Large vs small
- Thread starter bmwuk
- Start date
This morning I was contemplating this discussion and thought of a way to discuss how unimportant this small this issue is. We seem to get consumed with every Hz of bass we might or might not be able to get and go to great lengths to do whatever it takes to force everything we've got into making the bass better. But the streetwise logic that just making all the woofers in the room be working at the same time in the bass range is always better (it must be, right?), is just wrong - and I guess that is counterintuitive.
If you look at this specific discussion, concerning the Revel Performa3 F206 tower speakers and a great subwoofer, Bryan was obsessed with getting his mains and subwoofers to operate at the same time in the bass range. This isn't logically correct, but it seems to be intuitive because surely a subwoofer working with four 6.5" woofers has certainly got to be better than the subwoofer working alone, right?
Bryan also mentioned in another threat he felt he was under-utilizing the F206 speakers if he didn't let them operate down to their natural bass limits in the 40Hz range. This, too, is a misconception of how speakers work. I showed with the NRC THD chart how much those speakers really struggle to generate low distortion output below 100Hz, so asking them to work hard below 100Hz when you have an amazing subwoofer which can handle those frequencies better doesn't make much sense.
So, to show that the F206 speakers still have a ton of work to do, even if you set them to "Small" with a 80Hz crossover frequency, I stole the NRC listening window response measurement on those speakers and overlaid some clarifying data points:
I put a translucent blue box over the range which are being "lost" if you set them to small and have an 80Hz crossover. That small range isn't much considering all the other work the speakers are expected to be doing well. In fact, it is a mere 13% of the total operating range of the speaker and it is the portion of the range which the speakers struggle the most to do well at all. Why would you insist on making your speakers work hard in their worst performing range if it wasn't necessary?
Now, with crossovers all of the output in that "lost" range isn't actually lost. The crossover operates on a slope, meaning it rolls off the output as the frequency gets lower. So, at 80Hz it is 3dB quieter than at 110Hz and at 40Hz is it either 12dB or 18dB quieter than the output at 80Hz. That means it isn't 10dB down (which his where most consider the contribution to be impactful to the sound) until about 53Hz - assuming a common 12dB per octave slope. So, the main speakers will still have an audible contribution to the sound in the room potentially down to approximately 53Hz even when you set them to "small" with a 80Hz crossover. That impact is extremely small at 53Hz, but it is significant down to about 66Hz where the signal is about 6dB down. So, one isn't flat out sacrificing the main speakers' bass potential completely when setting to small with a 80Hz crossover, they are just limiting the contribution.
Now, if you owned a pair of main speakers which can generate loud, clean, powerful and dynamic output to well below 40Hz, I would say to set them to "large" and not have a subwoofer at all. Or, I'd recommend a preamp/processor with a more advanced bass management system so you could set the crossover to 40Hz, but that's a different situation than Bryan finds himself in.
If you look at this specific discussion, concerning the Revel Performa3 F206 tower speakers and a great subwoofer, Bryan was obsessed with getting his mains and subwoofers to operate at the same time in the bass range. This isn't logically correct, but it seems to be intuitive because surely a subwoofer working with four 6.5" woofers has certainly got to be better than the subwoofer working alone, right?
Bryan also mentioned in another threat he felt he was under-utilizing the F206 speakers if he didn't let them operate down to their natural bass limits in the 40Hz range. This, too, is a misconception of how speakers work. I showed with the NRC THD chart how much those speakers really struggle to generate low distortion output below 100Hz, so asking them to work hard below 100Hz when you have an amazing subwoofer which can handle those frequencies better doesn't make much sense.
So, to show that the F206 speakers still have a ton of work to do, even if you set them to "Small" with a 80Hz crossover frequency, I stole the NRC listening window response measurement on those speakers and overlaid some clarifying data points:
I put a translucent blue box over the range which are being "lost" if you set them to small and have an 80Hz crossover. That small range isn't much considering all the other work the speakers are expected to be doing well. In fact, it is a mere 13% of the total operating range of the speaker and it is the portion of the range which the speakers struggle the most to do well at all. Why would you insist on making your speakers work hard in their worst performing range if it wasn't necessary?
