Are 8's the new 12's?

[audioholic 5,000+ posts]

You are comparing the "same model subs" then you posted your candidate for reasoning, when in the same model all the subs were different! THAT is the point I've been trying to make, just because its in the same line doesnt mean its the same design. They have different motors and suspension to support the use of a heavier cone because its bigger! THAT is why the Fs is lower, the mass is higher for the given suspension! The second you change ANYTHING other than the mass of the cone, your entire arguement is thrown out the window. Guess what? You WON'T find the same everything except cone on ANY line out there (except for a Funky Pup type deal, which I've seen once, had like a 20 oz motor on all of them). Have you taken apart every one of those subs in the same line to find it has the same exact suspension, coil, and motor?
Here is a direct quote from your first post on this thread:

Right there you said the 8" wont have the same low end as the 10, 12, or 15 when in fact I have shown you a line of subs from 8 to 12 that WILL in fact deliver the same low end.

Maybe your knowledgable source should go build an SPL vehicle and tell me the Fs of the sub determines the F3. Maybe in a perfect world where everybody uses sealed boxes with proper alignments he would have a point, but I know how it works when you build boxes outside of manufacturer spec. Besides, F3 changes based on the environment too, gonna argue that next?

Oh, so you are acknowledging finally that my source is not 40 years old, as you tried to state before? And why did you do that? Were you "preaching about something you do not understand"? *gasp* Or, were you intentionally trying to deceive readers into believing my source was outdted? And btw, even if it had been a 40 year old source, physics behind t/s specs do not change, not even over decades. Now, Is a source from 1999 just way too outdated to question the mighty knowledge of ibanender?
So, you are saying an 8 will have the same low end as a comparable larger sub? //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif Look, the difference in Fs may be small, but there is a difference. THAT IS THE ONLY POINT IVE BEEN TRYING TO MAKE FOR 8 PGES NOW. Get it? You can come t me with its a small difference, that the difference is due to suspension (avoid sag) and all that other crap, but it still doesnt change the fact that (much more often than not) Fs goes down and cone size goes up.

I never said subs in the same line have the same 'everything' besides the cone. You assume too much.

"Maybe your knowledgable source should go build an SPL vehicle and tell me the Fs of the sub determines the F3."

Are you incapable of following simple logic? Getting real tired of repeating myself, and asking you to re-read my words and my soirces words, just because you are either incapable of following them, or refuse to in some attempt to skew the conversation in a direction you want to head. Where did I, or MY SOURCE, say that "Fs of the sub determines the F3". I didn't, my source didn't, quit making up BS. My source (and I) have said The F3 is affected by the Fs of the sub, not that its determined by it. Big difference in those two statements. So I ask again, are you hving a hard time following wht I, and my source, are saying? Or, are you intentionlly trying to misrepresent our words here? Either way, get your story straight.

"Besides, F3 changes based on the environment too, gonna argue that next?"

Uh yes, then I'll rgue that the sky is not blue, but in fact green! Your powers of deduction are amazing, really. When have I ever said anything remotely like F3 is not affected by the environment? I never said anything even remotely like that. Really, if your arguements are simply gonna boil down to trying to get me to say incorrect stuff, then WTF are you trying to do here exactly?

You say my arguement keeps changing, yet you are the one constantly trying to change my arguement. What Ive been saying hasn't changed since .... uh.... page 3? But every other reply from you tries to change MY words. Things like above. And then you turn around and accuse me of switching stories constantly. I see right through your lame attempts to get me to say something wrong, to paint myself into some corner. So really, just stop trying, its only making you look like a troll.

Also, in your latest post you forgot your usual implication that Im saying 8's can never have good low end output. Or, did that concept (that that's not my point nor did I ever say it was) finally sink in, and you are just wanting to move the arguement on to something else?

And you have not shown ANY line of subs with the same Fs from 8 to 15 (or whatever sizes). What you HAVE shown is a line (the RE) that have a very similar Fs. But we hve addressed that point already, haven't we? Maybe you think if you keep bringing it up I'll lose my mind, forget that 2hz IS a difference, and agree with you? Or, are you just wanting to see me type out "its a small difference, but it IS a difference" once again?

