Separate names with a comma.
Discussion in 'Cabinets & Speakers' started by pedecamp, Sep 9, 2010.
Yep, 8 ohm heavier gauge and less turns than the 16ohm... or 16 gauge has lighter gauge with more turns, however you want to look at it. The coils are very close but have very slight different weights although the electrical parameters are different and they interact with the mechanical parameters. All this equals some small tonal differences, some more and some less affected by a given enclosure.
You should add “when using a lower tap” before all this.. and it’s actually root 2 (1.414) times the current. If you use the proper tap, the amp does not work harder at 4 ohms than 16 ohms.. this is a myth.
The transformer has better coefficient of coupling on the 16ohm tap then the 4 ohm tap, thus the wider bandwidth you can hear (and measure). ;-)
4 ohm, less turns, bigger gauge.
16 ohm, more turns, smaller gauge.
In the end, it’s close to the same mass and surface area the way it’s wound. Nothing comes for free in our physical world! Look only to the watt rating if you want more electrical power handling.
16 if they are wired in series, 4 if they are wired in parallel (or re-wire to 16... which it likely already is)
I asked this question 10 years ago! I've come to the conclusion it doesnt matter except for what you said about a 2nd cab.
Being an “architect”? should also know that all these tube amp outputs are isolated with an impedance matching transformer which by virtue negates the load mismatch effects you have mentioned here.
Yep, something tells me he wants to omit our gain stages lol. Joking, all in good fun of course!
Right on! These posts are timeless and so many folks turn to them for help and so the odd time the mood hits me to help separate fact from science fiction haha!
I just had quite the revelation recently. I just assembled a B cab with four of my 8ohm 6402 cone greenbacks wired in parallel/series configuration and 8ohm. My other cab is a A cab with 16ohm 1777 cone greenbacks and 16ohm. Both cabs sound awesome and greenback all the way but they do not sound the same and the difference is pretty pronounced. The B cab is quite a bit cleaner, deeper, darker, tighter, and a different low end growl with more low end. It absolutely rules for metal.
I don’t know exactly what has caused so much difference but there is quite a difference between the two cabs. I don’t think the 6402 8ohm and 1777 16ohm sound exactly the same either. That was a observation I noticed years ago swapping those speakers around in my combo amps but never really gave it much thought. Once both types where in cabs the difference became very pronounced. Both sound great but I was surprised to hear quite a difference comparing both cabs with my JMP2203 and a JCM2204.
When taking just the speaker into consideration, there does appear to be a subtle tone difference between 2 versions of the same speaker, one wired 8 ohm (heavier gauge and less turns) and the other 16 ohm (lighter gauge with more turns). While testing, I noticed the biggest difference in tone & feel came more from which tap I used on the amp.
One test consisted of taking the actual speaker out of the equation. I wanted to test the behavior of the amp’s outputs. I used a reactive load box (UAD OX):
Amp’s 4 ohm speaker output into UAD OX set at 4 ohm
Amp’s 8 ohm speaker output into UAD OX set at 8 ohm
Amp’s 16 ohm speaker output into UAD OX set at 16 ohm.
The 4 ohm tap sounded tighter/more compressed and slightly dull. The 16 ohm tap sounded more open with top end clarity. The sound & feel of the 8 ohm tap was somewhere in the middle, best of both. I typically prefer the 8 ohm tap for my standard tone, but have used the other configurations as well to add different tone characteristics when recording guitar tracks. Running two 8 ohm cabinets parallel with the 4 ohm tap is some heavy desert tone goodness.
All that said, the behavior could just be a result of how my amp is designed. I get the same results as my test using real cabs. Other amps may react different. Regardless, go with what sounds best to you based on the tone you’re going for at that time. Try to avoid amp/cab impedance mismatches.
What if I wanted to add a 3rd cab? 412 -16 ohm, to the full stack?(16 ohm spk in all)
Would it be wired the same, Parallel?
Would all 3 cabs still be 8 ohm?
How would the cabs be plugged in,......seeing they all have single mono jacks?
The Weber Z-Matcher is a good tool for allowing you to you run various cab impedances (2, 2.6, 4, 5.3, 8, 16) with your amp. On the Z-Matcher, set the amp knob to match the speaker output that you are plugged into on the amp and set the speaker knob to match what ever the total impedance is of the combined speaker cab setup. To run all 3 cabs in parallel it does require two of the cabs to have 2 jacks. Place the mono jack cab last in the chain. Three 8 ohm cabs in parallel would be 2.6 ohms. Three 16 ohm cabs in parallel would be 5.3 ohms. Two 16 ohm cabs and one 8 ohm cab in parallel would be 4 ohms.
If your cabs only have a mono jack you could try a Radial Cab-Link or something similar. The Cab-Link has 2 speaker outputs. It would allow you to run 2 mono jack cabs with your amp in either a series or parallel config.
