Amp Pro -> PEQ just on the sub out ?

[manudrz]

Hi, I'd like to know if it would be doable to have the parametric EQ separate for main output and the sub out ? For exemple 8 of 10 EQ to the main output and 2 for subwoofer ? I think it's my only option to put a linkwitz transform without messing my main stereo speakers.
Anyway, thanks a lot, I love my Amp Pro

 

[Wiimer]

Hi, I'd like to know if it would be doable to have the parametric EQ separate for main output and the sub out ? For exemple 8 of 10 EQ to the main output and 2 for subwoofer ? I think it's my only option to put a linkwitz transform without messing my main stereo speakers.
Anyway, thanks a lot, I love my Amp Pro

Hi

I know this may not be helpful, but I have a splitter adapter connected to the sub out of the WiiM Amp Ultra, and a 2 RCA cable to the line in of the WiiM Pro. 2 subwoofers are connected to the Pro's line out. This allows the Pro's 10-band PEQ to be used exclusively for the subwoofers.

 

[manudrz]

Hum, thanks for the Idea but that's not really the way I'd like to take, double or triple conversion...
A few time back, I've tried SigmaStudio and if I remember well you can just add EQ where you want, til limits of your onboard DSP. Am I again the only one with tricky needs ?

 

[harkpabst]

I'm not quite sure I fully understand your problem. Are you using the automatic room correction process RoomFit or do you skip it and apply the PEQ filters for room correction manually?

If the former you can now apply an additional 10 bands of PEQ (or GEQ, which is not helpful here) for whatever you want on top of the RoomFit filters. This includes applying a Linkwitz transformation, of course. What's currently not possible is to apply the PEQ prior to performing a RoomFit run. You can set a fitting lower frequency limit for RoomFit, though.

If it's the latter you are totally free to place any number of PEQ filters below or above the subwoofer crossover frequency. They may not be technically reserved for the subwoofer output, but it's your very own decision to set the center frequency of any number of filters so low that it will only affect the sub.

This is relatively straight forward.

 

[manudrz]

Hello, I haven't used Roomfit yet so yes I use the PEQs manually. The PEQs applied as is influence the entire phase and impedance of my main speakers, I don't find this optimal. From my little knowledge I think it would be much cleaner to have a separate PEQ for the subwoofer output as I explained.
But thanks for the advice, I'll look into Roomfit soon, and I'm looking into adding 2 vents to my DIY sub so that might solve my problem.

 

[harkpabst]

Hello, I haven't used Roomfit yet so yes I use the PEQs manually. The PEQs applied as is influence the entire phase and impedance of my main speakers, I don't find this optimal. From my little knowledge I think it would be much cleaner to have a separate PEQ for the subwoofer output as I explained.

Don't worry. These are active digital filters placed before the power amplifier. They don't interfer with your speakers' impedance at all. The filter always just sees the constant and pretty much resistive input impedance of the power stage (mains) or the sub out buffer (subwoofer).

A high Q peak filter placed below the crossover frequency has no influence on the mains whatsoever. Each and every analogue (passive or active) or digital IIR filter will always influence the level and the phase of the signal at the same time. This is unavoidable. So, if you need to place a filter close to the crossover frequency (and consequently both the sub and the mains will contribute to the total output to a degree) you absolutely want the phase shift to be applied to both! Otherwise there was an inconsistency in phase that would lead to non-ideal accoustical summation.

From my point of view there's really no drawback to being able to distribute the filters freely across the frequency range.

But thanks for the advice, I'll look into Roomfit soon, and I'm looking into adding 2 vents to my DIY sub so that might solve my problem.

Give RoomFit a try. It works pretty well know.

If your sub's amp has the power and your driver has the required linear excursion there's nothing wrong with applying a Linkwitz transformation to a closed box design. Adding vents is means adding more variables to the equation. How did you calculate the enclosure before building this sub?

 

[manudrz]

Yeah, I got it but from my point of view it might be an improvment to the Wiim app. I'll try Roomfit when I'll find time, my sub is powered with a basic mono TPA3255. It's my 2 versatile Peerless P830668 SLS (parallel) in 200L / 7CuFt so I can both make closed/LinkwiztT/BR. I used a french site/database "Dome acoustique" but at that time I've had the 'here famous' DSPiy. So I designed my close box with the Linkwitz Transform in mind, and things has changed when my soundcard died I've took the decision to stop diying.
In fact I've stopped DIYaudio because I have DIYed all my little wood house so I needed to simplified my installation and be able to just listen music easily. As I was asking here, I've also asked how I can improve the Fs of my sub on french forum, and a "master" guy recommanded me to put 2 ports and it will be ok
I think I can show you here, maybe

https://www.homecinema-fr.com/forum/ressources/image/thumb/219583

Here =

https://imgur.com/a/AQIeJJd

As a good stubborn Norman (it's an espression here), I still think 1 or 2 PEQ would be much cleaner if they were separate for subs only Greatings

