10's or 8's...worried about low end.

[cotjones 10+ year member]

Wrong.

hows it wrong? i looked up a definition...

"In physics, resonance is the tendency of a system to oscillate at maximum amplitude at a certain frequency. This frequency is known as the system's resonance frequency (or resonant frequency). When damping is small, the resonance frequency is approximately equal to the natural frequency of the system, which is the frequency of free vibrations."

so resonance it what you get when you send energy into a tuning fork in the form of a vibration at a specific frequency...

every object has resonance

i also found this...

FsAlso called F0, measured in hertz (Hz). The frequency at which the combination of the moving mass and suspension compliance maximally reinforces cone motion. A more compliant suspension or a larger moving mass will cause a lower resonance frequency, and vice versa. Usually it is less efficient to produce output at frequencies below Fs, though motion below Fs can cause uncontrolled motion, mechanically endangering the driver. Woofers typically have an Fs in the range of 13–60 Hz. Midranges usually have an Fs in the range of 60–500 Hz and tweeters between 500 Hz and 4 kHz

hmmm... almost exacly what i guessed, //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif(without mentioning suspension compliance which i just took as a given and thus didn't mention)

 

[RAM_Designs 5,000+ posts]

hmmm... almost exacly what i guessed, //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif(without mentioning suspension compliance which i just took as a given and thus didn't mention)

riiiiiiiiiiiiiiight //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

It really is funny watching you argue by yourself. Everyone sits back and laughs at you, and you're the forum joke...but you still don't know it. Kinda sad, actually.

 

[Immacomputer 10+ year member]

(without mentioning suspension compliance which i just took as a given and thus didn't mention)

Hahhaha

 

[newusername 10+ year member]

Fs itself has nothing to do with motor strength.

Fs = 1/(2*pi*Sqrt(Mms*Cms))

 

[Flipx99 5,000+ posts]

Isn't BL motor strength?

 

[cotjones 10+ year member]

Hahhaha

what are you :laugh:ing about i mean suspension compliance is just obvious since the sub can barely vibrate at all without it, it was just so obvious i didn't think about it...

 

[cotjones 10+ year member]

Isn't BL motor strength?

sorta... Bl is the force that the magnet exurts on the VC x the current going through the voice coil...

so higher BL gives a stronger motor,

well...

actually, "the higher the BL, the larger the force on the coil generated by a given current" (definition)

 

[hoss 5,000+ posts]

sorta... Bl is the force that the magnet exurts on the VC x the current going through the voice coil...
so higher BL gives a stronger motor,

well...

actually, "the higher the BL, the larger the force on the coil generated by a given current" (definition)

you are on the right track, but still wrong.

Bl IS the motor strength, flat and simple. by definition it is the magnetic energy force created between the coil and the motor by a given amount of electricity flowing through the coil, and the length of the coil in the gap.

B = the force between the motor and the coil

l = the length of coil in the gap

thus, we get Bl, measured in tesla meters

you were close on this one though, i will give you that.

as for the Fs, devildriver, i have to say you are wrong with your statement that the motor force has nothing to do with the Fs. the Fs is comprised of two main factors, the Mms and the Qts, and the Qts is somewhat derived from the motor force.

 

[Pl8er 5,000+ posts]

I'd say go with an

888888888888

..888 .8888

..888 .8888

....8888

..888 .8888

..888 .8888

888888888888

Actually, I don't care....I just wanted to throw this in as the OP asks what he should go with and here we are on page 33 with you guys explaining how much you know 8 and brand wise, any reputable high end company that meets your personal needs and what you can afford

/thread

 

[newusername 10+ year member]

you are on the right track, but still wrong.
Bl IS the motor strength, flat and simple. by definition it is the magnetic energy force created between the coil and the motor by a given amount of electricity flowing through the coil, and the length of the coil in the gap.

