Does Your Guitar Amp Sound Better At 4, 8 Or 16 Ohms? – That Pedal Show

Take the same guitar amp, same speakers, same cabinet: does the sound change when you wire for 4, 8 and 16-ohm output impedance?

Life too short for long YouTube videos? Please see the ‘Interesting bits and go-to sections’ information below.

Welcome to the show. It’s a super tweaky one this week. We spend most of our time on That Pedal Show talking about the Big Things that affect tone – different guitars, amps and pedals as you would expect, plus all the various things within those categories, for example pickups, components, wattage, gain, EQ, speakers etc etc etc. Well here we’re getting a little more nuanced.
You might think that your amp’s output impedance is one of those things that makes no difference – you just plug in the cab and play, right? If it’s a combo, it’s probably always just plugged in and you’ve never given it a second thought. As we discover in this video, the differences are there. Do you care?
Enjoy the show!

SAFETY WARNING: When dealing with amplifier output impedance and speaker matching, IT IS VITAL that you follow the manufacturer’s guidelines. Failing to do so could risk voiding your warranty and/or causing damage to your amp.

Pedals & stuff in this episode…

• TheGigRig Three2One

• Sonic Research ST-200 Tuner (link for the ST 300 Mini)

• Greer Lightspeed

• ThorpyFX Warthog

• Walrus Audio Ages

• Strymon Compadre Compressor Boost

• Dunlop EP103 Echoplex

• TC Electronic Ditto

• MXR Clone Looper

• TheGigRig G2

Interesting bits and go-to sections…
- Intro playing: 00:00
- What are we doing today?: 02:00
- What is impedance?: 04:50
- Speakers & loads: 07:30
- But does is sound different?: 10:40
- Matchless 4- and 16-ohm comparison: 13:35
- Do you prefer 4 or 16 ohms?: 19:15
- Marshall at 4- and 16-ohm comparison: 23:55
- What have we learned so far?: 30:45
- Impedance mismatches: 32:00
- Mesa Lone Star comparison: 33:10
- Mesa at 4- and 8-ohm mismatch: 35:47
- What about 100 watts?: 38:22
- What have we learned today?: 39:38

Guitars in this episode:

Amps in this episode
• Marshall 1987x with Custom Zilla 2x12 / Celestion Alnico Ruby speakers

• Matchless HC-30 with Matchless ESD212 / Customised Celestion G12H30 and Celestion G12M Greenback speakers

• Mesa Lone Star Classic 112 / Mesa C90 speaker

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[jakesdaddy]

“Impy Dance” was possibly a simultaneous career high and low for TPS. I think we all loved that, thanks guys

[Davepotnoodle]

Dan's delayed realisation made that joke worthwhile. Never change guys.

[JensenSpeakersVideos]

Hi Dan & Mick et All, great video!
This is Ignazio, from Jensen Speakers. I'd wish to chime in and add one more ingredient in this discussion...
Not everybody may be aware of the fact that most speakers sound and measure differently, depending on their own impedance.
Or rather: the same speaker, say a Jensen Vintage Reissue C12N, or a Celestion V30 etc., will sound different if built with a 4Ohm, an 8Ohm or a 16Ohm voice coil. This is true, in different degrees, for any brand and any model of speaker.
Usually the 16Ohm version will be slightly brighter, and possibly slightly more efficient. The 4Ohm version will be darker, slightly quieter. The 8Ohm will be somewhere in the middle. This is due to the "moving mass" of the speaker (the complex of membrane + voice coil + former) being the lightest in 16Ohms and the heaviest in 4Ohms.
Depending on how the speaker is made, and what kind of cone, voice coil former, wire, etc. this may be more o less evident, but it's usually noticeable in an A/B test.
Therefore, part of the fact that many players like better the higher impedance speakers is also due to the increased presence and apparent loudness.
Hope this helps... or helps maybe just contributes in deepening the rabbit hole, hah!

[Adnjah_]

Back to the old style intro, AND they start off by mucking around and wetting themselves laughing. TPS is BACK ladies and gentlemen 😁👍

[justinmckinney]

I learned by building amps . . . the lower the impedance, the sharper the attack with a little more emphasis on higher frequencies - Key word is "LITTLE". Think of the difference between single coils and humbuckers - that's how I think of the difference between 4 ohms & 16 ohms. I prefer 4 ohms with humbuckers & pedals. But if I was clean with a single coil strat, I may prefer 16 ohms to thicken the receipe. Also, if you play in stereo with a Double Tracking Pedal, you would want a thinner sound going to each amp, this way they'll mix better on each other giving a thick but more clear sound. Speaker EQ's & magnet materials play a role in this as well. 100W Twin + 4 ohms + Ceramic Speakers with Higher Sensitivity and your going to have ear piercing attack.

