# Speaker wiring; calculating total watts not ohms

Discussion in 'Amps and Cabs [BG]' started by LeftyLB70P, Apr 27, 2009.

1. ### LeftyLB70P

May 4, 2005
Athens, Ga.
Ok, I need some help because I am baffled on this. I understand the rules in calculating ohms when wiring speakers in cabinets but I just stumbled on something that has me confused.

I have 2 cabinets that are loaded with the same speakers, 1 is a 4x10 and the other is a 2x10. Both contain speakers that are rated at 200watts & 8ohms. The 2x10 is wired parallel and has a 4ohm load and the 4x10 is wired parallel/series and has an 8ohm load. However (THIS IS THE PART THAT STUMPS ME) the 4x10 is rated as a 600 watt cabinet and the 2x10 as a 400 watt cabinet. So does the wiring scheme change the total wattage and what is the math (if 2 200 watt speakers in parallel = 400 watts then why do 2 'sets' of those in parallel not equal 800 watts -- you see my confusion)?

Thanks to anyone who can explain this to me.

2. ### Bassgrinder77Banned

Jan 23, 2009
No. Each speaker in the cabs you described takes equal power (watts) within it's cab.
According to their cab power ratings, your 2x10 has heavier duty drivers (200W each) than your 4x10 (150W each).

3. ### JustDavid

Oct 21, 2008
Your theory & math are fine. Something else is off.

With the numbers above, either the 4x10's max power is 800 Watts or it's drivers are 150 Watts each.

Might be something off the beaten track giving the 200 Watt derating in the 4x10. Best I could guess on that would be 1/4" jack's current rating. Anyone?

4. ### David Jayne

Jan 16, 2006
Brookfield, CT
5. ### Wes Whitmore

Mar 10, 2003
Columbus, OH
Maybe the crossover is the weak point here. Not many over 600 watt passive crossovers exist...and if they do, they are super expensive.

6. ### billfitzmauriceCommercial User

Sep 15, 2004
New Hampshire
Owner, Bill Fitzmaurice Loudspeaker Design
Either the drivers are not identical or someone flunked Second Grade math.

7. ### experimental bassist

Mar 15, 2009
+1

Max wattage of a cab should take into account every electrical component in the system and be calculated based on, yes, the "weakest point" whatever that may happen to be. In this case, probably the crossover.

8. ### bassmentguy

May 15, 2005
Some companies will actually underrate their cabs to keep their more adventurous customers from ruining a good product. It's good for a reputation if a product has never been known to fail.

9. ### IvanMikePlayer Characters fear me...Supporting Member

Nov 10, 2002
Middletown CT, USA
That has to be the quote of the year!