Speaker Impedance

[Phil J N.Z.]

You are misunderstanding the spec let alone what Marantz is indicating.

Well there is a 4 Ohm setting in the AVR, so why have it if as you say I am misunderstanding what they say, are you telling me Marantz don'y know what they are doing.

Below is what is printed in the manual for the AVR.

Use speakers with an impedance of 4 – 16 Ω/ohms.

So please tell me how I misunderstand what is written in the manual.

 

[Phil J N.Z.]

I just updated my last post to advise you buy a woofer tester, and settle the issue. If you set the amp to a lower impedance it can not increase the power. They don't give a four ohm spec. as they don't want you using 4 ohm speakers, but the fact is that you can not generally avoid it. It seems most consumers are prepared to tolerate this nonsense, including many members here. I say emphatically that I will not, and so avoid receivers like the plague.

Well I switched it to 4 Ohms last night and it still sounds ok to me. it's mot in a huge room and am only running a 5.1 setup.
I did some research on this issue with this speaker and it seem it is how it is wired if the woofers are wired in parrell or series, so I will pull it apart tonight and see how its wired and if I can change it so that it is 8 Ohms.

 

[TLS Guy]

Well I switched it to 4 Ohms last night and it still sounds ok to me. it's mot in a huge room and am only running a 5.1 setup.
I did some research on this issue with this speaker and it seem it is how it is wired if the woofers are wired in parrell or series, so I will pull it apart tonight and see how its wired and if I can change it so that it is 8 Ohms.

Do not wire the drivers in series, that is a bad idea, for one thing the crossover frequency will be completely changed and you will loose 6db of output to the woofers. If you are happy with it on the four ohm setting, then leave it that way. I can assure you the drivers are wired in parallel so you don't need to take it apart.

 

[Eppie]

The crossover in the speaker is designed specifically for the way it is currently wired. Changing the wiring will totally mess up the crossover and impedance.

The 6 ohm and 4 ohm settings are mostly marketing fluff and few people use it. It limits the power the amps can put out so in some sense it can provide a bit of protection with speakers that provide a difficult load. As was mentioned before, most speakers dip down to 4 ohms at certain frequencies and most amps can handle this just fine. There are exceptions like some B&W models which are known to provide a difficult load for AVRs. By using the 4 ohm setting you are giving up some additional head room... that reserve power in the amp for sudden loud passages or transients. Having additional head room is a good thing. If you are not pushing the AVR too hard it should work fine with the 8 ohm setting. If you're still worried about the AVR you can set it to 6 ohms and have peace of mind. Frankly you would gain more with a good cooling fan on the AVR. Heat is the real enemy and if the receiver is getting warm when played loud a cooling fan (like AC Infinty) will improve longevity.

 

[TLS Guy]

The crossover in the speaker is designed specifically for the way it is currently wired. Changing the wiring will totally mess up the crossover and impedance.

The 6 ohm and 4 ohm settings are mostly marketing fluff and few people use it. It limits the power the amps can put out so in some sense it can provide a bit of protection with speakers that provide a difficult load. As was mentioned before, most speakers dip down to 4 ohms at certain frequencies and most amps can handle this just fine. There are exceptions like some B&W models which are known to provide a difficult load for AVRs. By using the 4 ohm setting you are giving up some additional head room... that reserve power in the amp for sudden loud passages or transients. Having additional head room is a good thing. If you are not pushing the AVR too hard it should work fine with the 8 ohm setting. If you're still worried about the AVR you can set it to 6 ohms and have peace of mind. Frankly you would gain more with a good cooling fan on the AVR. Heat is the real enemy and if the receiver is getting warm when played loud a cooling fan (like AC Infinty) will improve longevity.

Cooling is a good idea. However he has blown a center amp channel. So he can keep his volume down, or force it to be down with the four ohm setting.
This is coupled with fact that I am fairly certain newer receivers are less robust than older ones.

Honestly receivers need to be able to handle four ohm loads at power, and have a four ohm spec. An amp without an honest four ohm spec. is not really fit for purpose. Four ohm speakers should be optimal for solid state amps. The current situation is not really good enough and frankly a disgrace.