 

[jdjd1]

J

Post in thread 'Separate PEQ for subwoofer channel'

Aug 31, 2025

Honestly this would be handy a seperate PEQ for subwoofer for one reason only imagine you want to use a BU2 high pass filter for main speakers and a LR4 for subwoofer (either by using sub integrated amp with dsp features) or using PEQ to achieve it. right now using PEQ with L/R or stereo you can set a HP filter with a Q of 0.70 or 0.71 best would be 0.707 which is a BU2 HP/LP filter (btw WIIM TEAM please make the Q's for LP and Hp to be 4 decimals or atleast 3 if possible) but then in the sub out page if you use main bypass or sub bypass it would still be affected by the PEQ HP/LP filters...

• jdjd1

 

[jdjd1]

"I wish Wiim would give us Wiim folks 10 channels dedicated to sub out ='( so basically today I redid everything, yes I know, can only get so far with EQ, but I think today I'm happier than yesterday, also did buy ear protection, and a laser distanciometer, so I did it at -10 dbfs and 90% wiim volume (limited at 95%), speakers are perfectly at same distance to LP, and impulse response confirms this, so I bypassed mains sub out crossover so now I have sub plus mains doing bass. which filled some weak spots. results below.



sub only eq is applied directly at sub internal amplifier as is the 120 hz crossover.

the first 3 left and right channel peq bands are actually for the sub but wiim doesnt have seperate sub PEQ ;'( ."

so basically I was again trying to tune my system and now I'm sure Wiim team should add seperate PEQ bands for SUB out, whats the point of BYPASSING mains in sub out page if then you are going to use PEQ L/R and you have to affect both speakers and subwoofer.

 

[KainTFM]

Hello, I haven't used Roomfit yet so yes I use the PEQs manually. The PEQs applied as is influence the entire phase and impedance of my main speakers, I don't find this optimal. From my little knowledge I think it would be much cleaner to have a separate PEQ for the subwoofer output as I explained.
But thanks for the advice, I'll look into Roomfit soon, and I'm looking into adding 2 vents to my DIY sub so that might solve my problem.

The absence of separate EQ for the subwoofer is really the only thing stopping me from purchasing a WiiM Amp Pro or Ultra right now. The below graph was done with separate EQ for the subwoofer and speakers using 2 USB-C Jcally dongles, one to an amplifier and one to the subwoofer, muxed together using Voicemeter and EQ'd with REW and Equalizer APO.

If I could do this with a WiiM Pro Plus or Ultra instead, I would upgrade in a heartbeat just to lose the 10ms delay from VoiceMeter, and to also have all that DPS available for non-PC outputs.

Any chance that's something they're working on with the WiiM app?

(Edit: I do have experience with the WiiM Amp as I got one for my parents who are not audiophiles and were happy with just stereo speakers)

 

[harkpabst]

The absence of separate EQ for the subwoofer is really the only thing stopping me from purchasing a WiiM Amp Pro or Ultra right now. The below graph was done with separate EQ for the subwoofer and speakers using 2 USB-C Jcally dongles, one to an amplifier and one to the subwoofer, muxed together using Voicemeter and EQ'd with REW and Equalizer APO.

If I could do this with a WiiM Pro Plus or Ultra instead, I would upgrade in a heartbeat just to lose the 10ms delay from VoiceMeter, and to also have all that DPS available for non-PC outputs.

Any chance that's something they're working on with the WiiM app?

(Edit: I do have experience with the WiiM Amp as I got one for my parents who are not audiophiles and were happy with just stereo speakers)
View attachment 33272

I'm still not sure why you think that EQ dedicated to the sub out was absolutely necessary.

This curve does look nice and smooth for sure. Move the mic 30 cm into any other direction and most likely it will look different at certain frequencies.

What you can do already is using PEQ (manually) on top of the automatic Room for PEQ. You can can limit the use of RoomFit to frequencies above the crossover frequency or even disable subwoofer correction altogether. In a next step you can manually dedicate all 10 PEQ filters to the frequency band covered by the subwoofer.

Isn't that all you need for the REW driven correction you're after?

 

[KainTFM]

I'm still not sure why you think that EQ dedicated to the sub out was absolutely necessary.

This curve does look nice and smooth for sure. Move the mic 30 cm into any other direction and most likely it will look different at certain frequencies.

What you can do already is using PEQ (manually) on top of the automatic Room for PEQ. You can can limit the use of RoomFit to frequencies above the crossover frequency or even disable subwoofer correction altogether. In a next step you can manually dedicate all 10 PEQ filters to the frequency band covered by the subwoofer.

