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Old 08-24-2006, 01:46 AM   #31
PuffDaddy_d

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Update: (8-24-06)

Since they appear to be quite popular these days, I have added the new line of TC Sounds drivers to the list for easy comparison.
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Old 09-04-2006, 12:03 AM   #32
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Quote:
Originally Posted by bassfreak
im not mad at him or anything. i just think its disimforming. for example. the mag in a direct dropin for the SX was 1db louder and this was a SQ install. the displacment jsut cannot speak the whole truth.
I'm not trying to start up another argument or anything, but for some reason, I just now noticed that you said this (yeah, I know im late ), and I wanted to point out that calculated linear displacement values for those two subs indicates exactly the same results that you witnessed.

The SX has 2.112L of LD (linear displacement) while the Mag has 2.304L of LD. The raw numbers indicate that the Mag should be louder. But, in order to notice a 3db increase in SPL, there needs to be about a 25% increase in LD from one sub to the next. The difference between these two subs is about 8.33%. This means that there should be a calculated difference in SPL of about 1db between these two subs when both are driven to xmax. This also happens to be the same SPL difference that you observed in your real world test.

So, it appears that displacement is speaking a good deal of "truth".

Last edited by PuffDaddy_d; 09-04-2006 at 12:07 AM.
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Old 09-04-2006, 03:50 PM   #33
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Well seeing as the mag does have more displacment there is no doubt it should be louder all other things being equal, which they aren't.
despite the fact that the Mag with the same power and same box not only getting lower but sounding better as well being 1DB louder may or may not be from efficienty, a more ideal appliaction or displacment. is not for me to say. to be honest i think that the mag does reach Xmax with a little less power, but reguarless it was louder and could be even louder when put in the exact same aligment(it did get louder lower) as the SX. to compare the Mag to the SX is not even right. i would really compare output to the older barahma and XXX woofers with way more powerhanling and on the mag 12 a much better suspension for SPL useage if needed.
another thing that some people want to to believe is that yo will hear a HUGE difference after xmax, when its pretty slight with many good curves. driven out of xmax takes a trained ear or soemone who is really listening for it. its noticable depending on the design and how much futher you go. what i am getting at is the XBL has a more linear curve over more throw but the B/L drops off FAST after Xmax while the mag still has plenty past 25mm.
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Old 09-05-2006, 01:09 AM   #34
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Quote:
Originally Posted by bassfreak
Well seeing as the mag does have more displacment there is no doubt it should be louder all other things being equal, which they aren't.
despite the fact that the Mag with the same power and same box not only getting lower but sounding better as well being 1DB louder may or may not be from efficienty, a more ideal appliaction or displacment. is not for me to say. to be honest i think that the mag does reach Xmax with a little less power, but reguarless it was louder and could be even louder when put in the exact same aligment(it did get louder lower) as the SX. to compare the Mag to the SX is not even right. i would really compare output to the older barahma and XXX woofers with way more powerhanling and on the mag 12 a much better suspension for SPL useage if needed.
another thing that some people want to to believe is that yo will hear a HUGE difference after xmax, when its pretty slight with many good curves. driven out of xmax takes a trained ear or soemone who is really listening for it. its noticable depending on the design and how much futher you go. what i am getting at is the XBL has a more linear curve over more throw but the B/L drops off FAST after Xmax while the mag still has plenty past 25mm.
Bingo!

A subs over-all performance can not be determined by a single factor alone. It requires some hands on testing to truly know how it performs (gotta put this statement in bold). But, we can use certain factors (like linear displacement) to help us weed out the subs we do not want to waste our time/money on testing.

If I was given a budget of $600 to purchase two subs in the list to see which would yeild in the most output in a sealed application, I can use the displacement figures to help me avoid picking the W6v2 as one of the two subs to test...as my money could be better spent elsewhere in order to acheive the desired results.

And yes, for many subs, there is still life after xmax. However, very few companies tell us how much life there is past xmax...so there's no way to make comparisons based on this. You are also right about how the loss in SQ past xmax isnt that huge either. Especially if one considers that generally, if a high xmax sub is being pushed past xmax, then the person is probably just trying to make the sub as loud as possible and could care less about it sounding amazing. You mentioned how the old XXX and brahma's B/L curve would have a steep drop off past xmax (which means a faster decrease in SQ), but you forgot to add that the old XXX had 32mm of one way excursion. Even if subs that still maintain a decent amount of B/L past xmax (like the Mag), the old XXX (and even the brahma) would still be within their linear range of output well past 24-25mm. Not to mention that all subs can only go so far past xmax before they reach their physical limits.

In an age where we may not be able to demo a subwoofer before we purchase it, it is nice to get at least an idea of how much output you can expect from it in a sealed application. I certainly would never spend more money trying to upgrade my subs if I wasn't sure that the new ones could get louder than the old ones.

Last edited by PuffDaddy_d; 09-06-2006 at 11:32 AM.
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Old 09-11-2006, 12:04 AM   #35
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Props

Puff, Bass, Geo, Thnking i just want to give you your props for knowing what you know and passing it on to people like me. ive learned alot in this thread, and im glad you guys kinda hash it out to make sure I have a chance to learn and hopefully someday be as knowledgeable as you.

on a side note i think that the AA Arsenal should be added to the original post as it ranks up there and is cheaper than most.
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Old 11-15-2006, 08:02 AM   #36
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Quote:
Originally Posted by chornet44
on a side note i think that the AA Arsenal should be added to the original post as it ranks up there and is cheaper than most.
Me too! Come on, let people see.
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Old 12-28-2006, 08:41 PM   #37
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would it be too much to post up the dd's?
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Old 12-28-2006, 09:18 PM   #38
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Quote:
Originally Posted by phelewski
would it be too much to post up the dd's?
Well, w/o going into too much detial, the DD subs are different. They dont advertise their xmax values for two reasons:

1) Their xmax ratings would appear to be very low compared to other drivers.

