Hi,
I am just curious what makes a driver a sub woofer (produce sound lower/low fs) instead of woofer or mid bass, with the same coil diameter, magnet, diameter, etc?
If I have two speakers/driver, one sub woofer (with damage coil), and another normal woofer, with the same mechanical spec, and I replace the membrane of woofer with one from sub woofer, will the woofer now have lower fs (goin to sub)?
Or which part make the difference?
Thanks,
Ervin L
I am just curious what makes a driver a sub woofer (produce sound lower/low fs) instead of woofer or mid bass, with the same coil diameter, magnet, diameter, etc?
If I have two speakers/driver, one sub woofer (with damage coil), and another normal woofer, with the same mechanical spec, and I replace the membrane of woofer with one from sub woofer, will the woofer now have lower fs (goin to sub)?
Or which part make the difference?
Thanks,
Ervin L
If the drivers you have are the same specification and one is called a subwoofer and the other a woofer then the only difference would be the marketing dept😉
I was always under the impression that a "subwoofer" driver usually had larger motor structure and larger suspension and surround, which I thought meant that they were (more) unsuitable for higher frequencies.
Now, what drivers are actually being labelled as what for marketing reasons as BaronGroog says, is another matter.
Now, what drivers are actually being labelled as what for marketing reasons as BaronGroog says, is another matter.
To make a driver a subwoofer, it should have a lower Fs and a longer stroke than a simple woofer.
To achieve this, the cone should be heavier (lowers Fs) and the voice coil should be longer (driving over a longer distance). For the same reason (more excursion) the spider and the surround could be different.
To achieve this, the cone should be heavier (lowers Fs) and the voice coil should be longer (driving over a longer distance). For the same reason (more excursion) the spider and the surround could be different.
Rudolf is correct.
Swapping a subwoofer cone into a normal woofer will not turn it into a subwoofer. While the subwoofer cone might be more massive and may lower Fs there are other design considerations. A cone swap just might produce a mongrel that performs worse that either driver did originally.
To reproduce the lowest frequencies a woofer must move lots of air. A good subwoofer should have a longer voice coil for greater Xmax. A more compliant suspension (the surround and the spider) may be needed to allow the subwoofer to reach Xmax and beyond. A byproduct of both is a lower Fs. The long voice coil adds to the moving mass, which lowers Fs. A more compliant suspension has less "spring" to it, which also lowers Fs. But a low Fs by itself does not guarantee good subwoofer performance. A heavy cone in a woofer with insufficient Xmax might extend the low frequency response, but with an increase in distortion.
If you swap cones you are still stuck with whatever Xmax was designed into that regular woofer.
Swapping a subwoofer cone into a normal woofer will not turn it into a subwoofer. While the subwoofer cone might be more massive and may lower Fs there are other design considerations. A cone swap just might produce a mongrel that performs worse that either driver did originally.
To reproduce the lowest frequencies a woofer must move lots of air. A good subwoofer should have a longer voice coil for greater Xmax. A more compliant suspension (the surround and the spider) may be needed to allow the subwoofer to reach Xmax and beyond. A byproduct of both is a lower Fs. The long voice coil adds to the moving mass, which lowers Fs. A more compliant suspension has less "spring" to it, which also lowers Fs. But a low Fs by itself does not guarantee good subwoofer performance. A heavy cone in a woofer with insufficient Xmax might extend the low frequency response, but with an increase in distortion.
If you swap cones you are still stuck with whatever Xmax was designed into that regular woofer.
There's a lot of grey area. Try not to worry about it too much. There are plenty of drivers sold as "woofers" that have plenty of displacement to carry bottom octaves, and plenty of "subwoofers" that have great mid-bass extension, -in otherwords, tons of overlap, marketing, labelling, etc.
Assuming the replacement moving element is very similar, the result should be acceptable... Differences in cone material/behaviour may effect response for mid-bass in undesirable ways though.
Assuming the replacement moving element is very similar, the result should be acceptable... Differences in cone material/behaviour may effect response for mid-bass in undesirable ways though.
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There is some grey area but I would put it this way. The differences are related to the different ways in which they are intended to be used. A sub driver is intended to be active while a woofer is intended to work as part of a full range speaker.
fs, xmax, thermal power handling, VC inductance, top end extension and sensitivity are key factors.
fs, xmax, thermal power handling, VC inductance, top end extension and sensitivity are key factors.
Thanks for the replies. At least I can a little bit understand the difference between "woofer" and "subwoofer". Anyway, I still can not read easily why one driver is called as woofer (while fs is lower, e.g. around 38 like good/hi-end driver), while another is called subwoofer although the fs is higher, or although fs is claimed lower (sub range), but I see in the response graph, the fs has much lower db than average of its sensitivity db. Could be just "marketing" side?