B = the force between the motor and the coil

l = the length of coil in the gap

thus, we get Bl, measured in tesla meters

you were close on this one though, i will give you that.

as for the Fs, devildriver, i have to say you are wrong with your statement that the motor force has nothing to do with the Fs. the Fs is comprised of two main factors, the Mms and the Qts, and the Qts is somewhat derived from the motor force.

Hey Hoss,

BL isn't actually the motor force, perse. It would be more accurately described as the motor potential or a force "factor" of sorts. Real motor force is BL*i where B is the magnetic flux field density, L is the length of the conductor in the magnetic field, and i is the current through the conductor.

Qts is not calculated in Fs. This parameter is derived entirely from Mms and Cms. The equation I posted above is correct.

 

[helotaxi 5,000+ posts]

Cot-an attempt to actually learn and a bit of humility on your part would go miles toward you getting a modicum of respect on here. Thinking that you are always right and then when confronted with a point on which you were totally off, coming back with "well that's so obvious that I didn't mention it" makes you look like even more of a know it all punk. You act like you have all the answers and sadly I think that you believe you do know everything. It is, however, amazingly apparent to the overwhelming majority of us that you don't know a **** thing and are incredibly insecure about your ignorance. As a defense mechanism you come up with these huge long winded explanations about how your utter drivel is correct to make yourself feel adequate. The real truth is that you are an insecure, ignorant little child that is coming to the stark realization that he is wrong more often than right and in an attempt to bolster his faltering sense of self worth, has to post these huge rants, not in an attempt to convince those of us that actually do know what we're talking about that you have a clue about anything and aren't totally out in left field, but rather to convince yourself that you really aren't an ignorant worthless POS. Having to lie to yourself is sad in its own right, but the saddest thing is that you've been telling yourself the same lie regarding your own adequacy for so long that it appears that you actually believe it even though you know it to be untrue. I hope I'm not around when you finally awake from your state of denial and get *****slapped by the reality of your pathetic existence.

 

[hoss 5,000+ posts]

Hey Hoss,
BL isn't actually the motor force, perse. It would be more accurately described as the motor potential or a force "factor" of sorts. Real motor force is BL*i where B is the magnetic flux field density, L is the length of the conductor in the magnetic field, and i is the current through the conductor.

Qts is not calculated in Fs. This parameter is derived entirely from Mms and Cms. The equation I posted above is correct.

that does make sense that the current is included in the equation, but i was always under the understanding that it was for a given amount of current. it seems like if that was the measure of Bl we would be reading T/s with tesla/meter-amps instead of just tesla/meters. ill go back and check what my ldc says about it though (ive always found it to be the most accurate source of answers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )

ill check that out too //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif . it might just be that im thinking that the Qts is a contributing factor to the Fs, might not be in the equation, but its something that helps yield the Fs.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[newusername 10+ year member]

that does make sense that the current is included in the equation, but i was always under the understanding that it was for a given amount of current. it seems like if that was the measure of Bl we would be reading T/s with tesla/meter-amps instead of just tesla/meters. ill go back and check what my ldc says about it though (ive always found it to be the most accurate source of answers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )

The current through the conductor is not included in the equation for BL...that's still and always will be a function of the magnetic flux and length of coil in the gap. But it's hard to have any real force in an electromagnetic motor without current going through the coil, no? BL itself doesn't describe actual force of a motor...it describes the force potential or force factor, as it is often termed.

ill check that out too //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif . it might just be that im thinking that the Qts is a contributing factor to the Fs, might not be in the equation, but its something that helps yield the Fs.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I'm not sure how Qts could be a contributing factor to Fs without actually being in the equation. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif Perhaps you are confusing Fs with Fc, which is the resonant frequency of a sealed system, where Qts is certainly relevant.

The only parameters that contribute or yield to any other parameter are:

BL

Mms

Cms

Re

Sd

Rms (although this doesn't hold much relevance for subwoofers)

Everything is calculated from those six parameters. There are also a couple of stand alone parameters (like Le or Xmax) but those six are what you need to get anywhere.

