• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Entry Level AVR with 4ohm minimum impedance

_thelaughingman

Major Contributor
Forum Donor
Joined
Jan 1, 2020
Messages
1,324
Likes
1,943
Hello folks,
I have scoured the search engines for a viable solution to my need. I have a pair of hand me down RTR G200s floor standing speakers with 4ohm impedance rating. These are currently mated to an onkyo to -sr302 AVR that has a range of 6 to 16ohm for speakers. The onkyo is 12 years old and I am looking to upgrade the AVR with something new that will support those RTR’s until I upgrade those in the future. Currently listening to music on vinyl through a At-lp120 and a Sony 5 disc cd changer and have an old school pioneer processor all routed through the receiver.
I’m looking for suggestions on an AVR or if an amp would be suitable for my use. Looking to spend maximum of $500, not a lot of money for a hi-fi avr but think it’s possible. Thanks for the help.
 
OP
_thelaughingman

_thelaughingman

Major Contributor
Forum Donor
Joined
Jan 1, 2020
Messages
1,324
Likes
1,943
All the AVRs handle 4 ohm load. For legal reasons they only state 6 ohm. Just make sure you have good circulation and cooling.

amirm,
Thanks for the response, I thought that was the case but thought I’d rather ask more knowledgeable individuals.
 
OP
_thelaughingman

_thelaughingman

Major Contributor
Forum Donor
Joined
Jan 1, 2020
Messages
1,324
Likes
1,943

3dbinCanada

Senior Member
Joined
Apr 29, 2020
Messages
408
Likes
242
All the AVRs handle 4 ohm load. For legal reasons they only state 6 ohm. Just make sure you have good circulation and cooling.
That statement needs qualifications... such as ...not driving the AVR into clipping and destroying speakers..closely related to the previous statement...trying to achieve concert level sounds in a large room which will drive an AVR into clipping.
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
All the AVRs handle 4 ohm load. For legal reasons they only state 6 ohm. Just make sure you have good circulation and cooling.

Handle without blowing up is one thing, but the distortion may be another. Amplifying voltage is easy. Amplifying current is harder.

I would wonder what the "legal reasons" are. Many amps are clearly rated for 4 Ohms. I was reading the 6 Ohms as rated for an 8 nominal impedance, as most consumers would think a 8 Ohm speaker was actually 8 Ohms, when the DC resistance is much closer to 6.
 

Chrispy

Master Contributor
Forum Donor
Joined
Feb 7, 2020
Messages
7,751
Likes
5,910
Location
PNW
Actually few avrs "rate" at 4 ohm except a vague dynamic rating. If you have really low impedance speakers and want to get loud at an appreciable distance I'd go with a more suitable amp (external if you have pre-outs). If the speaker is rated 4 ohms it certainly will dip below that, too.....
 

3dbinCanada

Senior Member
Joined
Apr 29, 2020
Messages
408
Likes
242
Actually few avrs "rate" at 4 ohm except a vague dynamic rating. If you have really low impedance speakers and want to get loud at an appreciable distance I'd go with a more suitable amp (external if you have pre-outs). If the speaker is rated 4 ohms it certainly will dip below that, too.....

Most of my PSB kiss 4 ohms at various frequency points which brings me to another point. Stating 4ohms is an incomplete spec and really dumb if you ask me. A 4ohm load with a 10 degrees phase angle is much easier to drive than an 8 ohm speaker with 60 degree phase angle. It also depends where in the frequency range that the 4 ohm dip occurs. I wish the industry would smarten the hell up and start publishing real specs.
 

beagleman

Major Contributor
Joined
Sep 24, 2020
Messages
1,156
Likes
1,576
Location
Pittsburgh Pa
Actually few avrs "rate" at 4 ohm except a vague dynamic rating. If you have really low impedance speakers and want to get loud at an appreciable distance I'd go with a more suitable amp (external if you have pre-outs). If the speaker is rated 4 ohms it certainly will dip below that, too.....


I tried a set of speakers (Polk lsi15) that are "quite" 4 ohm rated on my cheapo AVR I got recently. .(Yamaha Rx-v373) and despite all the naysayers, they worked fine, did not overheat, did not clip, or anything.

Was it the last word in perfection?.....No, but it almost seemed a non issue at the same time.
And yes I played them LOUD and avoided clipping and it was fine.

I think the 4 ohm worry is a bit overstated.
My Separates would go a bit higher with less stress, but for sure not fraught with danger with this Cheap AVR I tried it on.
 

3dbinCanada

Senior Member
Joined
Apr 29, 2020
Messages
408
Likes
242
I tried a set of speakers (Polk lsi15) that are "quite" 4 ohm rated on my cheapo AVR I got recently. .(Yamaha Rx-v373) and despite all the naysayers, they worked fine, did not overheat, did not clip, or anything.

Was it the last word in perfection?.....No, but it almost seemed a non issue at the same time.
And yes I played them LOUD and avoided clipping and it was fine.

I think the 4 ohm worry is a bit overstated.
My Separates would go a bit higher with less stress, but for sure not fraught with danger with this Cheap AVR I tried it on.

