Throw in a couple of subwoofers and you will also have a capacity in the lower octaves that few floorstanders can match. So it's simply a different experience.
Agree with all you writeDefinitely. His work dates back decades, and the diyaudio.com thread dates from 2008, so you see significant evolution/changes in his approach. Rather than looking for a cookbook, I learned from the back and forth, weighing the ideas, supporting scientific explanations, etc.
And yes, high-passing small mains would be required to fully benefit from the increased dynamic capabilities of adding multiple subs. He uses 15" pro woofers, previously vented, now sealed, and we know that pro woofers in relatively small sealed enclosures will lead to a fairly high F3.
My mains have a vented 12" woofer (I have thought a lot about plugging the port if only to see the effects of the lower slope/different phase characteristics, but haven't experimented with it yet). With four subs, I have a low shelf to bring the bass into balance. Combined with parametric eq at my stubborn 35Hz and 78Hz nodes, the mains' woofers are receiving less signal. Last night I played music at a very high level and they moved much less than I was expecting.
"Good and even bass is important, but midbass is also important, and often neglected."
I think so too. I have found that getting < 100hz is fairly straightforward. It is 100-200hz that is the struggle. I have been in a (probably ridiculous, or maybe just insane, per my family, as they listen to seemingly endless signal sweeps) experimental phase with mains placement and sub adjustment over the last week. Thankfully after last night I am back to "leave it alone and listen to music, dummy."
I am nervous about showing images of how it went, but I am pleased with my 100-200hz results, so will show them and they are perhaps illustrative.....please ignore if too much! Or maybe pictures are worth a thousand words? Above 300 hz there are SBIR effects and multiples of room modes. I have convinced my wife to do some radical acoustics work (after I finish the back porch project....), mainly the ceiling and rear wall (currently just treating first reflection points), so this will get better. Right now I am just using PEQs in my RME DAC to fine tune. First two subs are under the mains, fed L/R signals, other two subs fed mono. All 1/48 octave smoothing, 50db scale with target room curve I was shooting for:
Mains:
View attachment 177815
Add sub under left main (blue):
View attachment 177816
Add sub under right main (orange):
View attachment 177817
Clearly, because they are co-located with the mains, their effect on modes isn't huge, though there is some "moving around" and a bit of filling in the nulls.
Add Left rear sub (green):
View attachment 177818
Add fourth sub, R rear. Fascinatingly, the response was good, but there was one deep null at around 120hz remaining. I thought hmmm...let me try moving it a bit. After 3 or 4 moves I ended up with this (pinkish?):
View attachment 177828
Mains only and mains with 4 subs, no EQ:
View attachment 177831
After a bass shelf starting at approx. 85hz (relieving the mains to some degree as described above and 2 bands of parametric EQ in the RME (35 and 78Hz):
View attachment 177832
Sounds pretty good to me at this point. You will notice I don't have huge extension (subs are sealed 10" JBL studio units), but there is good dynamics and "power." I did have a bit of a learning curve to be able to do this in fairly short order, and I am NOT suggesting the OP (or anyone, really) takes this route. It is only for illustrative purposes. With his proposed equipment he will have an easier go of it with their built-in capabilities. I don't know how I could have smoothed > 100hz without higher crossovers.
Now I am praying that when I hit "reply" my formatting will stay and this won't look like a jumbled mess......
Bill
I suppose if one considers a 8331a to be a “satellite” then it could work.I think one of the big things people overlook when using small "satellite" speakers and subs is that if you are going to use subs located on the side of the room to eliminate room modes they need to be crossed 80Hz to 100 Hz so the sound is not localized. For best results the satellites need to play flat one octave below the crossover so 40Hz to 50 Hz.... many small satellite can't do this which makes integration with subs difficult. While expensive and "big" using "full / near full" range speakers and a sub is the best way to go and makes integration much easier (possible).
