Can resistor substitute for a speaker to get desired Ohmage

[Emetal]

I believe the speaker load and impedance selector are matched per the first post. There is no reason not to try paralleling an 8 ohm resistor with the 8 ohm speaker and connect it to the 4 ohm tap. The resistor will eat about half if the output power, of course, so the resistor should be rated for at least half of the amp's output power.

So amp is 100 Watts I should then get at least 50 Watts 8 Ohms resistor but if I can find I could get 100 Watts resistor too. OK then it would be just to my ears to see do I like the sound, but will not hurt the amp. Right?

[Emetal]

Get one of these:

http://taweber.powweb.com/store/zmatch.htm

It will alter the tone a bit as you are passing the signal through an additional transformer, but you wont hurt anything.

All the best.

Can't get that in Serbia.. thanks for good wishes

[Emetal]

My feeling is there is something else going on beyond load impedance. Are the cabs manufactured by the same company, and are they the same model? Do either of them have foam or glass wool batting in them? Are they both closed-back? Ported? Did you try both cabs in the same room, and in the same location in the room?

Yeah I know all the structural and environmental factors that influence the sound, there are differences between these cabs, but did not wanna go in to all of that, I do not expect to get exactly same sound, just wanted the quick way to convert my cab to 4 Ohms, without braking the amp/OT and here how it sounds..

[JazzGuitarGimp]

Yes, 8 ohm speaker || with 8 ohm, high power resistor, connected to 4 ohm output = no damage to the amp. If you intend to run the amp at full volume with heavy overdrive, I would suggest a 100 watt resistor. And it will get HOT, so be careful about where you place the resistor.

[Firestorm]

Again, from a tone perspective, a parallel resistor with a speaker will not sound the same. Near the speaker's resonant frequency, its impedance is quite high. It falls off to the nominal impedance quickly and then starts to rise again above 1kHz. So very low and very high frequencies will prefer to go through the resistor rather than the speaker and the tonal response of the system will be altered. If you have a 16 ohm tap, put the 8 ohm cab on that and it should sound very much a 4 ohm cab on your 8 ohm tap.

[selloutrr]

Weber sells a voice coil that is intended for dummy loads and power soaks. It behaves like a speaker because it basically is.

To achieve what you want. You would use an 8ohm match the wattage to the speaker you are pairing it up with.

[alvarezh]

If you can get a 100W (or 50W) 8 ohm resistor in Serbia, you are lucky, I can't get them here, everything guitar amp related must be shipped in!

While on the subject, how about an old (in working order) 8 ohm and over 50 watt speaker with the cone stripped out, wouldn't that work? That would be a reactive load with no sound being emitted.

All the best.

[Roe]

I'd try a 16ohms resistor

[overtone]

How can you get this level of difference mentioned merely from a different tap on the OT?
My gut reaction is that something else going on.
Apart from things already mentioned, maybe there is something sub optimal with this particular 8 Ohm tap in the first place?

If you want to carry on with your test, I have some links that to a supplier nearer to you:

one big 150W mother 8R resistor for under 10€:
http://www.tube-town.net/ttstore/produc ... -Watt.html

100W Z box impedance matcher 89€ and comes in tweed too if you want
http://www.tube-town.net/ttstore/produc ... -Watt.html

+ shipping.

All the best, tony

[Emetal]

How can you get this level of difference mentioned merely from a different tap on the OT?
My gut reaction is that something else going on.
Apart from things already mentioned, maybe there is something sub optimal with this particular 8 Ohm tap in the first place?

Well it's not just between 8 and 4, basically I notice difference between all the taps:
4 Ohms tap: kicks ass, lot of bass, just rich 3D sound if I can call it like that
8 Ohms tap: good, enough of bass and everything is OK but just not as 4 Ohm
16 Ohms tap: compressed sounding, lack bass, just nowhere close to above options
Pretty much same feeling as listening to music in wav. form then in MP3 with little compression and then MP3 compressed to like 96 kbps Well you guys have an idea..
Now, since I learned how to bias myself, situation is better, i discovered the amp was seriously cold running, that is taken car of now I'm at about 55% bias. Then I installed the Resonance Mod things got even better! But I still feel that difference between taps that's why I wanted to try this..

[Emetal]

If you have a 16 ohm tap, put the 8 ohm cab on that and it should sound very much a 4 ohm cab on your 8 ohm tap.

Nope, I do not wanna do any mismatch like that, I have never put 4 ohm cab in to 8 ohm tap. I mentioned already twice, all this talk is with the respect to taps and cabs always matched. I have all three tap options available on my amp, no need for mismatch.

[selloutrr]

My gut feeling is the speakers where a different wattage and the cabinet construction and air space complimented the tones you found attractive.

It's most likely less about the impedance unless you were intentionally mixing mismatched impedance.

[Emetal]

Mesa Boogie only has 8 Ohm or 4 Ohm cabs. Never 16 Ohms. There must be something behind that philosophy, and I believe less Ohms equal more bottom end, and bigger sound. Well, not a big deal I will try my cab with resistor or just get a 4 Ohm cab when I get a chance, thanks to everybody for participating

[NickC]

Mesa Boogie only has 8 Ohm or 4 Ohm cabs. Never 16 Ohms. There must be something behind that philosophy, and I believe less Ohms equal more bottom end, and bigger sound. Well, not a big deal I will try my cab with resistor or just get a 4 Ohm cab when I get a chance, thanks to everybody for participating

You could add another 8 ohm cab along with the 8 ohm you currently have. That would present a 4 ohm load. Parallel both on the 4 ohm OT tap.

[shoggoth]

Mesa Boogie only has 8 Ohm or 4 Ohm cabs. Never 16 Ohms. There must be something behind that philosophy, and I believe less Ohms equal more bottom end, and bigger sound. Well, not a big deal I will try my cab with resistor or just get a 4 Ohm cab when I get a chance, thanks to everybody for participating

That's more likely because it's simpler to get 4 ohm and 8 ohm impedance when combining multiple speakers.