 

[Eppie]

Cooling is a good idea. However he has blown a center amp channel. So he can keep his volume down, or force it to be down with the four ohm setting.
This is coupled with fact that I am fairly certain newer receivers are less robust than older ones.

Honestly receivers need to be able to handle four ohm loads at power, and have a four ohm spec. An amp without an honest four ohm spec. is not really fit for purpose. Four ohm speakers should be optimal for solid state amps. The current situation is not really good enough and frankly a disgrace.

Yes, it makes me wonder what to do for my next upgrade. Leaning towards a Denon X3700H as it has the same power as my current AVR but has pre-outs on all channels so I can add an amp for the front 3 if needed. Internal amps should be sufficient for surround duty.

Forgot that the op has a B&W center. I would still expect that receiver to work ok with it at moderate levels but hard to say without seeing impedance graphs.

@Phil J N.Z. it can get a bit confusing but the power rating is not really tied to the speaker impedance selector switch. The power rating is an electrical characteristic and is inversely proportional to impedance. The impedance of a speaker varies with frequency so manufacturers quote an average value but often lean to the high side as 8 ohm speakers sell better than 4 ohm. The 8 ohm selector setting is the default and runs the amps at rated power. With an 8 ohm load the amps can output up to 125W at the rated .05% total harmonic distortion (THD). Since power increases when impedance drops, the amps can output up to 165W into a 6 ohm load, also with the selector switch set to 8 ohms. The selector switch actually throttles the amps back a bit to protect them from low impedance loads, so at the 4 ohm selector setting you will get less than rated power but it offers some protection for the amps if that particular speaker happens to dip below 4 ohms at certain frequencies. While TLS Guy was not able to find an impedance graph for that model center, B&W has a reputation for designing speakers that dip well below their stated impedance. While the initial recommendation was to leave the setting alone, since you have B&W speakers up front that's one of the exceptions to using the lower impedance selector settings or to use an external amp via the pre-out jacks.

 

[Verdinut]

Yes, it makes me wonder what to do for my next upgrade. Leaning towards a Denon X3700H as it has the same power as my current AVR but has pre-outs on all channels so I can add an amp for the front 3 if needed. Internal amps should be sufficient for surround duty.

I've owned one X3700H for two years now, and either that AVR or the newer X3800H would be a good additon to your HT system. I'm using external amplification for my seven channels, but the AVR internal amps would be plenty sufficient for surround speaker driving.

 

[Verdinut]

The woofer tester which TLS Guy recommends, is now called the DATS Audio Component Test System that Parts-Express sell:

Dayton Audio DATS V3 Computer Based Speaker & Audio Component Test System

Dayton Audio DATS V3 Computer Based Speaker & Audio Component Test SystemDayton Audio DATS V3 Computer Based Speaker & Audio Component Test SystemThe Perfect Companion for Audio ProfessionalsWhen designing the DATS V3 measurement device, Dayton Audio took everything customers love about the DATS...

www.parts-express.com

 

[Eppie]

I've owned one X3700H for two years now, and either that AVR or the newer X3800H would be a good additon to your HT system. I'm using external amplification for my seven channels, but the AVR internal amps would be plenty sufficient for surround speaker driving.

Thanks, I appreciate the feedback. Reason I was looking at the X3700H was that it's the last model with component input for my Wii. They seem to be dropping component and composite support and I still have a PS2 and Wii, so legacy device support saves me from getting analogue to HDMI converters, and Denon does good upscaling. I found one on CentreHiFi for $1800 Cdn while the X3800H on Crutchfield is C$2050. X4700H bumps that up to C$2800 for 125W/ch but my current 105W/ch seems to be enough and the extra $1000 could go towards an amp for the front 2 or 3. Both the previous and current models are HDCP 2.3 so I have not found a compelling reason to go with the current model. Main difference I see is more 8k inputs but I have a new 4k TV so the X3700H is sufficient. Latest models add Dirac as well but I don't see that as a game changer for my smallish room.

Best I can hope for in my room is 7.2.2 but I'll likely change to 5.1.2 for now and experiment with rear speakers using the Wharfdale flat panels I acquired. I'll discuss proposed changes in my home theatre thread later. If anyone knows of a good reason to go with the X3800H or X4800H vs the X3700H I'm open to opinions but the X3700H looks to offer the best bang for the buck with the option to add amplification.

