Can I put a 4 ohm speaker in an amp that uses 8 ohm?

[Karma1]

I have a Weber Alnico Sig 8 - 4 ohm in my Vibro Champ - I wanted to try it in a a Vox Pathfinder that calls for an 8 ohm speaker. I think I remember reading that it wouldn't damage the amp, but could reduce the volume - but I could be way off on that. Any advice on this would be appreciated.

[insurrection]

You're good to go big guy... solid state amplifiers, especially small one's, aren't picky about impedance, as long as it's not extremely off

[mc5nrg]

SS amps usually have a minimum impedance or load which they can cope with.If the amp "sees" a load below this "x" figure which naturally varies with the amp design the amp/power transistors will probably fry.

 

Any info on the back of the Pathfinder? Or in the owners manual? Is there an extension speaker jack or just the hardwired 8 ohm speaker? If you just have the 8 ohm speaker and no extension jack I would suggest NOT using the 4 ohm speaker.

 

Rereading your original post I interpret "calls for an 8 ohm speaker" as 8 ohm minimum. Allow me do be redundant....DON"T use the 4 ohm speaker.

 

 

 

 

 

 

The above post fully endorsed by the Department of Redundancy Department aka the Squad Squad.

[tlbonehead]

 

You're good to go big guy... solid state amplifiers, especially small one's, aren't picky about impedance, as long as it's not extremely off

 

Horrible information. My Pathfinder says 8 ohms minimum on the back. Why would you risk someone else's equipment by giving out careless information like this? SS amps usually have a minimum allowable impedance. Higher impedances are fine, you just don't get as much power out of the amp.

[Electric Catfish]

What tlbonehead said.

 

Don't do it. If you do, and it fries, I"m sure insurrection will cover the repair bill, right, insurrection?

[slake moth]

 

I have a Weber Alnico Sig 8 - 4 ohm in my Vibro Champ - I wanted to try it in a a Vox Pathfinder that calls for an 8 ohm speaker. I think I remember reading that it wouldn't damage the amp, but could reduce the volume - but I could be way off on that. Any advice on this would be appreciated.

 

 

This is the opposite of how it really works. Using a higher impedance speaker is safe, but will lower the volume. Using a lower impedance speaker than the amp calls for can cause severe damage.

[GarysBlues]

Solid State, Tube...has NOTHING to do with OHMS! Stick with the minimum Ohm required. What you could do is use a coupe differnt same size,same ohm speaks that when ran together will equal what you need, Whether you run serie's are parellel.

[GibsonQC]

 

This is the opposite of how it really works. Using a higher impedance speaker is safe, but will lower the volume. Using a lower impedance speaker than the amp calls for can cause severe damage.

 

 

+1

 

 

You may safely be able to use a higher ohm speaker (16, for instance), but it is strongly recommended that you stick with 8 ohm if that is what the mfr recommends. It is never advisable to use a lower ohm speaker than recommended (i.e.: 2 or 4 ohms, in this case).

[Electric Catfish]

Exactly...that's why amplifiers list a MINIMUM load, particularly, even though it's preferable to match it up right. I don't know all the technical details, but essentially, too lower impedence speaker causes power to "back up" in the amp, with nowhere to go, basically, which fries the output transformer.

 

I'm not sure how accurate that is, technically speaking, but I'm not taking any chances, myself.

[garthman]

 

I have a Weber Alnico Sig 8 - 4 ohm in my Vibro Champ - I wanted to try it in a a Vox Pathfinder that calls for an 8 ohm speaker. I think I remember reading that it wouldn't damage the amp, but could reduce the volume - but I could be way off on that. Any advice on this would be appreciated.

 

 

It is perfectly safe (as some most people have said) to replace a lower impedance speaker with a higher impedance one. You will experience a drop in power and therefore volume - roughly, doubling the impedance will half the wattage.