2) Their subs really are designed to be used in ported applications.

DD subs get so insanely loud because they have lots (and i mean LOTS) of motor force, but dont really have lots of linear throw. This makes them perfect for ported enclosures and poor for sealed. The extra motor force is exactly what is needed in ported applications in order to make the port displace as much air as possible. So, I dont have them on the list because they really aren't normally used or recommended for sealed applications.

This post explains is nicely:
http://www.caraudioforum.com/vbb3/sh...7&postcount=50
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Old 12-29-2006, 11:45 PM   #39
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ok thank you
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Old 02-11-2007, 01:26 PM   #40
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Sorry if this doesnt belong here...but would the ED 19Ov.2 be on that super sub list or no?
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Old 02-11-2007, 05:29 PM   #41
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Quote:
Originally Posted by madcabbie
Sorry if this doesnt belong here...but would the ED 19Ov.2 be on that super sub list or no?
well, considering that the 19Ov.2 is not a 12" woofer...I'd have to say no.

But even the 12" version of the O series doesn't have enough output to be placed in the super-sub category. Besides, where it is listed in the thread doesn't matter. The thread is just a quick reference for those who want to compare the linear displacement capability of some of the most talked about subs on this forum, and it also provides you with the ability to calculate the LD of any subwoofer (given sd and xmax).
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Old 02-18-2007, 02:44 AM   #42
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Quote:
Originally Posted by geolemon
Thread made into a sticky.

Bear in mind, PuffDaddy_d and I and several people in CAF chat have had long extended discussions about this thread - it can only be "so good" - no sense in arguing that it isn't perfect - everyone already knows that.

This thread is good as a general guideline for telling you the absolute maximum output you could drive any of these subs to, in a sealed box, in a comparative way to other subs, if you could drive them to full excursion - and that involves a lot of box and a lot of amp.

That's all. And this thread really isn't taking into account how suitable for "Sealed box use" any one of these subs is, compared to another. That's not the scope of this thread.
There's a lot of factors to consider, that those of us with experience know to seek out - and those of us without experience don't - and at least a thread like this can be a useful tool in comparison - "displacement per dollar" I think is a great concept, something to really make you think "What am I getting for my money, in terms of actual performance?"

We are going to talk later - probably in another thread - about what matters in a vented box - things get more complicated - excursion (cough - displacement ) matters, and also BL matters (cough - actual force - BL^2/Re ) - and in different proportions of importance to each other depending on if you are an "SPL guy", a "daily driver guy", or a "SQ guy".
It gets complicated, and we knew we couldn't tackle it here... so no complaining that we aren't.

We'll handle that in another thread, come to a general concensus - and then maybe we can make THIS thread even better.

I think a BL^2/Re list would be very insightful. Getting that number is tricky because many TSP's don't list the DRC or even BL at which the TSP's are measured. If you have software, sometimes you can back out that number if you know the mms, Qes and SPL at 1 watt.

You could take it one step further and do Sqrt(BL^2/Re) which gets rid of the exponential term making it linear with the BL, rather than quadratic which would be more appropriate to compare drivers by.

Just a thought...

Last edited by TCS; 02-18-2007 at 02:47 AM.
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Old 02-18-2007, 03:26 AM   #43
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Quote:
Originally Posted by Thnking
Bl^2/Re is still a force "factor", just as Bl is.

Actual generated motor force is B*l*I

B*L = T*m or N/A

B*L*I = newtons

(B*L)^2/R = (T*m)^2/R = (N/A)^2/R = (N^2*R)/(V^2) = N^2 * 1/W = newtons ^2/watt

Sqrt((B*L)^2/R) is newtons /watt^1/2

Last edited by TCS; 02-21-2007 at 05:57 AM.
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Old 02-18-2007, 12:46 PM   #44
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Edit** How did you go from (N/A)^2/R to (N^2*R)/(V^2)

The solution you're looking for is;

(N/A)/Re = (N/A)/Re = [N/(W/V)]/Re =

N/(W/W) = N/W

But; If you took the Sqrt of (N/W) we are left with N/(Sqrt W)
Just like if you take the Sqrt of [(B*l)/Re], we're not left with what you're looking for.

But regardless, we still come to the same conclusion that B*l/Re is a just "factor", like B*l is just a "factor". Really, though since an amplifier is a low impedance source, we would want to know how applied voltage is related to motor force. That's also how someone would model a loudspeaker.

Last edited by Thnking; 02-18-2007 at 01:08 PM.
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Old 02-21-2007, 06:01 AM   #45
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Did'nt put the 1/2 term on the W... typo, but yes, it is a factor/number but is important because it remains constant from driver to driver where the BL won't if the Re is changed.

I like looking at the squared version because it shows more linear relationship from loudspeaker to loudspeaker which is as I explained more appropriate. No biggie really.

Also, there is nothing wrong with my "solution" -Its a simple Ohms law substitution and some simplification.

Last edited by TCS; 02-21-2007 at 06:05 AM.
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