Matching impedance between amplifier and speaker is incredibly important, but how many speaker cabinets can you connect to your amp? And which impedances are safe? We discuss the science so that you no longer will be Too Afraid To Ask. Leave your TATAs in the comments or on our dedicated TATA channel in the CSGuitars Discord Thank you to Patreon for funding the creation of this video #impedance #ohms #speaker More from CSGuitars: Gain access to exclusive content at: www.patreon.com/csguitars Join CSGuitars Discord - discord.gg/d7b6MY8 Buy CSGuitars Merchandise - www.csguitars.co.uk/store Website - www.csguitars.co.uk Contact - colin@csguitars.co.uk

Bold assumption that I was taught this in an American high school physics class.

I like how you kept the part of my question about digging shards of glass out of my eyes. :P

Headroom Bedroom 😂 Wow funny but makes sense

I need 2 cabs, one for each amp because I nearly forgot to plug it in before so having 2 cabs makes it easier not to make the amps go boom. Purely for convenience and safety

As a guitarist of 15 years who’s only ever had combos or modellers this was the primer I needed, cheers dude!

This probably the 18th video I’ve watched on this subject and I still don’t understand it.. that’s why I like combos.

Something I also see people sometimes get confused about is that a tube amp puts out the same rated power regardless of what impedance cab is used. In other words, a 100W tube amp is 100W whether it is into a 4ohm, 8ohm, or 16ohm cab. Unlike solid state where the wattage is dependent on the impedance of the cab it is connected to. So a solid state amp that is 100W into 4 ohms, is ~50W at 8ohms, and ~25W at 16ohms. Also, it's mind boggling to still see people think this, although it is usually with stereo systems for playing music rather than guitar amps and cabs, but higher wattage rated speakers does not mean they are louder speakers. The wattage is how much they can handle, not how much they will put out. The sensitivity of the speaker, and the wattage the amp puts through the speaker, are what determines the volume.

Drinking my coffee... waiting for Colin to begin. :)

Theoretically, you could connect four 8 ohm cabs to the 2x8 ohm connections on the back of the Orange amplifier you used as your demo in this video. Pair them up in series-parallel, as 2x8 + 2x8 where two cabs are connected in series with one another in each pair, and then the two pairs are connected separately to the 8 ohm outputs on the amplifier. In series, each pair of amplifiers will have an impedance of 16 ohms, and then in parallel those 16-ohm loads will appear as 8 ohms again. :) Likewise, you can connect two 8-ohm cabinets to the 16-ohm output by connecting them in series as well. Of course, you may need to get a little bit creative with your wiring if the cabs don't already have connections to allow for series configuration. But the math still checks out at the least. If you're crafty enough with your cables, you could build your own series cable with three jacks to make it work. I have to do my own creative impedance matching at some point in the near-ish future because I bought a Sony A/V receiver that expects 8-ohm loads, and, unfortunately, the 5.1 set of Sony speakers I have (that were part of a very self-contained "home entertainment system" that is proprietary everything, as is Sony's M.O.) are all, paradoxically, 3-6-ohms. I have to come up with an extra 2-5 ohms of impedance to put in series with each speaker before I can connect them to this A/V receiver. The easiest and dirtiest way for me to do that is to just put 2x10 ohm resistors in parallel in series with each speaker! 5 ohms of resistance should give approximately just under 5 additional ohms of impedance! (The frequency-dependent reactance of the speakers means that adding 5 ohms of pure resistance does not equate to adding exactly 5 ohms of impedance to the whole circuit, but that's a whole lot of extra electronics physics.)

Had questions of this for so long. Just have a tube amp that can change between ohms and one cab but never understood why I should set it to this amount of ohms. Just did what the guy said when I bought the amp and cab at sam ashe but this clears it up now! Love the video!!

Before I watch this I know very little about cabs and amps and the in-depth realm of guitar gear - as a learning player this is a topic I’m rather overwhelmed with. Your videos help a lot and would love to see more!

Love your channel man. Keep up the gold work. I subscribe to a ton of guitar channels (and that's like 90% of what I watch on KZfaq) but I think the best info I gets comes from you.

You literally answered the specific question I had that other videos didn't. Amazing thank you

I actually didn't know the parallel circuit thing with connecting two cabs of a higher impedance. This is a very well explained video. Thank you Colin!

Great info as always. Definitely a channel that never disappoints.

