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8 ohm vs 16 ohm in a 40 watt tube amp. is there any sound difference?


classicrox

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i recently purchased a blackstar ht 40, and i also ordered an 8 ohm Vintage 30 Celestion.

 

what is the difference between the 16 ohm and 8 in terms of sound?

 

if i where to compare an 8 ohms vintage 30 to a 16 ohms vintage 30, will it sound different?

 

don't go too technical on me lol :D i just wan't to know if there is a difference in sound or which ohm will SOUND better.

 

thanks!

 

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Absolutely not.

 

It makes zero difference so long a the head has variable of matching impedance.

Some tube heads have transformer tap switches that change impedance settings.

Others have a wide enough tolerance to accept say a 4 or 8 ohm load.

Transistor amps often have a minimum impedance and you can connect higher impedances.

So long as its within the amps specs, the amp is safe.

 

You only hear a difference if there's a mismatch. You may have a drop off of clean power and added distortion

when the amp is turned up, but that's an amp issue, not a tonal difference in the speaker.

 

The cone of a matching 4/8/16 is the same so the frequency response is the same. The only difference is the winds of the voice coil.

 

Maybe, (and this is really pushing possibilities) the added winds in a higher impedance coil add a tad more weight and increase inertia when the cone moves. I highly doubt it would make a tonal difference because those added winds also make for a stronger magnetic coil that responds to changes so any inertia would be easily overcome.

 

Your amp had a 16 ohm speaker for one reason. To make it easy to connect a second 16 ohm cab. 16 + 16 = 8 ohms in parallel.

The head is designed to run either 8 or 16 ohms. Running a single 8 ohm internal speaker needs to be connected to the single 8 ohm connection.

 

The manual has a warning.

WARNING: The output marked '1x16 Ohm' should never be used at the same time

as any of the outputs marked '1x8 Ohm or 2x16 Ohm' outputs. Failure to correctly

match the impedance of the amplifier and speakers will damage the amplifier.

 

They put that because the head has to have 8 or 16 ohms as a total load and the jacks tie into either the 8 or 16 ohm taps on the transformer. You cant use both transformer taps at the same time. If you plan on adding an additional cab you have to be careful.

 

In your case where you changed from a 16 to 8 ohm speaker, you will have to run that 8 ohm on the 8 ohm jack only and you cannot run a 16 ohm extension at the same time. There are ways around it however. If you put the 16 ohm speaker back in the amp, then purchase a second 8 ohm speaker and put the pair in a 2X12 cab (or two single cabs) then you wire the two 8 ohm speakers in series so they add up to 16 ohms.

 

Then you can connect the 16 ohm extension cab and the internal 16 ohm speaker together to get 8 ohms and run all three speakers together.

 

You cannot run the 8 and 16 ohm speakers together for two reasons. You cant use both the 8 and 16 ohm transformer tape at the same time and if you connect the two together on a single transformer tap you get an oddball impedance of either 24 ohms in series or 6 ohms in parallel. This is too high or two low for either the 8 or 16 ohm transformer taps and could damage the head.

 

To be truthful, you would have been better off buying a 16 ohm replacement then building (or buying) an additional cab to stick the stock speaker in and then you'd be able to run both in parallel safely at 8 ohms. As it is now, you can run either or, but not both at the same time because the two don't add up mathematically to provide an acceptable load.

 

You could buy a second 8 ohm and wire the cabs so you get 16 ohms with both connected, but you'd have to run them both and pay careful attention to the connections if you wanted to use only one cab. 2X8 = 4 ohms in parallel so you would have to ignore the way the manual tells you to connect them and do some jury rigging to connect the two in series to get 16 ohms.

 

And if you did buy another 8 ohm you may as well use all three speakers. It would make it simpler to connect and wire them in having a 2X12 16 ohm cab and a 16 ohm internal as I mentioned above.

 

Again, so long as the impedance matches the heads transformer taps, the impedance doesn't influence tone in speakers. Impedance matching ensures maximum power transference and maximum headroom without under/overload distortion that leads to head damage.

 

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Nothing to add but what was wrong with the speaker that was in the amp? What speaker was it? The features page only says "Celestion speaker' date='" which isn't incredibly helpful.[/quote']

 

nothing wrong with the stock speaker, it's a 12 inch celestion seventy 80 ( 16 ohm ).

 

i really like the sound of the blackstar HT-40 vintage pro (the one with vintage 30 speaker), it is the limited edition of the ht-40 model. but since i was not able to get one, i bought the standard version and ordered a v30, i forgot to specify the ohm and it should have been 16 ohm. but many people prefer the 8 ohm, so i did not bother.

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thank you so much for this informative reply man :) yeah, i was stupid enough to not read the manual before playing. i did mismatched the amp with the speaker, and switched between 1x16 to 1x8 while the amp was running, but i did it really fast though. then i realize i did a big mistake. so far, no harm done to my amp, haven't smelled smoke etc. i think i just dodged a bullet.

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