I recently purchased a JL Audio Stealth box that came with a 10w3 v2 6 Ohms

Due to the fact that my amp (Alpine MRV T420) can only handle 4 ohms bridged. I even traded to the store my 10w3 v2 6ohms for a 10w3 (not a v2) 2ohms. Now I am wondering if I made a mistake? Can someone elite me. Thanks.

Neil

 

The 10w3v2 looks like a slightly better woofer, and according to JL's website is available in a dual 2-ohm configuration, which will give you the 4-ohm load your amp needs. http://www.jlaudio.com/subwoofers/10w3v2.html

That said, your amp is rated at 240watts @ 4-ohms bridged, so the 10w3 (no v2) should be able to handle it (rated @ 250 watts). I think I would see if the shop can get a dual 2-ohm 10w3v2, but if you've already got it hook it up and see how it sounds!

 

It's already installed. I don't know if they would make another trade.

Neil

 

first question...

Is it 6ohm, 6ohm per voice coil or is it 3ohm per voice coil?

The first and the last, you're basically screwed. 4ohm amp running a 6ohm load would result in a lot less power from the amp (~1/2 power). with 6ohm per coil, you could make it a 3ohm load which would probably work well, BUT if you blow your amp, you've screwed your warranty PLUS your amp will run hotter trying to push 3ohm, so keep the gain down a bit.

 

If you're happy with the sound, then that's all that matters. The shop should have traded a v2 for a v2 (IMHO), but maybe their stock played a part in the deal. The v2 would have a little more power handling if you ever decided to get a more powerful amp. The v2's are about $20 more expensive than the w3's, so if the convenience factor of swapping locally is factored in, I'd say it's a reasonable trade. Like I said, if it sound good then crank it up and enjoy!

 

With a 6 ohm load he should get roughly 67% of the rated power, not 50%. I would suggest against making it a 3 ohm load if the amp isn't stable down to 2 ohms since you will start to have stability/oscillation issues.

 

Thanks

 

[QUOTE]Originally posted by MacGyver
[B]With a 6 ohm load he should get roughly 67% of the rated power, not 50%.

 

Yes....and no. They're roughly 3.3 ohms DC (what you can measure with a volt-ohm meter), but they present a 4 ohm load to AC signals, in particular, those around 1 kHz. The load is correctly termed impedance (as opposed to simply resistance) since there is an inductance and capacitance factor to take into account.

The issue with running a lower than rated impedance is not simply a factor of increased heat, although it is certainly something to be considered. The main issue is with amplifier stability. By stability, I am referring to the possibility of the amplifier oscillating uncontrollably when improperly loaded. This is a decidedly bad thing and can burn an amp out in short order if allowed to continue unimpeded (no pun intended).

Alpine amps are very nice, and running it at 3 ohms will probably not be much of an issue, especially if the gain is low, but it is definitely something one needs to consider when attempting to do this.