WinSD and Transfer function magnitude?

[Salami]

What the heck is it?

This is from the WinSD help page: "This graph shows gain in dB related to driver's limit efficiency n0. Which it theoretically reaches at infinite frequency. This is the basic graph, which is needed most."

What the hell does that mean?



Which graph/s should I be looking at when modeling speakers to get an idea on what the frequency response will be of an enclosure?

[BigAl205]

Link?

[Salami]

I can't, it is part of the help file of WinSD.


It literally says only what I quoted. How the hell is it most needed if I don't know what exactly it is telling me?

[claydo]

Lol.....sorry, can't help ya....reads like insurance contract fine print. Maybe someone with more win SD experience will come through here....

[BigAl205]

http://forums.audioholics.com/forums...-function.html

I will give you a basic look on the most important ones.

1. Transfer Function Magnitude: This is the anechoic response curve of any given woofer within the enclosure design specified in the program. Room interaction will change this when the woofer is placed in a room with this enclosure.

2. Transfer Function Phase: This is the phase response of the woofer in the enclosure specified. It will show you how far out of phase the response of the woofer will go at a said frequency

3. Group Delay: This will show any major detractions in transient response. Typically used when doing ported/bandpass/passive radiator enclosures, it will show if the woofer is slower to respond in a specified enclosre at any given frequency range.

4 & 5. Max Power/SPL: This is to show how much power is required in a specified enclosure to reach a given output level in an anechoic environment.

6. Amp Apparent Load Power: This is either is how much power you have available, or like above shows how much power is being used at a certain frequency.

8. Impedance: This just shows the impedance of the woofer at a given frequency withing the specified enclosure.

9. Impedance Phase: This shows the phase angle of the impedance at a said frequency.

What you want to look for is the smoothest/flatest response curve from 20hz-80hz when set to Transfer Function Magnitude. You do not want any large bumps above or dips below the reference point (listed as 0db). This will be the most important thing to look at. You will also want to check out the excursion level in a specified enclosure with specified amplifier power. You do not want the woofer to be over exerting itself within the useable range. You will also want to check the vent mach to make sure that you should not have vent noise issues. Impedance you can look into for any significant dips, but most good amplifiers should have no problem with most woofers.

Hopefully this helps.

[Strakele]

To continue that, the way I model speakers against each other is to:

1. Input all their specs correctly
2. Model each in whatever size of enclosure they're suited for -OR- model them in whatever size of enclosure I have available to see which will work best
3. Look at transfer function magnitude tab - this gives the basic relative response curve
4/5. Add in whatever type/slope/frequency high pass filter I intend to use
4/5. Put in the power rating of the amplifier I intend to use
6. Look at the cone excursion tab - here you check whether or not your speaker will exceed xmax given the power and high pass you selected in 4/5. Use this to determine how much power a speaker can handle at a given HPF frequency or where you should set the HPF to handle a certain amount of power
7. Finally look at the SPL tab - this will show you which speaker you're modeling will be louder over what frequency range (or if you're only modeling 1 speaker, it'll show you how loud it'll get with your chosen power/HPF... in an anechoic chamber)