I believe my 1960 b has a dual jack, and my jcm800ls Acab has the mono. Chances are if I obtain the 3rd 412 it will be a Bcab as well so it should have a dual jack..
Though it might be more cost effective to just get an attenuator ...solves both my issues,of additional cabs and low volume playing.
JCM900(93) ( 4/16 -8 )switch
Three 16 ohm cabs is 5.33 ohms.
What amp do you have/what outputs does your amp have?
If it has a pair of jacks with an ohm selector switch with a 4 ohm setting, the 4 ohm setting is a safe mismatch with three 16 ohm cabs.
If your amp has the modern Marshall 5 output jacks, you can plug one 16 ohm cab into one of the 8 ohm outputs, and the other two 16 ohm cabs into the pair of 4 ohm outputs, and that will give you a perfect impedance match. (Yes it sounds crazy, but I didn't get the numbers backwards -- we can explain it further if that's the type of amp you have.)
Some Marshall amps only have 8/16 outputs. Three 16 ohm cabs would be a stressful mismatch for those amps.
No stock Marshall 1960 has dual parallel jacks. Older ones have single jacks, newer ones have switching jackplates that give 4 ohms or 16 ohm mono, or stereo each side 8 ohms. The switching jackplates have two jacks, but they cannot be used for in/out daisy chaining. (In mono mode using all 4 speakers you can only use 1 jack at a time.)
Ok, I didn't realize this necro thread got revived from 5 years ago. A couple of observations that were determined years ago by Dave Friedman, George Lynch, Roy Blankenship and myself when testing identical 4x12's, one with 8 ohm M75's, and one with 16 ohm M75's.
1) The 16 ohm tap has more bass, and vintage feel. The 8 ohm tap has more mids and is slightly more aggressive in the upper mids. Hence the 8 ohm tap is brighter since it has more upper mids than the 16 ohm tap.
2) Voice coils are wound to a "spec". The mass/size/etc have to be very close to fit in the voice coil gap of the frame. The 8 ohm uses slightly thicker wire, 16 ohm uses thinner wire since it needs more winds.
3) It takes more power to push a 16 ohm cab/speaker than an 8 ohm. If I set the variac (or any amp in my pile) to 16 ohms, and then use it with an 8 ohm cab at the same volume, the 8 ohm cab is louder. How much? Varies with the output tranny, but typically 5-8w louder on a 100w head, 4-5w louder on a 50w Marshall head...roughly.
Any differences we heard between amps was attributed to the output tranny. Once you put two 16 ohm cabs to an amp, you have to set the output to 8 ohms, and the single cab results go out the window since you now have 8 speaker cones moving versus 4 cones moving.
Now, keep in mind, the four of us in that room probably had enough real world stage, studio, amp making and listening skills to come up with what I listed above.
Your mileage may vary.
This really should be a separate thread. Or a necro-bump of one of the threads where we talked about three 16 ohm cabs (or an 8 and 16 together -- electrically the same thing).
-For a given speaker model, the 16 ohm and 8 ohm versions are not 100% identical and thus will have some very small frequency response differences.
-16 ohm speakers DO NOT take more power to push than 8 ohm speakers. Simply a higher voltage and lower current ratio is the result which still multiply out to the same Wattage and thus efficiency.
-the 16ohm tap (on a multi tap transformer) has a better coefficient of coupling than its 8 ohm tap and even more so than its 4 ohm tap just by physical design so:
1. a 16 ohm cab on a 16 ohm tap will have a wider bandwidth meaning you will notice more of the very high frequencies come through, than an identical 4 ohm wired cab on the 4 ohm tap. (This can be best demonstrated on a 2x12” with 8 ohm speakers that can be wired either at 4 or 16 ohms.
2. Does one sound better than the other, well yes, if you use this knowledge to filter out unwanted top end by going 4 ohms, or if you need more extension then wire for 16ohms. It depends your preference, the amp, the guitar, and the cab for YOUR situation.
3. Mismatch loads can also have the same high pass effect as mentioned above. First, I don’t recommend you do it unless you completely understand the math and amp limits here or put your trust into some stranger like me who tells you they know what they are doing and gives you their “safe” mismatch advice.
a) In this case, higher impedance on lower impedance tap will extend the high end response.
B) Lower impedance speaker on high impedance tap will narrow the frequency response.
But don’t do it, you have a presence adjustment on the amp.. use it!
I always set my Superlead to 8 ohms with a 16 ohm 4x12 . It makes a difference and sounds better to me; more compressed maybe, less harsh, smoother?
With my 2x12 / 8 ohm Avatar cab, I use 8 ohm amp setting & it sounds great so I basically leave my head set at 8 ohms regardless of what cab I use.