question about new speaker ohm ratings and AV receiver compatibility

neuro99

Member
Hi
I have a Yamaha RXV-673
I have recently decided to upgrade my speakers to Dali Oberon 5.1 - here are their stated impedances (i didn't realise this may be an issue before making the purchase):

centre (vokal) - 4 ohms
fronts & rears - Nominal Impedance 6 ohms

here are the AVR specs


RX-V673
AV Receiver
Amplifier SectionChannel7.2
Rated Output Power (1kHz, 1ch driven)150W (4 ohms, 0.9 % THD [European Model])
Rated Output Power (20Hz-20kHz, 2ch driven)90W (8ohms, 0.09% THD)
Maximum Effective Output Power (1kHz, 1ch driven) (JEITA)150W (8ohms, 10% THD)
Dynamic Power per Channel (8/6/4/2 ohms)130/170/200/240W

i have been trying to get my head around this for some time and just wanted to get some confirmation that i would not be overloading my amp and potentially at risk of frying it.

I am of the understanding that the risk to the speakers in this scenario is low.

if theres an issue with the amp powering the speakers at volume, what sort of dB should I be worried about the health of the speakers or amp?

thanks in advance.
 
Last edited:

Gasp3621

Distinguished Member
With the normal lounge use there is no need to worry. Just keep the impedance switch on 8ohm default and don´t activate ECO mode to get the best performance and make sure the unit has good space (ventilation) top/sides. Naturally you will set speaker sizes small and check speaker crossover settings (not lower than 80hz) both after running YPAO. Hope you have some type of tripod or mic stand for the mic so it won`t be laying on the couch.
 

Kapkirk

Active Member
Should be fine but the amp will just run a little warmer on the amplifier channels that have lower impedance speakers, 4 ohm speakers are a little harder to drive than 8 ohm. Most modern amplifiers like the Yamaha can usually cope with this scenario. If you notice the amp gets very hot in use then you may need to change the impedance setting in the amp as detailed in the Manual below, but this will result in a slight loss of output power.

Setting the speaker impedance. YAMAHA RX-V673
Under its default settings, the unit is configured for 8-ohm speakers. When connecting
6-ohm speakers, set the speaker impedance to "6 Ω MIN". In this case, you can also
use 4-ohm speakers as the front speakers.
1
Before connecting speakers, connect the power cable to an AC wall
outlet.
2
While holding down STRAIGHT on the front panel, press
MAIN ZONE z.
MAIN ZONE z
STRAIGHT
3
Check that "SP IMP." is displayed on the front display.
SP IMP.
8 MIN
4
Press STRAIGHT to select "6 Ω MIN".
5
Press MAIN ZONE z to set the unit to standby mode and remove the power cord.
 

MattyBB

Active Member
Should be fine but the amp will just run a little warmer on the amplifier channels that have lower impedance speakers, 4 ohm speakers are a little harder to drive than 8 ohm. Most modern amplifiers like the Yamaha can usually cope with this scenario. If you notice the amp gets very hot in use then you may need to change the impedance setting in the amp as detailed in the Manual below, but this will result in a slight loss of output power.

Setting the speaker impedance. YAMAHA RX-V673
Under its default settings, the unit is configured for 8-ohm speakers. When connecting
6-ohm speakers, set the speaker impedance to "6 Ω MIN". In this case, you can also
use 4-ohm speakers as the front speakers.
1
Before connecting speakers, connect the power cable to an AC wall
outlet.
2
While holding down STRAIGHT on the front panel, press
MAIN ZONE z.
MAIN ZONE z
STRAIGHT
3
Check that "SP IMP." is displayed on the front display.
SP IMP.
8 MIN
4
Press STRAIGHT to select "6 Ω MIN".
5
Press MAIN ZONE z to set the unit to standby mode and remove the power cord.
Is this not similar to activating a 4ohm ECO mode?

As mentioned by @Gasp3621 and widely written about, using an "ECO Mode" or "4-ohm Mode" simply limits power available to the speakers and is for manufacturer testing purposes, not general use.
 

Gasp3621

Distinguished Member
Yep, Denon X6x00H (+2k£) level machine measured 18w 7ch driven when impedance switch was set to 4ohm. That switch should not be touched, ever! ECO mode does same thing. In D&M units person can use ECO "Auto" if required.

People are making the whole 4ohm big issue for normal users who aren´t even listening loud in first place. Also we can´t judge a speaker fully without seeing the impedance graph and phase angles. There is many 8ohm nominal speakers which would be questionable. Few years ago i talked with Wharfedale brand speaker designer and he shared lot of things about this as their budget speakers are 4ohm nominal also. Too much panic.
 

neuro99

Member
thank you all for your detailed responses.

you're right we generally won't be listening at loud levels, but will keep an eye on the amps heat
will set the speakers to small and crossover at or above 80
i'll leave the impedance settings on the amp as they are

unfortunately i don't have the ypao mic for the setup but thats another issue... will try with another mic but to my knowledge this isn't ideal

we generally set the larger speaker (i was using the vokal on its own before) to a lower setting just in case.
 

MattyBB

Active Member
unfortunately i don't have the ypao mic for the setup but thats another issue... will try with another mic but to my knowledge this isn't ideal
Could you borrow a YPAO mic or buy one 2nd hand on ebay? Would make a difference with all the room correction features.

If this isn't possible, a miniDSP UMIK-1 (c. £100) plus REW software (free) would be even better - a professional alternative with a lot more capability/accuracy.
 

Gasp3621

Distinguished Member
thank you all for your detailed responses.

you're right we generally won't be listening at loud levels, but will keep an eye on the amps heat
will set the speakers to small and crossover at or above 80
i'll leave the impedance settings on the amp as they are

unfortunately i don't have the ypao mic for the setup but thats another issue... will try with another mic but to my knowledge this isn't ideal

we generally set the larger speaker (i was using the vokal on its own before) to a lower setting just in case.

Where do you live? Ebay has YPAO mics i believe, just check it´s for your model. You can also get the YPAO mic from Yamaha direct. Otherwise you need to buy c-weighted spl meter.
 

Jester1066

Well-known Member
Why does EBAY come up with a bunch of saucy underwear when you search "ypao mic"? 😂
Of course I had to validate your statement 🙊🙈...😂

#INeverLearnDoI
 

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