 

[highfigh]

Speaker impedance is often shown as 'nominal'. The like shows several definitions, but this seems to match what might be intended by speaker manufacturers-

"b: of, being, or relating to a designated or theoretical size that may vary from the actual : APPROXIMATE"

Definition of NOMINAL

of, relating to, or being a noun or a word or expression taking a noun construction; of, relating to, or constituting a name; bearing the name of a person… See the full definition

www.merriam-webster.com

That means, look further if you want to KNOW how your equipment will work together.

 

[TLS Guy]

Speaker impedance is often shown as 'nominal'. The like shows several definitions, but this seems to match what might be intended by speaker manufacturers-

"b: of, being, or relating to a designated or theoretical size that may vary from the actual : APPROXIMATE"

Definition of NOMINAL

of, relating to, or being a noun or a word or expression taking a noun construction; of, relating to, or constituting a name; bearing the name of a person… See the full definition

www.merriam-webster.com

That means, look further if you want to KNOW how your equipment will work together.

To a loudspeaker manufacturer's sales department, Nominal means Obfuscation pure and simple.

 

[j_garcia]

Cooling is a good idea. However he has blown a center amp channel. So he can keep his volume down, or force it to be down with the four ohm setting.
This is coupled with fact that I am fairly certain newer receivers are less robust than older ones.

Honestly receivers need to be able to handle four ohm loads at power, and have a four ohm spec. An amp without an honest four ohm spec. is not really fit for purpose. Four ohm speakers should be optimal for solid state amps. The current situation is not really good enough and frankly a disgrace.

For what they are charging for AVRs right now, that is for sure that they are underpowered. I will also note I have not encountered many AVRs capable of handling a full compliment of 4 Ohm speakers at higher SPL. Maybe the older Outlaw AVRs which haven't been made in years.

 

[Trell]

For what they are charging for AVRs right now, that is for sure that they are underpowered. I will also note I have not encountered many AVRs capable of handling a full compliment of 4 Ohm speakers at higher SPL. Maybe the older Outlaw AVRs which haven't been made in years.

My 2015 model Denon AVR-X4200W does so with a 5.1 setup using 4 ohms speakers dipping down to 3.2 Ohm. A few years ago my new mains are only down to 4.1 Ohm or so.

I’m sitting 2.7 m from the mains.

 

[j_garcia]

My 2015 model Denon AVR-X4200W does so with a 5.1 setup using 4 ohms speakers dipping down to 3.2 Ohm. A few years ago my new mains are only down to 4.1 Ohm or so.

I’m sitting 2.7 m from the mains.

I had a full set of 4 Ohm speakers that dipped to 2.6 Ohms. My old Marantz 8200 could handle them at average levels, but not elevated levels. Since I had a large room, I moved the front 3 to an amp and never had issues after that.

 

[highfigh]

To a loudspeaker manufacturer's sales department, Nominal means Obfuscation pure and simple.

People in sales need a bit of science background but that would make consumers sad because they wouldn't understand what they were told. It would be similar to the late-'70s, when more specs were included in sales ads and people would come into the stereo stores to ask "How many Amps does this put out?".

 

[Phil J N.Z.]

The crossover in the speaker is designed specifically for the way it is currently wired. Changing the wiring will totally mess up the crossover and impedance.

The 6 ohm and 4 ohm settings are mostly marketing fluff and few people use it. It limits the power the amps can put out so in some sense it can provide a bit of protection with speakers that provide a difficult load. As was mentioned before, most speakers dip down to 4 ohms at certain frequencies and most amps can handle this just fine. There are exceptions like some B&W models which are known to provide a difficult load for AVRs. By using the 4 ohm setting you are giving up some additional head room... that reserve power in the amp for sudden loud passages or transients. Having additional head room is a good thing. If you are not pushing the AVR too hard it should work fine with the 8 ohm setting. If you're still worried about the AVR you can set it to 6 ohms and have peace of mind. Frankly you would gain more with a good cooling fan on the AVR. Heat is the real enemy and if the receiver is getting warm when played loud a cooling fan (like AC Infinty) will improve longevity.

I have set it to the 4 Ohms setting, it is well ventilated as well.