When designing a sub should I aim to get the SPL graph to match the equal loudness curve? That's what I was doing initially while trying to design something useful for a cheap driver. I didn't have much hopes for this driver, but found a design that should work well. It matches the equal loudness graph from 27-80Hz for 60dB listening. I wanted to compare its simulated performance to something, and having looked up a 15" Hsu sub, they show a mostly flat graph that slopes down as the frequency decreases. They should know what sounds good, so am I doing it wrong?
I don't know. I thought the point is to compensate for our subjective ears, but then part of that is up to whoever edits the sound track. As for nature, it depends on how efficient the source is at exciting a particular frequency. After further thought, it makes sense for it to be flat with the option to boost or buck a little. But then again, non-amplified instruments tend to lack in bass naturally. I know there have been some times when I listen to very quiet music just before sleeping, and that equal loudness curve matches what I think I'm listening to; 50-60db in the deepest bass, and almost nothing in the upper mid range. It is annoying when someone way over compensates bass in the recording or when it's almost nonexistent below 200Hz as in some recordings I found from the 70's
I agree, but often that EQ is not excessive. You might need to make small adjustments here and there but if in doubt don't go too far.
Unless you know better, it's more likely that one song triggers faults in your system that another doesn't and the issue sounds bigger than it is.
That's not to say you won't find reason to compensate for something, just don't blindly force it to follow equal loudness curves.
Unless you know better, it's more likely that one song triggers faults in your system that another doesn't and the issue sounds bigger than it is.
Reproduction should not simply take equal loudness into account because our ears play the same role in both cases, listening to speakers or listening to real things. There's no difference between the two in that regard.
That's not to say you won't find reason to compensate for something, just don't blindly force it to follow equal loudness curves.
Assuming the mix/mastering engineer's subjective taste matches yours, and you listen at the same SPL as that engineer did, no "loudness contour" adjustment would be needed for subwoofer with flat response.
Makes lots of sense, mix levels are all over the spectrum.
Actually, you may want considerably more compensation (a steeper contour) than for 60dB SPL at 1kHz (60phon) if you were listening 60dB lower, "almost nothing in the upper mid range", where ~70dB is required to even hear 20Hz, and 60dB for 30Hz.
Anyway, nothing wrong with designing in some "loudness contour" if you know the particular system will generally be used at levels far below the usual mix levels for the genre, but a +60dB 20 Hz relative to 100Hz contour won't work when you listen at "normal" levels...
Exactly this ^ IMO the goal for obtaining correct FR balance is to follow the intended target curve used in final mixing and mastering. Otherwise, just make it sound the way you prefer and don't worry about what others say or do. If you're in a car, you'd need to push the bass even more due to road noise, which varies quite a bit from car to car. Your own ears and taste will tell you what is RIGHT for YOU, especially in the 2.5 - 4k range.
Without having checked any other software, this is the best I could get the MCM 55-3234 drivers to perform according to my preferences. Now I just need to run these designs through a subwoofer specific software to see how it matches up since WinISD doesn't consider how port characteristics affect SPL. I have these drivers sitting around in their box still with the hope of one day adding them to a 15cuft ported box that doesn't perform how I'd like (because I just built a box and put speakers in it with no simulations), but now I know that would make the problem worse.
4th order bandpass with 1, 2, and 4 drivers with the low pass and bass boost filters found on a plate amp keeps the size reasonable: 6cuft for the 2 quieter curves, and 10cuft for the higher, with that one having headroom for another 1kW peak output while the others are limited by excursion.
4th order bandpass with 1, 2, and 4 drivers with the low pass and bass boost filters found on a plate amp keeps the size reasonable: 6cuft for the 2 quieter curves, and 10cuft for the higher, with that one having headroom for another 1kW peak output while the others are limited by excursion.
Without saying so, we’d have to assume you’ve managed room modes. If you haven’t, then all this means little. If you manage room modes with subs and/or EQ, it also means little.
I tend to move the speakers or me around until it sounds good. Am I right in assuming that having the sub very close to the listening position is the easiest solution for dealing with room modes?
There are many ways you can do this. I'd suggest I hadn't conveyed my point that it's the end result that counts. A flat sub can be part of that. One way to ensure you've managed a mode is to get the sound as consistent around the room as you can. Your suggestion may also work.
So you only play at 60dB listening? How do you solve that?
The correction you need is the difference of this curve at the level it is played versus the level where it was intended to play ( basically at what level it was mastered)
Something like this:
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There should be no difference in performance if I divide the closed chamber of a 4th order bandpass box into 2 half size chambers with half the number of drivers per chamber, right? Just making sure, so I can build it to counterbalance driver mass vibrations so it doesn't walk around.
