Originally Posted by HYPURR DBL NKL
Okay I am no mthomas47, but I want to describe what I hear after doing this to see if what I hear is possible. I have a 5.1.2 set up using an SVS PB-2000 sub. Mains are at 80hz, Center is at 80hz, Surrounds 90hz and my 2 Atmos speakers 90hz. LPF LFE @ 80hz in AVR and Low Pass Filter @ 80hz on sub. First the center channel sounds clearer. The bass sounds, not sure how to describe this technically, sounds fuller but not bloated, more punchy and cleaner. It seems to stop quicker, like the difference between a less capable sub where the bass lingers and a good one that is fast and the bass notes hit and stop. The whole system sounds more articulate. I haven't had a chance to crank it up yet. But so far it sounds good. Is what I described on par with how my system should have reacted with how it is set up? Just curious, TIA.
Edited to fix Mike's screen name. I had the "m" capitalized at first.
Phil, whom I am quoting above, sent me a PM asking me if I could explain why he hears more clarity and punchier bass after implementing cascading crossovers. Although I tried to address the issue in Section III-C: Cascading Crossovers
, linked below, I decided to add more detail to that section. And, since I haven't posted on my own thread much lately,
I decided to share the additional explanation in this post.
To me, the relative increase in punchy bass is easier to explain. The subs are cutting-out more quickly--literally seeming to stop on a dime; more bass is being concentrated in the range where most people feel chest punch (<100Hz); and the mid-bass impacts accordingly sound and feel stronger.
The slightly more difficult phenomenon to explain is why we may hear more overall clarity, and I can address that explanation best by using the human voice, and the speech in movies, as an example. I will quote the older material from Section III-C first, and then add the new material starting with the asterisk. I should note that my initial experiments with cascading crossovers started at 100Hz, and then 90Hz, and finally 80Hz. I took my time, and made note of my impressions. I settled on 80Hz and have been extremely pleased with that setting. Here is the newly edited portion of that section:
"What I found when I tried this was that my mid-bass frequencies (up to 100Hz) seemed relatively louder than they had been, and my overall bass clarity improved. I especially noticed that I didn't have to boost my center channel as much as I had been doing, in order to hear clear dialogue. I think this is due to two factors. First, the higher bass content that had been played by my subwoofers was making the front speakers and surrounds a little heavy-sounding in proportion to the somewhat smaller center channel. And, second, since I was already using a heavy subwoofer boost, cutting-off the subs a little quicker imparted less bass coloration to the voices coming from the CC.
This is one of the reasons that I personally prefer not to use DEQ. I don't like boosting the bass in the center channel, with the voice coloration that I notice when I do that. Deep male voices typically only go down to a fundamental frequency of about 90Hz, so bass boosts above that frequency may make men's voices sound unnaturally thick and chesty to some people. As noted in other sections, however, whether we notice that sort of thing, or care about it, is strictly a YMMV issue. (I make up for not using DEQ by implementing a much more substantial subwoofer boost for movies.)
I decided to add a little more detail to the explanation of why we may hear more mid-bass and overall clarity when bass boosts don't go above about 80 or 90Hz. Using voices is an excellent way to describe what I think is happening, and that is where I personally notice the additional clarity the most. The human voice is actually an instrument with a large frequency range. I said that bass boosts above 80 or 90Hz may potentially make male voices sound "chesty". In vocal music, a chest sound is deeper and more resonant than a head tone, which is produced higher in the voice box. The chest tone requires more air, and it resonates lower in the voice box than the head tone does, but it can also sound "throatier", and it has less clarity or "brilliance".
Some consonants, such as "B", "C", "D", "G", "T", "V", and "Z" which all share the same long "ee" sound, may be more difficult to distinguish if they are pronounced with too much chest tone. Some vowels can also be harder to distinguish if more bass sound is added to them, because the voice will sound slightly thicker. I believe that is especially the case if the person speaking has a strong accent, or if he fails to articulate clearly, or if ambient noises in the soundtrack make voices harder to hear clearly to start with.
(When someone articulates, he says each syllable of a word clearly and distinctly. James Earl Jones is a great example of a person with a very deep and resonant voice who is nevertheless very easy to understand. But, he had a speech impediment as a child and worked very hard to learn to speak slowly and with excellent articulation. Most actors do not have that style of speech and that kind of articulate diction.)
Remember also that if subwoofers are strongly boosted, with the normal 80Hz crossover in the AVR, they are only rolling-off at 24db per octave above 80Hz. So, at 100Hz, the subwoofer has only rolled-off by 6db and can still provide quite a lot of bass coloration to male voices. To me, that can make the voices sound a little unnatural as well as more difficult to understand. So, where I may not mind a little additional bass resonance in some music (the cello or the kettle drum, for instance), I may not like it quite as much for some other instruments. And, where I absolutely want it for the low-bass special effects in movies (well below an 80Hz crossover), I may not want that extra resonance at all where the human voice is concerned.
I found that as I implemented cascading crossovers at 100Hz, and then at 90Hz, and finally at 80Hz, I was able to concentrate a little more bass below 100Hz, and then below 90Hz, and then below 80Hz. And, not only did the mid-bass clarity improve with each attempt, but my mid-bass tactile response also increased as a result. That chest punch sensation is explained in detail in Section VII, but briefly, most people seem to feel the sensation most strongly between about 50Hz and 100Hz.
There is some evidence that the sensation may peak for most of us at around 63Hz. That specific number was the conclusion of one study I read years ago, and some subwoofer makers, such as SVS, provide the capability to add a pre-programmed peak at that frequency into their higher-end subwoofer models which have advanced PEQ. If we make our subwoofers roll-off more quickly above 80Hz, by implementing a 48db per octave filter, we are doubling the roll-off. So, although there is still some transition between speakers and subwoofers, the subwoofers have rolled-off by 12db at 100Hz, and 24db at 120Hz. And, we are increasing the 'punchiness' of the bass in the range where most people feel those chest punch sensations most strongly. *
I offer this method of cascading crossovers as a means of potentially obtaining additional mid-bass SPL and chest punch, combined with potential improvements in overall bass clarity. (The clarity was the real key for me, but again, I use a lot of subwoofer boost for movies.) Determining where to set the LPF in the subwoofers themselves, and what slope to select if that is an option, is something which may require some individual experimentation. But, in my personal opinion, it may turn-out to be an excellent solution for someone wanting to maximize mid-bass SPL and clarity."