First, and most importantly, I want to sincerely thank JohnM, brucek, Sonnie, Wayne and all of the other stalwarts of this forum for so generously sharing their work and knowledge. I am a serial lurker, and had not until recently acquired both the required time and equipment to put all this wonderful information into practice.
The concept really is a miracle; gathering places like The Shack allow people from all over the world to learn things from each other in a rich and rewarding way. Even ten years ago, such collaboration would have been impossible. When I think of how much more learning I can do so much easier than our forefathers, I am humbled and amazed. A dear and wise friend once told me that in our lives, at any given point, we are always either the teacher or the student. Being mindful of that dynamic enables us to more thoughtfully care for each other.
I am not a technician. Oh sure, I'm the alpha geek in my family, but there are so many programmers and engineers around here that I wanted to reveal my predisposition towards the business process and user experience early on.
I'm still pretty early in my measurement and filtering process, but am very excited about what I've learned and experienced so far. I hope you will all bear with me as I continue the journey.
I am using a Soundblaster Live! 24 external card, a RS analog meter and a BFD. I have a big room adjacent to a big foyer and a SVS PB12-ISD. I have Axiom M60 mains and a very modest Denon 1804. There is a PC in my AV rack with vastly underutilized potential (I'll save that story for another thread!) but I am using it to process the REW measurements (i.e. not a laptop). It seems up to the task.
I learned a couple things that might be obvious, but cost me a bit of time.
1. The Soundblaster card is NOT a permanent installation for me at this time. My vision was to use it only for the measurement process and then employ it elsewhere and continue to use the AC97 coaxial output from the computer to the Denon. I learned that - even when specifying the Soundblaster specifically in the REW soundcard settings, I ALSO had to mute the line-in for the default sound device in the OS.
2. Not all cord, adapter and splitter manufacturers think that Red is Right or that White is Right. Even if you are absolutely certain you connected everything consistently and correctly throughout the signal path, it is possible that some problem you can't figure out is a "wires crossed" problem rather than a "buttons clicked" problem.
3. The meter "hears" much better than I do. Even though I had done a lot of listening and calibrating in this room previously, REW allowed me to discover a couple of really important and exciting things about positioning and phase.
Now, the questions (with no graphs at this time). I know they are dumb newbie questions, and will express my gratitude for your indulgence in advance. A certain amount of "hey, look at the new guy!" is expected
1. My Denon has a fixed crossover at 80Hz. I am using the auxiliary input on the front, and processing as Stereo with bass/treble flat. OK so far?
2. I don't understand whether I should be using a 12db or 24db per octave slope.
3. My understanding is that I should NOT consider doing any meaningful measurements or filtering "full range" (understood to mean above the crossover point?) without getting a better microphone. Is this correct?
4. My understanding is that - when calibrating the subwoofer - I should have the mains disengaged. Correct?
5. If #3 and #4 are "yes", how do I analyze the integration of the sub with the mains? Prior to starting the REW/BFD process, I had found that I sounds better to me to run the mains as "large". It seems like I'd either have to run measurements WITH them or run them as small.
6. I did some preliminary measurements yesterday from 20-200Hz (which was Fascinating and Amazing!) using both the sub and the mains. I discovered some really cool stuff about my room and phase adjustments. I also noticed pretty giant suckouts at about 90Hz and 190Hz. Is it *possible* that those anomalies are a result of either my method or my equipment? i.e. is there a known problem with the RS meter approaching 200Hz?
7. When I powered up my BFD (while holding the magic button) the display read "1.0". I think this means I got lucky and the BIOS version - while old - will accept MIDI input without eprom modification. I got the unit used from a good seller on Ebay, so it seems possible that it's not the 1.3 load. Yes?
I've tried hard to find my answers in the top-notch written materials already available, and I apologize if my research was substandard. At a certain point, it is not only efficient but also fun to engage other people in conversation about your passions rather than pursue them independently.
Thank you so much for your tutelage and counsel. I look forward to being a more involved member here as time allows.