Ohm Question

[VicariousVIRUS]

Hey guys, I can't really find an awnser for this question.

I'm getting a Splawn 2x12 (Probably with Small blocks.)
But until then I've got to use my Oversized Slanted 4x12 Mesa cabinet,
With my newly accquired Splawn QuickRod.

So basically, there is two 1/4th inch out's on the back of the Quickrod. Obviously a 4/8/16 ohm selector.

My mesa cab, has an 8 ohm in, an out (to connect to another cabinet.) And two 4 ohm inputs. It says for Stereo or bi amping.

I'm running half power so obviously I should run into the 8 ohm slot? with 4 ohms on half power.

If I was running full power, could I go out of the splawn and into BOTH 4th ohm inputs on my mesa cabinet for Stereo?

Basically I'm just trying to find out my options.

Also if I were to make my mesa a detuned cabinet, by removing the bottom two speakers, what ohm should I run just two v30's on?

Thanks a lot in advance!!!!

[splawndude]

I'll take a stab at this but I'm not 100% either. You may need to send Josh at Splawn an email.

Part of this depends on how the Mesa is wired. I'm sure it is wired in Series-Parallel. That means you have 2 sets of speakers wired up in Series and then THOSE 2 pairs of speaker sets wired up in parallel. That is what allows the Stereo operation. Why you would want to run in stereo with only one amp head I'm not sure - unless you were running a wet/dry rig. Let me know. If you were running full power then you would just match up 1 for 1 to the cab (either 4 or 16).

Assuming the Vintage 30s are 16 ohms each and you only want to use two then I see a few choices. You can leave the cab alone and plug into one of the stereo jacks on cab (4 ohm I guess) and that will activate half of the 412 cab. Or you can possibly rewire two V30s in parallel for 8 ohm total.


anyone want to +1 / - 1 that?

[VicariousVIRUS]

Well basically I was trying to find the most efficient way to run this cab with the quickrod. I was really wondering why there are two Speaker outs on the QR.

I was only wanting to use 2x12's if I did the detuned cabinet method. Basically I'd pull the two bottom speakers, resulting in a open front baffle, with a closed back. This would allow more air, bass and treble to bleed through. It would make the cabinet sound less tight I'm sure though. But It's something everyone should experiment with. Most people that try this method say that the detuned cabinet sounds HUGE compared to a normal 4x12.

[splawndude]

^ so like a poor mans ported cab?

I 'think' that would lose all the benefits of the closed back for what you play. I honestly have never heard anyone doing that. Not saying it won't sound good. I believe the 2nd speaker out would be for a second cab in the event that the first cab had no 'daisy chain' capability. I believe most pairs of speaker outs on all amps are for parallel operation (FYI) so if you have 2 - 16 ohm cabs the resulting ohms that the amp would prefer is 8.

Now half power mode always screws me up. I know you halve the ohmage but if I have an 8 ohm cab does that mean I run the amp at 4?

I believe it was Scott or Josh that said 'yes' so that is what I do. I know the trannies can handle just about whatever.

[VicariousVIRUS]

Read up on detuned cabinets. You'd be suprised brother!

Yeah if your running at half power at 8 ohms, the amp should be on 4, and you should be plugged into the 8 ohm still.

I always run full power, 8 ohms, then turn the amp off, switch it to half power and 4, and let it rip.

[splawndude]

^ I'll look into it.

any linky's?

yeah, I got confirmation from HQ that you cut amp load in half when running at half power so a 4 ohm amp >>> 8 ohm cab.

[VicariousVIRUS]

Yessir, give me a little time to find the links and I'll post them back on here. It's been awhile since I've looked them up. Thanks for the help brotha!

Good thing Scott confirmed, I had no idea.





Kidding, lol. =]