You showed good judgement with the volume control...
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
Most of my PSB kiss 4 ohms at various frequency points which brings me to another point. Stating 4ohms is an incomplete spec and really dumb if you ask me. A 4ohm load with a 10 degrees phase angle is much easier to drive than an 8 ohm speaker with 60 degree phase angle. It also depends where in the frequency range that the 4 ohm dip occurs. I wish the industry would smarten the hell up and start publishing real specs.

You and I may understand that, but the average consumer only sees one number and does not even understand what it means. They buy amplifiers based on the rated power and speakers based on how many drivers they see. Bigger and more has to be better, right?

If one only cares about blowing up or loud, fine. If one cares about distortion and stability, read up on amplifier design and very quickly you will understand why I don't build 4 Ohm speakers. Class D may be a different question, I have no experience. Just class A and AB. Some amps may remain stable at low Ohms, some are not. Distortion goes up with current. Can one get away with it? Sometimes. People jump out of perfectly good airplanes too. They usually get away with it. I know two who didn't.

This does not answer the suggestion 6 Ohms is specified by some legal regulation. I kind of doubt it. It is likely where they know that the amp will live if it is cranked to rated power into a resistor of that size, it will survive being cranked all the way up into a speaker. Legal as in not getting sued , not because of a mandate. Could be wrong. The EU has mandated all kinds of things.
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
I've not heard of any EU regulation that mandates 6 ohms rating, but there's an IEC standard (IEC/EN 60268-5 I think it is) which states that a loudspeaker should not drop it's impedance below 80% of its rating, so for a nominal 8 ohm loudspeaker, the minimum impedance should exceed 6.4 ohms, or to round down, 6 ohms. However, there's no legal requirement for loudspeaker manufacturers to adhere to this IEC standard, and very few do.

S.
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
That's a logical answer Serg. So an amplifier with a 6 Ohm rating means it is suitable for an 8 Ohm nominal speaker. I am sure the lawyers would not allow the term "nominal" in the spec. You can get away with it as so many people think they need 200W when they are using all of 20.

The one disaster I remember was I think, an Apogee ribbon where the load was almost capacitive. It would upset almost all amps at the time. Shame, nice speakers.

For those who understand how transistors work, really serious amplifiers have more pairs of outputs. A hint is the 4 Ohm power rating will be close to twice the 8 Ohm rating. That means the power supply has enough current to maintain the rail voltage and it has enough outputs to distribute the load. Very few go to this expense, but sonically it is worth it. Take a basic Self Blameless and double the outputs to see/hear what I mean. I did it on a cheap Chinese MV-50 clone kit. Real benefit is a more linear operating range of the outputs. Marketing department would then say to up the voltage and advertise it as a much bigger amp as that is what sells and you are back to square one.

Beef I have with specs is class D is by standard agreement, rated at 1% distortion. So some nice new Hypex may be .001% @ 90W, they list it at 1% @ 100W. Fine for cars ( where the standard came from) but not for hi-fi. Fortunately a few respectable companies give us a graph. Unfortunately, some not so nice amps are .5% across the band!
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
That's a logical answer Serg. So an amplifier with a 6 Ohm rating means it is suitable for an 8 Ohm nominal speaker. I am sure the lawyers would not allow the term "nominal" in the spec. You can get away with it as so many people think they need 200W when they are using all of 20.

The one disaster I remember was I think, an Apogee ribbon where the load was almost capacitive. It would upset almost all amps at the time. Shame, nice speakers.

For those who understand how transistors work, really serious amplifiers have more pairs of outputs. A hint is the 4 Ohm power rating will be close to twice the 8 Ohm rating. That means the power supply has enough current to maintain the rail voltage and it has enough outputs to distribute the load. Very few go to this expense, but sonically it is worth it. Take a basic Self Blameless and double the outputs to see/hear what I mean. I did it on a cheap Chinese MV-50 clone kit. Real benefit is a more linear operating range of the outputs. Marketing department would then say to up the voltage and advertise it as a much bigger amp as that is what sells and you are back to square one.

Beef I have with specs is class D is by standard agreement, rated at 1% distortion. So some nice new Hypex may be .001% @ 90W, they list it at 1% @ 100W. Fine for cars ( where the standard came from) but not for hi-fi. Fortunately a few respectable companies give us a graph. Unfortunately, some not so nice amps are .5% across the band!

Yes, if only loudspeaker manufacturers took any notice of the IEC standard. So many quote nominal 8 ohms, because that's what the public understand, it's a nice single number. Quoting impedance for example as nominal 8 ohms, minimum 3.8 ohms @ 80Hz would only confuse people.

As to the Apogee ribbon, that was a pretty much purely resistive load, not capacitative, but the Scintilla presented a load of only 1 ohms, which didn't half upset most amps. I understand that the Krell was developed as one of the very few amplifiers of the era capable of driving the Scintilla.