 

You can actually do it the other way around (substitute low for high) but you would need to be careful not to use the amp at high volume because the opposte effect occurs, viz, wattage will double if impedance is halved.

[Electric Catfish]

It is perfectly safe (as some most people have said) to replace a lower impedance speaker with a higher impedance one. You will experience a drop in power and therefore volume - roughly, doubling the impedance will half the wattage. You can actually do it the other way around (substitute low for high) but you would need to be careful not to use the amp at high volume because the opposte effect occurs, viz, wattage will double if impedance is halved.

 

Um, no.

[garthman]

Um, no.

 

Um, roughly (as I said), yes - most modern amplifiers can handle a speaker with an impedance of anywhere between 4 and 16 ohms.

[Electric Catfish]

 

Um, roughly (as I said), yes - most modern amplifiers can handle a speaker with an impedance of anywhere between 4 and 16 ohms.

 

 

I was referring more to the "wattage will double" part, which is ridiculous.

 

That being said, mismatching is NEVER a good idea.

[The Blue Garden]

Impedence is simply resistance to electrical flow. This is commonly referred to as "load" in the context of amps and speakers.

 

Reducing an amplifier's load by substituting a 4 ohm speaker for an 8 ohm is essentially cutting this resistance in half, allowing the amp to pour out more current than it is safely designed to handle. At low volumes, maybe not a problem if you're lucky, because the overall current flow is restricted, but as soon as the amps' output current reaches its safe limit by turning the volume up, look out - overheating, fried speakers, or worse.

 

Always heed your manufacturers minimum load ratings.

[Electric Catfish]

 

Impedence is simply resistance to electrical flow. This is commonly referred to as "load" in the context of amps and speakers. Reducing an amplifier's load by substituting a 4 ohm speaker for an 8 ohm is essentially cutting this resistance in half, allowing the amp to pour out more current than it is safely designed to handle. At low volumes, maybe not a problem if you're lucky, because the overall current flow is restricted, but as soon as the amps' output current reaches its safe limit by turning the volume up, look out - overheating, fried speakers, or worse. Always heed your manufacturers minimum load ratings.

 

 

Thank you for bringing better technical information to the thread.

 

The types that tell you mismatches are o.k. will also tell you that you can get by with using a shielded instrument cable in place of an unshielded speaker cable. IGNORE THEM!

[GCDEF]

 

Solid State, Tube...has NOTHING to do with OHMS! Stick with the minimum Ohm required. What you could do is use a coupe differnt same size,same ohm speaks that when ran together will equal what you need, Whether you run serie's are parellel.

 

 

Actually it does. I'm not well versed enough to give a detailed technical explanation, but the output stage on tube amps works differently than SS.

[Burningleaves]

Impedence is simply resistance to electrical flow. This is commonly referred to as "load" in the context of amps and speakers. Reducing an amplifier's load by substituting a 4 ohm speaker for an 8 ohm is essentially cutting this resistance in half, allowing the amp to pour out more current than it is safely designed to handle. At low volumes, maybe not a problem if you're lucky, because the overall current flow is restricted, but as soon as the amps' output current reaches its safe limit by turning the volume up, look out - overheating, fried speakers, or worse. Always heed your manufacturers minimum load ratings.

 

 

 

[Electric Catfish]

 

Actually it does. I'm not well versed enough to give a detailed technical explanation, but the output stage on tube amps works differently than SS.

 

 

Impedence is the same thing on any electronic equipment. He's right...it doesn't have anything to do with "solid state/tube". Solid state and tube amps do have different kinds of output transformers, I believe, but 4 ohms is still 4 ohms.

 

You can't go wrong using the correct load, on either.

[GCDEF]

 

Impedence is the same thing on any electronic equipment. He's right...it doesn't have anything to do with "solid state/tube". Solid state and tube amps do have different kinds of output transformers, I believe, but 4 ohms is still 4 ohms. You can't go wrong using the correct load, on either.

