Is a Db a Db?

[An-i-no 86]

Ok so...we all know that some vehicles are louder than others, some are more prone to flex so on and so forth. We all know that a 150 in one car can look and feel drastically different than a 150 in a different car.

But what I want to know is... can there be more force behind a woofer's stroke which would in turn translate into moving more air and more flex BUT, it's not as loud on a meter?

Let's take say...a pair 6x9. I can make the 6x9's play louder (to my ear anyway) than my pair of 12's but they move less air and hardly flex anything. It doesn't sound very "powerful," if you will. At the same time, my subs at a lot lower volume can move my mirror which the 6x9's can hardly do when playing at higher volumes. They're LOUDER yes, but less...forceful.

Here's where it gets fuzzy. Can a system be more forceful and move more air but be quieter than another system in the same environment playing the same song/frequency? Can one system be an easy, crushing 150 while another is just squeaking out a 150? Or is it exactly the same and only a difference in our heads? If I have 15 burping a 150 at 45hz and switch to 4 15's and upgrade to the point where I can do constant 150's would it sound and feel the same?

If it's too long...can a speaker have more force but less volume?

[User 1]

With more force comes more volume. All speakers/subs do is move air which converters to sound waves which is sound. The more air you move the more sound you create. One 15 hitting 150 takes more power than four 15s because there's more cone area. The single 15 has to work harder to produce that much air movement.

[ChevyBoy95 15]

Ok so...we all know that some vehicles are louder than others, some are more prone to flex so on and so forth. We all know that a 150 in one car can look and feel drastically different than a 150 in a different car.

But what I want to know is... can there be more force behind a woofer's stroke which would in turn translate into moving more air and more flex BUT, it's not as loud on a meter?

Let's take say...a pair 6x9. I can make the 6x9's play louder (to my ear anyway) than my pair of 12's but they move less air and hardly flex anything. It doesn't sound very "powerful," if you will. At the same time, my subs at a lot lower volume can move my mirror which the 6x9's can hardly do when playing at higher volumes. They're LOUDER yes, but less...forceful.

Here's where it gets fuzzy. Can a system be more forceful and move more air but be quieter than another system in the same environment playing the same song/frequency? Can one system be an easy, crushing 150 while another is just squeaking out a 150? Or is it exactly the same and only a difference in our heads? If I have 15 burping a 150 at 45hz and switch to 4 15's and upgrade to the point where I can do constant 150's would it sound and feel the same?

If it's too long...can a speaker have more force but less volume?

wouldnt feel or sound the same, with the multiple 15s you would have more air movement drastically changing the environment your in to a message chair rather than something that makes your nose itch. Ive gone from 1 15 to 2 15s (and went from 1k to 2krms) and it went from loud to loud where your ears would hurt also instead of shaking a few things a little, my dash was shaking, along with the steering wheel and about everything in the truck.

as far as burp to burp like 1 12 doing a 140 and 2 12s doing a 140, i have no clue. all i know is more power with more cone area makes a big difference.

Edited August 23, 2011 by ChevyBoy95

[shizzzon 461]

the answer is frequency...

Frequency has drastic differences even if all frequencies produce the same dB.

[An-i-no 86]

the answer is frequency...

Frequency has drastic differences even if all frequencies produce the same dB.

Assuming the same frequency?

Or do you mean the frequency RESPONSE is the difference?

[///M5 2,833]

If you assume the same frequency and both dB's are referenced appropriately to 20microPascals then yes a dB is a dB.

Your example does not relay that you are referring to the same frequency.

[An-i-no 86]

If you assume the same frequency and both dB's are referenced appropriately to 20microPascals then yes a dB is a dB.

Your example does not relay that you are referring to the same frequency.

OK, pair of 6x9's. I turn the volume up, play a song, they make bass.

Disconnect the 6x9's turn subs on, same song, much lower volume than the 6x9's. I can FEEL the subs playing, something the 6x9's can't do. They made louder bass to my ear but the subs just sound so much heavier, more forceful. What I'm asking is why is that? Can something measure lower on a meter, but feel more intense, move more air, cause more flex?

The 6x9 thing is just an example really. The way people say a 6x9 can never replace a sub is something I figured everybody could relate to.