Now, with crossovers all of the output in that "lost" range isn't actually lost. The crossover operates on a slope, meaning it rolls off the output as the frequency gets lower. So, at 80Hz it is 3dB quieter than at 110Hz and at 40Hz is it either 12dB or 18dB quieter than the output at 80Hz. That means it isn't 10dB down (which his where most consider the contribution to be impactful to the sound) until about 53Hz - assuming a common 12dB per octave slope. So, the main speakers will still have an audible contribution to the sound in the room potentially down to approximately 53Hz even when you set them to "small" with a 80Hz crossover. That impact is extremely small at 53Hz, but it is significant down to about 66Hz where the signal is about 6dB down. So, one isn't flat out sacrificing the main speakers' bass potential completely when setting to small with a 80Hz crossover, they are just limiting the contribution.
Now, if you owned a pair of main speakers which can generate loud, clean, powerful and dynamic output to well below 40Hz, I would say to set them to "large" and not have a subwoofer at all. Or, I'd recommend a preamp/processor with a more advanced bass management system so you could set the crossover to 40Hz, but that's a different situation than Bryan finds himself in.
Be sure to go through the subwoofer tuning exercise each time you make a change like that. Crossovers and EQs add phase shifts, inherently, so the settings on the subwoofer may need adjusting when you have different crossover settings.
If your speakers are vented, you may consider comparing them plugged versus open - and again you need to adjust the subwoofer phase and levels to ensure a clean match with each port status situation.
bmwuk
Well-Known Member
@Flint I blame @Dentman for all of the bad advice. Just kidding.
I think you nailed my initial line of thinking that more is better from the speakers. But laid out like you did it now makes more sense. I have already moved the F206s to small but I haven't had time to mess with everything including port plugs. I do want to A/B that before committing. Also I need to see if the center can stay on large and have my subwoofer still involved.
Down the road I'd love a preamp with better bass management and also eat up such less space in an AV console
Given this conversation, why?
bmwuk
Well-Known Member
Oh thought you had said fine on center. But nevermind. Sheesh.
Oh thought you had said fine on center. But nevermind. Sheesh.
He he he....
I mentioned it earlier in this thread, mix engineers generally don't put deep bass in the center channel anyway.
With the Revel Performa3 F206, I would not do that. It is clearly not designed for that application if you look at the performance.
But, generally, sure, that would work. I mentioned it in my recommendations several times.
I got the impression Bryan cannot do that.
Dentman
Well-Known Member
I only recall you asking me how to do it, not if you should do it.
I only recall you asking me how to do it, not if you should do it.
oh, SNAP!
Yes... I recall you saying the crossover was fixed to 80Hz.
bmwuk
Well-Known Member
No. I have the ability to adjust crossover. It is universal for all speakers. Not sure the surrounds should go further down
Ah... even so.. the difference between 80Hz and 70Hz is pretty darn small, and 60Hz isn't much more. I'd just stick with 80Hz and enjoy.
All of my comments really are about a system designed for movie/TV watching ideals. Bryan has said the vast majority of his usage is with movies and TV, so trying to make a killer "stereo" isn't the goal. When compromises are required, what compromises are better for soundtracks often conflict with those which are better for stereo music.
bmwuk
Well-Known Member
Yes Flint is correct. I do enjoy watching movies primarily but will listen to music as well but 10% of the use is music. Should the speakers be plugged on the ports for music?
Or what might be changed in the setup? Thanks
First, plug the ports.
As for compromises, you cannot do both. Pick one, period. Do you want the best sound for movies or for music? If you try to balance the two, you'll be forced to compromise quite a bit on both. It would be better to get one mostly right then compromise more on the other, trust me.
As for compromises, you cannot do both. Pick one, period. Do you want the best sound for movies or for music? If you try to balance the two, you'll be forced to compromise quite a bit on both. It would be better to get one mostly right then compromise more on the other, trust me.
Your subs aren't still hot for movies?