Experience Wiim Amp at 2.67 load?

[marticus24]

Greetings, all!

I'm considering using a WiiM Amp for an outdoor patio zone that will have 6 x 8 ohm satellite speakers (similar to Sonance MAG system). If I run 3 in a left channel (in parallel) and 3 in a right channel (in parallel), it will end up presenting with a 2.67ohm load to the amp on each channel.

Official WiiM manual and documentation says minimum supported impedance is 4 ohms, but if I look at the UK version, it says 2.67. There is also a forum post from what appears to be the WiiM official account on this forum (over in WiiM Pro announce thread, from just a month or two ago), stating that 2.67 is actually the minimum supported and that documentation is still being updated.

So, here are the questions I'd appreciate anybody's input on:

• Does anybody have experience running this kind of load on either the Amp or Pro? If so, what has your experience been?
• Any chance that @WiiM Team can officially confirm if a 2.67 would/would not be supported?

Note: I'm aware of alternatives that include other amps + WiiM Pro, or impedance matching devices, but I'm really just seeking experience/input on the WiiM Amp in the configuration above before I go either route.

Thanks!

 

[Burnside]

@WiiM Support are official WiiM staff, but if you want it said again straight from the horse’s mouth, I’d raise a ticket thru the more/ feedback section in the WiiM Home app.

 

[slartibartfast]

Greetings, all!

I'm considering using a WiiM Amp for an outdoor patio zone that will have 6 x 8 ohm satellite speakers (similar to Sonance MAG system). If I run 3 in a left channel (in parallel) and 3 in a right channel (in parallel), it will end up presenting with a 2.67ohm load to the amp on each channel.

Official WiiM manual and documentation says minimum supported impedance is 4 ohms, but if I look at the UK version, it says 2.67. There is also a forum post from what appears to be the WiiM official account on this forum (over in WiiM Pro announce thread, from just a month or two ago), stating that 2.67 is actually the minimum supported and that documentation is still being updated.

So, here are the questions I'd appreciate anybody's input on:

• Does anybody have experience running this kind of load on either the Amp or Pro? If so, what has your experience been?
• Any chance that @WiiM Team can officially confirm if a 2.67 would/would not be supported?

Note: I'm aware of alternatives that include other amps + WiiM Pro, or impedance matching devices, but I'm really just seeking experience/input on the WiiM Amp in the configuration above before I go either route.

Thanks!

Presumably those 8 Ohm speakers will not be a constant 8 Ohm load and will dip below 8 Ohms at some frequencies.

 

[marticus24]

@WiiM Support are official WiiM staff, but if you want it said again straight from the horse’s mouth, I’d raise a ticket thru the more/ feedback section in the WiiM Home app.

Thank you, great call. Will do this, as well.

 

[marticus24]

Presumably those 8 Ohm speakers will not be a constant 8 Ohm load and will dip below 8 Ohms at some frequencies.

Yes, understood. Further why I'm interested in hearing directly from WiiM or anybody that has run this kind of load. I realize it can/will differ even across different 8 ohm rated speakers.

 

[harkpabst]

Yes, understood. Further why I'm interested in hearing directly from WiiM or anybody that has run this kind of load. I realize it can/will differ even across different 8 ohm rated speakers.

It will not just differ a little. Many - if not most - 8 ohm speakers today will dip down to 4 ohm (or even less) in certain frequency ranges. You could end up with a 1.33 ohm load which is definitely too low for the WiiM Amp.

 

[marticus24]

It will not just differ a little. Many - if not most - 8 ohm speakers today will dip down to 4 ohm (or even less) in certain frequency ranges. You could end up with a 1.33 ohm load which is definitely too low for the WiiM Amp.

Thank you - running anything in parallel like this is completely new to me. Something I've only ever done (blindly) with 4 speakers, never 6. So, this helps. Can you help with another question... what happens in the case that the load dips too much? Would the amp just enter some sort of protection mode, burn out, blow the speaker? Not an electrical engineer, so, I realize this may be rudimentary stuff, so thanks in advance.

Regardless, it's looking more and more like I'll need to go with Plan B or C, which is either 1 x Fosi stereo v3 amp (says can handle 2 ohm load) + WiiM Pro or get an impedance leveling device and run with WiiM Amp.

 

[harkpabst]

Regardless, it's looking more and more like I'll need to go with Plan B or C, which is either 1 x Fosi stereo v3 amp (says can handle 2 ohm load) + WiiM Pro or get an impedance leveling device and run with WiiM Amp.

The V3 is not going to be a solution. It implements a single TI TPA3255 in bridge-tied load configuration. It won't be able to reliably pump out the required current into 2 ohm loads, even if the specs say "Terminating Impedance: 2-8Ω". For real compatibility with 2 ohm loads you need two TPA3255 in parallel tied-bridged load configuration.

A pair of V3 Mono would be a better (and obviously much more expensive) choice, but even the V3 Mono cannot keep it's output voltage fully stable into 2 ohms. The absolute amount of power is still very high. The 3e Audio amplifiers A5, A7 and A7 mono would also be suitable choices, producing even less distortion, but again at a higher price. Might not be worth it for outdoor use.

If you can find actual impedance measurements of the speakers you are after then we could compare judge on a less abstract level.

 

[Mr Ee]

I don't think wiim will advocate 6 speakers.
4 yes, 6 unlikey!

Post in thread '4 speakers'

Dec 30, 2023

Their nominal impedence is 8 ohms, so try it.
If the amp gets really warm when you turn it up then you know to use just one pair!

