Sierra Tower w/RAAL in room response question

[davef]

Well, I don't know whether to laugh or cry. Just on a hunch, I took an older laptop that had less manufacturer device add-on's (ie. Realtech) and had both 2.0 and 3.0 usb ports, attached my Modi 3+ Dac and Umik1, set it up in my main listening position and ran a quick sweep from 10Hz - 20kHz - FLAT RESPONSE CURVE END TO END!!!! I am not sure where the problem lies with respect to my original laptop, but this laptop yields frequency response data more like what I was expecting. I am still playing around with the Umik1 connections to usb 2.0 and usb 3.0 on this laptop (they seem to behave slightly different, but I am not sure just yet). Once I am convinced that I have the setup on this new laptop correct, I will be running some controlled sweeps of my tower/sub setup and re-post them here. I think the insidious thing about this whole exercise is that the Umik1 partially worked. Had it not worked at all, I could have spent my time fixing a real problem instead of chasing my tail for 2 weeks.

Very happy you resolved the issue! Yes, please post the measurements now, I always enjoy looking at these.

Your issue is one of the reason I generally don't trust measurements taken using laptops / PC's etc. I have a very old and basic laptop (Windows XP) that is fully dedicated to trying out software like REW.

[jimlucci]

In an effort to remove any effects from the Windows audio stack and have equalizer capabilities, I have installed EqualizerAPO and removed the original APO's (windows/realtech maybe?). I ran very modest equalizer parameters in the REW EQ feature, created a .txt file of filters and loaded these into EqualizerAPO (only 3 filters all under 120Hz). My room is pretty heavily furnished, but I am not really able to install room treatments (not a dedicated listening area). Here is an spl and waterfall of my Sierra Towers w/RAAL and Rythmik L12 subwoofer:

SPL:

feb5eq-spl.jpg

Waterfall:

feb5eq_waterf.jpg

....Jim

[davef]

In an effort to remove any effects from the Windows audio stack and have equalizer capabilities, I have installed EqualizerAPO and removed the original APO's (windows/realtech maybe?). I ran very modest equalizer parameters in the REW EQ feature, created a .txt file of filters and loaded these into EqualizerAPO (only 3 filters all under 120Hz). My room is pretty heavily furnished, but I am not really able to install room treatments (not a dedicated listening area). Here is an spl and waterfall of my Sierra Towers w/RAAL and Rythmik L12 subwoofer:

SPL:

feb5eq-spl.jpg

Waterfall:

feb5eq_waterf.jpg

....Jim

Hey Jim,

Looks great, but it does appear phase integration between the sub and the speakers can be improved. Rythmik has some good info regarding this:

https://www.rythmikaudio.com/phase1.html

[jimlucci]

Hey Jim,

Looks great, but it does appear phase integration between the sub and the speakers can be improved. Rythmik has some good info regarding this:

https://www.rythmikaudio.com/phase1.html

Thanks Dave - I have revisited that reference again. Rythmik has very good info/explanation regarding alignment of mains and subs.

Because my HK3490 has no eq, delay or crossover adjustability do you think there would be any benefit in my setup by adding a 2X4 minidsp module between the pre-amp out and amp in connections? I am thinking that would allow more timing control between the mains and the sub as well as pass filter capability and eq if I wanted. As it stands the only timing alignment options I have are speaker/sub location and the delay/phase control provided on the Rythmik L12.

I am going to play around with separate measurements of each main and the L12 to see if I can get them
to all align better with positional modifications and the phase/delay on the L12. I have not re-run sweeps like that since I corrected the problem with REW and Umik1.

[davef]

Thanks Dave - I have revisited that reference again. Rythmik has very good info/explanation regarding alignment of mains and subs.

Because my HK3490 has no eq, delay or crossover adjustability do you think there would be any benefit in my setup by adding a 2X4 minidsp module between the pre-amp out and amp in connections? I am thinking that would allow more timing control between the mains and the sub as well as pass filter capability and eq if I wanted. As it stands the only timing alignment options I have are speaker/sub location and the delay/phase control provided on the Rythmik L12.

I am going to play around with separate measurements of each main and the L12 to see if I can get them
to all align better with positional modifications and the phase/delay on the L12. I have not re-run sweeps like that since I corrected the problem with REW and Umik1.

Hi Jim,

All you really need is the phase control on your sub. This is the first and simplest step, we can revisit if you don't get better results.