Isn't that all you need for the REW driven correction you're after?

In my case, due to speaker placement limitations, my speakers have some unusually high spikes and nulls in the sub bass (10 - 15 decibels or so) resulting in needing a higher than usual crossover (I think I settled on 105hz) and a couple of Peaking filters to bring the spikes down further than the high pass filter could achieve to keep the subwoofer and speakers from interfering with each other. There's no way to fix this without being able to EQ the subwoofer and speakers independently. 200hz and below is where most Equalizing is done, so I doubt I'm alone in this issue.

I guess having a second WiiM or a MiniDSP or similar between the first WiiM's sub-out and the subwoofer would be a solution, albeit an expensive one, but my hope was for a less complicated solution like an app update else my current setup will probably have to suffice. Unfortunate as the WiiM Amp is a delightful little tool.


Ooh, now there's an idea! A separate WiiM module slimmed down such that it's really only meant for DSP. Something like that for under $300 would fly off the shelves give how pricey the alternatives are (miniDSP and the like) and would solve my problem nicely.

 

[canard]

In my case, due to speaker placement limitations, my speakers have some unusually high spikes and nulls in the sub bass (10 - 15 decibels or so) resulting in needing a higher than usual crossover (I think I settled on 105hz) and a couple of Peaking filters to bring the spikes down further than the high pass filter could achieve to keep the subwoofer and speakers from interfering with each other. There's no way to fix this without being able to EQ the subwoofer and speakers independently. 200hz and below is where most Equalizing is done, so I doubt I'm alone in this issue.

I guess having a second WiiM or a MiniDSP or similar between the first WiiM's sub-out and the subwoofer would be a solution, albeit an expensive one, but my hope was for a less complicated solution like an app update else my current setup will probably have to suffice. Unfortunate as the WiiM Amp is a delightful little tool.


Ooh, now there's an idea! A separate WiiM module slimmed down such that it's really only meant for DSP. Something like that for under $300 would fly off the shelves give how pricey the alternatives are (miniDSP and the like) and would solve my problem nicely.

But in a way, that's already the case, and for DIY enthusiasts, if the analog inputs* were of good quality, they would be even better with, for example, a "plus"
Can use it for example...preamp /wiim/ amp...or just for headphone etc etc
;-)
(*You can use this to help the minidsp pocketadc)

 

[KainTFM]

I'm still not sure why you think that EQ dedicated to the sub out was absolutely necessary.

This curve does look nice and smooth for sure. Move the mic 30 cm into any other direction and most likely it will look different at certain frequencies.

What you can do already is using PEQ (manually) on top of the automatic Room for PEQ. You can can limit the use of RoomFit to frequencies above the crossover frequency or even disable subwoofer correction altogether. In a next step you can manually dedicate all 10 PEQ filters to the frequency band covered by the subwoofer.

Isn't that all you need for the REW driven correction you're after?

See below. This is the right speaker. As you can see, there's a significant (15 decibel) peak in the 70 - 80hz range right where the subwoofer would, ideally, be taking over. I can't see a way to pull that down to where it needs to be if any EQ done to it effects the subwoofer frequency as well.

My own solution was to significantly increase the crossover slope in addition to a PK filter specifically targeting it separately from the subwoofer.

My subwoofer also has a null in the 40hz range right where the speaker has a significant peak. Even with the crossover low and high passes, trying to fix it when the EQ would effect both speaker and subwoofer just isn't possible.

 

[Wiimer]

See below. This is the right speaker. As you can see, there's a significant (15 decibel) peak in the 70 - 80hz range right where the subwoofer would, ideally, be taking over. I can't see a way to pull that down to where it needs to be if any EQ done to it effects the subwoofer frequency as well.

My own solution was to significantly increase the crossover slope in addition to a PK filter specifically targeting it separately from the subwoofer.

My subwoofer also has a null in the 40hz range right where the speaker has a significant peak. Even with the crossover low and high passes, trying to fix it when the EQ would effect both speaker and subwoofer just isn't possible.

View attachment 33319

I'm not sure if this will be helpful for you, but I connect the Pro to the Amp Ultra's Sub-out, and then connect two subwoofers to the Pro. I then use the Pro's PEQ to correct the two subs. The Amp Ultra's RoomFit is for the main speakers only.

I'm no expert, but so far this method seems to be working well in my room.

Post in thread '[2 subwoofers] Challenging RC with WHA alone'

Aug 23, 2025

Excellent and hard work, congratulations!

One question:

The 100 Hz cut in the main speakers was done with the SUB tool in the Ultra menu - OK;

How did you do the 100 Hz cut on the subwoofers from the Pro, was it done directly on them? Have you tried using the HS filter on the PEQ?

I thought all your work was fantastic, I intend to implement something similar here, and it helped me a lot to be able to “see” the entire process.