After a decade of experimentation, I believe that you pick the guitar first, then the pedals, then the amp, then the cab.

[digiscream]

Stop me if this is addressed later in the video, but...one of the reasons they might set the cab up as 4 ohm instead of 16 is that it's safer for the amp. 16 ohm is both speakers in series, so if one driver blows (or one of the spade connectors works loose) it'll present an open circuit to the amp and will thus be a hazard to your output valves and/or transformer. In 4 ohms, the drivers are in parallel and if one fails it'll just double the impedance (ie just one of the 8 ohm speakers). Still not great for the amp, but a hell of a lot less damaging than an open circuit.

[chewybang]

"... That's what the transformer does. Boom!"
"Hopefully not boom". Haha, brilliant!

[tgmotz]

Yes yes, impedance matters, matching amp and speaker impedance matters, wiring speakers in series and parallel matters but the point of all this, hoping it would have been stated in your final conclusions was a wordy description of the notable differences between 4, 8, 16 ohms as the audio across the studio speakers and audiophile headset doesn't really ring through and also worsened by the Youtube video compression algorithm. So, how would you describe the difference? I got the sense that 16 ohm was a cleaner, higher quality but quieter experience? What does the resonance feel like? How is the perception of the "breathing" amp and air movement in to the room? Feedback? Pinch harmonic differences? Which one would be great for a 50 person cafe/bar blues riff vs a rocker crowd or jazz crowd?

[nrdgmr]

Maybe it's me or maybe lost to youtube compression, but it's hard to tell to be honest. With that being said I could see Dan's point of 4ohm having more low end. I guess that's why we see bass amps operating with 2, 4 and 8 ohm versus guitar amps typically using 8 and 16ohm. But then again bass amps also push alot more power 500+ watts versus the 100w guitar amps.

[hoagyguitarmichael]

Another informative show guys. I toured for two years with a Bandmaster reverb head (4ohms), a Marshall 4x10 cab and a custom-built EV cab, both 8ohms. The mis-matched impedance, when using only one cabinet, acted as an attenuator, letting me use the inefficient Celestions of the Marshall alone in smaller clubs, the more efficient EV alone in slightly larger ones, and on rare occasions, both together, matching the 4ohm impedance for a glorious sound.

[jtn]

trying to boil this down to a TL;DR (or DW), correct me if I'm wrong:
-When matching impedances; 16 ohm output and speaker equals more low end due to using more windings
-When mismatching impedances, "better to go from 8 ohm to 16 ohm" (37:41) than 16 ohm to 8 ohm? Due to increased current and "asking the output transformer to do more work"
- mismatched: 4 ohm vs 8 ohm, 8 ohm seems louder due to correctly matching impedance
-(39:15) Rectiverb "seemed tighter" going 4 ohm out to 8 ohm speaker

[RubyRoks]

This being someone's first TPS episode would be magical

[jeremiahMc]

Dan said something interesting that I think is worth repeating: there’s a difference between manufacturing process to cut costs and sonic changes. They may affect each other but they also may improve a certain character. Manufacturers saving money does not equal bad tone.

[ehoc]

You know if Dan is sitting there looking like he’s in church listening to a sermon that the tone is good lol

[eranmontiel]

Big shout out to whoever provided the nitrous oxide fueling the giggle-fest that was the first 5min of this episode.

[robertprice]

I know Dan Boul recommends running his 65 Amps, if possible, at 16 ohms, to use the full amount of winds of the output transformer, while another friend says that is great of vintage Voxes, but likes vintage Marshalls to run at 8 ohms, with two 16 ohm cabinets. Here we go down another rabbit hole.

[duncanwestbrook]

THE BEST first 3 minutes of any video I think I've ever watched! The playing, the laughter, Dan's laugh is just so infectious ahaha! This is why I love this channel, one of if not the best channels on YouTube. End of. Amazing

[bradruhfel]

I think Dan needs to write a book about electricity for guitarists.

[brymills]

When I saw Mick’s dance... I thought we were talking about gnohms....

[darkenergy]

Hi fellas. I just want to say thank you. Rewiring cabs back and forth, controlling all variables. That is a huge undertaking and a lot of work. I would call this the definitive impedance comparison. So thank you, it is very much appreciated.