CSGuitars: “This is Day 1 Electronics class stuff” Me: *laughs in American public school system” also me: what’s an “electronics”?

Was hoping to glean something but I knew this stuff already. But Colin explains it very well as always. My amp, Peavey Classic Stereo 50/50 has switchable impedance 4,8,16 for each channel. I'm running a single 15 for 8 ohm in one cab and 2x10 for 4 ohms on the other channel. Sounds great!- I am always careful to double check the switches and cabs every time I set it up. My transformer would be very hard to replace. - Don't let the magic smoke out of the amp!

One of the best speaker impedance videos I've seen. Makes me wonder though why orange put two 8 ohm stickers on those jacks if they really represent 1x8 OR 2x16.

Awesome information Colin As I used to take Electronics classes in college, I'd say this is brand new to me. To be truly safe, I play unto one 16 ohm cab just so I don't kill my ears. Even with a 15 watt amp, it has multiple connections for this to apply for another 16 ohm cab, but I don't want to shell out the extra cash just to go deaf, not to mention drive my neighbors insane.

Thanks, Colin! Much appreciated!

For me physics 101 was something that happened to someone else. But you really explain it all very clearly. Thanks! I really want to understand how my guitar and amp work, and now I do (a bit more).

Colin, always with the bangers, every video.

Great video! Earned a like and subscription. Thanks!

I just learned something from this vid, cheers! btw, have you done any vids on mono and stereo cabs? maybe explain that one next?

Great TATA as always Colin. I would add to this that there is a MYTH out there in guitar land that it's ok to unplug a cab from the amp when it's switched on, people will claim they have done it loads of times and have never had a problem. This has caused false information claiming that disconnecting a cab from a valve amp will do no harm which is 100% FALSE! The people that have got away with it have had VERY little to no signal getting to the power amp stage in their valve amp. If you are playing through your amp or if a guitar lead is plugged into it and you are getting the mains 50Hz hum coming through your speaker and you unplug the cab, most likely YOU WILL DESTROY THE OUTPUT STAGE OF THE VALVE AMPLIFIER! I speak from personal experience. My ex guitar tutor years ago unplugged one of the speakers from my Marshall 20/20 Rack Mounted Stereo Power Amp while I was playing and then plugged it back in. Some days or weeks later later I started to get a strange noise from that side of the amp, when I opened it up I noticed the valves on that side were ''red plating'', glowing red hot and there was sparks inside the output transformer that I could see flashing through the paper insulation wrapped around the core. Fortunately for me I'm an electronics engineer by trade so it just cost me the price of a pair of matched EL84's and an output transformer. Uncle Doug has some great videos on the technical aspects of valve amps, including this one on output transformers. kzfaq.info/get/bejne/pLScg8qa1660ZGw.html

Dude, you are a legend!!! I was looking at getting an amp modeller (hx stomp) and a power amp (not sure which yet) and I was totally clueless about what cab I needed!

Thanks Colin. Informative.

I’m getting an ac30 and now I know thanks to you and your video what to look for when buying a speaker cab to pair with it

Great video as always... just one thing I think it’s missing in here and is about safe mismatch and why.... basically amp Z out

Great explanation. Thank you!

Great video. Spot on 👍

I lost count of how many times I have told sound guys to NOT connect the soundboard into one of my amp's speaker outputs. Are soundguys really THAT stupid? Connecting the soundboard into speaker output is the fastest way to set the amplifier on fire.

Thank you for referring me to this video. Both Freyette (Power Station 100) and Radial (Cab-Link) have boxes that can be put between the amp and cabinets which have input impedance selectors and output impedance selectors. My goal, as I stated in my other comment, is to run 3 2x12 16 ohm cabinets per head. Per this video above, it seems that the best way is to have custom amps built that have multiple output transformers (is this even doable). Or to take a post pre-amp out to separate clean power amps as splitters. To make this clearer, my goal is to have 3 stacks of 3 2x12s (9 cabinets in all) in a wet/dry/wet 3-way system running at 16 ohms. To make this even more difficult is the fact I want to use Hiwatt as the primary tones and textures amp. Hylight amps have more outputs than Hiwatt. Seriously, the more time I spend on this the more sense it makes to just have custom amps built to my specs. Can a guitar amp have multiple output transformers? If so, how many could a Hiwatt 100 handle? I know this sounds a bit crazy, but I am trying to do something that hasn't been done before (to my knowledge) by anyone. Thanks again!

