A tube amp sounds darker if you put a higher load right? Same for SS amps?

[Iplayloud]

You how for example if you put a 16 ohm speaker in a 8 ohm amp, it will sound a bit dark. Is it the same for ss amps? Reason is I installed a 16 ohm speaker in a practice ss amp. It does sound darker so I was wondering if it may be the reason, or if it's just the nature of that speaker. Thx

[Jazz P Bass]

The output of a Solid State amp is 'load dependent'.

Meaning if you run the amp into an 8 ohm load it will provide X power.
If you run the amp into a 4 ohm load it will provide 2x X power to the load.
How successful this is depends on the output configuration and the power supply.

Tube amps are a different animal.
There is a dependency of the output load into the output transformer that reflects back into the output tubes.

Not too sure how any of this can transpose into a "dark' sound.

[Enzo]

FAR more likely it is the result of the different speaker rather than the impedance-ness.

[Leo_Gnardo]

it's just the nature of that speaker.

Were the two speakers otherwise identical, besides their impedance rating? If not, you have discovered the following maxim:

Different speakers . . . . . . . . . . sound different.

Heck, sometimes speakers that are same manufacturer, same model, same impedance, presumably identical, sound different one to the next. Ask Eric Johnson. He'll tell you. "And recones? Don't get me started..." EJ.

[nickb]

You how for example if you put a 16 ohm speaker in a 8 ohm amp, it will sound a bit dark. Is it the same for ss amps? Reason is I installed a 16 ohm speaker in a practice ss amp. It does sound darker so I was wondering if it may be the reason, or if it's just the nature of that speaker. Thx

You have to compare like speakers ( already been said but worth saying again).

You simply don't have two types of amps called "SS" and "tube". What matters is the circuit topology. For example many SS amps employ current feedback that will alter how the amp behaves with different loads. There are many other variables.

BTW, given two identical (frequency response) speakers but with different impedance and considering the typical tube amp topology, I would expect the frequency response to move higher i.e less lows and more highs if you use a higher impedance load due to the effect of the output transformer, ignoring other factors.

[Iplayloud]

Thanks for all the answers. Ok I should have mentioned I'm not a noob haha. Sometime I write on forums and feel like I come straight from another planet. After 25 years of playing/modding tube amps it's always been standard knowledge to me that if you plug the same 16 ohm cab in an amp's 8 ohm tap (vs the correct 16 ohm tap), higher frequecies are slightly attenuated. I've never paid attention to ss amps and the question came up with a practice amp I want to leave somewhere. I'm often maxed out on the treble and was wondering if a 16 ohm speaker which I already have would be a good candidate. Was just worried if that same phenomena happened with ss amps I may run short on treble.. It's a Celestion G12-H30 and yes I did try it already and yes it seems to sound darker but I don't have 8 ohm model and just thought I would ask. Thx

[pdf64]

...it's always been standard knowledge to me that if you plug the same 16 ohm cab in an amp's 8 ohm tap (vs the correct 16 ohm tap), higher frequecies are slightly attenuated...

I query that
It may have appeared to work that way sometimes, eg perhaps overdriven Marshalls with EL34, but I can confirm that it isn't my experience with other amp types.
But my hearing is pretty shot, so perhaps I'm oblivious to the higher freq range you're referring to

[Enzo]

The tube amp has a transformer to match the speaker impedance to the tubes. A solid state amp doesn't have that. SS amps do not have 4 ohm or 8 ohm outputs. If you plug the same cab into a "wrong" jack on your tube amp, the speaker is now mismatched to the amp to some extent. Won't hurt anything, but still mismatched. On a solid state amp, there is no specific impedance to match, so there is no separate impedance jacks.

Now can two same type but different impedance speakers sound different? Sure. Individual speakers react to individual amps. As someone pointed out, som SS amps use current feedback, and a higher impedance speaker draws lower current.

[mozz]

16 ohm on 8 ohm tap, most likely less wattage, fletcher munson curves.

[cerrem]

Totally makes sense and is easily measurable ....
The reflected plate load would be approximately twice.... The winding capacitance stays the same but now works against a larger Plate load value..
In some transformer designs the winding geometry is not optimized when mis-matched , thus the leakage inductance may be higher with non utilized sections of the secondary, coupling will suffer...this also will roll off highs earlier..
Since the primary inductance is now working in parallel to twice the plate load, the Low frequency POLE will not be as low....
Distortions will be different ...which may monkey with the highs as well....

[nickb]

In some transformer designs the winding geometry is not optimized when mis-matched , thus the leakage inductance may be higher with non utilized sections of the secondary, coupling will suffer...this also will roll off highs earlier..

I'm doubtful of that claim. The coupling is not affected by the load impedance as it a property of the geometry of windings and core. Thus the leakage inductance will be constant. If that is so then having a higher load impedance means less drop across the leakage inductance and so more HF. Even if there were some effect that caused the leakage inductance to vary I can't imagine that it would have nay like the effect of changing the load impedance. On the other hand, I have no doubt that the HF will not be boosted* due to the effect of eddy current.

*I meant to say "as much as expected" here.

[cerrem]

I'm doubtful of that claim. The coupling is not affected by the load impedance as it a property of the geometry of windings and core. Thus the leakage inductance will be constant. If that is so then having a higher load impedance means less drop across the leakage inductance and so more HF. Even if there were some effect that caused the leakage inductance to vary I can't imagine that it would have nay like the effect of changing the load impedance. On the other hand, I have no doubt that the HF will not be boosted due to the effect of eddy current.

Never said the coupling is affected by the Load impedance ........
I'll give you an example.... You have some transformers with multi-tap primaries and with secondary sections that need to be re-wired for different secondary impedances... So in affect your changing the winding geometry arrangement on the secondaries..
So,

[mozz]

So if i run a freq sweep, then switch the same 16 ohm load to the lower tap, i am going to see a difference? I can easily do this on my Syscomp. With speaker or dummy load, i don't think there will be any difference.

[olddawg]

I’m in the “different speakers sound different” camp. BUT if you mismatch the impedance you may have less effective power. Most amps have a “sweet spot” if you are then operating out of that sweet spot to get the same volume, you could have a tonal difference. Totally subjective of course... especially if that spot is right on the edge of breakup.

[nickb]

Never said the coupling is affected by the Load impedance ........
I'll give you an example.... You have some transformers with multi-tap primaries and with secondary sections that need to be re-wired for different secondary impedances... So in affect your changing the winding geometry arrangement on the secondaries..
So,

Thanks. I see what you are referring to.

I don't think it's relevant to the OP as that is with a fixed geometry (not a multi tap transformer). All that is being changed is the load impedance. Therefore my statement about about the whole frequency band shifting higher still stands.