What makes a loudspeaker loud?

[audioholic 5,000+ posts]

I know its linear excursion and surface area that create sound pressure...But I know that there are more variables than that...
Some people say that it's motor design, but if you have two similar sized woofere vibrating at the same frequency, and moving the same air, can one be louder?

Ultimately loudness comes down to the amount of air displaced. You can do this many ways... a small diameter cone with tones of excursion, a large diameter sub requiring less excursion, cone motion + enclosure efficiency (vented systems), or a combination of those three ways.
To complicate things some, cone excursion can be achieved in more than one way as well. For example, a highly efficient sub with less wattage has the potential to move as much as a less efficient sub utilizing more power.

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[audioholic 5,000+ posts]

What makes an enclosure efficient?

Enclosure efficiency is affected by several things. The size of the enclosure, if its ported or sealed, size of port and tuning... even placement/positioning of the enclosure will affect over all system efficiency. But that's getting a bit off topic I think.

 

[Tehgregzor 10+ year member]

I'm enjoying the learn in this thread. I too am interested in this.

Also, what's the trade off if i designed (making up variables) an 18" cone with superb excersion abilities mechanically. What am i sacrificing?

 

[Rashaddd 5,000+ posts]

I'm enjoying the learn in this thread. I too am interested in this.

Also, what's the trade off if i designed (making up variables) an 18" cone with superb excersion abilities mechanically. What am i sacrificing?

poor reproduction of higher frequencies

 

[SPLEclipse 10+ year member]

Also, what's the trade off if i designed (making up variables) an 18" cone with superb excersion abilities mechanically. What am i sacrificing?

it the sub needs a lot of power to meet the mech. excursion limits, you loose efficiency. if the suspention is "loose" and you dont need a lot of power to reach the mech. excursion limits, you have to put it in a large enclosure. pick two of the three:

1) efficiency

2) power handling

3) enclosure size for optimal frequency response

search for hoffmans iron law for more info.

to the OP: if you have two woofers with the same box/power playing at the same tone and producing the exact same amplitude...you have two of the same sub or two subs who just happen to do that at the same frequency based on the impedence curve among other things. its kind of like comparing a 300HP honda with a 300HP mustang. yes..they will both be fast, but the mustang will have better 60' times, while the honda might have a higher trap speed. theyll both complete a quarter mile race..but the way they do it is different.

 

[Louisiana_CRX 5,000+ posts]

I read somewhere on here its how many watts a woofer puts out //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[nauc 10+ year member]

if you want your speaker to be loud, you have to throw it real hard/fast and have it hit like a big piece of thin metal

BANG!!!!!!!!!!!!

mahahahah

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[Blue Fury 10+ year member]

poor reproduction of higher frequencies

oh no. I think depending on its compression rating, it becomes insignificant.

 

[helotaxi 5,000+ posts]

pick two of the three:
1) efficiency

2) power handling

3) enclosure size for optimal frequency response

search for hoffmans iron law for more info.

#2 above is not part of it. The final part of the trade is low frequency extension. So for example, you want an efficient system in a small box, it will suffer in the frequency extension department. You can get efficient low freq extension but it means a big box or you can get low freq extension in a small box but it will be very inefficient.

to the OP: if you have two woofers with the same box/power playing at the same tone and producing the exact same amplitude...you have two of the same sub or two subs who just happen to do that at the same frequency based on the impedence curve among other things. its kind of like comparing a 300HP honda with a 300HP mustang. yes..they will both be fast, but the mustang will have better 60' times, while the honda might have a higher trap speed. theyll both complete a quarter mile race..but the way they do it is different.

Terrible analogy. In your analogy, the different cars with the same power would perform very differently. A better analogy would be 2 different cars that run the same 1/4 with the same trap speed have different weights and thus require different power to achieve the same performance. To answer the OP's question, if the drivers had the same cone area and moved the same amount at the same frequency in the same box, they would have the same output.

 

[Rashaddd 5,000+ posts]

oh no. I think depending on its compression rating, it becomes insignificant.

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[helotaxi 5,000+ posts]

The fact that they peak really well and can handle a lot of power. That power handling allows them to actually use more of their excursion capability around the tuning frequency where the enclosure is the most efficient and the cone movement is at its lowest because of enclosure loading on the cone. Xmax only means something if you are actually using it. Most subs hardly move at all in a ported box at tuning. It doesn't matter if the sub has an Xmax of 32mm if it only has enough motor strength to move 1mm at the frequency that your car peaks.