So I've heard the sub modeling can have huge variance from real world application. I'm NOT talking about in cabin acoustics here.
I've heard that one can model several subs in a box and the loudest one in the model might be the quietest one in actuality and visa versa. Also heard that along with output that a sub model can lie about group delay and box sizing and anything else I suppose.
Do these discrepancies exist and if so how could one go about identifying them in order to make box modeling a useful tool?
Unfortunately, sub modeling isn't always an ends to a means because many manufacturers lie about certain T/S parameters or publish specs from "perfect" production samples. The only subs that I measured close to spec with a Woofer Tester 3 were those from JL Audio. A certain other manufacturer is always lying about their FS, but I won't name them because I am nice.
2012 Subaru WRX - JL Audio C5-650s run active off a Lunar L450; Digital Designs 1508 powered by a Lunar L1500; Pioneer DEH-80PRS as the source unit.
Unfortunately, sub modeling isn't always an ends to a means because many manufacturers lie about certain T/S parameters or publish specs from "perfect" production samples. The only subs that I measured close to spec with a Woofer Tester 3 were those from JL Audio. A certain other manufacturer is always lying about their FS, but I won't name them because I am nice.
Is that why I always have to fudge the numbers to get WinISD pro to accept a new sub? Lol
So I've heard the sub modeling can have huge variance from real world application. I'm NOT talking about in cabin acoustics here.
I've heard that one can model several subs in a box and the loudest one in the model might be the quietest one in actuality and visa versa. Also heard that along with output that a sub model can lie about group delay and box sizing and anything else I suppose.
Do these discrepancies exist and if so how could one go about identifying them in order to make box modeling a useful tool?
Have you heard this, or have you actually experienced or proven it? I haven't yet modeled something that I couldn't prove in a real world environment. You can identify all of those discrepancies by getting the most information you possibly can when modeling your box. Its not an exact science by any means, and the simulations are just that; simulations, but they get us pretty close to what the final response will be.
The sub box models don't lie; they're either misinformed (inaccurate published T/S parameters), or certain elements are left out, such as a non-defeatable high pass filter, which will actually reduce the total group delay by as much as 20ms. Again, things WinISD may not necessarily model for you, or at least not easily. There are so many things that come into effect that its not even funny. For the record, I never liked WinISD Pro.
Quote:
Originally Posted by ChrisB
Unfortunately, sub modeling isn't always an ends to a means because many manufacturers lie about certain T/S parameters or publish specs from "perfect" production samples. The only subs that I measured close to spec with a Woofer Tester 3 were those from JL Audio. A certain other manufacturer is always lying about their FS, but I won't name them because I am nice.
You are 100% correct, it isn't a means to an end. Some manufacturers list their T/S specs before the subs are broken in. For sub box modeling I do for people in person, I break in the sub overnight playing a test tone at high excursion, let the voice coil cool, and measure the T/S parameters with my WT3 so I can model from there. It changes the results a bit, but often its not too significant. In fact, I just built a set of mini bookshelf speakers with a 3.5" driver, and the published Fs was 13hz off from the measured broken in Fs.
Quote:
Originally Posted by Fricasseekid
Is that why I always have to fudge the numbers to get WinISD pro to accept a new sub? Lol
There might be a lot of reasons. All I know, modeling is all we've got. You can either go by what the manufacturer recommends, or you can model it. Last time I checked what Alpine recommended for their new 8" sub, the vent velocity at max power was near 60m/s. That's absolutely insane. In cases like those, I'd rather model the box, and so far, people have come back either in my thread or through private messages telling me that the box sounded exactly what I modeled it to sound like and they absolutely love it. Not one person has come back yet saying they were unpleasantly surprised by the results.
Try mr kings papers on quarterwave modeling they are written around modeling and measuring and having acurate results to back up the model very closely
Every single 1508 I owned and my 1010. The last 1508 I measured had a Fs of 59.22 Hz and the 1010 that I gave to my sister measured at 39.03 Hz. According to DD, the 1508 has a Fs of 42.39 Hz and the 1010's is 27 Hz.
2012 Subaru WRX - JL Audio C5-650s run active off a Lunar L450; Digital Designs 1508 powered by a Lunar L1500; Pioneer DEH-80PRS as the source unit.
Is that why I always have to fudge the numbers to get WinISD pro to accept a new sub? Lol
For Pro, you need to enter things a certain way, in a certain order, for the program to accept them.
Conversely, you can model things quickly with only Fs, Qts, and Vas entered. The downside is lack of excursion info and the like. But that's the fast way to get a box size.
860MP | 5-channel Class D SQ amp | Enigma + Ebony + AE IB15 "Plan for the best, EQ for the rest" - Zaph
For Pro, you need to enter things a certain way, in a certain order, for the program to accept them.
Conversely, you can model things quickly with only Fs, Qts, and Vas entered. The downside is lack of excursion info and the like. But that's the fast way to get a box size.
Yeah it took me some time, but I finally figured out that it seems to have a sort of priority order. There is definitely a learning curve.
Yeah it took me some time, but I finally figured out that it seems to have a sort of priority order. There is definitely a learning curve.
Try the software I'm using by jbagby. Its a bit easier to understand, and everything is modeled on one screen, one page, and its easy to see the effects your changes have.
Try the software I'm using by jbagby. Its a bit easier to understand, and everything is modeled on one screen, one page, and its easy to see the effects your changes have.
