The following are a few points that make a compelling reason for implementing missing fundamental in the lowest octave.
1) There is very low music content in this octave.
2) Maybe there are some effects in movies.
3) The lowest octave is more forgiving and hence a good candidate to 'simulate'.
4) This results in a smaller driver or simple sealed boxes for sub duty.
5) Lower amp/power requirement.
ADAU1701 has 'super-bass' algorithm that can generate harmonics based on missing fundamental.
Are there any other chips that can do it?
Can it be done in analogue? Maybe detecting energy in a few bands (6 bands?) in the lower octaves and feeding that to synthesise harmonics. Is it possible as a DIYer?
1) There is very low music content in this octave.
2) Maybe there are some effects in movies.
3) The lowest octave is more forgiving and hence a good candidate to 'simulate'.
4) This results in a smaller driver or simple sealed boxes for sub duty.
5) Lower amp/power requirement.
ADAU1701 has 'super-bass' algorithm that can generate harmonics based on missing fundamental.
Are there any other chips that can do it?
Can it be done in analogue? Maybe detecting energy in a few bands (6 bands?) in the lower octaves and feeding that to synthesise harmonics. Is it possible as a DIYer?
Suboctave harmonic generation in analog or digital is pretty difficult to get right. As an effect it can work. The lower the frequency of the mid-bass the less quickly the peaks and valleys pass us by, so our circuit that does analysis (zero-crossings, or direction changes, even if predictive) or FFT engine, requires significant time delay before it can gather enough data points to start synthesizing a waveform and it will necessarily have a noticeable slew time.
So, what this means is, the synthetic waveform will not (typically) have the appropriate detail and will usually be instead a sine wave or dirty sine or soft triangle/trapazoid instead of that complicate wavefront that gave audible ques as to the type of street material and building walls (for instance during an explosion)...
What I'm getting at is that the impulse response and timing of the waveform we're talking about is several cycles behind and sloppy in that the mid-bass to bass group delay becomes an "effect" rather than an acceptable artifact.
Whenever bass notes are 2ms or more delayed from the upper harmonics the bass starts to sound bigger (but of course it is not accurate to the recording, it is a psycho-acoustic trick, one sometimes used in mastering.)
There are a bunch of really bad sub-octave generators in guitar pedal land. The schematics are simple. My own intuition says tracking the phase can help estimate the rate of change a lot quicker than waiting for tons of cycles however complicated waveforms would require big branching circuit structures that do q-sort type routines and some sort of probability locking to determine what is actually important content and phase... Doing this realtime is a mess and doing it non-realtime is well, also a mess although the tech always continues to improve. Maybe someday I won't be bothered by it. BTW, motown mastering technique was to blow out the 2nd harmonic of bass lines so that crappy radios would still rock... Love those mixes... So much better than most of today's over-produced phasemush.
Good luck,
So, what this means is, the synthetic waveform will not (typically) have the appropriate detail and will usually be instead a sine wave or dirty sine or soft triangle/trapazoid instead of that complicate wavefront that gave audible ques as to the type of street material and building walls (for instance during an explosion)...
What I'm getting at is that the impulse response and timing of the waveform we're talking about is several cycles behind and sloppy in that the mid-bass to bass group delay becomes an "effect" rather than an acceptable artifact.
Whenever bass notes are 2ms or more delayed from the upper harmonics the bass starts to sound bigger (but of course it is not accurate to the recording, it is a psycho-acoustic trick, one sometimes used in mastering.)
There are a bunch of really bad sub-octave generators in guitar pedal land. The schematics are simple. My own intuition says tracking the phase can help estimate the rate of change a lot quicker than waiting for tons of cycles however complicated waveforms would require big branching circuit structures that do q-sort type routines and some sort of probability locking to determine what is actually important content and phase... Doing this realtime is a mess and doing it non-realtime is well, also a mess although the tech always continues to improve. Maybe someday I won't be bothered by it. BTW, motown mastering technique was to blow out the 2nd harmonic of bass lines so that crappy radios would still rock... Love those mixes... So much better than most of today's over-produced phasemush.
Good luck,
I'm pretty sure the OP was wanting to 'simulate' low bass instead of adding it. Adding low bass results in more power and subwoofage requirements, not less.
The ultrabass ( or dB 120A, or similar) is quite the opposite of the Maxxbass. If you're not carefull a true sub-synth can blow woofers, where bass enhancers try to make life easier for the woofers while creating the illusion of low bass.
And the Behringer sub-synth is a POS compared to the dbx.
The ultrabass ( or dB 120A, or similar) is quite the opposite of the Maxxbass. If you're not carefull a true sub-synth can blow woofers, where bass enhancers try to make life easier for the woofers while creating the illusion of low bass.
And the Behringer sub-synth is a POS compared to the dbx.
Thanks wg_ski. Harmonic bass enhancers 'simulate' bass by harmonics. Other things being equal this results in a drastically smaller system.
The ones from the pro audio field are quite the opposite, they increase LF content and need bigger boxes and bigger amps, I believe by as much as 4 times.
The ones from the pro audio field are quite the opposite, they increase LF content and need bigger boxes and bigger amps, I believe by as much as 4 times.