[shizzzon 461]

Um.. same thing i said earlier...

2 different sets of speakers are playing or should i say peaking at different frequencies.

[///M5 2,833]

If you assume the same frequency and both dB's are referenced appropriately to 20microPascals then yes a dB is a dB.

Your example does not relay that you are referring to the same frequency.

OK, pair of 6x9's. I turn the volume up, play a song, they make bass.

Disconnect the 6x9's turn subs on, same song, much lower volume than the 6x9's. I can FEEL the subs playing, something the 6x9's can't do. They made louder bass to my ear but the subs just sound so much heavier, more forceful. What I'm asking is why is that? Can something measure lower on a meter, but feel more intense, move more air, cause more flex?

The 6x9 thing is just an example really. The way people say a 6x9 can never replace a sub is something I figured everybody could relate to.

Different dB's and different frequencies.

Um.. same thing i said earlier...

2 different sets of speakers are playing or should i say peaking at different frequencies.

Exactly.

[An-i-no 86]

Uhmm...ok sorry but I'm really not understanding. What do you mean by different Db's M5?

And Shizz, what do you mean by peaking at different frequencies?

Just forget the 6x9 example then. I don't think it's getting across what I mean.

[shizzzon 461]

i guess unless you give us an EXACT example of something you witnessed.. we can keep stating what we are saying...

And even then.. i'm going to say i'm probably going to say the same thing no matter what your example is.

Fact is this-

You are using your ear...

IF you had a meter with the graph right in front of you, you will see what you are hearing.. THEN we can talk about that...

Otherwise, I think you need to reword what you are saying or you may never catch on to what we are saying.

[stevemead08 752]

A car with 2 15 burping 145 @ 32 sounds and feels much louder than my truck burping the same score/same freq. with one 12.

[///M5 2,833]

You aren't comparing apples. By different dB's I mean they will measure differently which is where your difference is. As for peaking, Shizzon is describing the efficiency curve in the frequency domain. ie, each drive will have a different response so if you use the same song then by default the two different drivers will be playing different dB's. In other words, both Sean's are saying the same thing.

Perhaps we don't understand your question. Some reading might help though. An acoustic dB is referenced to 20micro Pascals and therefore by default they ALL have to be the same. Do some reading on dB's and your question should be easier to put into words.

[///M5 2,833]

A car with 2 15 burping 145 @ 32 sounds and feels much louder than my truck burping the same score/same freq. with one 12.

Why do you associate that with the 15's versus the 12? Where are you measuring the dB? If you are using your chest (or any part of your body for that matter) as a reference shouldn't you make sure they measure the same there? Also curious on your burp tone and what it is. You may be feeling things beyond what is being played or playing things you are feeling that aren't affecting the measurement.

[An-i-no 86]

Ok, this is feeling a bit over my head now. I can try to simplify it though. I've never heard something then been told what it metered so when you give me numbers say...145, that means nothing to me as I have no point of reference to even guess with.

People often refer to bass in ways that are completely subjective and hard to measure. Deep, heavy, quick, punchy. If I'm sitting next to you in the car, you can say, "do you feel how punchy that is?" and since we're for the most part experiencing the same thing, I can agree or disagree, but with just words that means nothing.

What I want to know...and it'll probably seem redundant at this point...is....

People consider Db's to be the "true" measurement of "intensity" as more Db's ideally equals more sound. HOWEVER, if you take a setup that peaks at a certain frequency and puts up a certain score at that frequency, then take a setup that is drastically different but peaks at and puts up an identical score at the SAME frequency, would it be the same experience?

I think the obvious answer is no, but what I want to know is why is that? I understand every car is different, every box, sub, and install is different (so I'm assuming the above qualities are the same simply for the sake of comparison).

Shouldn't the install that can blow hair around and knock dome lights loose meter higher than the single sub install burping at the same frequency? This...difference in intensity, how do you measure that? Like SteveMead's example above, it meter's the same but it feels and sounds much louder. What is the difference?

I hope everyone understands lol

[An-i-no 86]

A car with 2 15 burping 145 @ 32 sounds and feels much louder than my truck burping the same score/same freq. with one 12.