You are describing greater SPL, not response. Yes, more cone area is more likely to be louder as it displaces more air. However, the amount of air displacement is not a direct relation to how well it can reproduce a given frequency.

Now YOU are trying to confuse freq response and SPL, not him.
Its not a direct relation to how "well" it can reproduce frequency? depends on what you mean by "well". If you simply mean hit the frequency, sure no big deal, hell a tweeter can play bass if its not required to do so too loudly. But, as Im sure your super smart brain already knows but just wants to be difficult about, the lower the frequency, the more air that must be displaced in order to reproduce that note at a given volume. In other words, the lower the note, the more air that must be displaced to reproduce it at a certain loudness.

So Im sure you'll come back with "well" means something else, or maybe twist mine or T3mpest words into something else entirely, but that doesn't really matter. What really matter is, how much air can be displaced certainly affects frequency response versus output, as the frequency lowers.

 

[CBFryman2 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif The Fs discussion is going in 'round and 'round in circles.//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

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

 

[helotaxi 5,000+ posts]

Few other things...

Anechoic F3 has no real bearing on actual in car response. A sealed box can pretty well play flat well into the infrabass region regardless of the sub in it thanks to cabin gain.

There are also several subs (very popular ones on this forum at that) that have F3s in the neighborhood of 80hz in a Chebysev or Butterworth ported alignment. The Fs of said subs are in the low 20's, but without the right Qts, the Fs has no bearing on the F3, which has no bearing on incar response. Anyone with real experience in car audio will know that a sealed box with an anechoic F3 of 60Hz will play lower than you can hear. Whether or not the sub really rattles your guts at that freq is going to depend on how much air the subs are moving. It's going to take about 4 8s to move as much air as a single 12 and play as loud.

The whole stereotype of bigger subs playing lower is based entirely on volume at low frequency not flat frequency response at low frequencies. Bigger drivers are louder. Not just at low freqs but across the entire range that they play. Because of that simple fact it would logically mean that they are louder at low freqs, too.

Fs is dependant on two things: Vas and Mms. It is inversely proportional to the two. An increase in one without a proportional reduction in the other will lower the Fs. Since an increase in cone diameter will result in an an exponential increase in Mms. Duh. Increase Mms without stiffening the suspension comensurately and you get a lower Fs. Stiffening the suspenion and/or increasing the Mms will also lower the efficiency of the driver.

I can think of a couple of series of drivers that have the same motors and generally same suspensions throughout the model line. In every case the larger driver has a lower Fs (and also needs a MUCH bigger box). In every case, that higher Fs did not keep the smaller driver from playing well into into inaudibility on the low end. It just didn't play as loud as it bigger brothers.

Basically , you're both right. The larger drivers have a lowr Fs and Fs isn't the end all be all of determining low freq response. That's the long and the short of the whole thing.

 

[audioholic 5,000+ posts]

Thankyou helotaxi (again //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif), very well laid out response.

 

[Pl8er 5,000+ posts]

*blink* When I left for Erie Pa this was on page 2 ROFL...its going to take me an hour to read through what everyone wrote

 

[ibanender 10+ year member]

Infrabass is 20Hz and down. And that RE 8 isnt pushing 130+ at 25Hz.

Really? You were in my car?

I said it played 25 hz fine, I didn't say it was as loud as 32 hz. When you are tuned at 32 hz, SPL is obviously going to be lower 7 hz below tuning. If you've owned an RE8 you'd know that if you go too far with it, it wont live to tell about it. I'm still rockin that sub in a 4th order so its obviously not damaged by playing 25 hz in that box.

 

[ibanender 10+ year member]

Oh, so you are acknowledging finally that my source is not 40 years old, as you tried to state before? And why did you do that? Were you "preaching about something you do not understand"? *gasp* Or, were you intentionally trying to deceive readers into believing my source was outdted? And btw, even if it had been a 40 year old source, physics behind t/s specs do not change, not even over decades. Now, Is a source from 1999 just way too outdated to question the mighty knowledge of ibanender?
So, you are saying an 8 will have the same low end as a comparable larger sub? //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif Look, the difference in Fs may be small, but there is a difference. THAT IS THE ONLY POINT IVE BEEN TRYING TO MAKE FOR 8 PGES NOW. Get it? You can come t me with its a small difference, that the difference is due to suspension (avoid sag) and all that other crap, but it still doesnt change the fact that (much more often than not) Fs goes down and cone size goes up.