 

[J31Rob 5,000+ posts]

This thread is still going on? *shrugs*

 

[hoss 5,000+ posts]

Perhaps you are confusing Fs with Fc, which is the resonant frequency of a sealed system, where Qts is certainly relevant.

actually, are you confusing Qts with Qtc? (btw, not being an ******* here, just trying to make sure we are using the same terms //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )

im refering to the Q of the total system of the driver, including the motor and suspension. im not speaking in terms of anything in a closed box system. i can see how those parameters can yield you everything that you need to know, but it still seems to me like the Qts is going to be related to the Fs as a direct result of diaghram control.

 

[newusername 10+ year member]

actually, are you confusing Qts with Qtc? (btw, not being an ******* here, just trying to make sure we are using the same terms //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )

Fc=(Qtc*Fs)/Qts if I remember correctly. That is what I was referring to.

im refering to the Q of the total system of the driver, including the motor and suspension. im not speaking in terms of anything in a closed box system. i can see how those parameters can yield you everything that you need to know, but it still seems to me like the Qts is going to be related to the Fs as a direct result of diaghram control.

If we assume that we are talking about the driver only, then no, Fs is not derived in anyway from Qts.

 

[hoss 5,000+ posts]

im not saying that it one is derived from the other, but that the two can be related to each other (in the sense that one is going to change as a result of changing the other.)

 

[newusername 10+ year member]

im not saying that it one is derived from the other, but that the two can be related to each other (in the sense that one is going to change as a result of changing the other.)

Can you describe how changing Qts will change Fs mathematically without attributing this to Mms or Cms? I don't see how one can be changed by the other if one is not derived from the other. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Again, the only factors in Fs are Mms and Cms. This is well covered in Thiele's original work and there must be 100 papers by now discussing these relationships. Hell, there is a page about it on Wikipedia.

What I think you are trying to describe are the decay, damping, and ringing effects around Fs that Qts, in part, describes, but in no way does this actually say anything about Fs. Fs only describes the frequency at which a driver resonates, which Qts has nothing to do with.

If you changed Qts by changing BL or Re (without changing Mms or Cms), you would not have changed Fs at all.

 

[audioholic 5,000+ posts]

Cot-an attempt to actually learn and a bit of humility on your part would go miles toward you getting a modicum of respect on here. Thinking that you are always right and then when confronted with a point on which you were totally off, coming back with "well that's so obvious that I didn't mention it" makes you look like even more of a know it all punk. You act like you have all the answers and sadly I think that you believe you do know everything. It is, however, amazingly apparent to the overwhelming majority of us that you don't know a **** thing and are incredibly insecure about your ignorance. As a defense mechanism you come up with these huge long winded explanations about how your utter drivel is correct to make yourself feel adequate. The real truth is that you are an insecure, ignorant little child that is coming to the stark realization that he is wrong more often than right and in an attempt to bolster his faltering sense of self worth, has to post these huge rants, not in an attempt to convince those of us that actually do know what we're talking about that you have a clue about anything and aren't totally out in left field, but rather to convince yourself that you really aren't an ignorant worthless POS. Having to lie to yourself is sad in its own right, but the saddest thing is that you've been telling yourself the same lie regarding your own adequacy for so long that it appears that you actually believe it even though you know it to be untrue. I hope I'm not around when you finally awake from your state of denial and get *****slapped by the reality of your pathetic existence.

While Im confident you wasted your time with Cot, I applaud your words. On the money.

 

[RedStangHappy 10+ year member]

I'm just curious through all the flaming of people......The original question is what goes lower 10's or 8's? And although we all know that 2 10's are not as loud as 4 8's , Isn't it impossible for 8" subs to go as low as 10" subs? If not could you post numbers, not dB's but Hz. Appreciate the responses, and before it starts I am truly a car audio newbie, not audio just car audio.