LFE Downmix into 2.0 on Ultra

tabata

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Joined
Feb 12, 2025
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Hi @WiiM Team and @WiiM Support ,

I’m trying to create interest for a feature that:

1) isn’t provided elsewhere
2) would be super valuable to many users, even many who don’t even know it yet
3) that WiiM is uniquely capable of providing on existing hardware, and given their engineering talent
4) is actually about providing audio features and performance (rather than, say, all of the attention on the VU meters lately)

Please, please, please offer the ability to downmix LFE from multichannel sources into 2.0 output on the Ultra.

Before anyone goes any further, if you have a very bass-capable system that currently does not receive LFE: 1) Stream the Severance opening title theme on Spotify or Tidal Connect, 2) go onto your TV or streaming player and play the same theme by watching the start of an episode. The Spotify/Tidal version has the LFE mixed into the 2 channels, and it is incredible. It makes the hair on the back of my neck stand up. The video streaming version is very meh. Convinced? I certainly am.

Currently, anyone without a full-sized AVR cannot get a downmix of LFE into 2.0. AVRs are very expensive, large, and completely overkill for this task.

The Wiim Ultra no doubt has the processing power and the app control ability to offer the option of taking a 5.1 signal via HDMI, break it down, and add LFE to the L+R.

Before anyone starts saying, “but Dolby white papers say the LFE channel should be ditched in a 2.0 downmix.” Great, thanks, but that’s dumb! There are many full range speakers or sat+sub combos that would benefit by this, and that’s why so many AVRs offer downmixing the LFE into the 2.0. My system is a perfect example, and there are many others like it, and I don’t think people know how much information they’re missing on the LFE. WiiM would be heroes.

Or maybe the counter-argument is, “but you have to understand the LFE is a bass-boosted signal, often 10db higher than the mains, and that creates issues for combining them into one output.” Ok, but that’s completely surmountable. The Ultra has very powerful digital signal processing to manage that and prevent clipping. It could even offer a slider in the app for users to attenuate the LFE signal in relative terms to the mains so that we could fine tune the signal for the next device in the chain.

To be clear, I do not want the LFE broken out and put on the subwoofer output of the Ultra. That would completely defeat the purpose for me. I have a miniDSP SHD 2x4 processor that is vital to my system that would be downstream of the Ultra. In my 2.2 system, the SHD handles independent stereo time-alignment for my two subs, my HPF and LPF crossovers, gain structure for my power amp, delays, Dirac Live correction, etc. It can only take a 2 channel input. The downmixed 2.0 with LFE needs to be available on the digital optical and coax outputs of the Ultra (huge, huge preference for digital output here), or on the two channel RCA outputs if for some reason that is the only workable method.

I already own the Ultra in a different 2.1 music-only system where it is my sole preamp (and where I’m using the Ultra’s sub output), but I would absolutely 100% buy another Ultra for my 2.2 home theater system simply for it to perform a single task: taking a multichannel source and adding LFE to the 2.0 output. That’s how bad I want it, and how limited the options are elsewhere.

So many people don’t know what they’re missing because they aren’t even aware of what’s being stripped out, or even if they are aware it’s happening, they downplay the difference it would make. This is a chance for WiiM to offer something unique and that opens people’s eyes. I think experiences like that are the core of WiiM’s appeal, and why I’m such a fan. Thank you!
 
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I'm aware of this, I believe it's possibly down to lack of DTS/DD decoders, that is required and then possibly could then be downmixed.

That's why from my experience downmixing DD/DTS streams with a AVR sounds better than using PCM out from the source (I have ability to do both)

Plus native codec, even when downmixed to stereo, sounds better than the TV/kodi box outputting PCM. But yes massive loss in bass quality not having discrete LFE channel, or being re-directed.

Also the issue could be is people will damage their speakers, so ideally it should be redirected to the subwoofer pre out on the Wiim devices.
 
Before anyone starts saying, “but Dolby white papers say the LFE channel should be ditched in a 2.0 downmix.” Great, thanks, but that’s dumb!
Dolby's specs never explicitly stated that the LFE must be ditched in a downmix. Unfortunately, they kept it all very vague and threw in some information on how their own processor hardware did actually do that. Pretty much every AVR ever made does include the LFE, so there's certainly nothing wrong with doing so.

I also agree that this topic is totally independent of routing the output to a subwoofer or not. As long as the speaker setup is capable of playing back what's in that recording it's irrelevant what makes it capable of doing so.

However, this certainly had to be an option, and in my view it should be off by default.
 
I'm aware of this, I believe it's possibly down to lack of DTS/DD decoders, that is required and then possibly could then be downmixed.

That's why from my experience downmixing DD/DTS streams with a AVR sounds better than using PCM out from the source (I have ability to do both)

Plus native codec, even when downmixed to stereo, sounds better than the TV/kodi box outputting PCM. But yes massive loss in bass quality not having discrete LFE channel, or being re-directed.

