"Stand Subwoofers" like the Genelec W371, Kii BXT, etc. Ideally with DSP & Multi-Drivers

[Rick Sykora]

Folks in this thread dismissing "subwoofer stand" positioning, despite lots of well-regarded commercial examples and experiential evidence to the contrary. If this was such a flawed topology, why did we ever have tower speakers in the first place? By this logic, then every pair of tower speakers capable of putting out deep bass is fatally flawed.

I agree (as I step on my soap box)... If you can get your speakers away from the back walls and at room intervals that reduce standing waves, there is no reason that you cannot have your monitors on subwoofer stands and get good bass. Before home theater started getting marketed, it was rare that anyone tried to sell you more than one subwoofer. My listening room is about 20 x 25 with 8 ft ceilings. For most of my music listening (alternative and progressive rock), one good subwoofer reproduces very realistic bass.

While acknowledging that more than one subwoofer does produce more even bass, am pretty sure there are more than a few folks with that are happier with having some standing waves during movie special effects! If you are spending more time measuring your system than enjoying it, stop measuring it. Soapbox disengaged.

 

[thewas]

If this was such a flawed topology, why did we ever have tower speakers in the first place?

Because it was the best we could get at that time for a given space and surface used on the floor, but that doesn't also automatically mean that it cannot get better.
The Genelec W371 for example has three different operating modes allow a choice of flat and neutral LF response avoiding ‘acoustic notching’, continued directivity of the main monitor down to the lowest LF frequencies, or reduction of detrimental reflections by the walls, ceiling or floor of the room, all stuff which you cannot do with just "parallel" working (sub)woofers.

The one thing I can say without reservation is that lower crossover points are always beneficial assuming the main speakers are capable enough.

A lower crossover point increases the group delay http://www.neumann-kh-line.com/neum...ing_knowledge_faqs_general-answers_question13, almost everything is a compromise.

 

[JohnBooty]

To be clear, when defending "subwoofer stands" arrangements, I'm responding to those that are flatly saying "don't do it" (which a few have said)

If you have the room for more elaborate and ideal subwoofer positioning, go for it!

If WAF or other considerations prevent that, subwoofer stands may be a well-performing option. Not ideal, but well-performing and certainly preferable to a single subwoofer in a compromised location.

A lower crossover point increases the group delay http://www.neumann-kh-line.com/neum...ing_knowledge_faqs_general-answers_question13, almost everything is a compromise.

Subjectively I have always found this a minor compromise worth making. But everybody should experiment with various crossover points. I think too many people just pick 80hz without experimentation!

 

[Rick Sykora]

LInkwitz was trying to design around the idea of having the sub as a stand

I think somewhere there was a measurement about vibration send up from sub to the main.

More to the OP, Linkwitz bass module is a dipole. It excites room modes differently than a traditional monopole subwoofer. Am guessing the Kii is more omnipolar, but the point is that there are other solutions than having to locate subwoofers to avoid room modes.

This is another example of a subwoofer solution that is less sensitive to room placement. Here is a simpler Linkwitz dipole subwoofer design...

 

[Purité Audio]

Traditional loudspeakers had no form of adjustment, listeners pulled them away from walls in an attempt to ‘cancel‘ ( quarter wave) bass peaks.
Modern designs allow you place the speakers close to walls , thus avoiding cancellations and then Adjust their bass output.
If you place the subs into the corners you avoid cancellations and create the most headroom.
The Kiis boundary filters can be individually adjusted and the last firmware update includes PEQ.
Keith

 

[hege]

Modern designs allow you place the speakers close to walls , thus avoiding cancellations and then Adjust their bass output.

But.. but.. every other thread I read someone claims that Imaging is destroyed close to walls.

 

[Purité Audio]

No nearly every ‘pro speaker’ manufacturer Advises placing speakers within 50-60 cm to avoid cancellations.
Genelec, Neumann etc.
Keith

 

[hege]

No nearly every ‘pro speaker’ manufacturer Advises placing speakers within 50-60 cm to avoid cancellations.
Genelec, Neumann etc.
Keith

I'm half joking, of course I know this.

But just try googling "imaging close to wall" and one can find many (misguided?) threads about imaging and lacking soundstage depth. I have no problem with my Gennies at the wall and subs under them in "non-optimal" position (see my pic previous page).. of course one could iterate positions for weeks to find the most optimal placing, if it even exists..

Example:
https://www.soundonsound.com/sound-advice/q-should-monitors-be-near-rear-wall

One down side of placing the speaker very close to the back wall is the effect it has on stereo imaging and the perceived depth of the soundstage. In general, the further the speaker is from the back wall, the greater the impression of soundstage depth becomes.

 

[lkong]

More to the OP, Linkwitz bass module is a dipole. It excites room modes differently than a traditional monopole subwoofer. Am guessing the Kii is more omnipolar, but the point is that there are other solutions than having to locate subwoofers to avoid room modes.

This is another example of a subwoofer solution that is less sensitive to room placement. Here is a simpler Linkwitz dipole subwoofer design...

View attachment 49684

I dont think the picture you've linked is dipole.

