WiiM Amp

[Steve Woodhouse]

Many TVs can also pass the sound through. However, the receiver must then be able to handle the sound format.

Vanilla ARC won’t pass higher bitrates.

 

[harkpabst]

Isn't this a fundamental "risk" when using HDMI ARC as the source for a stereo amplifier, regardless of what amp that may be?

I think it's safe to say that.

My perception is content sources differ in how they choose to "mix" a stereo output from a native 5.1 (or higher) original audio tracks. So you may get more or less center in your L/R stereo signal, and center is where dialog is often predominantly placed.

"Sources" in this context would usually refer to the HDMI ARC source, usually the TV. Unless e.g. the 5.1 programme material has already been converted to 2.0 on a different level, maybe by a Blu-ray player or even a streaming service. However, in both cases it's not too unlikely that the downmix to 2.0 is not done in real-time. The Blu-ray disc may contain a downmix done "properly" in the studio and the streaming service may have access to that same source.

I've noticed this myself using an NAD D3045 connected via ARC from my LG TV. The other day I was watching a WNBA game on the Ion network, and the dialog from the announcers was very low, while the background noises from the court & stadium were unusually loud. I speculated that Ion was simply feeding L and R from a 5.1 native source to the L and R for a stereo downmix, rather than mixing center into both L and R for the downmix. When I reverted to my AVR and used true L/C/R signals, the dialog was fine.

Sounds indicative to me. As long as we stay in-universe (Dolby universe in this case) things are relatively simple.


(https://professionalsupport.dolby.c...d-Stereo-downmix-settings-work?language=en_US)

As long as Dolby licensed gear is used throughout you can be sure that these rules are obeyed. This is not necessarily the case for what TVs might put out as PCM. It can definitely hit or miss.

Please note that the .1 channel (I'm avoiding the term LFE or subwoofer here) is explicitly not part of the stereo downmix. Yep, that's actually true. A real LFE (there I said it) just contains additional, non-essential effects, not all the bass content below 120Hz. The main channels should contain all meaningful bass. More on this can be found here:

The Misunderstood 0.1 LFE Channel in 5.1 Digital Surround Sound - HomeTheaterHifi.com

In 5.1 digital surround sound, the 0.1 channel is called the LFE or Low Frequency Effects channel. While in the commercial system it is referred to as the subwoofer channel, this is not necessarily true for home theater setups.

hometheaterhifi.com

The biggest issue with HDMI in from ARC (and it’s not just WiiM) is that, by definition, the WiiM only gets the audio after it’s been ‘processed’ by your TV.

It shouldn't be an issue if the downmix is done correctly.

Many TVs can also pass the sound through. However, the receiver must then be able to handle the sound format.

The WiiM Amp can only handle two channel stereo PCM. This is what you need form your TV.

Vanilla ARC won’t pass higher bitrates.

Don't underestimate ARC. I can't handle uncompressed hir-res multichannel audio. But that's not really a restriction with what the WiiM Amp can handle.

 

[Steve Woodhouse]

I think it's safe to say that.


"Sources" in this context would usually refer to the HDMI ARC source, usually the TV. Unless e.g. the 5.1 programme material has already been converted to 2.0 on a different level, maybe by a Blu-ray player or even a streaming service. However, in both cases it's not too unlikely that the downmix to 2.0 is not done in real-time. The Blu-ray disc may contain a downmix done "properly" in the studio and the streaming service may have access to that same source.


Sounds indicative to me. As long as we stay in-universe (Dolby universe in this case) things are relatively simple.

View attachment 9138
(https://professionalsupport.dolby.c...d-Stereo-downmix-settings-work?language=en_US)

As long as Dolby licensed gear is used throughout you can be sure that these rules are obeyed. This is not necessarily the case for what TVs might put out as PCM. It can definitely hit or miss.

Please note that the .1 channel (I'm avoiding the term LFE or subwoofer here) is explicitly not part of the stereo downmix. Yep, that's actually true. A real LFE (there I said it) just contains additional, non-essential effects, not all the bass content below 120Hz. The main channels should contain all meaningful bass. More on this can be found here:

The Misunderstood 0.1 LFE Channel in 5.1 Digital Surround Sound - HomeTheaterHifi.com

In 5.1 digital surround sound, the 0.1 channel is called the LFE or Low Frequency Effects channel. While in the commercial system it is referred to as the subwoofer channel, this is not necessarily true for home theater setups.

hometheaterhifi.com

It shouldn't be an issue if the downmix is done correctly.