Also the issue could be is people will damage their speakers, so ideally it should be redirected to the subwoofer pre out on the Wiim devices.

1) The Ultra has Dolby 5.1 decoding and PCM 5.1, I don’t see what the problem is.

2) People can already damage their speakers a million different ways. That should have zero bearing here. This would be an option, and it could come with a warning when you click it.
 
1) The Ultra has Dolby 5.1 decoding and PCM 5.1, I don’t see what the problem is.

2) People can already damage their speakers a million different ways. That should have zero bearing here. This would be an option, and it could come with a warning when you click it.

Also needs dts decoders, otheewiee what's the point in 50% support

If it had e-arc then ideally want all decoder support for hd audio downmixing.

With optical/coaxial limited to standard Def audio or dts core.

Unless you use analogue out so more flexibility in khz/nitrate support
 
Also needs dts decoders, otheewiee what's the point in 50% support

If it had e-arc then ideally want all decoder support for hd audio downmixing.

With optical/coaxial limited to standard Def audio or dts core.

Unless you use analogue out so more flexibility in khz/nitrate support

You’re making this too complicated. The Ultra supports Dolby 5.1 and PCM 5.1. That’s just fine for a $330 device with a small form factor that doesn’t have HDMI output/passthrough.

Nothing about this feature request is about fundamentally changing the Ultra or adding licensed decoders like DTS, it’s about taking the 5.1 support it already offers and adding a simple, optional downmix of LFE. That is all, and it would be worlds better than what is currently offered.
 
Also needs dts decoders, otheewiee what's the point in 50% support

If it had e-arc then ideally want all decoder support for hd audio downmixing.

With optical/coaxial limited to standard Def audio or dts core.

Unless you use analogue out so more flexibility in khz/nitrate support
Some TVs and TV boxes convert 5.1 dts to 5.1 Dolby
And also 80% of movies have Dolby sound
So I wouldn't say that it is 50% support
 
Some TVs and TV boxes convert 5.1 dts to 5.1 Dolby
And also 80% of movies have Dolby sound
So I wouldn't say that it is 50% support

Exactly. Saying my feature request for LFE downmix “needs” DTS is nonsensical. The whole dang device doesn’t have DTS and it’s perfectly fine.

I get it. Enthusiasts like DTS better than Dolby, and they’re both better than PCM. But guess what’s indisputably the worst possible? Taking any multichannel source and throwing the LFE in the garbage before giving users a chance implement it properly.
 
Ideally if it had DD, then want DTS as well. Not sure what ratio is but it's certainly a fair amount. Personally don't have need of this feature but can understand why people want it, but again needs to be all codec.

Perhaps the wiim devices with ARC could accept multi channel LPCM that would be one option.

otherwise it's like some TV's where it outputs DD, but not DTS, so for those with DTS movies you're out of luck. If it has to be an additional license cost, perhaps offer that option? I use a AV pre amp/AVR's for this reason whenever it's a multi media system

Sub setup is triple so yeah know what LFE is, and how much is bass lost when I select PCM out from my movie sources.
 
I think this is enough for now.

Please keep it civilised. This is a feature request thread and if you don't support the idea saying saying so once should be the accepted maximum.
 
I would downvote this feature request, but that feature has been removed for some reason.
Why downvote something proposed as an option, that only adds and doesn’t subtract, and that is considered a standard feature on full-size multichannel processors?
 
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Why downvote something proposed as an option, that only adds and doesn’t subtract, and that is considered a standard feature on full-sized multichannel processors?
For the same reason that you want a feature that is of no interest whatsoever to me, and probably most other Ultra owners.
 
Okie dokie. I’ll just say, if right now we stripped out all of the currently available features we think “most” people don’t use, we’d be left with an absolutely terrible device. Versatility is key to value, and what makes WiiM’s philosophy so special.
 
So I'm reporting that I'm also very interested in this feature and would be excited about it. And also from downsampling DTS (and DD+ and eARC), but that's for another thread. This is an opportunity for Wiim to create a unique device that will have no competition. Because who else but such an innovator and market disruptor should come up with it.
 
So I'm reporting that I'm also very interested in this feature and would be excited about it. And also from downsampling DTS (and DD+ and eARC), but that's for another thread. This is an opportunity for Wiim to create a unique device that will have no competition. Because who else but such an innovator and market disruptor should come up with it.

Only stereo device that I'm aware of decoder is a Arcam SR-250
 
So I'm reporting that I'm also very interested in this feature and would be excited about it.
If you want to make sure that your vote counts, hit that stylised arrow icon below (mobile view) or to the right (desktop view) of the original post.
 
Thanks, I did it. My reply was primarily in response to QuarryHunslet, who wrote that most Ultra users don't care about this feature. That may be true, but I wanted to say that tabata is not alone :)

If you want to make sure that your vote counts, hit that stylised arrow icon below (mobile view) or to the right (desktop view) of the original post.
 
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