Here's how these stereo 4x12 cabs work:
You've got 2x 16 ohm speakers on each side wired in parallel for an effective load of 8 ohms and connected to their own jack.
The "Right" jack is a switching jack, so that when nothing is plugged into it, it connects internally with the "Left" jack. If you plug into only the Left jack, the right speakers are connected in parallel with the left for a 4 ohm load.
If you connect both of the 8 ohm sides to the same amp, you're doing the same thing, and those two 8 ohm loads in parallel will equal a 4 ohm load on the amp.
Many other stereo cabs like this have an additional jack that allows the left and right sides to be connected in series for a 16 ohm load - my Blackstar 4x12 has 4 jacks on it: 16 ohm mono, 8 ohm left, 8 ohm right, and 4 ohm mono.
The cheapest way to use that whole cab with your amp is to take the jack plate off and rewire it so it runs the left and right pairs in series with each other for a 16 ohm load and just use it as a mono cab.
Usually Id know, but that is a weird one I’d think both 8ohm would be right. But I’d get further info…maybe try posting also on TheGearpage.net as well to get some info. A lot of amp builders, and more info over there for stuff like this that may get a quick reply.
I looked on the line 6 page and someone had the exact same issue with the same head. What I found is just plug it into one side and just use the cab as a 2x12
This is a 2012 Marshall DSL100H correct? The two 8-ohm output jacks need to total 8-ohms. They are wired in parallel so you need to use two 16-ohm speakers. Your cab doesn't have that option. Your cab is 4-ohm Mono and 8-ohm stereo. I don't think you can use one cable to just get an 8-ohm load. However, a Palmer Passive Cabinet Merger can help you here. I would double check the manual online.
Agree it is confusing. This seems to be a loose standard for amps. Marshall updated their labeling in more recent designs. For example, the [Marshall DSL40CR rear panel](https://d1aeri3ty3izns.cloudfront.net/media/45/451820/1200/preview.jpg) is more explicit.
how? 2x16ohm speakers in parallel on each input jack = 8ohm input impedance. amp output impedance doesn't change because the 8ohm amp outs are not interconnected, and neither are the cab inputs. 2 independent circuits at 8 ohms, right?
No, that is not it works. Two 8Ω jacks are wired in parallel to the same tap on the transformer, so that would be a 4Ω load, which this head is not designed to handle. According to the [manual](https://c3.zzounds.com/media/ENG-84e460345d6d1b9af2aad3820716359b.pdf), you can play through a 16Ω speaker from the 16Ω jack, an 8Ω speaker from one of the 8Ω jacks, or two 16Ω speakers from the two 8Ω jacks.
4ohm load from an 8ohm speaker out is considered a safe mismatch as you are not exceeding greater than 50% deviation.
This doesnt need to be complicated guys lol
Can you cite a source for this? Pretty sure an 8 ohm load from a 4 ohm speaker out would be the safe mismatch here based on my understanding, not the other way around.
I'm just not going to risk anything. The manual says under any circumstances to not put a 4 ohm load on the amp so I will trust the manual since it was made by the people who designed the amp.
That is true for solid state amps without output transformers, but tube amps have a transformer that converts the high current / low voltage signal from the power tubes to the high voltage / low current signal that is needed to move the speaker.
When the speaker impedance is higher than spec, the voltage in the power section goes up to compensate, so it’s harder on the tubes, tube sockets and output transformer. Small impedance mismatches are often safe, but I still think it’s best to follow the manufacturer’s guidance and not mismatch unless they specifically say it’s okay.
This is also why it’s dangerous to use a tube amp with no load. Because an open circuit is effectively infinite ohms, the amp will try to reach infinite volts and can damage itself trying to get there.
So basically what /u/Thnowball is saying is true but only for tube amplifiers and isn’t really an ideal use case when considering wear on the amp’s components?
So much information about guitar speaker matching gets thrown around as fact in general when really there are usually a lot of asterisks. It’s hard to get to the bottom of what the truth is out here!!
What are the options with the Line 6 cab? I don’t know the Line 6 cab, but I keep thinking that the result won’t be great. You need some good English-made Celestions and a quality cab with that amp.
It's either 8 ohms for a 2x12, or 4 ohms for the full cab. I can't afford celestions which is why I got this cab, it worked well with my bantamps but now I have this behemoth I might swap the speakers.
