Looking at buying an amp that is rated at 200w rms @ 4ohm, or 350w rms @2ohm. Mono amp.

How do I achieve the 2ohm rating? Do they specifically make 2ohm subs? Or would I have to use a DVC 4ohm? (and exactly how would I go about that....?)

Thanks.
Dave

 

Although a few companies make 2 ohm woofers it is much easier to find a DVC 4 ohm speaker. When you wire a DVC 4 ohm in parrallel (positive to positive, negative to negative) you get a final load of 2 ohms.

Series Wiring is additive.

Parrallel wiring is like this [(R1)*(R2)]/[(R1)+(R2)] (R is the resistance of the coil)

 

if you want to run 2 subs, then get 2 single vioce coil 4 ohm speakers and wire them parallel to get a 2 ohm load as well.

 

You can also check out a dual voice-coil sub. Meaning one subwoofer, two seperate voice coils each rated at a 4OHM load, wire those in parallel and viola, 2OHM load with one speaker.

Keep in mind that by decreasing the ohm load two things will happen,
1) the amp will heat up more since it will be pushing more power out to the speaker
2) the sound will not be as 'tight' depending on what type of enclosure you use. From the amp side of things this canusually be seen by looking at THD % and comparing between the 2ohm and 4ohm output. 2ohm will typically be higher meaning there is more distortion at the lower load.

 

sorry, forgot to mention I will be running only 1 sub.

 

One 4 ohm DVC sub with a mono amp that is stable at 2 ohms is a match made in heaven.


Derf00,

That second statement is 100% false. The sub will not sound less tight or anything of that nature. THD % has basically no effect on subs. THD generally effects higher frequencies and therefore a class A/B amp is used to power full range speakers. Class D amps (typically used for subs) have significanly higher THD but are used for subs becuase you will not be able to hear a difference. That is of course you are comparing roughly equivalent amps. A mcintosh will most certainly be "cleaner" then a pyramid at the same power level regardless of load.