How a subwoofer affects soundstage?

[Miguelón]

I don't think anyone said the soundstage, per se, is better. As @Westsounds said, soundstage is an illusion caused by how a person hears the speakers, their distances to speakers, the mix, and how the speakers reflect off the walls. As the sub is a long wavelength filling the room, I don't think it is part of what one perceives as SS.

You will get more even frequency response and a fuller sound. Subs are usually a much larger driver than a speaker's woofer, which in my opinion, gives a more physical bass. But that's me.

When you cut your speakers at 80-85, or wherever, you free up the speaker response so it has better articulation for the mids as it's not trying to do both bass and mids off one surface. Maybe that makes a better SS? No idea on that.

Yes, you’re right: no one said soundstage will be improved. Was a mistake, at least soundstage will not be affected as the frequencies that can be localized spatially will still sound from two sources.

Hum, as articulation will be improved probably so soundstage perception. Or at least instrumental differentiation that was my original worry about subwoofers but finally expressed in terms of soundstage.

As monoaural sound obtained by L+R fusion has poor sound quality because superposition of different phases and time delays, my concern was more about if bass instruments will sound like muffed or blurred. I didn’t formulate the right question…

Nevertheless it was answered by Elebob who told “bass will be more consistent”, my idea of subwoofers was that they increase frequency range or increase bass response but at the price of giving a poorer bass articulation

 

[Chrispy]

tldr but "soundstage" doesn't seem to apply in this use.

 

[terryforsythe]

no one said soundstage will be improved

In my system, the subwoofer makes the soundstage appear larger, more immersive, in certain music.

but at the price of giving a poorer bass articulation

If the subwoofer is not properly integrated with the speakers, the result can be poorer bass articulation. Properly integrated, though, the bass articulation should be better.

To integrate my subwoofer with my speakers, I played with different crossover frequencies and slopes. For each frequency I tried, I adjusted the time delay for the subwoofer to get the subwoofer in phase with the speakers at the listening position. This is critical. If they are out of phase you will not get a good frequency response through the crossover region. If your subwoofer is closer to the listening position than the speakers, you may need to put the delay on the speakers, depending on how much group delay there is. If you leave the ports unplugged, the group delay of the speakers probably will be larger, and less linear, around the crossover region in comparison to having the ports plugged. That was one of the issues I faced, which is why plugging the ports on my speakers helped integration with the subwoofer. It still is not perfect, as can be seen in the chart I posted, and I have more tuning to do.

I may be repeating what already has been said, but do yourself a favor and get a USB microphone and download REW so that you can measure the frequency response when you tune your system. The UMIK-1 microphone from miniDSP costs around $100 + shipping. REW is free, though they do accept donations.

 

[Miguelón]

In my system, the subwoofer makes the soundstage appear larger, more immersive, in certain music.



If the subwoofer is not properly integrated with the speakers, the result can be poorer bass articulation. Properly integrated, though, the bass articulation should be better.

To integrate my subwoofer with my speakers, I played with different crossover frequencies and slopes. For each frequency I tried, I adjusted the time delay for the subwoofer to get the subwoofer in phase with the speakers at the listening position. This is critical. If they are out of phase you will not get a good frequency response through the crossover region. If your subwoofer is closer to the listening position than the speakers, you may need to put the delay on the speakers, depending on how much group delay there is. If you leave the ports unplugged, the group delay of the speakers probably will be larger, and less linear, around the crossover region in comparison to having the ports plugged. That was one of the issues I faced, which is why plugging the ports on my speakers helped integration with the subwoofer. It still is not perfect, as can be seen in the chart I posted, and I have more tuning to do.

I may be repeating what already has been said, but do yourself a favor and get a USB microphone and download REW so that you can measure the frequency response when you tune your system. The UMIK-1 microphone from miniDSP costs around $100 + shipping. REW is free, though they do accept donations.

Thank you for the advice, I appreciate all them.
Genelec have a test to make it by ear, if not achieve good results I will do it with instruments.

The crossover on the 7040 is fixed at 85 Hz, and phase varies on 90, 180, 270 degrees so not many variables for do the job. With the piano is even easier to tune, as I can hear very quickly a “bump” or a “notch” at the crossover frequency.

I always trust this method over mic systems (for me not so useful, always have their one behavior), since when we play we are normally sensitive to variations on less than 0.25 dB on intensity and minor changes on transient (quite sharp in piano sound, but I can even use a bass guitar emulation to make a sharper transient) will help to notice phase misalignment

 

[Willem]

Maybe irrational but I never use digital EQs, perhaps with time I will get an Elisya analogue PEQ or something similar.

Elysia xfilter qube

Ecualizador estéreo portátil Topología Class-A 100%, Auténtico Link estéreo, Filtros High y Low Shelf, Filtro pasoalto y pasobajo con resonancia, Dos medios paramétricos con Q conmutable, High-Band pasivo adicional, Potenciómetros secuenciales...

www.thomann.de

Digital equalization is far more accurate. As for your neighbours, they are best served by dealing with the peaks at roommodes. Those are what generates the boom boom noise. Also, with respect to contact noise through the building's construction, for that a subwoofer with dual opposed drivers such as the KEF KC62 and KC92 is much better.

 

[er|κzvio1in]

There is no localization below 80-100 Hz so that is not an argument in favour of stereo subs. However, there are real advantages in summing the two channels at these low frequencies, because two subs in different locations have different peaks and dips from room modes, and summing those will smoothen the response. Two mono subs with dsp room equalization is about the minimum for clean low frequency sound. The most sophisticated dsp equalization software is probably Multi Sub Optimizer. I have achieved very good results and over a wide listening area using three subs in uncorrelated locations, and equalized by MSO. Particularly user friendly MSO is not, unfortunately.

I messed around a lot with REW and MSO for my 2.2 setup with dissimilar subs and I concluded I'm not a fan of MSO because I couldn't get it to sound right and create filters that make sense. I've currently developed a set of manual settings that sound great: phase reversal, time alignment and PEQ on individual output channels and shared input channels.

 

[Willem]

It worked for me with three very dissimilar subs, although I still have more work to do (MSO is not easy). The most impressive thing was how the correction was effective across a very large part of the (large) listening room.

 

[er|κzvio1in]

If you can get a measurement mic and REW, then you can see what is happening in your room. My living room, for example, had a bass null that I could not correct given the limited places I could put a single subwoofer. So I had to add a second, smaller, sub in the rear of the room. That fixed it. As the cost of the measurement mic is much less than a good sub, it's useful to have those tools so you know the problem (if any) you are trying to fix before spending $ on another sub.

"You can't improve what you don't measure."

 

[Miguelón]

Digital equalization is far more accurate. As for your neighbours, they are best served by dealing with the peaks at roommodes. Those are what generates the boom boom noise. Also, with respect to contact noise through the building's construction, for that a subwoofer with dual opposed drivers such as the KEF KC62 and KC92 is much better.

Fortunately I can try before buying, as the 7040 only has 6,5 inch woofer and goes to 35 Hz I prefer to probe this one at first: very good reviews at Thomann and other sites with 8030 or 8020 coupling in small or complicated rooms. Also think probably is better to stick with the ensemble that proposes Genelec for better matching

 

[Repdetect]

Dual subs improved , i.e. expanded my soundstage significantly. Helped reduce a room mode somewhat. I won't be going back to 1 sub.

Of course an improved soundstage is dependent on the recording having a decent soundstage in the first place.