Stereo subwoofers

[Chris Bolkan]

Hi Wiim team!

I just bought the Wiim Ultra (hasn't even arrived yet), and I've been reading and learning all I can about it. I already have a feature request. You might consider it a corner case, but I think it may be doable and it would be awesome for more people that you might think. It would really be a combination of two feature requests, so it may not even be possible with just a software/firmware update....but I'll ask anyway.

1) The first feature would be to implement simultaneous outputs.... analog and digital.
2) The second feature would be to implement stereo crossovers

Doing this would make the ultra one of the most powerful solutions out there for high end audio. It would enable me to hook a second DAC up to the digital output and extract stereo bass for stereo subs. This would be my use case.
Another use case would be folks who want to bi-amplify two way speakers. It would really open up the capability of the Ultra.

Thanks for your consideration

Chris Bolkan

 

[Smartplug]

I have dual subwoofer connected on ultra using Y cable. Subwoofer sit next to the main on each one of them. It pressurize the room much better than single, it create much deeper soundstage as well well balanced sound.

 

[goodmore]

I have dual subs with a Y cable out of my Amp Pro. They fill the room very nicely. I replaced a Marantz Amp that had the subs wired into the speakers. I was using the crossover on the subs to send the higher freqs to the speakers. I was getting true stereo subs. My point....two mono subs don't sound any different. You really can't tell where the low frequency are coming from.

 

[Burnside]

I may have misunderstood your request, but WiiM have said its usb audio output can be sent to more than one external DAC via a USB hub, but not sure if they meant simultaneously

https://forum.wiimhome.com/threads/...5-2-632547-update-oct-15-2024.5140/post-85051

 

[Hazenhart]

Low frequencies vis a vis a subwoofer aren't really localizable and not really amenable to presenting a stereo image. Multiple subwoofers can be run in parallel via line-level splitters as described in the is thread.

 

[Chris Bolkan]

Thank you for the replies. I already have dual subs. Each sub is located directly underneath the main speaker that sits above it. Crossover frequency is currently 90Hz with both subs playing a summed mono out. My goal is to have both left and right channels play complete DC to light of the content for each particular channel. The system layout is attached. WRT LF localization, I am already at/above the frequency where I can localize bass. and I would like to experiment with even higher crossover to reduce cone excursion on the mains and see what that sounds like. It's a hobby and I love to tinker.

I plan on using a Y cable for now having both subs play the summed L+R mono signal from the WIIM Ultra. Stereo bass is the goal I want to achieve. This post is just to see if stereo bass is possible out of the Ultra and if there is any additional interest in such a feature.

Thank you!

Chris

 

[Hazenhart]

Fascinating setup. I expect those can rattle the room.
In lieu of a stereo sub output from the Ultra, could you split the main L/R output and feed the subs from that? I guess in that case you wouldn't have independent control of the sub eq, but you could use passive line level crossovers and attenuators to suit...

 

[Chris Bolkan]

Hi Hazenhart!

Yes what you propose is possible I think, by buying a minidsp flex or something like that, feeding the digital full range out of the Wiim, and doing the crossover in the Flex. or do it in the analog realm as you mention. But the Flex is twice what I paid for the Wiim, and analog crossovers are possible but expensive too. The Ultra is poised to do almost everything the Flex does or analog crossovers, plus provide the best streaming experience out there in the cleanest way with the features I am requesting. I mean it never hurts to ask, right?

Regards,

Chris

 

[KNVPStudios]

Low frequencies vis a vis a subwoofer aren't really localizable and not really amenable to presenting a stereo image. Multiple subwoofers can be run in parallel via line-level splitters as described in the is thread.

I agree. Stereo subwoofers isn’t a thing. The bass or low frequency channel is monoural in nature and is not localizable as Hazenhart says. However if you are referring to dual subwoofer outputs then absolutely is a thing. My Marantz SR6013 has dual subwoofer outputs and it is magical.

