#1
What are these terms in reference to making guitar cabs? how do you measure them?

Also, I need suggestion for a lightweight 12in neo speaker and 2 6in neo PA speakers all within 3db efficiency of each other that will tonally complement each other.
- Cody


Quote by Ninja Vampirate
What a faggot, do a few lines of cocaine and have a shot of whiskey or 5 if you want to study right
#2
When i get some spare cash to throw around, i was looking at getting some eminence neo speakers... i believe they were called 'tonkerlite's... Apparently they're pretty close sounding to a V30 (but a bit darker i think).

But sadly i have no idea what those first terms mean. QTA is a really dodgey computer company and F3 is our freeway here in Aus
- Ibanez S470 (2004)
- late 70's vintage Fender Stratocaster (USA)
- VOX VT100 Amp
- Digitech Whammy Pedal
- Weeping Demon Wah Pedal
- Visual Sound Volume Pedal
- MXR Micro Amp
#3
Well, i know Qta is the ability to recover from resonance in a cab, but i dont know what that means practically, nor do i know how to measure it. and i have absolutely no idea what F3 is, but i heard it is important in a designing a cab.
- Cody


Quote by Ninja Vampirate
What a faggot, do a few lines of cocaine and have a shot of whiskey or 5 if you want to study right
#4
I think you mean Qts which is the so called Damping factor or quality factor and one of the Thiele Small parameters you need to calculate cabinet sizes. It is a combination of the mechanical damping Qms and the damping of the coil by the magnet Qes.

Fs is the resonant frequency of the speaker.

Although it is a crude approximation you could think of the cab acting like the suspension of a car acting as both suspension and as dampers (shock absorbers in the UK) Get it right and the car follows the bumps in the road, get it wrong and the car (speaker cone)will bounce around like mad or fail to respond to undulations. You need to know Qts and Vas to calculate the exact size of the cab and match it to the performance you want.

I've a UG article on this if you want http://www.ultimate-guitar.com/columns/gear_maintenance/choosing_speakers_to_drive_your_cabs.html There's also loads of good stuff on the Eminence website.

Cheers
#5
thanks so much phil! that loks like exactly, what i want, but is there a way to measure it, like a tool? and is there a standard unit?
- Cody


Quote by Ninja Vampirate
What a faggot, do a few lines of cocaine and have a shot of whiskey or 5 if you want to study right
#6
You can measure Qts from an impedance plot and Vas by remeasuring with the speaker in a standard box. Its a moderately complex procedure and you'll need decent meters and a signal generator (though these are available as software using your computers souncard) You'll have to build your own test box for Vas which is notoriosly difficult to measre as it is temp and pressure sensitive. Almost all manufacturers provide these figures though, I've never needed to measure them myself though some say that manufacturers figures are not always accurate.

I reckon you should be able to find this somewhere on the internet but if you can get a copy of the loudspeaker design cookbook by Vance Dickason that's a good start.