RoomFit Guidance

[DanGB]

To get me going more quickly (and prevent a divorce) I could do with some guidance please.

I’ve had my Wiim Pro Plus for a while but shortly after buying it, a fault arose with my active speakers. Over a year later I finally have them back from repair. The transformers had failed. If you ever need spares, I can’t recommend Tiger Toroids highly enough. Great quality and cost me about a fifth of the price the original manufacturer would have charged to make a pair.

I have just tried playing around with RoomFit for the first time. I used Blue Snowball in omnidirectional mode, but I have decided to bite the bullet and order a Umik-1 which is currently on its way to me.

The system comprises the Wiim Pro Plus into a Benchmark DAC2 feeding a pair of old Meridian M33 active speakers using the balanced outputs and a BK XLS200 MKII front firing 10” sub connected to the RCA outputs. The speakers are wall mounted flush with the sides of a chimney breast, and the sub is at the bottom of the left side of the chimney breast (on some acoustic foam).

The room this system is in isn’t great and I have no scope to reposition the speakers or sub. There are no soft furnishings. I know the results will be limited because of this but from the few hours I spend experimenting, I believe there is scope for significant improvement. It's about 15' by 13' but the wall the speakers are on is angled (the room isn't rectangular).

The speakers were originally rated 55Hz-20kHz at +/-3dB.

My thoughts regarding the sub settings were to set the gain to about two thirds and the cutoff frequency to about 60Hz. Does this seem sensible?

Regarding the RoomFit settings, I have set smoothing to 1/12 Octave (should I use variable now that it is available or something else?) and switched on Multiple Measurements. I have always used individual channels.

I switched off Non-Boost Mode.

I haven’t tried Moving Mic Measurement. Should I?

Once I have the Umik, my plan is to try and save three profiles, one for each of flat, B&K and Harman.

I would appreciate comments regarding the above settings and help with the frequency range, max gain, min gain and max q settings. I will continue reading up on this but some suggestions to get me going quickly would be really appreciated.

I am wondering whether to set the frequency range to the maximum or limit it to the lower frequencies (or something else).

On every reading so far, there has been a significant dip around 50Hz. Any suggestions with this? One thought on this was that if the sub gain is set quite high, the equaliser could reduce the lower frequencies (and increase around 50Hz) to improve things but I don’t yet really know what I’m doing.

Trying a 20Hz to 400Hz range did sound quite good. More mid-range clarity. Setting it to 20Hz to 20kHz produced quite a drastic change but I’m not sure whether it was for the better or not. I haven’t taken too much from this as presumably the results using the Blue Snowball will be unreliable and potentially not very good, but it has demonstrated the potential for marked improvements such that I decided to buy the Umik.

I am also wondering whether it would be best to buy an Ultra at some stage so that I could use the USB output to my Benchmark DAC and the sub out from the Ultra. Would this result in better scope for the subwoofer tuning?

It’s a shame the Pro Plus doesn’t have USB out as I could use it in my other system which has no sub but I’m reluctant to forego the asynchronous USB connection with the other Benchmark DAC 2 I have in that system.

I will no doubt look into REW in due course but am wary of falling further down the rabbit hole at the moment due to other things I have going on in my life that need to take priority right now.

 

[dominikz]

Hello and welcome!

I have just tried playing around with RoomFit for the first time. I used Blue Snowball in omnidirectional mode, but I have decided to bite the bullet and order a Umik-1 which is currently on its way to me.

That's great, a calibrated measurement mic will give you more confidence in your measurements.
Note that the results may actually be similar - this only depends on how accurate the Blue Snowball microphone is, which you unfortunately can't know without having a calibrated reference (which the UMIK-1 will provide).

The speakers were originally rated 55Hz-20kHz at +/-3dB.

My thoughts regarding the sub settings were to set the gain to about two thirds and the cutoff frequency to about 60Hz. Does this seem sensible?

That is a reasonable starting point, but RoomFit response measurements will reveal if further tweaking is necessary.

Regarding the RoomFit settings, I have set smoothing to 1/12 Octave (should I use variable now that it is available or something else?) and switched on Multiple Measurements. I have always used individual channels.

If you only correct at low frequencies (e.g. <300Hz, which is what I'd recommend in most cases) both 1/12 and variable smoothing should give comparable correction results.
If however you want to apply RoomFit to higher frequencies as well (e.g. full range correction) then I'd definitely advise to use variable smoothing instead of 1/12.

I switched off Non-Boost Mode.

