Tremoverb and dual cab impedance question

[matao]

Hey first time poster here. I am sorry if this information can be answered in a previous post, so please brick and redirect if necessary!

Ultimately this is a question about tone and how to channel low end and high end to different cabs through my Tremoverb. Also, I'm a novice at a lot of this but want to understand! Really trying to preserve tone and signal in my rig.

My Rig:

I have a Trem-o-verb head, and had a cab made with 2 V30 speakers wired in parallel. I noticed that my low end was being crushed a lot when I played gigs and rehearsed. I use a POG2 octaver to add a lot of low end to heavy parts of our music.

So I got a cab with 4 eminence speakers that have a mono 4ohm input. There is an 8ohm input as well, but the guy I bought this from said it doesn't work for whatever reason (and the washers/nuts are gone so the jack has fallen into the cab lol) so I'm happy just running it mono at 4ohms.

I want ultimately to use my 2x12 V30 cab for high/mid range output and pump my bass/mid through the 4x12 eminence cab.

Is this possible? Can I do this using just my Trem-o-verb or do I need another piece of equipment (a rack eq or something?)

Do I just plug the 4x12 cab into the 4ohm slot in the head and the 2x12 into the 8ohm slot?

I also don't want to send the wrong impedance through the 2x12. I was running it through the 8ohm slot by itself for awhile, and then heard that I could healthily mismatch it and send it through the 16ohm slot that could keep it from using up too much energy but it might end up sending more signal through the 4x12 resulting in I'm trying to do... I don't know about that so I wanted to see what y'all think!


Sorry that this is so confusing.

 

[iHatePop]

You technically can't use both cabs at once safely. You'd need two 8ohm cabs to use the two 4ohm inputs, or 2 16ohm cabs to use the 8ohm inputs. Always plug a cab into it's correct impedance output. 8ohm goes to 8ohm. 4ohm to 4ohm.

This being said, Mesa is really intense with some amps and puts in reeeally good transformers, so you can cheat. My DC-5 for example, can run 2 impedance different cabs safely, according to Mesa. Check your manual and see. You would need to rewire the 4x12 to be 16ohm, but you might be able to plug the 16ohm 4x12 into the 8ohm and the 8ohm 2x12 into the 4ohm (I could be incorrect about this, so check)

See this link to figure out safe mismatches: http://www.mesaboogie.com/media/Amplitudes/2013/June/Speaker%20Impedance%20Matching%20and%20Hookup.pdf

It's not possible to separate treble and bass frequencies without a crossover. Stereo speakers use this to split which frequencies go into each driver. There's potentially a way to do this, although I have no idea how. You might be able to buy a crossover that would work, but my knowledge is strained here, so I won't try to go any further, as I really have no clue if it's doable or not. In theory it is, but the cost and effort probably isn't worth it.

 

[afu]

I'm betting you have 8 ohm speakers in the Eminence cab. You'll need to repair that jack or rewire the 4 ohm to series-parallel wiring for 8 ohms. You could get a load box to change the impedance, but rewiring takes less time and money.

Impedances in parallel reduce. A 4 ohm cab and another cab both being run from the amp will reduce to a rating of 3.2 ohms. That's not good. If you daisy chained cabs in series you get 20 ohms which is also going to put stress on the tranny, but I think going over a little is better than going under. My understanding is that it is never ok to go under 4 ohms on these amps.

As an alternative, if you have another amp available, you could split the loop signal and run one signal into the return of a second amp with one of those cabs attached. Even a good budget amp can get great results when used as a slave in that fashion, since the preamp is totally bypassed. Splitting it also gives you the chance to EQ signals separately to get that bass/treble emphasis you're going for.

Anyway, just food for thought.