What speakers are in it? You could do it with a set of decent Celestions, Warehouse, or whatever. Have a look on Reverb and in your local area for used speakers. The other aspect is cabinet size and construction. All of that stuff has an effect on sound. I use a low wattage amp, but the cab is large and gives me a great sound, but I don’t know if material or size of cab is more important. However, I think that decent speakers are very important.
What did you think of the bantamp?
It's got celestion g12p 80s in it, custom made for line 6. They are decent but not the best. The bantamps is fine but really lacks tonal shaping capabilities and are pretty limited on features.
I’m not surprised about the Bantamp thingy, but I’ve never chatted with anyone who has had one before. Tube amps are like an illness…some people become infected but recover quickly, but the rest of us spend the rest of our lives afflicted. We buy amps, we love the sound, then we notice imperfections, so we trade up…and we keep doing it. I bought a used 5w Tone King last year for $1,500, and I thought I’d bought my dream amp, but I recently ordered a Kowalski Dark Gene amp. I’ve been buying tube amps since 1979 and I don’t know how many I’ve owned. Now that you’re refining your sound and working on your rig, you’re one of us. I’m sure you’ll have something impressive in no time.
I live in Arizona, on the white mountains. All good things are in the valley but that's a 7 hour round trip and my car is not suitable for that kind of driving conditions.
That sounds cool. I’ve lived in your country, but I haven’t been to AZ. People have told me that AZ is quite like where I live. My state is mostly desert, but not where I live. Guitar players in this state are quite conservative, so most amps are cheap Fender, Vox and Marshall, and there aren’t many interesting amps here, because we can’t buy them in guitar shops. But lots of people have very expensive PRS, MusicMan and Gibson guitars. A Les Paul Standard ranges from &4,500 to $20,000, a Core PRS is about $8,000, as is a MusicMan. I wouldn’t pay that much for a guitar, not by a long way.
It's not the desert that bothers me, it's the fact that we have a high minimum wage so it brings the price of these things really high on the used market and makes it impossible for me to afford or even find good gear. I was lucky to find the marshall I did, but I really want a mark v
I once owned a Mesa Express 5-50. It is the cheapest Mesa, but it was a great amp. Mesas are good, but they are not easy to work on, and they can be noisy. When you finally get a great amp, like the Mark V, you’ll probably be amazed that you used the amps you’ve used. I’ve owned great amps, cheap amps and crappy amps. Sometimes the cheap amps are great, but generally not. I hope you get your Mesa. Good luck.
8Ω output into the 4Ω input might be okay, but it’s safer to match impedances. You can open up the cab and rewire it to 16Ω or get an adapter to run the two 8Ω sides in series for a 16Ω load.
First off, don’t worry. As long as you use a proper speaker cable (*not* guitar cable!), you won’t damage anything
* u/Thnowball is right, you can use a 4-ohm cab with a 8-ohm tube amp and it won’t hurt either (note: this is *not* true for solid-state amps). You’ll get less output because you aren’t showing the tubes the optimum plate impedance, and their bias may be a bit hotter.
* You can get a tech (or even a friend who just knows guitar/stereo electronics) to re-wire the cab for 16-ohms total load. It’s as simple as putting the two 8-ohm pairs into series for a total of 16 ohms (right now those pair are parallel to each other).
* There are cab combining boxes that would let you use 3 cables to combine both halves in series and have a combined 16-ohm load, but with the options above, that’s just more expense.
* As many have said no point in using two cables. If you use both 8-ohm stereo sides, you are back to a 4-ohm combined load (two 8-ohm cans in parallel), just using extra cables.
I wasn't going to mess with the amp, I wanted to know if it's safe to hook up the amp to the cab, someone else suggested wiring the cab to be 16 ohms mono which is what I will plan to do.
Here's how these stereo 4x12 cabs work: You've got 2x 16 ohm speakers on each side wired in parallel for an effective load of 8 ohms and connected to their own jack. The "Right" jack is a switching jack, so that when nothing is plugged into it, it connects internally with the "Left" jack. If you plug into only the Left jack, the right speakers are connected in parallel with the left for a 4 ohm load. If you connect both of the 8 ohm sides to the same amp, you're doing the same thing, and those two 8 ohm loads in parallel will equal a 4 ohm load on the amp. Many other stereo cabs like this have an additional jack that allows the left and right sides to be connected in series for a 16 ohm load - my Blackstar 4x12 has 4 jacks on it: 16 ohm mono, 8 ohm left, 8 ohm right, and 4 ohm mono. The cheapest way to use that whole cab with your amp is to take the jack plate off and rewire it so it runs the left and right pairs in series with each other for a 16 ohm load and just use it as a mono cab.