Setting up my Carvin X100B. This helped TREMENDOUSLY. Thanks Dad.

Very well explain. Merci

I have been schooled, and I feel good because of it. Cheers, Colin. 🤘

Thank You for the video, I was always confused about this

Thanks for these videos, Colin. I learn loads from them. Most things I already sorta knew about, but you give the detail i didn't know in an easy to follow way

Thank you!! Forums are full of people arguing which way you can do it

Modern solid state amplifiers are more lenient on impedance, but it's always best to check the manual. Some old BJT output circuits require specific output impedances to not fry themselves. They can even be damaged from not having a speaker connected.

Best explanation of impedance and impedance matching that I have found.

I've been waiting for this video!

I love it when Colin covers my TATAs

Thank you!!!

Another great post.

Thanks Colin

Great video and explanation bro, thank you! I found out the hard way by buying a Katana MKII 50, it only has a 4 OHM speaker... I didn't do enough reading up on it before I bought it. The 100 and other Katana's models have 8 but only the 50 has the 4. I just assumed (should never do that, lol) it was an 8 OHM speaker and I could swap speakers if I wanted to upgrade to that Katana Artist series speaker... Nope I think I'm stuck with whats in it, thanks again for the video 🎸🎸👍

I also have a harley benton 2x12, since it has a switch in the back four different ohm numbers I just put it on Mono 8ohm and plug all my tube amps into the 8 ohm to 8ohm socket. I have been extremly anxious about connecting them wrong. I have heard you can blow or damage your transistor and screw up your amp and such. I watched countless videos on youtube and read some websites on the subject matter about it to make me understand it more. Probably the best video is from Philip McKnights video. I also have two cabinets and have always wondered if you can connect them both to the same amp. you can only do it with a few heads. as you said yourself in the video.

Very helpful!

Very clear

I'm just glad Barry made another appearance. He needs his own channel

Nice. OF course now someone is going to ask (and I'll play this part) : If you could pick an identical speaker in 4, 8 or 16 ohms, what would you expect as difference. What are the likely pros/cons ? Which would be "best" for guitar and perhaps, which would be best for bass.

Thanks, Leon

Great video it answered a lot of questions I had. However there is one area that still can't seem to find an answer to. You addressed connecting cabs to the amp and how the ohms need to be matched. How does that work when the speaker cab itself has an "Out" jack to connect another cab to it. Will that lower the ohms or how do I calculate the ohms to ensure I do not blow up my amp. Thank you for sharing all this great knowledge.

AMP / Speaker Brands hate this guy! Less dead Amps/Speakers -> less sold new gear :D

Now the funny thing is when it gets wild. I have an 80's amp that has 2x speaker outputs which both read "4, 8 or 16 ohm". It's a solid state though, but still has an obvious, albeit mild effect on the sound. Interesting test, very convenient when the cab is something like marshall 1960 with two connections, one for 4, one for 6 and both used 8 each. Somewhat follows the descriptions found online. More or less bass/mid/treble and more or less perceived gain. The critical failures are the most interesting ones. I understand that on a valve amplifier it's not that likely to get a critical failure with smaller load than expected, but with a higher load there's a chance that in failure the transformer arcs through and burns the isolation resulting in nasty things. And from what I understand, it is kinda reverse with solid states but not guaranteed. I wonder if talking about the failures and effects would be too confusing for an average user to avoid an average viewer from making a big mistake after watching? Or if your experience covers that kind of stuff. Like the effects of less efficiency and different eq curve, or as simple as wiring or combining speakers/cabinets. The way it sounds written gives me kinda "not suitable content for the channel" vibe despite being interesting. The most obvious answer usually is "only do what the manufacturer tells you and how it's supposed to be used" but hey, every gigging musician has probably faced the scenario of "what even is my backline cabinet" without an amp with versatile speaker connections. The way this Orange had it labeled is probably the most confusing from user standpoint "connect two 16 ohm cabinets to these two 8 ohm outputs". It makes sense when explained how it works and if using a single output, but the fact of there being two makes it confusing. Great and quick episode.

This is the greatest moment of my life

I was actually hoping to find a proper video on this subject. Thankfully, Colin to the rescue. If there's a better way to kick off a Friday morning, it hasn't been invented yet.