I never said subs in the same line have the same 'everything' besides the cone. You assume too much.

"Maybe your knowledgable source should go build an SPL vehicle and tell me the Fs of the sub determines the F3."

Are you incapable of following simple logic? Getting real tired of repeating myself, and asking you to re-read my words and my soirces words, just because you are either incapable of following them, or refuse to in some attempt to skew the conversation in a direction you want to head. Where did I, or MY SOURCE, say that "Fs of the sub determines the F3". I didn't, my source didn't, quit making up BS. My source (and I) have said The F3 is affected by the Fs of the sub, not that its determined by it. Big difference in those two statements. So I ask again, are you hving a hard time following wht I, and my source, are saying? Or, are you intentionlly trying to misrepresent our words here? Either way, get your story straight.

"Besides, F3 changes based on the environment too, gonna argue that next?"

Uh yes, then I'll rgue that the sky is not blue, but in fact green! Your powers of deduction are amazing, really. When have I ever said anything remotely like F3 is not affected by the environment? I never said anything even remotely like that. Really, if your arguements are simply gonna boil down to trying to get me to say incorrect stuff, then WTF are you trying to do here exactly?

You say my arguement keeps changing, yet you are the one constantly trying to change my arguement. What Ive been saying hasn't changed since .... uh.... page 3? But every other reply from you tries to change MY words. Things like above. And then you turn around and accuse me of switching stories constantly. I see right through your lame attempts to get me to say something wrong, to paint myself into some corner. So really, just stop trying, its only making you look like a troll.

Also, in your latest post you forgot your usual implication that Im saying 8's can never have good low end output. Or, did that concept (that that's not my point nor did I ever say it was) finally sink in, and you are just wanting to move the arguement on to something else?

And you have not shown ANY line of subs with the same Fs from 8 to 15 (or whatever sizes). What you HAVE shown is a line (the RE) that have a very similar Fs. But we hve addressed that point already, haven't we? Maybe you think if you keep bringing it up I'll lose my mind, forget that 2hz IS a difference, and agree with you? Or, are you just wanting to see me type out "its a small difference, but it IS a difference" once again?

Now YOU are trying to confuse freq response and SPL, not him.

Its not a direct relation to how "well" it can reproduce frequency? depends on what you mean by "well". If you simply mean hit the frequency, sure no big deal, hell a tweeter can play bass if its not required to do so too loudly. But, as Im sure your super smart brain already knows but just wants to be difficult about, the lower the frequency, the more air that must be displaced in order to reproduce that note at a given volume. In other words, the lower the note, the more air that must be displaced to reproduce it at a certain loudness.

So Im sure you'll come back with "well" means something else, or maybe twist mine or T3mpest words into something else entirely, but that doesn't really matter. What really matter is, how much air can be displaced certainly affects frequency response versus output, as the frequency lowers.

I've seen plenty of sources written in the 60's refering to what it would take to achieve a goal, which are outdated based on current technology. I have a book somewhere that says to achieve a flat response from low bass on up it requires a huge box like 10 or 12 cu. ft. for a 15. Your reference may hold true if you are using a 0.707 alignment or even trying for a flat response curve, but what was said is clearly not correct if you are using an enclosure designed for a high peak in a range well above the Fs.

Same shit different smell here again. You keep saying that as a result of the cone size going up the Fs goes down, and that is not the case, even with your precious t/s params. Your t/s params will tell you that the Fs goes down as a result of mass, not diameter of the cone. You said subs in the same line, the larger cone will have a lower Fs because the cone is bigger. Now you say you never said they had the same parts in those cases. If they didnt have the same parts, that makes them different subs, but your ride my *** when I compare 2 different subs. That is exactly what you are doing if the parts aren't the same. Way to go hypocrite!

I brought up the environment changing the F3 point because you talk about it like you will die if your F3 point isn't where you want it because the Fs is too high. Basically, your entire argument, is flawed by the fact that the environment itself changes everything. It doesn't matter what this, that, or the other number is because the environment changes that.

