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18" - why no love?

#244
CL400Peavey said:
I dont think you understand how sound works. 40hz is the same speed regardless of what size driver produces it. Same with 100hz, and 1000hz. By definition they are the same speed.
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In fact, they're all the same speed. Speed of sound in air doesn't change with frequency, amplitude or wavelength. Maybe it seems slower because 18" speakers are substantially cooler as some would suggest... than the sizes we commonly use? ;)
 
#247
agedhorse said:
Yes, this is generally true unless the horn scales up considerably. By this time, it becomes quite impractical though. One of the challenges is to develop sufficient motor strength and diaphragm rigidity to overcome the forces of compression that result. The larger the cone the more difficult as there is a squared factor in the stiffness equations which works against getting too large.
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By modern standards, the old Acoustic stacks with folded horns weren't terribly high powered. The power section in a 361 cabinet was 200 watts. The power section in a 370 head was something like 300 or 325 watts, max. The new version has a 400 watt power section, which is still not a huge amount of power according to the usual TalkBass wisdom. The power is plenty for what those cabinets do, and the system works very well in total. The new one has a high frequency horn mounted in the cabinet, and that solves any range problems, at least to my ears. I like the way they sound, so I'll be schlepping them around until I can't.
 
#248
CL400Peavey said:
Here is a car analogy that actually holds up.

What is faster, a VW with a 4,000 pound curb weight, or a 2,000 pound Fiat 500 arbath?

What is that VW is a Bugatti?

Engineering makes up for a lot of preconceived notion on what determines performance.
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Ah... But be aware that the Bugatti is faster because of a higher power to weight ratio. Just like adding more amplifier power to drive that heavier speaker.
 
#251
spigmu said:
But if something is capable of moving more air but more slowly it's not all win, at least in my feeble reasoning. I don't have much experience with 18" cabs but what it it did tell me was that they noticeably didn't respond quick enough, so it didn't matter how loud or good they sounded.
Click to expand...
CL400Peavey said:
I dont think you understand how sound works. 40hz is the same speed regardless of what size driver produces it. Same with 100hz, and 1000hz. By definition they are the same speed.
Click to expand...

I'm not talking about the speed of the wave or anything frequency response related. By "didn't respond quick enough" I was referring to transient response, response to my fingers. Even with a high freq driver in the cabinet the 18" has to travel a certain distance and go back. In a similar size cabinet multiples of 12"s and especially 10"s don't move as much distance as the 18" when putting out a reasonably similar volume and sound., and it wouldn't be solved by having multiple 18"s.

There may be much myth there as well, but my experience has been that the difference between playing staccato on an 18" and anything else isn't totally due to cabinet design. Could be related to my lack of motivation to find an 18" based rig to own, but I've played through enough over the years to feel they wouldn't suit me for that reason, that in whatever ways they are equal to other sizes there are at least a few where they're different.

Best,

s
 
#252
spigmu said:
I'm not talking about the speed of the wave or anything frequency response related. By "didn't respond quick enough" I was referring to transient response, response to my fingers. Even with a high freq driver in the cabinet the 18" has to travel a certain distance and go back. In a similar size cabinet multiples of 12"s and especially 10"s don't move as much distance as the 18" when putting out a reasonably similar volume and sound., and it wouldn't be solved by having multiple 18"s.
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If the two speakers are capable of producing the same frequency, lets say 500hz, The smaller drivers would have to move more to match the output of the 18.

spigmu said:
There may be much myth there as well, but my experience has been that the difference between playing staccato on an 18" and anything else isn't totally due to cabinet design. Could be related to my lack of motivation to find an 18" based rig to own, but I've played through enough over the years to feel they wouldn't suit me for that reason, that in whatever ways they are equal to other sizes there are at least a few where they're different.
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Each cab is an individual. For the same reason as every 410 sounds different, every 18" based cab will as well.
 
#253
Transient response (or impulse response for that matter) is directly related to frequency response or bandwidth. It is very difficult to achieve practical HF extension with an 18" driver due to the higher moving mass involved and the forces necessary for the acceleration necessary for higher frequencies.
 
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#254
agedhorse said:
Transient response (or impulse response for that matter) is directly related to frequency response or bandwidth. It is very difficult to achieve practical HF extension with an 18" driver due to the higher moving mass involved and the forces necessary for the acceleration necessary for higher frequencies.
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kind of sounds like you're saying when receiving the same power, 18s are slower than their smaller counterparts :thumbsup: this is very good! :cool:
 
#255
Dash Lashes said:
kind of sounds like you're saying when receiving the same power, 18s are slower than their smaller counterparts :thumbsup: this is very good! :cool:
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No.

agedhorse said:
Transient response (or impulse response for that matter) is directly related to frequency response or bandwidth. It is very difficult to achieve practical HF extension with an 18" driver due to the higher moving mass involved and the forces necessary for the acceleration necessary for higher frequencies.
Click to expand...

He is saying that it is harder to get a larger mass to accelerate in the manner that is conclusive for HF output.
 
#258
so... 'scientists' stare 'science' right in the face. they see 'science', and proceed to tell you all about 'science', then turn around and tell a non-scientist; science doesnt exist :confused:. what is the point! i kinda want to know why, but i dont care. so now im like: whatever :rollno:

have fun in here folks. *unwatch thread :angel:

118" forever! _dash

(edit/add: this is just a soft rage quit lol)
 
#260
Dash Lashes said:
so... 'scientists' stare 'science' right in the face. they see 'science', and proceed to tell you all about 'science', then turn around and tell a non-scientist; science doesnt exist :confused:. what is the point! i kinda want to know why, but i dont care. so now im like: whatever :rollno:

have fun in here folks. *unwatch thread :angel:

118" forever! _dash
Click to expand...

Speed is a measurement of the rate an object is traveling. Acceleration is a vector, the first derivative of velocity. Speed =|= velocity =|= acceleration.
 
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