Already did. The software wouldn't work on my computer for some reason. I haven't had time to try and reload it yet. Besides I got WinISD figured out now.
Already did. The software wouldn't work on my computer for some reason. I haven't had time to try and reload it yet. Besides I got WinISD figured out now.
Did you get the macros enabled and working? The spreadsheets are useless if the macros don't work.
I like WinISD, as said before, it is not the end-all be-all for making a system, but if you dont want to go the trial and error route on box biulding, it works pretty well. you may have to adjust port length a little to tune it just right, but for the most part, it is right on. I have made many boxes based on what it said and have always been happy with the results.
For day-to-day stuff, I still use LFDES.
The really detailed stuff, and on those occasions when the T/S parameters appear to be
provided by the marketing, rather than the engineering department, I use LEAP/LMS.
If you don't trust the numbers provided, LMS can measure them accurately.
LEAP can model things most of us don't even know exists!
Just remember GIGO................
For day-to-day stuff, I still use LFDES.
The really detailed stuff, and on those occasions when the T/S parameters appear to be
provided by the marketing, rather than the engineering department, I use LEAP/LMS.
If you don't trust the numbers provided, LMS can measure them accurately.
LEAP can model things most of us don't even know exists!
Just remember GIGO................
Here's something someone said in my thread regarding to a box I modeled for them a few weeks ago.
Quote:
Originally Posted by NucFusion
I can tell you that the modeled response he made for me based on a box I already had made is almost spot on from what I measured using test tones and a rat shack spl meter. I haven't built the sealed box yet to see if the modeled response would be correct or not. I'm going a bit of a different direction with my box placement, so not sure if I wil build it or not, just to see.
Yes, LEAP/LMS is expensive, but I do product development for some companies,
I'm in Hong Kong, which is next door to China's primary manufacturing centers,
so the expense is justified.
LEAP/LMS requires proprietary hardware, in addition to its software, so you've
unlikely to find any useful cracked versions. I've heard of a V4.51 crack, but have not
found it necessary.
I've had LFDES in my computers forever, and I don't know what's become of the
company that published it so long ago. Company's name was SpeakEasy, from Newton, MA.
I know it's a tease, but LFDES is really my go-to program. I especially like the
CURVE FIT function. Makes me lazy at times......................
I think the software is great for comparing subs. I modeled the Tempest X IB before installing it and I didn't know what to make of it. Then I did the same with my AE IB15s. Comparing both subs showed exactly what I heard. The Tempest X was a super bottom heavy sub with very little past 40hz and required over twice the power of the IB15. I really didn't know how it would sound based on just one subwoofer but with both graphed out after listening it all made sense. Now I always have the IB15 up when modeling other subs since I'm familiar with their sound.
'84 GN 10.60@ 127mph. Infinity 3.5 coaxials and a cheap Sony HU.
'06 TL. Front stage- Dynaudio 110, 430, 182.... 2x AE IB15.....2x JL HD600/4, Infinity Digital 300, PS8....SecondSkin....
i like Super slim subwoofer
1. slim----can save a lot space Size: 345X240X68mm,
2.cable controled--- convenient
3good sound quality
4. All aluminum metal housings --good for heat radiation
5. Wight: 6KG-- shockproof
6.Easy to install
Reference:12vcity.com
I think the software is great for comparing subs. I modeled the Tempest X IB before installing it and I didn't know what to make of it. Then I did the same with my AE IB15s. Comparing both subs showed exactly what I heard. The Tempest X was a super bottom heavy sub with very little past 40hz and required over twice the power of the IB15. I really didn't know how it would sound based on just one subwoofer but with both graphed out after listening it all made sense. Now I always have the IB15 up when modeling other subs since I'm familiar with their sound.
This is what I've been doing. My past sub set up had no bottom end and was very boomy due to peaks around 60 hertz. So I compare all my models to that model to get an idea of how it may sound. My next set up is 5 db louder at 60 and 11 db louder at 30 hz. and my last set up was exceeding xmax and my new set up stays under xmax. None if this includes cabin gain but I'd still conclude that the difference will be night and day in SPL and SQ. I hope I'm right. How realistic is that gonna be in a real world situation ?
This is what I've been doing. My past sub set up had no bottom end and was very boomy due to peaks around 60 hertz. So I compare all my models to that model to get an idea of how it may sound. My next set up is 5 db louder at 60 and 11 db louder at 30 hz. and my last set up was exceeding xmax and my new set up stays under xmax. None if this includes cabin gain but I'd still conclude that the difference will be night and day in SPL and SQ. I hope I'm right. How realistic is that gonna be in a real world situation ?
Understanding that the human ear perceives a 2x increase in volume every time output is increased by 10db, that's 2x louder at 30hz and 50% louder at 60hz. That's a HUGE difference. What was the Qtc on your old box?
Understanding that the human ear perceives a 2x increase in volume every time output is increased by 10db, that's 2x louder at 30hz and 50% louder at 60hz. That's a HUGE difference. What was the Qtc on your old box?
Ok, don't laugh at me. I've built boxes before but this is the first time I've actually learned what I'm doing....
My new box will be right around .801
And the old one was around 1.2, but the woofers are very high Q woofers.
I'm not sure exactly what that means aside from the shape of the response graph.
Is sub modeling really useful?
Linear Mode