The WiiM Amp can only handle two channel stereo PCM. This is what you need form your TV.


Don't underestimate ARC. I can't handle uncompressed hir-res multichannel audio. But that's not really a restriction with what the WiiM Amp can handle.

Granted, but I think it’s good to share the information.

 

[LucAce]

I think it's safe to say that.


"Sources" in this context would usually refer to the HDMI ARC source, usually the TV. Unless e.g. the 5.1 programme material has already been converted to 2.0 on a different level, maybe by a Blu-ray player or even a streaming service. However, in both cases it's not too unlikely that the downmix to 2.0 is not done in real-time. The Blu-ray disc may contain a downmix done "properly" in the studio and the streaming service may have access to that same source.


Sounds indicative to me. As long as we stay in-universe (Dolby universe in this case) things are relatively simple.

View attachment 9138
(https://professionalsupport.dolby.c...d-Stereo-downmix-settings-work?language=en_US)

As long as Dolby licensed gear is used throughout you can be sure that these rules are obeyed. This is not necessarily the case for what TVs might put out as PCM. It can definitely hit or miss.

Please note that the .1 channel (I'm avoiding the term LFE or subwoofer here) is explicitly not part of the stereo downmix. Yep, that's actually true. A real LFE (there I said it) just contains additional, non-essential effects, not all the bass content below 120Hz. The main channels should contain all meaningful bass. More on this can be found here:

The Misunderstood 0.1 LFE Channel in 5.1 Digital Surround Sound - HomeTheaterHifi.com

In 5.1 digital surround sound, the 0.1 channel is called the LFE or Low Frequency Effects channel. While in the commercial system it is referred to as the subwoofer channel, this is not necessarily true for home theater setups.

hometheaterhifi.com

It shouldn't be an issue if the downmix is done correctly.


The WiiM Amp can only handle two channel stereo PCM. This is what you need form your TV.


Don't underestimate ARC. I can't handle uncompressed hir-res multichannel audio. But that's not really a restriction with what the WiiM Amp can handle.

I didn't say otherwise.

 

[harkpabst]

I didn't say otherwise.

I didn't say you'd said otherwise. @Inertiaman had quoted my post so I thought I'd might be entitled to give my own view.

 

[gasolin75]

Havn't read all replys

Questions

Can usb be used to get sound from a pc ?

If you sub is on will it make a thumb sound when turning the amp on,off (not the subwoofer, that is on)

Any hiss,noise ?

Is bt stable, does it disconnect alot ?

 

[cooky560]

With the right driver a PC can do almost anything, I have usb headphones on my pc for example.

However whether a WiiM can accept a PC output is another matter.

 

[gasolin75]

I have heard it can but not shure have read the manual

 

[Brantome]

Havn't read all replys

Questions

Can usb be used to get sound from a pc ?

No, usb on the Amp doesn’t support usb audio in.

I’ve heard some say you could use the optical out from your pc, or if it doesn’t have one, use a usb to optical convertor and use its output into the Amp

 

[gasolin75]

Okay i have to use toslink if i buy one

What about noise hum if i get one made in 2024 ?

 

[thierryb92]

No, usb on the Amp doesn’t support usb audio in.

I’ve heard some say you could use the optical out from your pc, or if it doesn’t have one, use a usb to optical convertor and use its output into the Amp

I have a cheap SMSL DAC/Converter 'PO100 AK' that does it very well and I get audio from my mac (USB-C) to Optical for the Wiim Amp. Of course you can't control volume from your mac keyboard, but the sound no delay and perfect sound. I bought 'open box' SMSL for 48 euros.
T

 

[skillconjunction]

I've created a side mount to work with the Wiim amp and tested on my own unit. It should be strong enough to mount upside down also. I have some concerns about heat build up, but so far its been fine with several longer sessions at higher volumes with inefficient speakers, it gets warm but not hot.

Please let me know if you find it helpful, and if anyone thats interested doesn't have a 3D printer PM me and I can print a set and ship out.

Wiim Amp Corner brackets by skillconjunction

I remixed this to allow wall mounting of WIIM Amp. I used #10 pan head screws to mount. Using double sided tape to hold them in place while mounting on the wall makes it a lot easier.Mounts will clear the volume knob if rotated correctly.

www.thingiverse.com