 

 

Yeah, 4 ohms is still 4 ohms. But SS amps have a minimum impedance you can safely run. That's not the case with tube amps as I understand it. A 16 ohm cab on a 4 ohm min SS amp is safe. A 16 ohm cab on a 4 ohm tube amp may cause problems.

[Electric Catfish]

Yeah, 4 ohms is still 4 ohms. But SS amps have a minimum impedance you can safely run. That's not the case with tube amps as I understand it. A 16 ohm cab on a 4 ohm min SS amp is safe. A 16 ohm cab on a 4 ohm tube amp may cause problems.

 

Both have a minimum impedence.

 

That has nothing to do with tube/solid state. Impedence deals with the flow of electricity, simply put. Both tube and solid state amps should be matched up to the correct load.

 

I'm not sure where you guys are getting this stuff, but all I can say is, it's your gear.

[Burningleaves]

 

Yeah, 4 ohms is still 4 ohms. But SS amps have a minimum impedance you can safely run. That's not the case with tube amps as I understand it. A 16 ohm cab on a 4 ohm min SS amp is safe. A 16 ohm cab on a 4 ohm tube amp may cause problems.

 

 

 

 

Mmm...I recall reading in some audiophile site a bit back that with tube amps you have more leeway if you do decide to not match up your impedience.

[GCDEF]

Both have a minimum impedence. That has nothing to do with tube/solid state. Impedence deals with the flow of electricity, simply put. Both tube and solid state amps should be matched up to the correct load. I'm not sure where you guys are getting this stuff, but all I can say is, it's your gear.

 

I know what impedance is, and I'm not sure why you're arguing with me.

 

There is no "correct" load with solid state amps, only a minimum. There is a "correct" load with tube amps.

[GCDEF]

Both have a minimum impedence. That has nothing to do with tube/solid state. Impedence deals with the flow of electricity, simply put. Both tube and solid state amps should be matched up to the correct load. I'm not sure where you guys are getting this stuff, but all I can say is, it's your gear.

 

"One thing you CAN do to hurt a tube output transformer is to put too high an ohmage load on it. If you open the outputs, the energy that gets stored in the magnetic core has nowhere to go if there is a sudden discontinuity in the drive, and acts like a discharging inductor. This can generate voltage spikes that can punch through the insulation inside the transformer and short the windings. I would not go above double the rated load on any tap"

 

http://www.geofex.com/tubeampfaq/TUBEFAQ.htm#tolerances

 

According to that, higher impedance will hurt tubes.

[Electric Catfish]

 

"One thing you CAN do to hurt a tube output transformer is to put too high an ohmage load on it. If you open the outputs, the energy that gets stored in the magnetic core has nowhere to go if there is a sudden discontinuity in the drive, and acts like a discharging inductor. This can generate voltage spikes that can punch through the insulation inside the transformer and short the windings. I would not go above double the rated load on any tap" http://www.geofex.com/tubeampfaq/TUBEFAQ.htm#tolerances According to that, higher impedance will hurt tubes.

 

 

I never said it wouldn't.

 

My position all along has been (pretty clearly, I think) to use the correct impedence speaker/cab for either one.

 

My bassman has "minimum load 4 ohms" on it, too. That doesn't mean I'm going to use a 16 ohm cab, or even an 8 ohm. 4 ohms is the correct load. A lot of people run them with 8, NOBODY in their right mind would run it with a 2 ohm load, but either way, 4 ohms is correct.

 

You're putting too much stock in the word "minimum".

[Electric Catfish]

the rating on the speaker is it's resistance. If you have an amp that is set to send out a current that will be resisted by atleast 8 ohms, but have a speaker that will only give a resistance of 4 ohms it will fry your amp eventually. You always want a your speaker to have a resistance of more or equal value to the amp. Bu the safest thing is to use an equal value. SS or tube, follow the maufacturers intructions, it's why they have it there. To protect you and them.

 

Unless it's a modelling amp. Those ohms are different.