If you only correct at low frequencies (e.g. <300Hz, which is what I'd recommend in most cases) my suggestion would be to have Non-Boost Mode enabled, and to set Max Gain to +12dB, Min Gain to -12dB, and Max Q to 10. This way you avoid any risk of introducing new resonances/ringing after correction.

If you want to apply full-range correction then Non-Boost Mode may or may not be suitable - we'll need to look at some test runs to know.

I haven’t tried Moving Mic Measurement. Should I?

Similar to what I said about smoothing, for corrections at low frequencies single-point sweep, multi-point sweep and moving mic measurement should all give comparable correction results. So any of these methods should be OK.

A single point sweep is the fastest way to measure, and it is quite noise-resistant - so in most cases that is good enough.

If however you're interested to see your system's response presented in a way that better correlates to how we hear, then I'd advise to use moving mic measurement (MMM). The spatial smoothing inherent to MMM will hide some of the response irregularities that should anyway be audibly benign.

Again, if you want to apply RoomFit to higher frequencies as well (e.g. full range correction) then I'd suggest to use MMM instead of single-point sweep.

Once I have the Umik, my plan is to try and save three profiles, one for each of flat, B&K and Harman.

That is reasonable - though note that the difference between them is mainly in the amount of bass.
My suggestion instead would be to just use the B&K target in RoomFit, and then fine tune the amount of bass and treble to your preference using EQ (link to guide) - that is IMHO simpler (no need for multiple calibrations), and gives you more control.

I would appreciate comments regarding the above settings and help with the frequency range, max gain, min gain and max q settings. I will continue reading up on this but some suggestions to get me going quickly would be really appreciated.

See my comment above where I talked about the "Non-Boost Mode".

I am wondering whether to set the frequency range to the maximum or limit it to the lower frequencies (or something else).

My suggestion would be to start with 20Hz to 300Hz, and paste screenshots of the responses so we can see if fine-tuning is needed.

On every reading so far, there has been a significant dip around 50Hz. Any suggestions with this? One thought on this was that if the sub gain is set quite high, the equaliser could reduce the lower frequencies (and increase around 50Hz) to improve things but I don’t yet really know what I’m doing.

Given the information you provided this could be either phase cancellation between subwoofer and loudspeakers, or possibly SBIR/LBIR (in case your speakers / sub / listening position is approx. 1,7m away from a wall).

Trying a 20Hz to 400Hz range did sound quite good. More mid-range clarity. Setting it to 20Hz to 20kHz produced quite a drastic change but I’m not sure whether it was for the better or not. I haven’t taken too much from this as presumably the results using the Blue Snowball will be unreliable and potentially not very good, but it has demonstrated the potential for marked improvements such that I decided to buy the Umik.

20Hz to 400Hz range is a reasonable starting point.
20Hz to 20kHz correction will definitely sound different, but this kind of full range is very likely to make things worse - regardless of the quality f your measurement microphone.
I'd only attempt fullrange correction as a last resort.

I am also wondering whether it would be best to buy an Ultra at some stage so that I could use the USB output to my Benchmark DAC and the sub out from the Ultra. Would this result in better scope for the subwoofer tuning?

Ultra would give you some additional subwoofer tuning parameters (e.g. you could select the crossover point and delay values for subwoofer or speakers). This can help with integration, but sometimes pretty good integration can also be achieved without it.
In any case if I were you, I'd first try to see how good you can get it with what you already have.

I will no doubt look into REW in due course but am wary of falling further down the rabbit hole at the moment due to other things I have going on in my life that need to take priority right now.

That's reasonable. Luckily RoomFit should be able to get you pretty far!

Good luck!

 

[DanGB]

Thanks @dominikz

I really appreciate you taking the time to help with all my points. I am working from home today so shall find it hard to wait to try again!

I'll give it a go with my Snowball as my Umik won't arrive until Sunday.

 

[DanGB]

 

[DanGB]

This is with the Snowball set to omnidirectional and the sub set to about 70Hz. 300 Hz max. B&K.

 

[dominikz]

View attachment 33065View attachment 33066

This looks pretty good, all things considered.
I see a few issues:
1) Response iregularity above 1kHz, which might be either due to your microphone and/or the loudspeaker. We'll know once you get the UMIK-1.

2) Right channel dip around 95Hz. Most likely a side wall interference cancellation (SBIR) - is the side wall around 3ft from the right speaker? In any case, given that you have no flexibility with placement there's not much to do about it.

3) The deep notch at 50Hz. This one looks like it migh be a phase cancellation between the sub and the speakers.
Have you tried inverting the polarity on the sub to see if that helps? If that doesn't help try re-running RoomFit with a few different positions of the sub's phase potentiometer (e.g. min, 9h, 12h, 3h and max positions).