 

[Chris Bolkan]

I think "stereo subwoofers" is a bad term for me to use. What I am after is the ability to bi-amplify each channel. I desire to have the equivalent of 2 truly "full" range speakers. I realize that as frequency gets lower it becomes increasingly difficult to pinpoint its location.

 

[harkpabst]

I agree. Stereo subwoofers isn’t a thing. The bass or low frequency channel is monoural in nature and is not localizable as Hazenhart says. However if you are referring to dual subwoofer outputs then absolutely is a thing. My Marantz SR6013 has dual subwoofer outputs and it is magical.

It depends on the crossover frequency and subwoofer placement.

You can get away with somewhat highish crossover frequencies if you place the mono subs exactly below or beneath the main speakers. But that means giving up the advantage of independent placement. If you want to take advantage of the latter, the crossover frequency has to be fairly low, so the extend to which the main woofers' cone excursion can be reduced is limited.

With stereo subs you can have it both. If the recording contains sub bass signals panned to the right or the left you will lose a bit of efficiency regarding reduced excitement of room modes, but in practice this is a rare case.

 

[Chris Bolkan]

It depends on the crossover frequency and subwoofer placement.

You can get away with somewhat highish crossover frequencies if you place the mono subs exactly below or beneath the main speakers. But that means giving up the advantage of independent placement. If you want to take advantage of the latter, the crossover frequency has to be fairly low, so the extend to which the main woofers' cone excursion can be reduced is limited.

With stereo subs you can have it both. If the recording contains sub bass signals panned to the right or the left you will lose a bit of efficiency regarding reduced excitement of room modes, but in practice this is a rare case.

Yes exactly. My system is configured exactly as you describe with the woofers co-located with the mains and as you can see in the images they are fixed location by construction. The system also has high crossover frequency because of the high LF roll off of the main speakers, which in my mind requires co-location. However, each woofer is capable of adequate output for the entire system even if only one outputting signal.

 

[rccarguy]

I have dual subwoofer connected on ultra using Y cable. Subwoofer sit next to the main on each one of them. It pressurize the room much better than single, it create much deeper soundstage as well well balanced sound.

How are you aligning each subwoofer? You would need subs with phase control.

 

[Smartplug]

How are you aligning each subwoofer? You would need subs with phase control.

I set both sub same and run auto timing it see it as one. I don’t hear any anomaly when playing music that would make me react. With the release of independent rc today which I got the update I would have to make compromise with or without. I only need sub on below 40hz as the main speaker can produce those effortlessly. Do I need to go down below if I listen to John Lennon imagine?

 

[rccarguy]

I set both sub same and run auto timing it see it as one. I don’t hear any anomaly when playing music that would make me react. With the release of independent rc today which I got the update I would have to make compromise with or without. I only need sub on below 40hz as the main speaker can produce those effortlessly. Do I need to go down below if I listen to John Lennon imagine?

If the subs are in different location they will be phased cancellations. I have a four sub layout with minidsp and for each sub they have to be set different delays, so yours probably be the same.

What you want to do is play frequency sweep with just one sub. Then the other. Then both. Then with both adjusting phase every 45 degrees. Then compare each one.

What'll happen is you'll get boosts and cancellations across the range so you want to determine who h is the best.

 

[jed1]

One can use a line-level outboard crossover such as Behringer CX3400 V2 (~$110). That way, one can integrate dual subwoofers to act as parts of speakers with main speakers. FYI. My setup is effectively 4-way active (3-way active main and dual opposite firing sub per side).

 

[Chris Bolkan]

Interesting discussion on merits (or not) of completely full range speakers vs mono bass. And some ideas how to achieve my objective. Thanks!

The original post is a request to implement the ability to bi-amplify. Possibly using a digital output and an additional DAC. To me that would be a very useful function.

I am new to this forum. Do actual WIIM engineers ever comment on 1) can a particular feature request be done or does the hardware not permit it? 2) is it something they would consider or have any interest doing? Just curious.

My Ultra is scheduled to arrive tomorrow! I am SO excited!

Thanks again!

Chris