When are you gonna build something and test it so you can see how things really work? When are you gonna order those subs like I told ya to so you can see how sub design works? I thought you were done in this thread, yet you keep yammering about how big cones make low bass.

 

[ibanender 10+ year member]

Few other things...
Anechoic F3 has no real bearing on actual in car response. A sealed box can pretty well play flat well into the infrabass region regardless of the sub in it thanks to cabin gain.

There are also several subs (very popular ones on this forum at that) that have F3s in the neighborhood of 80hz in a Chebysev or Butterworth ported alignment. The Fs of said subs are in the low 20's, but without the right Qts, the Fs has no bearing on the F3, which has no bearing on incar response. Anyone with real experience in car audio will know that a sealed box with an anechoic F3 of 60Hz will play lower than you can hear. Whether or not the sub really rattles your guts at that freq is going to depend on how much air the subs are moving. It's going to take about 4 8s to move as much air as a single 12 and play as loud.

The whole stereotype of bigger subs playing lower is based entirely on volume at low frequency not flat frequency response at low frequencies. Bigger drivers are louder. Not just at low freqs but across the entire range that they play. Because of that simple fact it would logically mean that they are louder at low freqs, too.

Fs is dependant on two things: Vas and Mms. It is inversely proportional to the two. An increase in one without a proportional reduction in the other will lower the Fs. Since an increase in cone diameter will result in an an exponential increase in Mms. Duh. Increase Mms without stiffening the suspension comensurately and you get a lower Fs. Stiffening the suspenion and/or increasing the Mms will also lower the efficiency of the driver.

I can think of a couple of series of drivers that have the same motors and generally same suspensions throughout the model line. In every case the larger driver has a lower Fs (and also needs a MUCH bigger box). In every case, that higher Fs did not keep the smaller driver from playing well into into inaudibility on the low end. It just didn't play as loud as it bigger brothers.

Basically , you're both right. The larger drivers have a lowr Fs and Fs isn't the end all be all of determining low freq response. That's the long and the short of the whole thing.

I should just let you say it, less typing for me! Good post.

 

[audioholic 5,000+ posts]

I've seen plenty of sources written in the 60's refering to what it would take to achieve a goal, which are outdated based on current technology. I have a book somewhere that says to achieve a flat response from low bass on up it requires a huge box like 10 or 12 cu. ft. for a 15. Your reference may hold true if you are using a 0.707 alignment or even trying for a flat response curve, but what was said is clearly not correct if you are using an enclosure designed for a high peak in a range well above the Fs.

But, we aren't talking about 'goals' here, we are tlaking about Fs as it relates to LFE. That will not change, from the 60's, the 40's or 12 B.C. And unfortunately for that entire theory of yours, as I pointed out earlier, the reference is dated 1999, not the 1960's.

Same shit different smell here again. You keep saying that as a result of the cone size going up the Fs goes down, and that is not the case, even with your precious t/s params. Your t/s params will tell you that the Fs goes down as a result of mass, not diameter of the cone. You said subs in the same line, the larger cone will have a lower Fs because the cone is bigger. Now you say you never said they had the same parts in those cases. If they didnt have the same parts, that makes them different subs, but your ride my *** when I compare 2 different subs. That is exactly what you are doing if the parts aren't the same. Way to go hypocrite!

First, quote me saying in this thread, or absolutely anywhere, that subs in the same line have exactly the same parts. I never did, its impossible, you are a broken record.
Second, Im not saying 'as a result of' the cone size going up, Fs goes down. Im saying that it does. Ive said numerous times now that I didn't fully comprehend why. Yet here you are, acting as if Im pretending to be some expert on the subject, and berating me for it. Again, broken record buddy, and not even accurate.

I brought up the environment changing the F3 point because you talk about it like you will die if your F3 point isn't where you want it because the Fs is too high. Basically, your entire argument, is flawed by the fact that the environment itself changes everything. It doesn't matter what this, that, or the other number is because the environment changes that.

Yes, nice reasoning. The environment changes it, so why even talk about it. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif If we used that logic, we would never discuss any raw driver data, or enclosure perameter for that matter. We'd just say what the hell, the environment is gonna change it anyway, who cares. Yes, very well planned out logic there.

