Is a Db a Db?

[Randal Johnson 544]

From what I have seen from the BIG number vehicles and talking to their owners ...

One thing is always the same ... More flex equals pressure lost ...

Reinforced metal and very thick windows, bracing, and literally bolting doors (and every other entry point) to prevent air from excapeing the vehicle ...

Hope this helps out some and didn't get too far of topic ...

Thanks

[stevemead08 752]

I kinda figured thats what you were after.

Yes M5 is super smart, but maybe too smart in his answers for some of us. But many people may be looking for the answer that M5 gave.

[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.

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?

No. i understand your point but i think its not the answer to his question.

[///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?

No. i understand your point but i think its not the answer to his question.

I know you understood, answer was for others.

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?

BTW, this is what I took as the actual question with relation to dB from the topic title.

[shizzzon 461]

From what I have seen from the BIG number vehicles and talking to their owners ...

One thing is always the same ... More flex equals pressure lost ...

Reinforced metal and very thick windows, bracing, and literally bolting doors (and every other entry point) to prevent air from excapeing the vehicle ...

Hope this helps out some and didn't get too far of topic ...

Thanks

this is a must for those who are willing to do it...

The vehicle is now the box...

Would you want your box to be visibly flexin and floppin all the time? lol of course not.

Do any of these to a daily driver though and it will not be fun...

[trod2902 26]

How do these variations in cabin space cause us to hear and experience something different from what the meter reads. If the reflections in the space are cause the waves to amplify then why do they not meter higher since they carrie more energy? Im talking about how a 145 might feel louder than a 145 in another vehicle.

[///M5 2,833]

How do these variations in cabin space cause us to hear and experience something different from what the meter reads. If the reflections in the space are cause the waves to amplify then why do they not meter higher since they carrie more energy? Im talking about how a 145 might feel louder than a 145 in another vehicle.

First you need to study where you measured and what. Again a single number does NOT describe acoustics. If it feels louder are you measuring where you feel it? What frequency are you measuring and why do you think it pertains to any other frequencies that the system plays?

[trod2902 26]

Ok, so what you are saying is that a system that creates an audibly louder experience should meter louder if enough testing with mic placement and peak frequencies are done? The reason that 145's dont all sound the same is because the numbers measured are just a small analysis of a much bigger picture?

Edited August 24, 2011 by trod2902

[///M5 2,833]

Ok, so what you are saying is that a system that creates an audibly louder experience should meter louder if enough testing with mic placement and peak frequencies are done? The reason that 145's dont all sound the same is because the numbers measured are just a small analysis of a much bigger picture?

Almost. Frequency has to be the same.

On top of all of the other factors your ears do NOT hear all frequencies with the same efficiency. There is even a switch based on intensity.

The problem with the question is that there are a ton of factors. It just isn't super simple. There are many things that will make things sound differently.

[orlando144 20]

M5 is right. I.E. A 140 @ 30hz can sound louder to the ear than a 145 @ 47hz. Like in a SQ car... Tweeter,midbass,coaxil position makes all the diference. Sounwaves reflect from diferent places in the car which makes it sound/feel louder in one place than another.

[trod2902 26]

Yes i realize frequency must be the same, and i believe your inner hear has a dampening mechanism for the lower frequencies correct? Is this the switch your talking about?

[///M5 2,833]

Yes i realize frequency must be the same, and i believe your inner hear has a dampening mechanism for the lower frequencies correct? Is this the switch your talking about?

No, sorry my wording wasn't very good.

Your ears sensitivity changes with frequency

Your ears sensitivity changes with intensity (dB)

In other words both in the frequency domain and at different sound levels your ears do not respond linearly.

Your "realize that frequency must be the same" is a bit vague. In order to meter the same the output from both systems would have to be the same for ALL frequencies. If you take that a step further you should be measuring where you will hear/feel the difference if you are trying to make a comparison. ie, there will be loud spots and quiet spots comparatively in different locations in your vehicle for different frequencies and it isn't logical to compare from one number and one frequency somewhere else in the car.

[trod2902 26]

Gotcha, i feel i have a much clearer understanding now, i hope the OP feels the same. Thanks man

[Randal Johnson 544]

From what I have seen from the BIG number vehicles and talking to their owners ...

One thing is always the same ... More flex equals pressure lost ...

Reinforced metal and very thick windows, bracing, and literally bolting doors (and every other entry point) to prevent air from excapeing the vehicle ...

Hope this helps out some and didn't get too far of topic ...

Thanks

this is a must for those who are willing to do it...

The vehicle is now the box...

Would you want your box to be visibly flexin and floppin all the time? lol of course not.

Do any of these to a daily driver though and it will not be fun...

LOL ... sure ... The vehicles I've seen like this is almost as heavy as a loaded 18 wheeler ...