Fantastic video. I knew about matching but not how. Now I do. Thanks to you. I am not a musician. I do fiddle about with amps speakers and microphones. So Sir take it from an old man. You are in my opinion The Jedi leader of guitar stuff. Live long and prosper.

Coolest electronics teacher ever!

a lot of info here is based on Voltage controlled power sources, like most push pull amps and a few single ended designs. some single ended designs are current sources, meaning that with a higher impedance, the power can be higher. my class A transistor amp is a current source and has about 3.2 times the power in to a 16 ohm compared to a 4 ohm load. due to this current control, its fully resistant to shorting out!

I have a Tremonti amp. I want to hook up 1x15 and 2x12 cabs Thanks to Colin, I now know it can be done if both are 16ohm

Thank you so much for answering this question. Although in this case, for me it was more a "Too Late To Ask"

Would you consider offering an explanation of LFOs? How do they work, particularly in the context of different types of modulation?

Instructions and knowledge... who knew we needed such things 🤔

I'ma like the video so long cuz I know it's going to be good!

I have a 16-ohm Orange PPC212 cab and a Suhr Badger head that only has 4 and 8 ohm outs. I've used the 8 into 16 for years with very good results. It's a mismatch but it works.

Colin, you are smart. I thought you should know this.

Dammit! I bet my girl you were going to say hi Colin here! Always awesome videos!🤙

Got myself a micro terror for Christmas and made myself a cabinet out of an old suitcase! Two 4ohm speakers in series! Sounds killer! :)

Two things: Why do tube amps need something to be connected to the output, and what specifically happens if you turn on a tube power stage without a load connected? Second, impedance matching is not quite the optimal arrangement. To get the most accurate performance out of a speaker (meaning that the speaker is most closely replicating the signal it is being sent), you want the impedance of the speaker to be ten times greater than the output impedance of the amplifier. For the curious, the ratio of the speaker impedance to the amp's output impedance is known as the damping factor, and there is a pretty good explanation on the blog of NwAvGuy. It is important to note that the law of diminishing returns kicks in hard with damping factor, such that going much beyond 10 _might_ produce a measurable improvement, but the improvement will almost certainly not be audible.

i’m a bedroom player who uses a marshall 1x12 tube amp so this stuff doesn’t matter to me all too much yet but i had to watch anyway to show my support 🤘🏽💯

Colin , would you do a video showing the difference of the harmonic content of a tube amp distortion versus a pedal distortion? You could show it with white noise or sine wave. I think it would be interesting. What do you think? 🙂

I had to rewire my twin cab in series to suit my orange Brent Hinds Terror as I have Jenson 8ohm speakers. I'm not sure if this sacrifices the sound. It certainly doesn't to my ear. Great vid!

A couple of years back at a gig, I connected my 4 ohm bass head to an 8 ohm cab linked to another 8 ohm cabinet. So I figured, at worst, it would result in a 4 ohm impedance because 1/8 plus 1/8 is 1/4, right? I absolutely suck at electronics, but I do remember how resistances sum in parallel (or how capacitors sum in series). I got to play one note in the line check before my amp blew up and I still don't know exactly why that happened. Other bands using similar amps on the same cabinet setup had no trouble that day, so I was able to borrow an amp after much faffing about. Also, this happened on the first of several gigs we played in a ~two week period, so I had to borrow amps for every subsequent show that month. Not quite a tour, but the closest we've ever come to one so far. Fortunately, my amp was still under warranty, and while it wasn't possible to replace it with the same make and model, I did get another amp of a similar value at no cost to myself.

Following on your comments about the phase element of impedance matching, I've read that with "safe" mismatches (for instance, running an 8ohm head into a higher resistance cabinet at 16ohm) it can cause tonal changes. Which I think speaks to the frequencies of the signal being amplified, as you said. And if I'm not mistaken, often running an output transformer into a higher impedance than it's expecting can cause changes to the mid-range of your output, almost like a mid scoop or mid boost?

This was very useful. I would like to know more. If you made a course in valve amplifiers I would sign up right away.

Thanks mate, enlightenment at last! Ohhhm. But what I’d like to k ow is whether if you connect two cabinets, one wired in series and one in parallel, and the nominal resistance of each is say 16 ohm, whether the amp (say the orange used i this demo) will see what it needs to see?