I believe the chip is non existent for DIY community, only meant for OEM/ODM.
Harmonic generation has to use some sort of FFT in digital or splitting the bandwidth into bands and then generating harmonics for each band. Thats the point, how to do it in analog?
Taking the signal and sending thru a coarse distortion maker from guitar land is not going to do it. Thats sort of hard limiter. We need a very controlled generation for each harmonic. We dont want a distorted sound, we want to simulate the original via harmonics by using our ears processing such that the ear feels that there is a fundamental, whereas its not
I was looking at the same thing in the past and contacted them. I got this reply:
"Thank you for contacting Waves.
Unfortunately, MX3000 chip is no longer available.
Our technologies are now available on some of the chips from Realtek, Nuvoton, Actions and more in the near future."
I think I found some chips from ebay, but the ads were so suspicious that I didn't wanna risk my money.
The chip seemed to be quite easy to use and tune, too bad it isn't available. I would have tested it in a boombox that I'm building.
It looks like they have moved to the more lucrative laptop and android. Their IP is available for these platforms for OEM/ODM on the respective OSs.
Looking at the bluetooth speakers and the fact that their bass really is good for the diminitive size, my gut feeling says they are relying on the MaxxBass chip. Such a small box even with the passive radiators is not going to produce that bass
Looking at the bluetooth speakers and the fact that their bass really is good for the diminitive size, my gut feeling says they are relying on the MaxxBass chip. Such a small box even with the passive radiators is not going to produce that bass
Actually, the brain is really good at reconstructing missing fundamentals. That's why speakers lacking low-end extension, let's say falling off relatively early beginning at 200Hz, still sound like music. You can still hear bass notes you know the speaker can't possibly be actually playing. Even without chip enhancement or processing.
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It can actually sound like the fundamental is there if you drive the woofer symmetrically past x-max. It will generate the necessary 3rd and 5th harmonics. Really works best if the sub/woofer is separately powered - so the distortion doesn't get into your midrange and give away the fact that you're listening to distortion.
Yeah, as said the types of bass enhancers people are referring to can be divided into 2 main categories.
Firstly units that actually simulate extra, lower octave bass, and add it into he program material. The downside of these is that, while some units can do this well, your sound system has to be able to produce this extra bass for it to be effective. Really easy to overdrive your subs and give yourself problems.
The kind the OP is referencing adds upper harmonics of the bass notes into the audio, and your brain oes a very good job of filling in the missing root note that should be there based on the pattern of harmonics. Waves makes the most well known of these units, both in plugin form and in a hardware unit which I own. (there is another hardware unit that works the same way, can't remember what one it is). You can actually up your high pass a little and take a little of the train off your subs with these ones, or use it to bring out some bass and some fullness in a less than capable system.
It's definitely intended for Pro audio rather than home, and as long as you use it just to fill out the bottom end and don't try and be too crazy with it it works really well.
k
The behringer does add extra low frequencies but it also has other settings like the 'punch control' that thicken up all bass frequencies etc. If you had any meaningful experience with it you'd know.
I managed to get very full sounding bass from speakers with a cutoff about 50hz. I used it for years and it really adds weight to the low end and yes it DOES add to upper harmonics as well.
I've been fine-tuning my system since recently adding a sub that plays really nice down to 12Hz.
17 foot pipe sub 12-230 Hz ±5dB
Last day or two, I've been listening to my ESL panels playing full-range with no EQ, crossover, or subs. Including some of recordings with RTAs showing content below 35 Hz. The ESL panels are notably wonderful, flat, and clean but drop off fast below about 90 Hz.
While a fan of bass like myself can tell something is missing on organ pedals... barely. My ear can barely barely tell the difference which is mostly visceral and even then barely (but nicely, of course). I guess I was expecting zilch from the panels on certain organ pedals but the sound was remarkably intact with a good sense of that tone beating you'd get in a big church and it must all aural.
Likewise, years with a Klipshorn bass brought me astonishing bass even though it pumps out little below 38 Hz.
So I wonder if a clean, flat, not-too-localizable speaker output can produce truly nice perceived bass while lesser systems do not do as well?
BTW, the clarity of sound from my ESLs playing full range makes me also wonder if the full-range-speaker enthusiasts aren't so misguided after all.
B.
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Ben, you are both stuck up and amusing. ;-)
There are ups and downs to any system. I think the zealots always have a suboptimal system. Multiway, fullrange, religious, political.
Many of the fullrange enthusiasts are just tinkerers and have tried lots of stuff. I think once you have found what works well with a set of fullrange drivers, it is probably mnot worse than a well designed multiway system. Warts and all.
No shame in admitting it's growing on you. ;--)
There are ups and downs to any system. I think the zealots always have a suboptimal system. Multiway, fullrange, religious, political.
Many of the fullrange enthusiasts are just tinkerers and have tried lots of stuff. I think once you have found what works well with a set of fullrange drivers, it is probably mnot worse than a well designed multiway system. Warts and all.
No shame in admitting it's growing on you. ;--)
Actually you'd be surprised. I've built a pair of Bluetooth passive radiator speakers (not yet on the website) that have useful bass output down to 60Hz. It's quite remarkable.
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