Hello romney80,
I'm now 62 and realize my long journey with both audio and video is now closer to the end than the beginning. But I'm okay with that since they've both been interesting and pleasurable journeys and my A/V system has never had a better picture or sounded better. I guess that means I was paying attention and learned a few things along the way.
In retrospect, there are a few things I know now that I wish I'd learned earlier but, if I had to pick one major lesson or bit of advice that would be most beneficial and would like to pass on, it would be the following:
Treat your complete system as comprised of 2 independent and separate individual systems: a mono bass system and an everything else system
1. A Bass System -
All bass below 80 Hz is mono and there's no stereo imaging with bass below about 80 Hz. Use at least a pair of very good quality subs in mono mode, regardless of your main speakers, to create a powerful, solid and dynamic bass foundation that works well on all types of music and HT content.
Set the volume and crossover frequencies as low as possible with the bass still sounding very good to you (solid, powerful, detailed, smooth, fast and natural). Position each sub sequentially and optimally in the room using the sub crawl method (you can google it for details). For best results, definitely do not just place a sub next to each main speaker or where they are most convenient. You don't want to be constantly aware that the subs are active, just when the music or HT content calls for it.
The benefits of multiple subs begin to be realized with the use of 2 subs. Of course, you'll notice the bass becomes more powerful and dynamic because there are now 2 of them instead of just 1 and, since bass in a room is cumulative, the bass is capable of being as powerful and dynamic as the source material content calls for. The bass becomes more accurate with less distortion and a greater sense of ease since neither sub is operating anywhere near its limits.
Perhaps unexpectedly, the benefits of using a pair of good quality subs also includes the bass being faster, smoother, more detailed, better blended or integrated with the main speakers and even improvements in mid-range, treble and sound stage imaging performance due at least partly to decreases in bass boominess and masking of higher frequencies. Depending on amplification and main speakers utilized, some systems also benefit through the use of multiple subs by reducing the burden of reproducing the demanding bass frequencies through the main amps and speakers.
On systems already utilizing a pair of subs, even further significant overall system improvements can be gained by adding a 3rd and possibly 4th sub. These improvements are basically further continuations of the positive gains made from deploying a pair of subs but with the added benefit of this high quality bass performance existing throughout the entire room and not being restricted to a bass sweet spot at the designated listening position.
It's often true that these gains can be attained utilizing smaller, less powerful and less expensive models as the 3rd and 4th subs than the original pair of subs existing in the room. It's not necessary that all 3 or 4 subs in the room are identical.
In my opinion, the lack of very powerful bass impact and bass dynamics is the main obvious indication that one's listening to recorded music on a home audio system rather than a live performance. In my experience, very good bass performance is the hardest aspect of home audio to get sounding right, realistic and natural, especially in smaller domestic sized rooms.
2. An Everything Else System - This can be also be more accurately considered and described as a mid-range, treble and stereo imaging system. The goal is to find a pair of main speakers that you love for their mid-range, treble and stereo imaging qualities and it's not that important for overall system performance if they're low frequency restricted.
In my experience, it's much less difficult to attain high quality mid-range, treble and stereo imaging performance in a typical room than it is to do the same for bass performance, especially if a high quality pair of main speakers are utilized. It's important to spend as much time as needed to carefully and precisely position the main speakers, and use various room treatments at strategic positions, to attain high quality performance but these tried, true and reliable methods don't vary much from room to room.
The goal is to position the pair of main speakers in precise room positions, and in relation to your designated listening position, until the mid-range and treble tone and pitch sounds very accurate and natural along with creating and projecting a wide and deep stereo sound stage illusion that projects 3 dimensional, solid and stable images that, on good recordings, gives you the impression that the musicians and vocalists are playing live in your room or that you've been transported to the venue.
This installation or placement of this high quality Everything Else system on top of the solid foundation of the mono Bass System completes your high quality overall audio system. If care was taken to properly set up both component systems, the integration between both should be seamless and overall system performance is very likely to be subjectively spectacular.
In giving my advice to you, I've made an effort to be humble, respectful and factual. But the thing I'm most proud of, and you most likely appreciate the most, is that I never once referred to you as "young grasshopper", "sparky" or "tiger".
You're welcome,
Tim