Assuming the single closed chamber "A" volume equaled the divided chamber, and the front chamber "B" volume (and port dimensions) remained the same
the low frequency response of the above cabinets should be the same.
The leakage of upper out of band response through the port may be affected by driver orientation.
the low frequency response of the above cabinets should be the same.
The leakage of upper out of band response through the port may be affected by driver orientation.
I don't really agree with the equal loudness curve.
In my system, my subs are boosted below 50hz. I find it is a good compromise for a general use system. It doesn't fatigue my ears for general use, but the LFE of a movie can still shake the floor.
I've seen measurements of systems where 100hz and below is boosted, but my ears really don't like that for extended periods of time!
In general, if you want more bass, I think you need a better sub, not necessarily a louder sub! My system uses sealed subs above ~50hz, and the bass comes through clearly even at low volumes, and with a flat response curve.
The correction need to be volume control dependent, its the only way to do it right. (Except if you play with unchanged volume control all the time 😉)
If you need high efficiency, then to get basic QB3 or QB4 alignments the box is big.
For those speaker types. No way around it.
If speaker Fs is 85 to 65 Hz that is it. No magical box for more bass, no magical port for " more bass"
End of the road
If you want 40 , 30 or 20 Hz buy a speaker with a Fs below that.
Ports have no wires. It is a velocity ramp.
The energy comes from the speaker, A port is not that efficient in real life.
It adds slightly more bass. That is it.
At low listening levels our ears perceive bass different. You Boost
Yes Equal loudness curve.
At high levels , cut bass or reach distortion with boost anyways.
You cant " tune" for equal loudness.
Port Frequency is no big Mystery. The speaker Fs. 3rd order 3 to 5 Hz above. 4th order 3 to 5 Hz below.
End of story.
Tuning High or adding Q with a port is pre baked bass boost.
Low levels maybe ok, high levels boomy . bloomy and unloads faster.
Waste of time. Adjust the EQ to add Q
The speaker suspension is so stiff or so tight and there is that much magnet. That is it all it does.
Speaker Fs or resonate frequency is what it is, that is all it does.
This stiff or that loose. the box will be this big to align to a .707 filter.
So the volume of box needed wont get smaller than .707 you can go bigger .577
Forcing speakers into small boxes or high tuning for Q is nonsense.
WinIsd is a spreadsheet with the correct theory. Enter parameters.
Open project. It already knows the math. It will auto alighn.
It will say sealed or ported based on the parameters. If ported it knows the right alignment.
press the button, that is it. No magic secret port or forcing speakers into smaller boxes.
A EQ will add 3 or 6 or 12 dB a port will never do more than 2 or 3 dB. Below 200 Hz in real life
you can loose up to 5 dB. So a port is what it is. More bass than sealed, you get what you get.
A 707 filter curves down, not up. If Q is over 0 dB line in transfer function or crosses 0 dB many times.
It is nonsense.
For those speaker types. No way around it.
If speaker Fs is 85 to 65 Hz that is it. No magical box for more bass, no magical port for " more bass"
End of the road
If you want 40 , 30 or 20 Hz buy a speaker with a Fs below that.
Ports have no wires. It is a velocity ramp.
The energy comes from the speaker, A port is not that efficient in real life.
It adds slightly more bass. That is it.
At low listening levels our ears perceive bass different. You Boost
Yes Equal loudness curve.
At high levels , cut bass or reach distortion with boost anyways.
You cant " tune" for equal loudness.
Port Frequency is no big Mystery. The speaker Fs. 3rd order 3 to 5 Hz above. 4th order 3 to 5 Hz below.
End of story.
Tuning High or adding Q with a port is pre baked bass boost.
Low levels maybe ok, high levels boomy . bloomy and unloads faster.
Waste of time. Adjust the EQ to add Q
The speaker suspension is so stiff or so tight and there is that much magnet. That is it all it does.
Speaker Fs or resonate frequency is what it is, that is all it does.
This stiff or that loose. the box will be this big to align to a .707 filter.
So the volume of box needed wont get smaller than .707 you can go bigger .577
Forcing speakers into small boxes or high tuning for Q is nonsense.
WinIsd is a spreadsheet with the correct theory. Enter parameters.
Open project. It already knows the math. It will auto alighn.
It will say sealed or ported based on the parameters. If ported it knows the right alignment.
press the button, that is it. No magic secret port or forcing speakers into smaller boxes.
