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[Luca Rossi]

I always wonder what is the treshold for feeling bass frequencies (40-80 Hz range) in the cest like vibration or "punch" wich makes nice sensation.. I find a good site wich tell me moething about but it's not very complete with my question!

this is the url: http://www.makeitlouder.com/Decibel%20Level%20Chart.txt
It says: At 116 dB(?) HUMAN BODY BEGINS TOPERCEIVE VIBRATION IN THE LOW FREQUENCIES.

But it doesn't explain if it is talking about dBA, dBC or what other kind of pondaration, because from A and C there is a difference of 30 dB at 50 Hz!! So if 116 dB is the right level, what is the ponderation and frequency? Maybe 116 dBC at 80 Hz it's like 130 dBC at 20 Hz... I'd like to know it..

[chuck clark]

I always wonder what is the treshold for feeling bass frequencies (40-80 Hz range) in the cest like vibration or "punch" wich makes nice sensation.. I find a good site wich tell me moething about but it's not very complete with my question!

this is the url: http://www.makeitlouder.com/Decibel%20Level%20Chart.txt
It says: At 116 dB(?) HUMAN BODY BEGINS TOPERCEIVE VIBRATION IN THE LOW FREQUENCIES.

But it doesn't explain if it is talking about dBA, dBC or what other kind of pondaration, because from A and C there is a difference of 30 dB at 50 Hz!! So if 116 dB is the right level, what is the ponderation and frequency? Maybe 116 dBC at 80 Hz it's like 130 dBC at 20 Hz... I'd like to know it..

Hey T, its a rule on this site you gotta use your real name to post so your gonna have to fix that before any one can respond to a locked thread
chuck

[chuck clark]

Hey T, its a rule on this site you gotta use your real name to post so your gonna have to fix that before any one can respond to a locked thread
chuck

Ok, Luca, welcome back. Yeah! that bass that HITS and vibrates your body is what a lot of people really LOVE! Lol. I've always felt that way over the 30 some odd years I've been doing sound professionally.  I remember asking a tech @ Peavey about that very thing back in the 80's. He told me the human chest cavity has a resonance around 80hz that gives you that "kick in the chest" sensation. I remember thinking to myself-"I wonder what the resonant frequency of the human ass is?! Lol
Looks like I was ahead of my time-but happy days are finally here. I could load you up w/ a lot of data, but unless your an engineer you could get bogged in the numbers, so let me just boil down 30 yrs. of experience for ya'!
Yea, the body sensations START at about 116 but it;s more like 120db where it's more noticeable. (I use standard meter "A" scale)  These days 130db is more of the threshold for a piece of equipment to be considered professional " and the best stuff in the world will reach 140db and some will even reach momentary peaks beyond that. 146db is about the highest people can stand for a few minutes at a time because instant permanent damage to their hearing will be the result if these levels are surpassed not to mention physical damage to property like blown out windows and such.  These are general guidelines as it varies from one individual to the next. This is why most audio pros have ear plugs handy. So should you. Have fun!
Chuck

[chuck clark]

I should probly mention that the reason for the difference in A and C scales is because of the difference in sensitivity of the human ear to different frequencies. Google " loudness curves" or "equal loudness contours" for some enlightenment there. The same db levels of low frequencies that feel good would be painful to the ear at higher frequencies that the ear is more sensitive to! That 30 db difference at 50 hz means that a 50hz tone has to be 30 db louder to be perceived by a human as being the SAME volume as a 1k hz tone! Interesting stuff. Have a great day and remember to always protect your precious hearing. It is a gift that no one fully appreciates until they start to lose it! Modern pro audio gear can hurt you, so have fun, but proceed w/ caution!
Chuck

[Luca Rossi]

Woow chuck, you are very clear! That's interesting for me.
You said about 120dB A weighting around 80 Hz right?  Doesn't seem to be a bit high? Anyway if you have data to load, i will be happy to know more stuff!

[chuck clark]

Woow chuck, you are very clear! That's interesting for me.
You said about 120dB A weighting around 80 Hz right?  Doesn't seem to be a bit high? Anyway if you have data to load, i will be happy to know more stuff!

like I said, check out loudness curves. It's really key to understanding what's going on. 120 db would be a bit high for frequencies between 1 khz and 6 khz where the average human ear is most sensitive, but below 100 hz, where the ear is MUCH less sensitive you can withstand much higher levels. Most modern pro level subwoofers will operate in the 130 to 140 db range as measured @ 1 meter distance. Of course as you move away from the box the level drops 6db for every doubling of distance.  Are you an engineering buff who likes physics, or simply an enthusiast trying to get a feel for some of the numbers that get thrown around all the time in audio? At this website there is a lot of us who are a mixture of both!
Chuck

[Luca Rossi]

I'm not a engineer but i like physics acustics and public address! I heard many set up and when there was big sizing they played with a very good chest pounding...So i wonder what should be the sound intensity to make body vibration. I also wonder if this tactile feedback is due to high particle velocity or just to the pressure level. For example i know in near field there is less pressure but a lot of particle velocity and they are out of phase to match sound intensity. I also know that pressure is air acoustic impedance per velocity, (P=Zxv).

