Skills. You need to come up with a model that takes into account both the mechanical movement and the thermal system involved. I haven't seen enough on thermal models and tests to say anyone is right (or close, especially at very high power levels).How do you predict the behavior of a subwoofer using TS parameters when dropping massive amount of power into it?
Yes, but unfortunately even posting what you wrote on some of the other more SPL-oriented forums still won't deter people from chosing one sub over another because of one or two simple parameters.Thiele/Small parameters are just as useful for SPL subs as they are for any other driver as they decribe certain physical characteristics of the driver. It is not enough information to describe the driver in full, but does allow us to identify drivers that might be more useful than others.
But you know why that is, right? It doesn't mean that Thiele/Small parameters are any less useful.We use a 42mm tall coil in the Monster where "linear" x-max by overhang is only 8.5mm but one of them got up to 154.9dB in my Jeep... it was "throwing" 30mm easily despite a low linear x-max.
Of course Thiele/Small parameters don't tell you frequency response vs amplitude. They're still very useful; as useful as they are for any application.So... basically... most T/S specs and even excursion specs don't mean a whole lot in raw SPL output.
OK. But what does any of this have to do with how relevant Thiele/Small parameters are for the application? Misuse of statistical data never invalidates the potential for use of said data.Yes, but unfortunately even posting what you wrote on some of the other more SPL-oriented forums still won't deter people from chosing one sub over another because of one or two simple parameters.
As Jake pointed out, he has seen through testing that Mms alone has an impact on the SPL ability of a subwoofer with everything else remaining constant, even though by common belief Mms doesn't matter. Unfortunately too many people still rely on Xmax and BL figures to determine what driver will produce the most SPL for their application. Vas and Mms are often overlooked, but like you and Jake said (and I agree) that looking at a few T/S parameters isn't the only thing to look at when determining whether or not a particular driver will produce the most SPL in your vehicle. Box size, actual power available, and a clearly defined goal (broad-band high SPL or "I don't care as long as it hits hard") are often overlooked.
I never said that the data was invalid. I said that people tend to look at the wrong one's (or just a few and not enough of the others) when analyzing drivers for their non-defined goals and/or applications.OK. But what does any of this have to do with how relevant Thiele/Small parameters are for the application? Misuse of statistical data never invalidates said data.
Great info! Now, how do you go about making an appropriate SPL/StreetBass enclosure for the Monster?I forgot to add one more... CMS - also useful to an extent in SPL.
Although, still doesn't tell you much without knowing CMS vs. excursion. I've tested equal at-rest CMS drivers and one is substantially louder than the other as one has a linear compliance and the other tightens up. Besides the suspension they were otherwise identical.
So you have to have a the same "type" of suspension to use CMS as a comparison figure.
The most compliant (softest) suspension that I can get away with without having the driver break apart is the loudest in all my testing -- I am not a fan of overly stiff suspensions.
I am going to further my testing into the mass correlation by building a driver with equal BL^2 / RE to the Monster but over 100 grams less moving mass in the coil.
Hey dude, I didn't take it as being rude. I actually found it pretty amusing. Now thinking about it Thiele_large is funny as hell too. Mr Thiele would love to know that we are having a discussion about his large parameter.Hey Porky,
Sorry for my '*******-ish' first reply to your post. I guess reading the question wrong + some of my own ignorance about what you were saying caused me to make a fool of myself.
I'll add some more to that ignorance here --> If there are "small" signal parameters and "large" signal parameters, is it possible to measure said subwoofer under "large" signal parameter conditions to get a better idea of the performance of the sub at that level?? Like instead of Thiele-Small you get Thiele-Large? :laugh::laugh: I mean, there has to be a more scientific way to go about it that just building 50 different boxes or trying 50 different subs in a box you've built... right?