Suppose I have good woofer (read from spec, e.g. light propylene cone with low fs), If I put it in large volume than minimum recommended (e.g. deeper, more depth box), can I get quality sound produce as if subwoofer driver is put there?
Suppose I have good woofer (read from spec, e.g. light propylene cone with low fs), If I put it in large volume than minimum recommended (e.g. deeper, more depth box), can I get quality sound produce as if subwoofer driver is put there?
Hi ervinl,
It's very difficult to properly answer your questions because you have incorrect premise residing in the questions.
If you want to see the effect of various box designs on a driver, you should download and learn to use various simulation software. I like hornresp personally.
It's very difficult to properly answer your questions because you have incorrect premise residing in the questions.
If you want to see the effect of various box designs on a driver, you should download and learn to use various simulation software. I like hornresp personally.
Thanks for reminder. I am still confious how such a driver labelled as sub or just woofer. But anyway, I can conclude that "a sub" does not arrive just from fs, but also XMax, thermal handling, magnet etc.
Just wonder if the "marketing" has some criteria to decide/label one as sub or just woofer.
For the rest (question), I might post in other thread and possibly room, to avoid ambiguity.
Just wonder if the "marketing" has some criteria to decide/label one as sub or just woofer.
For the rest (question), I might post in other thread and possibly room, to avoid ambiguity.
Same Motor Structure - Sub Bass = Possible
The loudspeakers voice coil when fed a full range sound passes it on to the cone .
The Cone - can be optimized to reproduce a certain frequency ,
This will depend on the following factors :-
1) Upon the amount of hardening binder / chemical & compounds used while pressing the cone (Paper Cones)
2) The hydraulic press pressure
3) The temperature of press
4) Process of pressing
5) Process of treatment after pressing & drying
6) The form of pressing Dye (Shape of Cone)
Just by simply replacing the cone one can optimize a speaker for a certain frequencly range .
There After :- In this argument - Keeping the Motor Structure Same
1) The voice coil inductance plays a big role in influencing efficiency of the frequency range passed on to the cone - just by changing vc inductance - one can take the lodspeaker in subwoofer range
Additionally :- Of Course
To produce a larger wavelength one must choice suitable suspension parts to allow the cone to travel and produce Subbass
2) By changing only the surround material and spider diameter and travel limits one can change a drivers efficiency in a particular frequency pass band .
Suranjan Dasgupta
The loudspeakers voice coil when fed a full range sound passes it on to the cone .
The Cone - can be optimized to reproduce a certain frequency ,
This will depend on the following factors :-
1) Upon the amount of hardening binder / chemical & compounds used while pressing the cone (Paper Cones)
2) The hydraulic press pressure
3) The temperature of press
4) Process of pressing
5) Process of treatment after pressing & drying
6) The form of pressing Dye (Shape of Cone)
Just by simply replacing the cone one can optimize a speaker for a certain frequencly range .
There After :- In this argument - Keeping the Motor Structure Same
1) The voice coil inductance plays a big role in influencing efficiency of the frequency range passed on to the cone - just by changing vc inductance - one can take the lodspeaker in subwoofer range
Additionally :- Of Course
To produce a larger wavelength one must choice suitable suspension parts to allow the cone to travel and produce Subbass
2) By changing only the surround material and spider diameter and travel limits one can change a drivers efficiency in a particular frequency pass band .
Suranjan Dasgupta
Marketing criteria for labeling woofers and subwoofers
Marketing criteria for labeling woofers and subwoofers:
1. Demand on the market
2. Higher perceived value (which can be sold for more?)
3. How much will the guys from engineering/product dept. complain if marketing renames a woofer to subwoofer
Spec. have nothing to do with it. 😱
Marketing criteria for labeling woofers and subwoofers:
1. Demand on the market
2. Higher perceived value (which can be sold for more?)
3. How much will the guys from engineering/product dept. complain if marketing renames a woofer to subwoofer
Spec. have nothing to do with it. 😱
Another big issue is creating those long wavelengths with enough spl ( HT = lots of extension way down with the ocassional need for "special effects that could damage the foundations ! ..................) Whereas music is "usually" <genre dependant> not going much below the 30's) If you have a big room to fill , then you need better kit to do it without distortion.
If you nearfeild monitor at 79 db then your low driver can be less of a monstor- hunk-O- metal 😛
If you nearfeild monitor at 79 db then your low driver can be less of a monstor- hunk-O- metal 😛
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