Will 2 stacked make an improvement?
There are French entry doors in the other back corner that preclude traps there, so I am left with only one more available wall-wall corner to treat.
I am also considering bass-shakers of the musical variety to bridge the bass gap in front. I do not want anything overwhelming since I will also be listening to music in this room, probably from the front row due to proximity of the AVR and disc player.
Components:
AVR: Onkyo DTR6.5
BD: Oppo BD83
DVD: DPT1
Mains: Paradigm Studio 80's
Sub: Velo F-1500, re-edged and re-amped
Note: I tried a spare SVS PB12-plus with no benefit. However, it did exhibit unacceptable port chuffing in the low frequencies that I never noticed before.
Sub-Amp: Dayton HPSA1000
Center: Paradigm CC350
Surrounds: Paradigm ADP190
Projector: 6500UB with latest FW..."low" FI is awesome now
Screen: 92" diag DaLite DaMat...perfect for the room and 12' throw
Dark brown walls, dark wood trim, black curtains, dark brown faux leather media couches (2x3 seats with cup/storage consoles between seats and leg rests), medieval and Gothic art.
Best Regards,
Brad Minter
HT Enthusiast
Feel free to comment on any aspect of construction taht may need improvement, but my main complaint is the bass null in the front row seating. I have also reached out to GIK and RealTraps for possible solution.
First of all, thanks for everyone's posts in the spirit of DIY and product guidance. I have been a DIY guy to this point, but have reached an impasse and would like to know if anyone can suggest an improved configuration or product that can fix my problem.
The HT is a 2-row seating arrangement, and the front row has a HORRIBLE null at most practical bass frequencies in music and movies. This is due to the mid-placement of the front row, but cannot be changed due to room layout, screen distance, legroom etc. My room is dedicated HT 12’x17’x10’ with a sloped/flat reflective ceiling and absorptive carpet floor.
For EQ, I am using a RS SPL meter and a spreadsheet, 1/6 octaves test tones, 16-160Hz, played on the Okyo DPT-1. The Oppo BD83 had trouble with the track splits on the burned test tone CD.
I began EQ with a parametric sub-amp that allows one cut/boost, and the AVR which allows another at set frequencies (40Hz being the only usable one). I was trying to decide if a BFD would help and discovered that I have much bigger problems.
My brother proclaiming “it needs more bass!” from the front row during a movie, while I was being bass-massaged in the back, did not settle well with me either.
The sub is slightly off the screen wall and 1/3 from the corner. I tried lateral 2/7 with reduced front seating output; 3/7 is not feasible placement. 7” off the wall was better than 3”; 12” was worse. I also tried side-wall, fore of the front row, but that also reduced output. No other sub-placement is really feasible due to the small room layout.
-Sub-amp X-over is ~90Hz, mains are set "small" in the AVR
-AVR X-over is set at 80Hz
-Sub-amp is reduced -2dB at 18Hz, 1/6 octave BW to reduce clipping in bass intensive explosion scenes. Gain is at 0.5.
-AVR amp is set at -2 at 40Hz as a result of measurements in the back row, and +1 at 80Hz to help the X-over dip. Raising the 40Hz range helps mitigate the null attenuation in the front row, but causes overwhelming increases in the back row.
I may remove that 18Hz cut and reduce the amp gain to prevent clipping, but right now the front lacks so much that I was compelled to turn up the gain and cut the sub-sonic for the benefit of the “audible” frequencies.
Walls are ½” + 5/8” sheetrock with 60oz GG per sheet, on 16” centers. Ceiling is the same except on 24” centers. All are covered in very heavy “mud” texture.
Floors are second story wood sub-floor with 1/8” polyethylene underlayment beneath 1/8” MLV with padding and carpet.
There are curtains in the screen-wall corners behind the mains, and soon there will be parted curtains mid side-walls for appearance and some first reflection absorption. Back walls are empty for now, with good mix of reflection/diffraction due to the heavy texture.
I have a 8’x10’x8”riser along the back wall that has the top-back 9” of deck open, and filled with 50% ultra-touch for the purpose of adding some bass trapping. No additional holes or ports. Measurements open and covered show that this does not make a difference, concluding that a small riser-trap is ineffective (except to raise the back row. I did use GG between the deck ply and MDF layers, attached on 16” centers.
My trapping consists of front corner super-chunks of the R21 UltraTouch, 23” across the face, floor to ceiling, covered with 1mil plastic. No trapping exists in the back corners where the tremendous bass lives, and I am not undertaking any more construction in the room.
Bass Measurements in trouble:
20Hz: FrontRow 76dB; BackRow 78dB (OK)
25Hz: FrontRow 90dB; BackRow 95dB
28: 91; 100
31.5: 92; 106
36: 82; 104
40: 86; 102
45: 95; 96
50: 94; 91
56: 93; 100
63: 98; 101
71: 97; 100
80: 90; 88
89: 80;91
100: 88; 87
111: 92; 84
125: 81; 65
WTH??
So, how do I fix this? Will Monster Bass Traps or Mondo Traps in the one available back corner help the 25 to 56Hz range? Will 2 stacked make an improvement?
There are French entry doors in the other back corner that preclude traps there, so I am left with only one more available wall-wall corner to treat.
I am also considering bass-shakers of the musical variety to bridge the bass gap in front. I do not want anything overwhelming since I will also be listening to music in this room, probably from the front row due to proximity of the AVR and disc player.
Components:
AVR: Onkyo DTR6.5
BD: Oppo BD83
DVD: DPT1
Mains: Paradigm Studio 80's
Sub: Velo F-1500, re-edged and re-amped
Note: I tried a spare SVS PB12-plus with no benefit. However, it did exhibit unacceptable port chuffing in the low frequencies that I never noticed before.
Sub-Amp: Dayton HPSA1000
Center: Paradigm CC350
Surrounds: Paradigm ADP190
Projector: 6500UB with latest FW..."low" FI is awesome now
Screen: 92" diag DaLite DaMat...perfect for the room and 12' throw
Dark brown walls, dark wood trim, black curtains, dark brown faux leather media couches (2x3 seats with cup/storage consoles between seats and leg rests), medieval and Gothic art.
Best Regards,
Brad Minter
HT Enthusiast