That voice in your head is called "Isaac Newton" aka "Physics" or "The Laws Of Nature"Something in me tells me 2 big sub boxes with in total 4 times 10-14 inch drivers will please my needs more then the mini D&D box working hard when playing loud AND equalizing backfiring
If you're serious about perfect integration, I'd continue the discussion focusing on room treatment rather than electronics
But as someone may have mentioned, room treatments of any reasonable size don't work at low frequencies (their wavelengths are too long). So low frequency integration becomes a matter of playing a lot with positioning of the satellites and subwoofer(s), the highpass and lowpass frequencies, and/or room correction software.I understand that treating the listening room is first priority.
That’s true… but there’s also a lot of sound that isn’t at very low frequencies that can be optimized through room treatment.But as someone may have mentioned, room treatments of any reasonable size don't work at low frequencies (their wavelengths are too long). So low frequency integration becomes a matter of playing a lot with positioning of the satellites and subwoofer(s), the highpass and lowpass frequencies, and/or room correction software.
The magical 80 Hz came out of research done at I believe THX. So we can imagine the test conditions are a more ideal room, probably not with a cathedral ceiling or open to a kitchen or with hallways coming out. And high quality transducers.many are concerned about localization of the subs and 80hz seems to be the number people agree on. I also don't think the physics supports this notion. And it is the 90-120hz that I always find the most difficult to get smooth in my room and I don't think I could do it without crossing the subs higher. It is possible I am fooling myself, but I can't locate subs crossed at 120-130hz.
The magical 80 Hz came out of research done at I believe THX. So we can imagine the test conditions are a more ideal room, probably not with a cathedral ceiling or open to a kitchen or with hallways coming out. And high quality transducers.
- If the subwoofer has high distortion at those midbass frequencies, you might well localize the harmonics. Likewise if even a "quality" subwoofer has a forward facing port with a big port resonance. "Cleaner" subs could be harder to localize.
- Where the subs are versus the mains will make a difference-a sub behind you will be easier to localize than one right next to a front speaker.*
- Every person's hearing is different!
I'm curious why you say the physics doesn't support the notion. Not disagreeing, just wondering your reasoning.
*JL Audio actually recommends such a higher crossover in systems with no room correction like Audyssey etc., so their built-in DSP can affect those upper midbass frequencies. https://www.stereophile.com/content/jl-audio-fathom-f110v2-powered-subwoofer-measurements
Nice post above @Digital_Thor- If the subwoofer has high distortion at those midbass frequencies, you might well localize the harmonics. Likewise if even a "quality" subwoofer has a forward facing port with a big port resonance. "Cleaner" subs could be harder to localize.
- Where the subs are versus the mains will make a difference-a sub behind you will be easier to localize than one right next to a front speaker.*
- Every person's hearing is different!
I'm curious why you say the physics doesn't support the notion. Not disagreeing, just wondering your reasoning.
Cheers mateNice post above @Digital_Thor
"If the subwoofer has high distortion at those midbass frequencies, you might well localize the harmonics. Likewise if even a "quality" subwoofer has a forward facing port with a big port resonance. "Cleaner" subs could be harder to localize."
I think that the belief in the perceptibility of distortion in the low frequencies is overemphasized on this site. But yes, what you say is true, if the distortion is high enough to produce perceptive "doubling"the source could be localized. And port resonances, etc.
"Where the subs are versus the mains will make a difference-a sub behind you will be easier to localize than one right next to a front speaker."
I think this is the case only as described above, or (and perhaps more commonly?) buzzes, rattles, cabinet resonances, i.e. mechanical sounds. But not with a theoretically perfect sub.
Re. physics, I have written it in a few areas here, but would refer you to this paper by Geddes. I am no disciple, but he is a very smart dude, and his discussions re. the physics make sense to me at my current level of understanding.
Bill
I'll go along with that, as Earl is indeed quite smart and what he says makes sense. One problem: my room opens to a hallway, a kitchen, and french doors to what used to be a sun porch. So not a perfect room at all, and no available corner. I'm pretty sure a lot of people are in the same boat. Fun fact: when Earl was at Ford he offered me a job. I chose to take a job at home in Chicago for more money and not have to move to Detroit. I sometimes wonder what my life would have been like. I probably would have been sent to Brazil, that would have been transformative.this paper by Geddes