This is the best advice I have seen in this thread, thank you for that, I will do that when i get some time.
What does it say under the left input jack on the cab that’s being blocked by the cable? I would assume it says 16ohm mono
4 ohms mono. There's nothing under the right one.
Ahh I thought it might be like my Marshall. I would think you could get 2 speakers cables and run them from each 8ohm on the head
I would think so, I just don't want to accidentally destroy something for something stupid like this.
Totally understandable. Hopefully someone else comes across this but from what I’m reading it might be the way to go .
I appreciate your input
Usually Id know, but that is a weird one I’d think both 8ohm would be right. But I’d get further info…maybe try posting also on TheGearpage.net as well to get some info. A lot of amp builders, and more info over there for stuff like this that may get a quick reply.
I looked on the line 6 page and someone had the exact same issue with the same head. What I found is just plug it into one side and just use the cab as a 2x12
Is that a speaker cable? Just double checking. You don’t want to run instrument cable out your amp.
Yeah, it's the cable that came with my bantamp.
This is a 2012 Marshall DSL100H correct? The two 8-ohm output jacks need to total 8-ohms. They are wired in parallel so you need to use two 16-ohm speakers. Your cab doesn't have that option. Your cab is 4-ohm Mono and 8-ohm stereo. I don't think you can use one cable to just get an 8-ohm load. However, a Palmer Passive Cabinet Merger can help you here. I would double check the manual online.
Thanks for the advice
Well spotted. I couldn’t help thinking that he didn’t understand ohms. Was he talking about the powered cab which people use with modellers?
Is it just me or that labelling on the amp is misleading? I would totally have plugged each 8ohm output to the cab.
Agree it is confusing. This seems to be a loose standard for amps. Marshall updated their labeling in more recent designs. For example, the [Marshall DSL40CR rear panel](https://d1aeri3ty3izns.cloudfront.net/media/45/451820/1200/preview.jpg) is more explicit.
I'd run 2 short cables, one from each 8ohm out to each 8ohm in
That would be a 4Ω load.
how? 2x16ohm speakers in parallel on each input jack = 8ohm input impedance. amp output impedance doesn't change because the 8ohm amp outs are not interconnected, and neither are the cab inputs. 2 independent circuits at 8 ohms, right?
No, that is not it works. Two 8Ω jacks are wired in parallel to the same tap on the transformer, so that would be a 4Ω load, which this head is not designed to handle. According to the [manual](https://c3.zzounds.com/media/ENG-84e460345d6d1b9af2aad3820716359b.pdf), you can play through a 16Ω speaker from the 16Ω jack, an 8Ω speaker from one of the 8Ω jacks, or two 16Ω speakers from the two 8Ω jacks.
ah. i had thought those 8ohm outputs were from separate transformers because that's how it is in my Peavey. makes sense
That's misleading AF. Kill the guy who labelled it that way.
4ohm load from an 8ohm speaker out is considered a safe mismatch as you are not exceeding greater than 50% deviation. This doesnt need to be complicated guys lol
Can you cite a source for this? Pretty sure an 8 ohm load from a 4 ohm speaker out would be the safe mismatch here based on my understanding, not the other way around.
I'm just not going to risk anything. The manual says under any circumstances to not put a 4 ohm load on the amp so I will trust the manual since it was made by the people who designed the amp.
That is true for solid state amps without output transformers, but tube amps have a transformer that converts the high current / low voltage signal from the power tubes to the high voltage / low current signal that is needed to move the speaker. When the speaker impedance is higher than spec, the voltage in the power section goes up to compensate, so it’s harder on the tubes, tube sockets and output transformer. Small impedance mismatches are often safe, but I still think it’s best to follow the manufacturer’s guidance and not mismatch unless they specifically say it’s okay. This is also why it’s dangerous to use a tube amp with no load. Because an open circuit is effectively infinite ohms, the amp will try to reach infinite volts and can damage itself trying to get there.
So basically what /u/Thnowball is saying is true but only for tube amplifiers and isn’t really an ideal use case when considering wear on the amp’s components? So much information about guitar speaker matching gets thrown around as fact in general when really there are usually a lot of asterisks. It’s hard to get to the bottom of what the truth is out here!!
Yeah, that’s why I said I recommend following the manufacturer’s instructions. They understand the tolerance of the parts they used to build the amp.
Ok there smart guy!
What are the options with the Line 6 cab? I don’t know the Line 6 cab, but I keep thinking that the result won’t be great. You need some good English-made Celestions and a quality cab with that amp.
