posted
With a single woofer, the impedance is straight forward. There are 2 ways to wire a pair of woofers: parallel and series. Series wiring connects the positive of one woofer to the negative of the other. The remaining positive and negative terminals, one on each woofer, are then connected to the amplifier. With series wiring the impedances of the 2 woofers are added : two 4 ohm woofs is 4+4=8; a 4 and 8 ohm in series is 4+8=12; etc. Parallel wiring connects the positive of each woofer together and then to the amp, and all the negatives all together and to the amp. Parallel wiring decreases overall impedance. To find the value, multiply the two impedances together and then divide it by the sum of the two: two 4 ohm woofers is (4x4)/(4+4) = 16/8=2 ohms; and a 4 and an 8 ohm together would be (8x4)/(8+4) = 32/12=2.666 ohms. When dealing with a pair of woofers of the same impedance you will notice that a parallel pair presents half the impedance of a single woof: two 4 ohm parallel is 2 ohms, two 8 ohm in parallel is 4 ohms, etc. A bridged amplifier 'sees' half od the impedance presented to it: ie. a 4 ohm mono load is the same amount of work to the amp as a 2 ohm stereo load.
If all this is WAY confusing, check out www.jlaudio.com and go to the tutorials - they have illustrations to help!
------------------
Lord Dukk The Big Show The Dukk says: Know your bass: PORT your damn box!! Have HoleSaw, Will Travel!
posted
Yes if you run that amp in stereo and the subs are single voice coil. You can run them parallel to each channel of the amp and that will be a stereo 2 ohm load...
------------------ _____________________ 1999 USAC Finals Qualifier Usac Sactioned Judge -----Judged----- 1999 Spring Break Nationals 1999 Midwest Regional 1983 Camaro-152dB old system..new system on the way. -Irc Chat Room- chat.talkcity.com ports 6667,6668,6669,7000 Room Name #auto-audio I am the room coordinator for this room. Stop by sometime and say hi...We are busy after 9:00cdt usually.
Posts: 8036 | From: Huron,Oh | Registered: May 1999
|
posted
Ok what if u have 4 dual coil 6ohm that breaks down to a 2.4ohm load right? So can an amp that is 2ohm stable handle that or do u need another amp?
------------------
Posts: 45 | From: Omaha,Nebraska | Registered: Jun 1999
|
posted
That kinda depends on the AMP. For most amps you can run the load really low for a short period of time "ie. during a competition" but running amps lower than their recommended load makes them get hella hot. If you get 2 fans and do a push/pull configuration on that amp you could run the omhs down some but your just asking for trouble. Like I said at the beginning it depends on the amp, a RF amp would be fine in most cases but something from radio shack would fry
posted
4 dual 6 ohm subs gives you 1.5 or 6 ohms stereo or 3 or .75 ohms mono. Most amps can do this since you won't be playing it at full power for long periods of time.
Printer-friendly view of this topic