Doubling output into 4 ohms from 8 is indeed what a 'perfect' amplifier with a fully stabilised supply will do, and in practice there are very few Class A or AB amplifiers that actually do it. There's the output impedance of the amplifier itself, which won't be zero, although can be close, and the regulation of the power supply. One way of making sure it'll happen is to design the amplifier to provide, say, 200 watts into 4 ohms, (or 400 watts into 2 ohms!) then it'll provide 100 watts into 8 ohms easily. The temptation then is for commercial reasons to rate the amplifier at, say, 120 watts into 8 ohms, in which case it won't double power into 4 ohms, even though it's the same amplifier!

As to the 1% distortion figure, it's a way of getting the power number up, without being silly about distortion, in that very brief clipping that takes the amp to 1% will be generally inaudible provided the amp clips cleanly and recovers fast. I measure my amps to the onset of clipping, so still at 0.01% or whatever. One caveat is that valve / tube amps may not have a fixed sharp clipping point, so rating those at 1% distortion makes a certain sense.

S.
 

3dbinCanada

Senior Member
Joined
Apr 29, 2020
Messages
408
Likes
242
I've not heard of any EU regulation that mandates 6 ohms rating, but there's an IEC standard (IEC/EN 60268-5 I think it is) which states that a loudspeaker should not drop it's impedance below 80% of its rating, so for a nominal 8 ohm loudspeaker, the minimum impedance should exceed 6.4 ohms, or to round down, 6 ohms. However, there's no legal requirement for loudspeaker manufacturers to adhere to this IEC standard, and very few do.

S.

Thats the dumbest regulation for a speaker I've seen and clearly made by a beuracrat rather than a seasoned speaker designer. Unless one uses active speakers with digital filters, impedance is going to be all over the map based on crossover type and order and driver characteristics.

Panel speakers such as made by Martin Logan are almost pure capactive loads, with huge phase angles.
 
Last edited:

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
Thats the dumbest regulation for a speaker I've seen and clearly made by a beuracrat rather than a seasoned speaker designer. Unless one uses active speakers with digital filters, impedance is going to be all over the map based on crossover type and order and driver characteristics.

Panel speakers such as made by Martin Logan are almost pure capactive loads, with huge phase angles.
I disagree. It then behoves loudspeaker designers to be truthful about their impedance rating. Instead of saying every loudspeaker is 8 ohms, some could be 6.3 ohms, some might be 5.2 ohms, some might be only 2.1 ohms. Much more truthful, but I accept, commercially would be a disaster. As it's not a legal requirement, just about every manufacturer I know of, with the possible exception of Harbeth, ignore it completely.

Anyway, impedance variations are not always a necessary consequence. KEF had a very successful range of passive three-way loudspeakers that presented an almost purely resistive 4ohm load, by using a technique KEF called Conjugate Load Matching. It didn't sacrifice sensitivity but added considerably to the complexity and cost of the crossover such that even they abandoned it later, presumably because it wasn't perceived as a benefit worth paying for.

S.
 

beagleman

Major Contributor
Joined
Sep 24, 2020
Messages
1,156
Likes
1,576
Location
Pittsburgh Pa
You showed good judgement with the volume control...

Absolutely. And I did not mean to come off as leaning way "Pro Avr" for everything, but simply found the truth is a bit of both. Yes it got warmer, and yes some restraint was needed at times, but its not the "NO GO" that I have seen some state either.

My idea was to treat it like I would a good 35 watt "4 ohm rated" receiver, instead of a 8ohm rated Avr with 65 Watts/channel, as it is truly rated.
 
OP
_thelaughingman

_thelaughingman

Major Contributor
Forum Donor
Joined
Jan 1, 2020
Messages
1,324
Likes
1,943
Update to the my request. After going back and forth and thoroughly researching the availability and options that suit my needs, I bought myself an amplifier.
Purchased a Denon PMA600Ne amplifier rated for 70w at 4ohms. These will power a pair of RTR GS200 speakers rated at 120w at 4ohm. These are old and functional until I upgrade to a good pair of speakers. This completes my entry level hi-fi setup.
Turntable- Audio Technica LP-60
Sony 5 disc cd changer
Pioneer stereo processor from 70’s
Ifi zen dac blue
Art DJ phono preamp
 

Attachments

  • IMG_0072.jpeg
    IMG_0072.jpeg
    183.9 KB · Views: 164
Last edited:

3dbinCanada

Senior Member
Joined
Apr 29, 2020
Messages
408
Likes
242
I disagree. It then behoves loudspeaker designers to be truthful about their impedance rating. Instead of saying every loudspeaker is 8 ohms, some could be 6.3 ohms, some might be 5.2 ohms, some might be only 2.1 ohms. Much more truthful, but I accept, commercially would be a disaster. As it's not a legal requirement, just about every manufacturer I know of, with the possible exception of Harbeth, ignore it completely.

Anyway, impedance variations are not always a necessary consequence. KEF had a very successful range of passive three-way loudspeakers that presented an almost purely resistive 4ohm load, by using a technique KEF called Conjugate Load Matching. It didn't sacrifice sensitivity but added considerably to the complexity and cost of the crossover such that even they abandoned it later, presumably because it wasn't perceived as a benefit worth paying for.

S.

Do you have any material on what KEF did other than KEF's advertising? I would like to read up on this as it seems interesting.
 
Top Bottom