A EQ will add 3 or 6 or 12 dB a port will never do more than 2 or 3 dB. Below 200 Hz in real life
you can loose up to 5 dB. So a port is what it is. More bass than sealed, you get what you get.
A 707 filter curves down, not up. If Q is over 0 dB line in transfer function or crosses 0 dB many times.
It is nonsense.
I believe the equal loudness curve is a myth in most listening situations. But if you need to use it convince your wife that you need a bigger subwoofer, I won't stop you. (But you should really buy another subwoofer...)
It seems clear to me that the equal loudness curve is a consequence of the ear being overloaded. When we hear a high frequency sound, a specific nerve is excited...but when we hear a low frequency sound, all the nerves are excited at the same time. So when exposed to loud music that contains high and low frequencies, the low frequencies start getting masked. When being over-loaded, the nerves tend to just "hear" the specific frequency they are attuned to, making us less sensitive to the low frequencies.
So it is a thing, but it is kind of like "clipping" for your ears when listening to loud music/ sounds.
If the low frequencies are boosted for "equal loudness", you will get ear fatigue. It isn't natural. It isn't good for your ears. It's better to train yourself to recognize what a correct frequency response sounds like.
I dealt with it all the time around musicians.
Practicing at home cranking the bass sounded fine.
Going to the garage or studio you would pretty much fart out your speakers.
Trying to use practice settings.
Equal loudness isn't really a myth.
At low levels you want more bass, really about it.
Recording hundreds of bands.
You know what the band sounds like.
You know what 30 hrs of mixing sounds like.
You also know what it sounds like to crank the monitors for the " customer"
so they stop whining and write a check.
The whole " audiophile" issue with the loudness button.
Basic nonsense. By yourself hit the button sounds great.
Basically if your too lazy to turn the bass or treble knob with different music
or different levels.
You dont want baked in bass boost. With a port
Or stare at a simulator graph for a million years thinking
your going to " make up" a better alignment
Or just like musicians.
Cry like babies because equipment is too big and heavy.
Audiophiles need small this and small that.
When a coffee table is 10x larger than a big studio monitor.
What do you do? Spin in violent circles all day and need space.
Practicing at home cranking the bass sounded fine.
Going to the garage or studio you would pretty much fart out your speakers.
Trying to use practice settings.
Equal loudness isn't really a myth.
At low levels you want more bass, really about it.
Recording hundreds of bands.
You know what the band sounds like.
You know what 30 hrs of mixing sounds like.
You also know what it sounds like to crank the monitors for the " customer"
so they stop whining and write a check.
The whole " audiophile" issue with the loudness button.
Basic nonsense. By yourself hit the button sounds great.
Basically if your too lazy to turn the bass or treble knob with different music
or different levels.
You dont want baked in bass boost. With a port
Or stare at a simulator graph for a million years thinking
your going to " make up" a better alignment
Or just like musicians.
Cry like babies because equipment is too big and heavy.
Audiophiles need small this and small that.
When a coffee table is 10x larger than a big studio monitor.
What do you do? Spin in violent circles all day and need space.
I use it in the form of dynamic EQ as executed by Marantz Audysey and I must say I am happy with it and don't recognize any of the above.
There is no correct frequency response, it is dependent on your listening level and at what level the recording was made.
If they are not the same you perceive a frequency response that is offset-ed by the deltas in the equal loudness response for these levels.
see also my post above: https://www.diyaudio.com/community/...raph-when-designing-a-sub.420775/post-7865566
People discover that "equal loudness curve" exists, and then they think it is a problem that needs to be fixed. That is the myth. I think it's kind of wrong too! But it's like the circle of confusion, where because someone wrote it in a paper now it is real.
There is a correct speaker response curve: anachoically flat. It's been proven scientifically, double blinded and all.
I'm currently listening to music that has prominent bass guitar, and the volume is very low. I did this with a few songs just now, but to name one in particular is Jackwise by Lespecial. SPL meter says 35-40dB. Ambient noise is 30-35dB. It is an extreme example to prove a point. I can hear every bass note!
If "equal loudness" curve was correct, the low frequencies should disappear into the noise floor at some point. I should need to crank the bass to still hear it, right?
But that is now what happens! I can hear everything; everything is balanced in it's place, as intended by the artists who created the music.
I don't identify myself a musician, but I have played different instruments in school. And to me, "equal loudness" can only mean that all the instruments are equally prominant in the mix. If I can pick out each instrument and hear what it is playing, to me they are equally loud.
And if "Equal Loudness" is about something other than the threshhold for hearing sounds of different frequencies, then what does it even mean?!
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