This was really interesting! Particularly happy that the rocker 15 terror is actually the amp I'm running so good to know I have been using it the right way after all. I do have a follow up question though, I use a load box (2 notes torpedo) between my cab and head so I can record direct through an IR for demos. I get nervous every time I power my amp up into the load box even though I know it should be fine, mainly because I dont understand quite how the relationship changes when using a load box instead of a cab, particularly given that it is still possible to use a cab with it and it also can attenuate the signal. Is this just some kind of wizard magic or is there a technical reason that this is able to do all these wonderful things?

Barry returns!!!❤❤❤

Thank you so much for this video ! If I have a 100 watt amp and hooked up 2 cabs to it. Would each cab only be getting 50 watts each ?

I had the prs mt15 for a while great amp but it was a 16ohm amp and there are very few 16ohm 2x12 on the market 1 had to run an 8ohm through one of the mono jacks. Sold it for far to little and got a drum set as I have a boss katana head and joyo zombie which were good enough for my skill level.

Hey Col! I've a Peavey 6505 connected to an Orange PPC212 (16ohm) and I'm considering acquiring another cab for live setups. Having the 6505 a switch at the back for the impedance, when connecting both speakers (16ohm) the switch should then be at 8ohm correct? Thank you for all the content, you're the man!

One missing fact, speakers are never 4, 8 or 16. Different speker, shows different resistance. For example most 8 ohm speakers are from 6 to 7.5 ohms. 16 ohm speakers are around 12-14. So, there's inconsistence all over the place.

I always read the manuals. The Mesa boogie manuals are actually entertaining too.

Holy cow dude. You just saved my orange rocker terror 15. I had it connected to 2 8 ohms only once and I played it at low volumes.

Combos FTW!

This guys gnar.

Petition for Colin to teach us physics!! I used to fall asleep in class and you make it way more interesting

Greatness.

Thankyou so much for explaining this! Does the same principle apply with a loadbox? For example some loadboxes are 8ohms and some are 16ohms

It's best to ask for proof when they say they're 16Ω.

Could you also do a TATA on attenuator?

Hi Colin! Im looking for a amp to my 4ohms Kustom jr cab. It came with 4 ohms amp so that means i cant relly use tube amps cause mist of them want 8 ohms impedance...most of the once i have seen on for axample at thomann, those smaller tube amps. Btw do you have any tips of good affordable amps for metal...that also can be used live(hopefully in the near future when live performance comes back)? Im looking at a Marshall MG HGFX 100 head, a orange crush 120....

I wasn't sure if this is the right place to put this but could you do a TATA on mids and mid frequency knobs on bass amps?

Colin, I have two combo amps. One being a JCM 900 Dural Reverb 4102 and the other being a Peavy Valve King 212 100 watt. They both use an 8-ohm output for the combo amp speakers. They both have a switch on the back for 16/8/4 Ohm connection. I have a PT410 Laney 8 Ohm guitar cabinet to connect to either amp. My question is should I set the Ohm to 4 since both amps are already 8 Ohm outputs, or should I set the Ohm setting to 8 to match the amp with the cabinet? From what I am understanding you are saying it should be half the ohm output. When I hook the external Laney cabinet to either amp, I always set the Ohn to 4 just to be safe. I do not want to ruin my amps in any way. But if I could change the setting to 8 ohms and get a better output from the external cabinet, I would do that. I just want to do what is safe and the best for my equipment. I am the first and only owner of these pieces of equipment and take ultimate care for my things. I would appreciate any input you have. I enjoyed your video and have not only liked but subscribed to your channel. Thank you in advance for any input you can give me. My apologies if I did not pick up on the answer you may have already provided and didn't comprehend.

do they make cables that split out the ground and hot of a cable so you can truly wire cabinets in series?

Hey Colin, I know this video was made a while back, but I’m gonna shoot a question at you anyway. So I have a combo amp that handles an 8 ohm speaker. It also has a cab extension output for an 8 ohm cab, but when you use that, it’s designed to mute the speaker in the combo itself. I was curious if there was a way to change the wiring of the output jack, so that if i swapped the two 8 ohm speakers (one in the combo, and the other in the ext. cab) for 16 ohm speakers, I could have both speakers functional? Thanks a lot!

Impedance is important on older solid state amps and newer SS amps!. Ive nearly fried my Darkglass microtubes because of their small ass 2/4 ohm switch in the back. And dont get me started on the labeling for my vintage butcher.. manuals are a godsend.