When are you gonna build something and test it so you can see how things really work? When are you gonna order those subs like I told ya to so you can see how sub design works? I thought you were done in this thread, yet you keep yammering about how big cones make low bass.

Again making assumptions about my background. You've already proven you are a miserable failure at it, why do you keep attempting it so?
I thought I was done with this thread too. But I have to admit, its entertaining. Hell, I already admitted I dont fully understand the subject here, and am learning... what do I have to lose? Im just having fun watching you continue to rant on and on about bullshit. Its a nice feeling walking away from a thread being the one who admitted he didnt know and needs/wants to learn, and still not feel like Im the one being the thread's retard. Thankyou for that.

 

[CBFryman2 5,000+ posts]

Really? You were in my car?
I said it played 25 hz fine, I didn't say it was as loud as 32 hz. When you are tuned at 32 hz, SPL is obviously going to be lower 7 hz below tuning. If you've owned an RE8 you'd know that if you go too far with it, it wont live to tell about it. I'm still rockin that sub in a 4th order so its obviously not damaged by playing 25 hz in that box.

No, but I know the RE 8 doesnt have the displacement to have good output at 25Hz wiht out the aid of a ported enclosure near tuning.

As far as yours go It is more of displacement limiting issue than a tunning issue. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I have owned 4 RE 8's, and yes I know that you put too much power to them the coil meets the back plate. Hard. The end of one of the 4 was the coil braking apart from the cone. Some superglue and epoxy and it worked agian...some kid bought it for $40 locally and never came back and said it broke so it's all good I geuss. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[GeeTEye 10+ year member]

To each their own. I didn't want to have to explaine or appologize to anyone who is listening to my system that "those are only 8's" . Its not like their is a huge difference in cost anyway. I had the money and a 10" of the same brand will dropped just as low but had more output, why not? I'd be lying if I said I'd never heard 8's rock but I've heard the 10's and 12's and no explaining or "take into consideration these are only....." was needed. The system spoke for itself. You build a system to the way you want it or need it. For me 2 12's would never be needed for my tastes. If I had 8's on the other hand I'd be wondering "hmmm what if these where 10's or at least 1 10"? I did alot of searching on this board before I bought the 10" and it seemed like all the guys with 8's always preped you that they were running 8's. Maybe it was my misinterpretation.

 

[audioholic 5,000+ posts]

To each their own. I didn't want to have to explaine or appologize to anyone who is listening to my system that "those are only 8's" . Its not like their is a huge difference in cost anyway. I had the money and a 10" of the same brand will dropped just as low but had more output, why not? I'd be lying if I said I'd never heard 8's rock but I've heard the 10's and 12's and no explaining or "take into consideration these are only....." was needed. The system spoke for itself. You build a system to the way you want it or need it. For me 2 12's would never be needed for my tastes. If I had 8's on the other hand I'd be wondering "hmmm what if these where 10's or at least 1 10"? I did alot of searching on this board before I bought the 10" and it seemed like all the guys with 8's always preped you that they were running 8's. Maybe it was my misinterpretation.

I think that mainly comes from an over all lack of cone area (for the system, not individual subs). If someone is running a pair of RE8's in a sealed box, well yeah, dont expect tons of output. I doubt someone with a wall of 8's would give you that line though. Nor someone with a setup like Louisiana CRX's four 8's.

 

[newusername 10+ year member]

Dance, Dance...

We're falling apart to half-time.

Whoops, wrong thread!

 

[kuijo 10+ year member]

Dance, Dance...
We're falling apart to half-time.

Whoops, wrong thread!

//content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif i smell emo.

 

[Flipx99 5,000+ posts]

I don't have the technical skill to fully contribute but from my understanding of the thread, but it seems to me that ibanender is basing his argument off of his experience, whereas audioholic is basing his off literature. Not to say that anything is wrong with either one...It is a waste of space and anger.

I see the same thing on the seeking alpha and other such forums where stock makret junkies debate, argue, etc. about different investing methodologies. Some base their arguments off the calculus while others base thiers off experience. Atleast in car audio, you can repeat tests. In stocks, by simply testing, you affect the test.