Why do you associate that with the 15's versus the 12? Where are you measuring the dB? If you are using your chest (or any part of your body for that matter) as a reference shouldn't you make sure they measure the same there? Also curious on your burp tone and what it is. You may be feeling things beyond what is being played or playing things you are feeling that aren't affecting the measurement.

Sorry to double post, but I wanted to emphasize this.

THAT STUFF. The things he may be feeling beyond what is being played, what the hell is that?

Edited August 23, 2011 by An-i-no

[stevemead08 752]

Bigjon had two ns15s on 3k. I have two 10s of the same brand on same power and tuning. We both meter the same but have different cars. His feels very violent and beats you up pretty good, where as mine is far more mellow in terms of what you feel, hear, and see.

[///M5 2,833]

A dB is a dB. Let's simplify this a bit and remove the car. If you are in an anechoic (nothing to reflect off of) space and experience a perfectly pure (no distortion) xdB and it is generated by two different drivers, hell two different technologies or whatever it will not only sound but feel the same.

Now change one of those parameters and your experience could differ, but if you measure x dB it is absolutely x dB^*.

*with the caveat that you use a true measurement microphone AND report the value with the uncertainty of the measurement system included (ie not a TL -- the TL will give you relative but repeatable just isn't absolute)

In a reverberant space (ie your car - which has reflections) I would argue that you should measure and look for a peak around what you are using to determine it sounds different to see whose fooling who. Your car will not respond the same in all positions and will also vary with frequency. It will paint more of the story and help you understand your own question.

But if you are asking if all things are truly the same will it sound and feel the same? You bet. In fact even if its within a couple dB's and everything else is truly the same it will sound a feel the same to you.

[An-i-no 86]

A dB is a dB. Let's simplify this a bit and remove the car. If you are in an anechoic (nothing to reflect off of) space and experience a perfectly pure (no distortion) xdB and it is generated by two different drivers, hell two different technologies or whatever it will not only sound but feel the same.

Now change one of those parameters and your experience could differ, but if you measure x dB it is absolutely x dB^*.

*with the caveat that you use a true measurement microphone AND report the value with the uncertainty of the measurement system included (ie not a TL -- the TL will give you relative but repeatable just isn't absolute)

In a reverberant space (ie your car - which has reflections) I would argue that you should measure and look for a peak around what you are using to determine it sounds different to see whose fooling who. Your car will not respond the same in all positions and will also vary with frequency. It will paint more of the story and help you understand your own question.

But if you are asking if all things are truly the same will it sound and feel the same? You bet. In fact even if its within a couple dB's and everything else is truly the same it will sound a feel the same to you.

If all things are NOT truly the same, why does it meter the same. What is it that the mic is missing?

There's my real question. Thanks for narrowing it down. You're awesome.

[///M5 2,833]

Bigjon had two ns15s on 3k. I have two 10s of the same brand on same power and tuning. We both meter the same but have different cars. His feels very violent and beats you up pretty good, where as mine is far more mellow in terms of what you feel, hear, and see.

You do not meter the same. Frequency plays a major role, and yes even if you burp the same note and meter the same on that note, you do not meter the same. Hell, even if you did in one spot in your car and happen to find it, I would still say you do not meter the same. Your analogy leaves out some major considerations in frequency and mic location.

[///M5 2,833]

A dB is a dB. Let's simplify this a bit and remove the car. If you are in an anechoic (nothing to reflect off of) space and experience a perfectly pure (no distortion) xdB and it is generated by two different drivers, hell two different technologies or whatever it will not only sound but feel the same.

Now change one of those parameters and your experience could differ, but if you measure x dB it is absolutely x dB^*.

*with the caveat that you use a true measurement microphone AND report the value with the uncertainty of the measurement system included (ie not a TL -- the TL will give you relative but repeatable just isn't absolute)

In a reverberant space (ie your car - which has reflections) I would argue that you should measure and look for a peak around what you are using to determine it sounds different to see whose fooling who. Your car will not respond the same in all positions and will also vary with frequency. It will paint more of the story and help you understand your own question.

But if you are asking if all things are truly the same will it sound and feel the same? You bet. In fact even if its within a couple dB's and everything else is truly the same it will sound a feel the same to you.

If all things are NOT truly the same, why does it meter the same. What is it that the mic is missing?

