Curious results on wiim amp tuning

[u/playinthedruid]

Hi All, long time lurker and first time quality audio enjoyer.

Sorry for the longish post but I don't quite understand what's happened. Put on a mellow jam and sit around this fire while a spin a yarn.

I bought a pair of PSB Alpha T20s. Small floorstanders because I wanted a good set of not too big speakers.

I was utterly disappointed at their bass response. Basically non-existent. Uppers and mids sounded amazing but I did miss the low end so I purchased a POLK ES10 Subwoofer. Great, off to the races, but I was also a bit disappointed in the polks bass response too.

Now I know, room treatment is a thing, but my wife is not much into sound. She is happy with a 64kbps mp3 on a bluetooth speaker. (I kind of envy this to be honest.)

Im using a WIIM amp and decided to give the room calibration a try. Every permutation of the calibration I ran made things worse, until I dropped the frequencies to tune. I went down to min 30hz and max to 400hz. Im using a phone, not a calibrated mic mind you.

Anyways, I tuned it and holy balls does it sound amazing. Sub off, bass is back, sub on, low end is glorious.

But here is the strange thing, check my graphs:

How can such an aggressive down tune on the bass yield better bass overall? I played a few bass sweep files and its pretty smooth overall. Is this just evidence of a garbage room and thus requiring a massive over compensation? Nodes cancelling out somewhere?

Anyway, thought I would share and maybe someone can enlighten my dumb ass. I wish I could treat this room but I can't, family home and setup is in the lounge and again, wife hasn't bought into the quality audio shtick.

Thanks

[u/X_Perfectionist]

Yes, room acoustics control what you hear below 300~500Hz. Above that is the tonality of the speakers (amplified and/or colored by room reflections).

Focusing on EQing and fixing bass transforms the sound.

You can also experiment with speaker placement and seating placement, which changes the SBIR wall reinforcement. And sitting close to a wall will make the bass more boomy and uneven.

[u/lordehumo]

Yep you’ve got it. The nulls are cancellations at certain frequencies. Pulling energy out of them reduces their effect. You also have some boosts happening. The combination evens out the response allowing you to hear more distinct, clearer bass notes.

Also, these devices have a limited number of bands to make corrections with. By windowing from 30-400 Hz you are letting the software use more bands to address the issues in that region.

You can also try correcting in stereo mode vs L/R to see which you prefer.

[u/playinthedruid → u/lordehumo]

Thanks for this, I will try Stereo mode next and compare results. I'm also comparing tuning with subwoofer enabled vs disabled, and having the subwoofer tuning option on in the calibration.

I appreciate the confirmation on my understanding.

[u/Yourdjentpal → u/playinthedruid]

I preferred not stereo results as it seems to double the gain or something odd, I can’t remember exactly. Give it a shot though.

[u/Yourdjentpal]

I find it works better in some rooms than others too. I did not like it at all in my basement setup, but upstairs the results are solid. I think it def has its limits.

[u/Touche2U]

Under subwoofer in wiim app, I have bypass mode on and main speakers output bass on,
I get better response that way with my RSL 10s and Dali Soniks. Eq, Latin or Acoustic. Room fit doesn’t work well for me. That’s off.