Fordmods Logo

Wattage and Ohm question 

 

Page 1 of 1 [ 2 posts ] 

 
 Post subject: Wattage and Ohm question
Posted: Wed Jan 20, 2016 11:47 pm 
Fordmods Newbie
Offline

Age: 30

Posts: 9

Joined: 15th Nov 2010

Ride: 4.1 EFI XF Falcon S

Location: Swan Hill
VIC, Australia

Stupid question but I can't work out how to determine the total amount of ohms in a sub and amp system.

An amp wired at 2ohm to a dvc 4 ohm sub, so which value do I use? I understand 700w at 2ohm will be 350w at 4ohm and all the rest. But how much power from an amp delivering 700w at 2ohm will make it to a 4ohm dvc sub?

Thanks
Top
 Profile  
 
 
 Post subject: Re: Wattage and Ohm question
Posted: Thu Jan 21, 2016 12:03 am 
Technical Contributor
Offline
User avatar

Age: 34

Posts: 3714

Joined: 27th Sep 2006

Gallery: 20 images

Ride: ED Falcon

Power: 133 rwkw

Location: Leeton
NSW, Australia

Sound is an AC waveform... As such AC principals apply... The coil will have an inductance and a capacitance (stuff all capacitance)... Inductance and capacitance will add together to give reactance and it adds to the resistance to give a total impedance for the circuit (sounds hard but it's simple formulae to work out...)

You cannot just assume anything about the power level output... As even if you work out the speaker's impedance the output is not linear and you cannot apply a direct division scale to it... You'd have to contact the amplifier manufacturer and they should have test reports for each style they sell with ball park values...

Your sub as 2x 4ohm voice coils yeah? If you wire the coils in series... Ie in one, out of it into the other and then out of it to the amp you'll get 8ohms loading on the amp (4+4=8)...

If you wire the 4 ohm coils in parallel you'll get 2ohms loading on the amp (((4^-1)+(4^-1)) ^-1) which is you add the reciprocals of the impedances and then take the reciprocal of that...

So you can place 2ohms total loading on your amp... Amp's are designed to run a certain impedance for peak performance (not just peak power)... You'd do best to match that impedance...

Again to answer your question about that amp at 4ohms you'd need to contact the manufacturer for info...

Cheers,
Tim

 

_________________

93 Red ED 5spd Manual Build Thread

Performance: Complete AUII VCT Wiring & Power Train, Pacey Headers, 2.5" Exhaust, Exedy Clutch, DBA Rotors
Visuals: FG XR Wheel, XR Front, 17's, BA 5 Spd Shifter, BA Ghia Window Switches, NL Cluster
Tunes: 8" Pioneer Sub, JBL Speakers, Clarion Double DIN Headunit

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 2 posts ] 

Who is online

Users browsing this forum: Google Adsense [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Thu Apr 25, 2024 5:35 pm All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names