 

[Rick Sykora]

I dont think the picture you've linked is dipole.

Actually it is a dipole. Please see Linkwitz lab link below:

http://linkwitzlab.com/LXmini/LXmini+2.htm

 

[lkong]

Actually it is a dipole. Please see Linkwitz lab link below:

http://linkwitzlab.com/LXmini/LXmini+2.htm

My bad, was judging it by appearance.

 

[Habu]

Neumann does with the KH870 for the KH420.

And unoficially KH310 with KH750DSP in landscape mode (both KH750 rotated 90° in order to get the KH310 width)


Source : https://pinkfishmedia.net/forum/threads/neumann-kh-310-a-and-dual-subwoofers.228444/

 

[LTig]

And unoficially KH310 with KH750DSP in landscape mode (both KH750 rotated 90° in order to get the KH310 width)


Source : https://pinkfishmedia.net/forum/threads/neumann-kh-310-a-and-dual-subwoofers.228444/

View attachment 49730

This looks nice. Where did you get the stands?

 

[Bear123]

Folks in this thread dismissing "subwoofer stand" positioning, despite lots of well-regarded commercial examples and experiential evidence to the contrary. If this was such a flawed topology, why did we ever have tower speakers in the first place? By this logic, then every pair of tower speakers capable of putting out deep bass is fatally flawed.

I completely agree. Replace low sensitivity woofers that have a lot of excursion in order to attempt to play low and loud, with higher sensitivity woofers that play down to 40 Hz or so, an octave below where they should be crossed to well placed, quality subs. Higher sensitivity means less power required, less thermal effects on the driver, less chance of running out of power from AVR or amp, and better sound capability and sound quality above crossover to subs.

Full range towers that play lower than needed when crossed to subs are indeed a design compromise for optimal sound quality.

Woofers designed and engineered to play optimally above 40 Hz will have better sound quality and performance(in this range) than woofers designed to play with authority down to 20 Hz.....the excursion requirement and resulting lower sensitivity will indeed compromise performance at higher frequencies.

Just because there are lots of full range tower speakers that play lower than needed when crossed to good subs does not mean the design is optimal. There is a huge demand for full range tower speakers from misinformed audiophiles who think 2.0 is optimal for sound quality.

There's a reason why smart folks in this hobby run multiple subs even with Salon 2 level speakers.

 

[jhaider]

Modern designs allow you place the speakers close to walls , thus avoiding cancellations and then Adjust their bass output.

You can also do that with standard speakers and outboard room correction.

 

[phoenixdogfan]

LInkwitz was trying to design around the idea of having the sub as a stand

I think somewhere there was a measurement about vibration send up from sub to the main.

If you look closely, you'll see the sat does not rest directly on the sub. Rather that nice looking piece of wood is a bridge which the sub fits within without touching it at any point. That's what the satellite rests upon.

 

[Habu]

This looks nice. Where did you get the stands?

Hello,

The stands are not mine, neither the following post.
https://pinkfishmedia.net/forum/threads/neumann-kh-310-a-and-dual-subwoofers.228444/

 

[stevenswall]

Folks in this thread dismissing "subwoofer stand" positioning, despite lots of well-regarded commercial examples and experiential evidence to the contrary. If this was such a flawed topology, why did we ever have tower speakers in the first place? By this logic, then every pair of tower speakers capable of putting out deep bass is fatally flawed.



I'm not familiar with those Genelecs. At first glance it seems like the dual drivers achieve some sort of dipole thing and I think the intent is that you wouldn't need more than one unit. I'm not sure if a second unit would be beneficial, detrimental, or merely superfluous.

As for crossover slopes, a steeper slope may cause audible discontinuity particularly off-axis as the subwoofer will have a different dispersion pattern than the speaker to which you're crossing it over. On the other hand a shallower crossover slope probably opens you up to some more phase/cancellation issues as in my "80hz @ 12dB/octave" example where the subwoofer's playing somewhat audible content all the way up at 160hz. Bit of a cop-out answer but ultimately it comes down to experimentation with one's room and equipment I guess.

The one thing I can say without reservation is that lower crossover points are always beneficial assuming the main speakers are capable enough.

I'd try crossing over around 40-50hz... The Genelec 8260 should still be more than capable, and the bass from the woofers should be very omnidirectional at that point.


The W371 based on videos sounds like it improves the response of Genelec monitors because they don't have to control dispersion as low, and you can cross over to the bass extension tower higher than a normal sub.

 

[stevenswall]

Traditional loudspeakers had no form of adjustment, listeners pulled them away from walls in an attempt to ‘cancel‘ ( quarter wave) bass peaks.
Modern designs allow you place the speakers close to walls , thus avoiding cancellations and then Adjust their bass output.
If you place the subs into the corners you avoid cancellations and create the most headroom.
The Kiis boundary filters can be individually adjusted and the last firmware update includes PEQ.
Keith

This is something I really noticed with my Genelecs.... Previously I was following advice to place speakers away from the walls, but when I started measuring things, it made them worse with comb filtering basically.

Now I have things close to corners, and the only issue is a null at 100hz or so.

 

[Dj7675]

I always admired the JBL PT800.