Hi Mr Ee, Wunderkind, Team

I’d like to shed some light on the WiiM Amp’s advanced heat management. It employs PID control and internal temperature sensors, automatically adjusting power based on readings from these sensors. Therefore, it’s completely safe to connect 4 8-ohm speakers to the Amp. It won't affect the sound quality.

Look forward to hearing about your experience.

• WiiM Support

• 

 

[marticus24]

The V3 is not going to be a solution. It implements a single TI TPA3255 in bridge-tied load configuration. It won't be able to reliably pump out the required current into 2 ohm loads, even if the specs say "Terminating Impedance: 2-8Ω". For real compatibility with 2 ohm loads you need two TPA3255 in parallel tied-bridged load configuration.

A pair of V3 Mono would be a better (and obviously much more expensive) choice, but even the V3 Mono cannot keep it's output voltage fully stable into 2 ohms. The absolute amount of power is still very high. The 3e Audio amplifiers A5, A7 and A7 mono would also be suitable choices, producing even less distortion, but again at a higher price. Might not be worth it for outdoor use.

If you can find actual impedance measurements of the speakers you are after then we could compare judge on a less abstract level.

I'd looked at the v3 mono, as well. Plan B/C was going to be either the v3 mono (2 of them) or a single v3 stereo. Option D, I guess, was going to be running all 3 pairs into one of these https://www.crutchfield.com/p_543SS42/Russound-SS-4-2.html - with the WiiM Amp being the single supply. This would work, wouldn't it?

 

[marticus24]

@WiiM Support are official WiiM staff, but if you want it said again straight from the horse’s mouth, I’d raise a ticket thru the more/ feedback section in the WiiM Home app.

Support's official reply:

"The minimum impedance supported by the WiiM Amp is 2.67 ohms. Please refer to this link for more information.
https://wiimhome.com/wiimamp/specs". That very specs page said 4 the other day, or I completely missed it somehow. Might have been a shotgun update based on the question given the spelling of impedance on the page.

 

[harkpabst]

Support's official reply:

"The minimum impedance supported by the WiiM Amp is 2.67 ohms. Please refer to this link for more information.
https://wiimhome.com/wiimamp/specs". That very specs page said 4 the other day, or I completely missed it somehow. Might have been a shotgun update based on the question given the spelling of impedance on the page.

But again, remember that three 8 ohm speakers in parallel will never end up at a minimum of 2.67 ohm. The true impedance will always and with no exception be lower.

 

[slartibartfast]

Support's official reply:

"The minimum impedance supported by the WiiM Amp is 2.67 ohms. Please refer to this link for more information.
https://wiimhome.com/wiimamp/specs". That very specs page said 4 the other day, or I completely missed it somehow. Might have been a shotgun update based on the question given the spelling of impedance on the page.

This post was from September 2024 and clarifies the minimum impedance.

Post in thread 'Introducing WiiM Amp Pro'

Sep 24, 2024

Wiim's answer from Dec. 2023 did not assume that all four speakers "stay at 8 ohm." Their guidance was quite clear: powering nominally 8 ohm speakers in parallel (ie, four speakers in total) is OK and should not present any problems for the Amp, essentially because a pair of nominally 8 ohm speakers in parallel is an equivalent load to a single nominal 4 ohm speaker. Powering nominally 4 ohm speakers is parallel was discouraged, because the result is a nominal 2 ohm load, which can present problems to the amp.

Its common knowledge that an "8 ohm speaker" will present load...

• WiiM Support

• 

 

[dtc]

I'd looked at the v3 mono, as well. Plan B/C was going to be either the v3 mono (2 of them) or a single v3 stereo. Option D, I guess, was going to be running all 3 pairs into one of these https://www.crutchfield.com/p_543SS42/Russound-SS-4-2.html - with the WiiM Amp being the single supply. This would work, wouldn't it?

The Russound box was designed for just this type of setup. Look at the Niles option also. I think Monoprice has one also.

 

[RyanWithWiiM]

Great discussion everyone! Thanks for jumping in and helping out. In general we've found that many speakers may operate below their specified minimum impedance. Therefore, officially we recommend running only four 8-ohm speakers in parallel (two per channel) for optimal performance.

 

[marticus24]

The Russound box was designed for just this type of setup. Look at the Niles option also. I think Monoprice has one also.

Yeah, I think I have one of these lying around from like 12 years ago, also. Likely, if I go this route, will pick up a newer one. Leaning the one I linked because it supports 12 awg wire, which is what I have outside all the way to my equipment closet. Thanks for confirming.

 

[marticus24]

Great discussion everyone! Thanks for jumping in and helping out. In general we've found that many speakers may operate below their specified minimum impedance. Therefore, officially we recommend running only four 8-ohm speakers in parallel (two per channel) for optimal performance.

Thanks @RyanWithWiiM. Much appreciated. This clarifies things then. Here is what I'm taking away... while the amp does or can 'support' a 2.67ohm load (per the response I got from support and specs), it's not recommended to go beyond 4 x 8 ohm speakers in a parallel configuration for optimal performance... mainly because impedance can and often does dip below ratings across the frequency band.

So, I'm either going to have to find another amp option, add an impedance matching device like from Russound, or go with a parallel-wired speaker configuration with speakers rated with higher resistance, like these: https://www.crutchfield.com/p_735LS400/Definitive-Technology-LS-400.html (pricey, though).

I very much appreciate the helpful conversation and dialogue, everyone! I hope this helps others.