There's my real question. Thanks for narrowing it down. You're awesome.

Always simplify things, makes them more clear. All cars, all speakers, all boxes, all electronics, mechanics etc have their own signature on what they do acoustically or vibrationally when exposed to some sort of Kinetic energy. Mathematically it can be explained as a transfer function. ie, you ring a bell with a hammer and y lbs of force and at 1 ft it will ring this at x dB, in this case the bell resonates at a frequency and acts as a mechanical amplifier and then the structure moves around at that frequency and moves enough air to amplify the little energy you put into it. This resonation or amplification can occur in air as well as sound bounces off different objects in different defined spaces. You now have an acoustic response and structure borne noise changing the response and we haven't even spoken about the major differentiator in the box and driver, obviously these also follow the laws of Physics and can be understood in the same ways. Considering most people on here have dinked around with a box modeling software of some sort you can see what changing either t/s parameters or the box can have a drastic effect on the outcome so I won't go into that.

...but that is a little more complicated than saying if you keep everything the same and it meters the same it will be the same.

[stevemead08 752]

Bigjon had two ns15s on 3k. I have two 10s of the same brand on same power and tuning. We both meter the same but have different cars. His feels very violent and beats you up pretty good, where as mine is far more mellow in terms of what you feel, hear, and see.

You do not meter the same. Frequency plays a major role, and yes even if you burp the same note and meter the same on that note, you do not meter the same. Hell, even if you did in one spot in your car and happen to find it, I would still say you do not meter the same. Your analogy leaves out some major considerations in frequency and mic location.

Ok your right.

[stevemead08 752]

I think the original question was,,, could something sound and feel louder but not meter louder. answer is yes.

At least thats what my simple mind read.

[///M5 2,833]

I think the original question was,,, could something sound and feel louder but not meter louder. answer is yes.

At least thats what my simple mind read.

If you take an American V8 and a Japanese I4 and put a mic at 50' away and measure them to the same dB level do they sound the same to the ear?

[An-i-no 86]

A dB is a dB. Let's simplify this a bit and remove the car. If you are in an anechoic (nothing to reflect off of) space and experience a perfectly pure (no distortion) xdB and it is generated by two different drivers, hell two different technologies or whatever it will not only sound but feel the same.

Now change one of those parameters and your experience could differ, but if you measure x dB it is absolutely x dB^*.

*with the caveat that you use a true measurement microphone AND report the value with the uncertainty of the measurement system included (ie not a TL -- the TL will give you relative but repeatable just isn't absolute)

In a reverberant space (ie your car - which has reflections) I would argue that you should measure and look for a peak around what you are using to determine it sounds different to see whose fooling who. Your car will not respond the same in all positions and will also vary with frequency. It will paint more of the story and help you understand your own question.

But if you are asking if all things are truly the same will it sound and feel the same? You bet. In fact even if its within a couple dB's and everything else is truly the same it will sound a feel the same to you.

If all things are NOT truly the same, why does it meter the same. What is it that the mic is missing?

There's my real question. Thanks for narrowing it down. You're awesome.

Always simplify things, makes them more clear. All cars, all speakers, all boxes, all electronics, mechanics etc have their own signature on what they do acoustically or vibrationally when exposed to some sort of Kinetic energy. Mathematically it can be explained as a transfer function. ie, you ring a bell with a hammer and y lbs of force and at 1 ft it will ring this at x dB, in this case the bell resonates at a frequency and acts as a mechanical amplifier and then the structure moves around at that frequency and moves enough air to amplify the little energy you put into it. This resonation or amplification can occur in air as well as sound bounces off different objects in different defined spaces. You now have an acoustic response and structure borne noise changing the response and we haven't even spoken about the major differentiator in the box and driver, obviously these also follow the laws of Physics and can be understood in the same ways. Considering most people on here have dinked around with a box modeling software of some sort you can see what changing either t/s parameters or the box can have a drastic effect on the outcome so I won't go into that.

...but that is a little more complicated than saying if you keep everything the same and it meters the same it will be the same.

Ok I understand a little better. I'm sure Im not comprehending fully but I have an idea.

And Steve, you're spot on Haha. Yay for simple minded bassheads.