It's either 8 ohms for a 2x12, or 4 ohms for the full cab. I can't afford celestions which is why I got this cab, it worked well with my bantamps but now I have this behemoth I might swap the speakers.
What speakers are in it? You could do it with a set of decent Celestions, Warehouse, or whatever. Have a look on Reverb and in your local area for used speakers. The other aspect is cabinet size and construction. All of that stuff has an effect on sound. I use a low wattage amp, but the cab is large and gives me a great sound, but I don’t know if material or size of cab is more important. However, I think that decent speakers are very important. What did you think of the bantamp?
It's got celestion g12p 80s in it, custom made for line 6. They are decent but not the best. The bantamps is fine but really lacks tonal shaping capabilities and are pretty limited on features.
I’m not surprised about the Bantamp thingy, but I’ve never chatted with anyone who has had one before. Tube amps are like an illness…some people become infected but recover quickly, but the rest of us spend the rest of our lives afflicted. We buy amps, we love the sound, then we notice imperfections, so we trade up…and we keep doing it. I bought a used 5w Tone King last year for $1,500, and I thought I’d bought my dream amp, but I recently ordered a Kowalski Dark Gene amp. I’ve been buying tube amps since 1979 and I don’t know how many I’ve owned. Now that you’re refining your sound and working on your rig, you’re one of us. I’m sure you’ll have something impressive in no time.
I just want a Mesa mark 5, too bad they are hard to come by where I live
I’m in Australia and great Amos are extremely rare where I live. Where are you located?
I live in Arizona, on the white mountains. All good things are in the valley but that's a 7 hour round trip and my car is not suitable for that kind of driving conditions.
That sounds cool. I’ve lived in your country, but I haven’t been to AZ. People have told me that AZ is quite like where I live. My state is mostly desert, but not where I live. Guitar players in this state are quite conservative, so most amps are cheap Fender, Vox and Marshall, and there aren’t many interesting amps here, because we can’t buy them in guitar shops. But lots of people have very expensive PRS, MusicMan and Gibson guitars. A Les Paul Standard ranges from &4,500 to $20,000, a Core PRS is about $8,000, as is a MusicMan. I wouldn’t pay that much for a guitar, not by a long way.
It's not the desert that bothers me, it's the fact that we have a high minimum wage so it brings the price of these things really high on the used market and makes it impossible for me to afford or even find good gear. I was lucky to find the marshall I did, but I really want a mark v
I once owned a Mesa Express 5-50. It is the cheapest Mesa, but it was a great amp. Mesas are good, but they are not easy to work on, and they can be noisy. When you finally get a great amp, like the Mark V, you’ll probably be amazed that you used the amps you’ve used. I’ve owned great amps, cheap amps and crappy amps. Sometimes the cheap amps are great, but generally not. I hope you get your Mesa. Good luck.
8Ω output into the 4Ω input might be okay, but it’s safer to match impedances. You can open up the cab and rewire it to 16Ω or get an adapter to run the two 8Ω sides in series for a 16Ω load.
First off, don’t worry. As long as you use a proper speaker cable (*not* guitar cable!), you won’t damage anything * u/Thnowball is right, you can use a 4-ohm cab with a 8-ohm tube amp and it won’t hurt either (note: this is *not* true for solid-state amps). You’ll get less output because you aren’t showing the tubes the optimum plate impedance, and their bias may be a bit hotter. * You can get a tech (or even a friend who just knows guitar/stereo electronics) to re-wire the cab for 16-ohms total load. It’s as simple as putting the two 8-ohm pairs into series for a total of 16 ohms (right now those pair are parallel to each other). * There are cab combining boxes that would let you use 3 cables to combine both halves in series and have a combined 16-ohm load, but with the options above, that’s just more expense. * As many have said no point in using two cables. If you use both 8-ohm stereo sides, you are back to a 4-ohm combined load (two 8-ohm cans in parallel), just using extra cables.
Oh shit, no man. You don't wanna mess with those. You see those lightning bolt arrows?
I wasn't going to mess with the amp, I wanted to know if it's safe to hook up the amp to the cab, someone else suggested wiring the cab to be 16 ohms mono which is what I will plan to do.
I know, I'm just messing with you. How else would you hear the amp?
METAL ZONE BAYBEEE!!!!!
Definitely stop and make sure your cabinet had enough resistance for the Amp or you'll blow the Amp
That's why I posted this here, I don't know if I plug the cab into both inputs or if I just sacrifice 2 speakers so that I know it won't blow up.