[Alex Berry]

like I said, check out loudness curves. It's really key to understanding what's going on. 120 db would be a bit high for frequencies between 1 khz and 6 khz where the average human ear is most sensitive, but below 100 hz, where the ear is MUCH less sensitive you can withstand much higher levels. Most modern pro level subwoofers will operate in the 130 to 140 db range as measured @ 1 meter distance. Of course as you move away from the box the level drops 6db for every doubling of distance.  Are you an engineering buff who likes physics, or simply an enthusiast trying to get a feel for some of the numbers that get thrown around all the time in audio? At this website there is a lot of us who are a mixture of both!
Chuck

I am relatively sure that when speaker manufacturers measure their speakers' output, they don't use any form of weighting. Especially for subs, because if you have a sub producing 40hz at 130dbA, that's around 166db unweighted. That decibel level is basically impossible for a single sub to achieve in a live sound setting. Not to mention that 150db of bass unweighted is freaking loud as all hell. It modulates all the other sounds around you, and rattles your eyes. 160 would be almost intolerable for even the most seasoned of bassheads.

[chuck clark]

Good point Mr. Berry. Right on.  For many years I just used to whip out the old "Rat Shack" meter set to "A" scale, when there was a question of loudness of the rig. Later in life, I used the rta readout in a DBX 4800 w/ the DBX measurement mic to monitor things. No "weighting" there.  Lately I've just been using my ears, but a rig I put together and tuned was recently measured by a guy w/ an app on his Android, as running "around 114db with a peak of 140db during a keyboard part".   I don't think there's any weighting on the app but I'm told the little mic in a smart phone rolls off seriously below 200hz so don't expect to be able to make good subwoofer measurements without a decent mic that is flat to 20hz.
  I wonder what the heck they use for a measuring mic in those car competitions where they're hitting 160+db! ?
Chuck

[Alex Berry]

Good point Mr. Berry. Right on.  For many years I just used to whip out the old "Rat Shack" meter set to "A" scale, when there was a question of loudness of the rig. Later in life, I used the rta readout in a DBX 4800 w/ the DBX measurement mic to monitor things. No "weighting" there.  Lately I've just been using my ears, but a rig I put together and tuned was recently measured by a guy w/ an app on his Android, as running "around 114db with a peak of 140db during a keyboard part".   I don't think there's any weighting on the app but I'm told the little mic in a smart phone rolls off seriously below 200hz so don't expect to be able to make good subwoofer measurements without a decent mic that is flat to 20hz.
  I wonder what the heck they use for a measuring mic in those car competitions where they're hitting 160+db! ?
Chuck

I pretty much do the same thing currently. I just have a small SPL meter that only measures A weighted, but it does exactly what I need it to do. It tells me how loud the mid/highs are, and then I balance the bass to taste and/or something acceptable for the venue.

The mics they use in car competitions are called Term-Lab sensors made by either Wayne Harris Enterprises or Termpro, I can't tell. Anyways, I'm not entirely sure how the sensors work, but they use a sort of digital sensor which communicates over ethernet. The minimum SPL it can measure is 95db (all of this unweighted), and the maximum in can measure is actually above 193db.

[Scott Carneval]

I am relatively sure that when speaker manufacturers measure their speakers' output, they don't use any form of weighting. Especially for subs, because if you have a sub producing 40hz at 130dbA, that's around 166db unweighted. That decibel level is basically impossible for a single sub to achieve in a live sound setting. Not to mention that 150db of bass unweighted is freaking loud as all hell. It modulates all the other sounds around you, and rattles your eyes. 160 would be almost intolerable for even the most seasoned of bassheads.

The weighting scale is only applicable to broadband measurements in which you receive a single db measurement for the entire 20-20khz spectrum.  In rating a subwoofer you're hopefully going to get a measurement somewhere within the 'subwoofer spectrum' of about 20-100hz.  Any sort of weighting would be irrelevant here as you're just looking at a single frequency.  For example if XYZ manufacturer  says their sub does 133db continuous, that's likely to mean they measured 133db at a the loudest specific single frequency throughout the subwoofer spectrum. 

[Rob Spence]

  For example if XYZ manufacturer  says their sub does 133db continuous, that's likely to mean they measured 133db at a the loudest specific single frequency throughout the subwoofer spectrum.

Or, perhaps outside the expected spectrum. I recall reading here about a sub that maxed out at 150hZ so that was the number used. In the 30-80hZ range it was down considerably.

