How Flat is Flat?


I have been trying to optimize speaker placement in my small, dedicated room for the past couple of weeks. I started out by calculating all the theoretical "best" positions following the advice on the Cardas Webstie, the Rule of Thirds (and fifths, and ninths) AND multiple iterations with the RPG Acoustics software. For each possible speaker/listener location, I measured Frequency Response using the Radio Shack meter and several test CD's, and conducted extended listening tests with a variety of music. Leaving questions of soundstagingf aside, I can't get very flat response regardless of where I place the speakers/seat. Response is flat (+/- 3 dB) above 100 HZ and from ~ 40-45 Hz, but plagued with problems in the 50-80 Hz range. The "dip" is in the range of 6 to 15 dB, with the worst frequency being ~ 60 Hz. I have used the SGHT Excel spreadhseet to calculate the room peaks/nodes, and there shouldn't be any nodes at this frequency at any of the seating positions I have tried. I am pretty certain it's not the speakers (SF Guarneri Homage), since they measure flat in an anechoic environment. The room is 14 ft long, by 12.75 ft wide by 7ft9inches long (dimensions chosen using the SGHT spreadsheet based on the fixed height of my basement ceiling). I have minimal sound treatment at this stage (RPG foam at the reflections points, RPG Diffusers behind the listening position, Corner Tunes at the top and bottom corners behind the speakers). My questions is...is it desirable to do better, or am I just being REALLY anal? If desirable, is it possible to do better? How (short of getting a Sigtech or similar)? Would also appreciate any comments on the best scheme for speaker positioning you've tried. Anyone have experienve with the RPG software? The Cardas-based set-ups sound good..but the bect sounding one is VERY awkward even in a dedicated room! AlexC
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Showing 1 response by alexc

All Thank you very much for your replies. I meant to post a follow up much sooner...but work interfered (again!) with my hobby. I have however had a chance to try a few other positions, including a diagonal set up. I've gone back to one the "cardas" set-ups since it gave me the best (for me( imaging and nothing else I tried really smoothed the response. Nearfield listening was excellent for imaging, but felt a bit claustrophobic. Net, I am going to embark on the ASC journey (I am not as bold/brave as Greysquirrel!). Any suggestions on which Tube Traps to use in my room? Or should I follow the recommendation from ASC based on a MATT Test recording? Is it best to buy directly from ASC? I had a qestion for Bagwell on his Sigtech. Does it do analog? My LP collection is large (and still growing), and I have a lot of $$ sunk into my analog front-end. If the Sigtech won't "do" analog, are there other "equalizers" that will w/out completely degrading the sound? Has anyone tried professional parametic equalizers? Thanks!