Using two cabs. Piggy back or use two outputs from the amp?

[maddnotez]

Just looking to see what the differences are between using the 2 outs from the amp (1 out for each cab) or just piggy backing from one cab to the next.

Any tonal differences? Any weird ohm changes? Is one method recommend over the other?

The amp is a Rev 2 Uberschall if that makes a difference.

 

[JakeAC5253]

Literally no difference. So long as both outputs of the amp are identically rated, and the connection point on the cab is a "thru" jack, there is literally no difference between the two. Just don't forget to set the head to see the new impedance or you'll have trouble.

 

[311boogieman]

Using the amp speaker outs means you don't have to worry have 'halving' the impedance right? Direct taps to OT.

Piggyback might be better in a gigging situation if your amp is offstage somewhere.

Tonally, as mentioned above, I can't think of any differences. 2 long speaker cables from an amp offstage could introduce more interference I suppose but I'm not an engineer and do not have direct experience dude. Good question though.

 

[steve_k]

depends if they are wired series or parallel and what you have for output jacks.

 

[cardinal]

It shouldn't matter to the amp as long as the piggyback is parallel like the head's ouputs. However if one cab has some type of catastrophic wiring failure, you might be safer plugging both directly into the head, that way you'll be sure there's at least some load in the head.

 

[maddnotez]

depends if they are wired series or parallel and what you have for output jacks.

Damn, I knew nothing would be easy

I'm not sure how my one cab is wired. :/

 

[cardinal]

^ it's almost surely parallel.

 

[311boogieman]

depends if they are wired series or parallel and what you have for output jacks.

Damn, I knew nothing would be easy

I'm not sure how my one cab is wired. :/

I think he meant the amp not the cabinets. I think Cardinal was saying it depends on how the amps speaker outs are wired. The OT that is. Most amps would be parallel yes.

The speaker cabinets themselves don't matter so much. That is, the amp doesn't really care how the cabinet's speakers are wired.

That said - I bet the Mills cab is wired in series/parallel. That means one pair of speakers is wired in series and the other pair is wired in series. Then those two pairs are wired together in parallel. Assuming 8 ohm speakers that would result in an 8 ohm cab. 16 ohm speakers would result in a 16 ohm cab. You would also have the benefit of running stereo into the cab (two separate sides/pairs).

Cardinal - is that right? Is that what you were saying? Hope I didn't get this all sideways.


Maddnotz - what are you trying to accomplish? Can I assume you are on the hunt for a second cab?

 

[RJF]

I prefer running two cables from the amp, one to each cab. You have twice as much wire carrying the amp load out to the speakers, where with the old school way in theory you have twice as much load on that first cable going from the head to the 1st cab. Probably not an issue, since bass players use the same 1/4" cables and carry a lot more wattage to their cabs....but you know.. in theory..

 

[maddnotez]

depends if they are wired series or parallel and what you have for output jacks.

Damn, I knew nothing would be easy

I'm not sure how my one cab is wired. :/

I think he meant the amp not the cabinets. I think Cardinal was saying it depends on how the amps speaker outs are wired. The OT that is. Most amps would be parallel yes.

The speaker cabinets themselves don't matter so much. That is, the amp doesn't really care how the cabinet's speakers are wired.

That said - I bet the Mills cab is wired in series/parallel. That means one pair of speakers is wired in series and the other pair is wired in series. Then those two pairs are wired together in parallel. Assuming 8 ohm speakers that would result in an 8 ohm cab. 16 ohm speakers would result in a 16 ohm cab. You would also have the benefit of running stereo into the cab (two separate sides/pairs).

Cardinal - is that right? Is that what you were saying? Hope I didn't get this all sideways.


Maddnotz - what are you trying to accomplish? Can I assume you are on the hunt for a second cab?

Yeah I think you described my mills cab pretty well. Although I've never opened it to see what ohm the speakers are it's wired for 16. I'm getting a 2x12 and I'm sure at some point I'll want to run them both.

 

[SpiderWars]

Using the amp speaker outs means you don't have to worry have 'halving' the impedance right? Direct taps to OT.

If I'm understanding you then no, it shouldn't make a difference. It's the same impedance either way. So two 16 ohm cabs will be 8 ohms total load regardless of whether using 2 speaker outs or 1 speaker out/piggy-back.

 

[311boogieman]

Using the amp speaker outs means you don't have to worry have 'halving' the impedance right? Direct taps to OT.

If I'm understanding you then no, it shouldn't make a difference. It's the same impedance either way. So two 16 ohm cabs will be 8 ohms total load regardless of whether using 2 speaker outs or 1 speaker out/piggy-back.

Yeah. I should have been more clear though. Yes, the ohms are the same whether it is direct OT tap (speaker outs) or daisy chained (piggy-back). What I was trying to say is that if your amp has 2 speaker outs that are the same (and designed for that purpose) then you just match up and plug in. Not all amps will do that and you certainly wouldn't want to use a 16 ohm speaker out and an 8 ohm speaker out. I mean, we could argue as to whether or not that is safe but let's just say we need to match.

Maddnotez - you're welcome.

You'll def want to make sure you understand how the cab is wired. If you can unscrew one of the handles and peek inside then get the ohm reading off of one of the speakers and see if all the speakers are the same. If it is a stock cab then maybe get the specs from Mills. I tried looking that up last night and didn't get very far. Their website is not what I was expecting either.

You will want to make sure your new cab has the same impedance as your Mills. If your Mills is 16 ohms total then get a 16 ohm 212 cab. If your Mills is 8 ohm total, then get a 8 ohm 212 cab. How many insert jacks on are on the jack plate and what all does it say on there?

 

[LP Freak]

How do you get a 16 ohm load out of 2 speakers?

 

[311boogieman]

How do you get a 16 ohm load out of 2 speakers?

Who? Me?


2 - 8 ohm speakers wired in series will give you a 16 ohm load total.

But yeah. Good point. If his Mills cab is 16 ohms and he wants a second cab that will be a 2x12 then it will be 2 - 8 ohm speakers wired in series for 16 total.

 

[LP Freak]

How do you get a 16 ohm load out of 2 speakers?

Who? Me?


2 - 8 ohm speakers wired in series will give you a 16 ohm load total.

But yeah. Good point. If his Mills cab is 16 ohms and he wants a second cab that will be a 2x12 then it will be 2 - 8 ohm speakers wired in series for 16 total.

For some reason I thought the speakers were each 16 ohm

 

[SpiderWars]

How do you get a 16 ohm load out of 2 speakers?

Who? Me?


2 - 8 ohm speakers wired in series will give you a 16 ohm load total.

But yeah. Good point. If his Mills cab is 16 ohms and he wants a second cab that will be a 2x12 then it will be 2 - 8 ohm speakers wired in series for 16 total.

Doing that would make the wiring like a 4x12 in series/parallel which is kinda cool. I never really thought about it because I always just use a 4x12 but when using two 'typical' 2x12s (i.e. speakers parallel) then the wiring is parallel/series which I usually don't prefer. I wonder how Paul Gilbert does it, he's used 2x12s in pairs for years (decades).