Thanks for posting!

Hi @AdrianoWR,

Thank you very much.
Yes, the 100hz crossover is done in the WiiM app, and the Pro is connected to the Sub's...

• Wiimer

• 

 

[dominikz]

Even with the crossover low and high passes, trying to fix it when the EQ would effect both speaker and subwoofer just isn't possible.

But why not, exactly?
At the listening position you anyway measure the summed sub+speaker response, so if you apply EQ/RoomFit to the summed response it will knock the peaks down and match it to a target. I have to admit that I haven't seen any case so far where this didn't work well, and I have guided several people through 2.1 system calibration.
So I have to agree with others, I see no real practical benefit to having separate EQ bands for the sub output only.

My subwoofer also has a null in the 40hz range right where the speaker has a significant peak.

The 40Hz null is most likely an SBIR cancellation, have you perhaps tried moving the sub to see if the null moves accordingly? 40Hz null sounds like the sub might be about 2m away from from one or more walls. Moving the sub to a room corner might help (it also gives you more output/headroom prior to room correction).

I'm not sure if this will be helpful for you, but I connect the Pro to the Amp Ultra's Sub-out, and then connect two subwoofers to the Pro. I then use the Pro's PEQ to correct the two subs. The Amp Ultra's RoomFit is for the main speakers only.

I'm no expert, but so far this method seems to be working well in my room.

Post in thread '[2 subwoofers] Challenging RC with WHA alone'

Aug 23, 2025

Excellent and hard work, congratulations!

One question:

The 100 Hz cut in the main speakers was done with the SUB tool in the Ultra menu - OK;

How did you do the 100 Hz cut on the subwoofers from the Pro, was it done directly on them? Have you tried using the HS filter on the PEQ?

I thought all your work was fantastic, I intend to implement something similar here, and it helped me a lot to be able to “see” the entire process.

Thanks for posting!

Hi @AdrianoWR,

Thank you very much.
Yes, the 100hz crossover is done in the WiiM app, and the Pro is connected to the Sub's...

• Wiimer

• 

That is a really cool setup!
Though it should perhaps be noted that adding a Pro in the loop will add significant propagation latency to the subwoofer signal, which then needs to be compensated for by the "Subwoofer & Speaker Sync" function in the 'main' WiiM device.

 

[Wiimer]

Though it should perhaps be noted that adding a Pro in the loop will add significant propagation latency to the subwoofer signal, which then needs to be compensated for by the "Subwoofer & Speaker Sync" function in the 'main' WiiM device.

Yes, the delay compensation is set to 53ms. This was determined by playing a sine wave at the crossover frequency and setting it to the point where the sound was loudest. If RoomFit adds a delay compensation feature using an external microphone, I plan to measure it again. Thank you.

 

[dominikz]

Yes, the delay compensation is set to 53ms.

That sounds about right to me for a WiiM device. When I measured the propagation latency of a WiiM Mini it was quite similar at about 54-55ms (see this post).
The upcoming delay compensation feature using the external microphone should make this much easier and more precise!

 

[KainTFM]

But why not, exactly?
At the listening position you anyway measure the summed sub+speaker response, so if you apply EQ/RoomFit to the summed response it will knock the peaks down and match it to a target. I have to admit that I haven't seen any case so far where this didn't work well, and I have guided several people through 2.1 system calibration.
So I have to agree with others, I see no real practical benefit to having separate EQ bands for the sub output only.

The 40Hz null is most likely an SBIR cancellation, have you perhaps tried moving the sub to see if the null moves accordingly? 40Hz null sounds like the sub might be about 2m away from from one or more walls. Moving the sub to a room corner might help (it also gives you more output/headroom prior to room correction).

That is a really cool setup!
Though it should perhaps be noted that adding a Pro in the loop will add significant propagation latency to the subwoofer signal, which then needs to be compensated for by the "Subwoofer & Speaker Sync" function in the 'main' WiiM device.

One of the reasons for all the fuss is room limitations. I have quite the packed living room and don't even have room for speaker stands. The subwoofer is directly behind the TV at the wall while the speakers are in the TV's cabinet

I have tried EQing them all together but the result was the sub-bass being a complete mess. The predicted curve would be nice and smooth but the actual measurements would have massive peaks and nulls in weird places. Messed with different delays and phases but nothing seemed to put a dent in it until I did something similar to what Wiimer did and EQ'd them separately. Wiimer's idea of having a WiiM pro and its EQ in between the amplifier and the subwoofer is a good idea, but my main goal was removing any latency introduced by Voicemeter, and 50ms would be higher than that.

Anyway, thanks for the advice! It might come in handy when I mess with my parents ridiculously beautiful high-ceiling living room setup that is using TV speakers (blargh!)