As Ivan says, you need to see the response chart.

Sent from my iPad using Tapatalk HD

[Scott Carneval]

Or, perhaps outside the expected spectrum. I recall reading here about a sub that maxed out at 150hZ so that was the number used. In the 30-80hZ range it was down considerably.

As Ivan says, you need to see the response chart.

Sent from my iPad using Tapatalk HD

Yes, absolutely.  I considered that as I was typing my original reply, but felt it was irrelevant in the context of the original question (weighting scale of db specs) and would only add confusion to the answer. 

But unfortunately some manufacturers like to use marketing math and rate their subs at 150hz or greater just because that's where they're the loudest, even though they will most likely not be used in that range. 

[Luca Rossi]

That's true, but the question wasn't about marketing tactis. Anyway you can measure the real spl regardeless of manufacter specs. The goal is to know how does bass band spectrum affect the impact felt by our body. For example when you mix a kick drum, it's a common mistake to emphasize just around 60-80 hz to get more punch, because in this way you just reduce the attack of the kick.

[John L Nobile]

That's true, but the question wasn't about marketing tactis. Anyway you can measure the real spl regardeless of manufacter specs. The goal is to know how does bass band spectrum affect the impact felt by our body. For example when you mix a kick drum, it's a common mistake to emphasize just around 60-80 hz to get more punch, because in this way you just reduce the attack of the kick.

Can you expand on why boosting at 60 to 80 is a common mistake?

[Luca Rossi]

I said why. If you only boost the fundamental frequency of the kick, usually between 50-90 hz, you will loose the attack it self. That's true for high spl level i think. You have to get a flat frequency response, leaving the kick's energy to pass equally around the band. That is what i learned.
Try this: loops the kick in the mix with main speakers and subwoofers on.  After turn off main speakers, allowing only the kick' fundamental to pass through subwoofer. You will notice a lack in the punch. That's an extreme example but it gets the idea.

[Stephen Kirby]

I said why. If you only boost the fundamental frequency of the kick, usually between 50-90 hz, you will loose the attack it self. That's true for high spl level i think. You have to get a flat frequency response, leaving the kick's energy to pass equally around the band. That is what i learned.
Try this: loops the kick in the mix with main speakers and subwoofers on.  After turn off main speakers, allowing only the kick' fundamental to pass through subwoofer. You will notice a lack in the punch. That's an extreme example but it gets the idea.

Cutting out the tops is different than boosting the fundamental.  Most soundpeople also boost around 4k to enhance that attack and balance it out with the fundamental.  Along with carving out a lot above the fundamental to reduce the mud and leave space for the bass guitar.

[John L Nobile]

I said why. If you only boost the fundamental frequency of the kick, usually between 50-90 hz, you will loose the attack it self. That's true for high spl level i think. You have to get a flat frequency response, leaving the kick's energy to pass equally around the band. That is what i learned.
Try this: loops the kick in the mix with main speakers and subwoofers on.  After turn off main speakers, allowing only the kick' fundamental to pass through subwoofer. You will notice a lack in the punch. That's an extreme example but it gets the idea.

Still not getting it.
The hi end is still part of the kick sound. You'd never hear it without that. Just feel it.
Try eqing the kick at 50 or 60 hz and compare that to 80hz. But boost 3 to 5 k equally. I tried that tonight and it punched much better at 80.

[Luca Rossi]

Of course you can't feeling high frequency on your body. But hearing and feeling are both correlated. To perceive a good realism you must be capable to put out high spl level in all the spectrum. I also hate when the kick is too underdamped like 80-100 ms, it's good only for dance music. Ideal is when you get ringing within 30-50 ms.

[John L Nobile]

Of course you can't feeling high frequency on your body. But hearing and feeling are both correlated. To perceive a good realism you must be capable to put out high spl level in all the spectrum. I also hate when the kick is too underdamped like 80-100 ms, it's good only for dance music. Ideal is when you get ringing within 30-50 ms.

I think what you may be thinking of as punch, I would call point or presence. I think of punch as something around 80hz. A top end boost would accentuate the punch.
What do you mean by underdamping? Is that compressor attack time or a gate decay time? I'm always open to new things and I like to experiment.

[Stephen Kirby]

In a decent sized room there is often a fair amount of LF resonance and reverberation.  Coupled with ported subs that also rely on resonance and there is a lot of overhang or ring in the kick drum sound in the room.  While I personally hate kick drums full of laundry, in such rooms the net effect is of a fair amount of simulated sustain added to the kick.  So, if you damp the kick or gate it and let the room provide the sustain, you end up with a reasonably natural amount of note duration on the kick.  If you don't, it can sound like an SPL hatchback with this extended 808 like boom.

[ProSoundWeb Community]