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Getting subwoofers for the first time

Robert said:
I got a dealer loyalty discount (used some accumulated points) and a nice Monitor Audio glossy cabinet polishing kit thrown in, so the actual price difference came down to about £30.
Otherwise £100 is a bit steep for the gloss.
Click to expand...
I'm glad I got my downward-firing XXLS400 subs in black gloss even though it added a chunk to the price. They'd dominate the room too much if I'd gone for a matte or wood finish and, even if the veneer had miraculously matched that of my main speakers at the time, it would more or less kibosh any plans to change main speakers in the future!...
 
Here we go then, graph overload :)

Just rough measurements to get some understanding of room behaviour. I've applied no filters or tuning.

First the LS50 measured from the listening seat L&R overlayed.

Standard, open ports:

LS50 pair ported by Rob Holt, on Flickr

This surprised me as I didn't expect to see this much LF, though you can clearly see the primary 40Hz room mode lifting the response.

Sealed:

LS50 pair sealed by Rob Holt, on Flickr

Note the low end doesn't collapse it just shelves down - probably why the porting on these sounds better than usual.

This is the sub, wide open, no filters placed on the listening seat with the mic up against the grille:

Raw sub no filter by Rob Holt, on Flickr

I like that - pretty much the raw response of the sub and nicely flat and extended.

Next up, the sub in the listening seat and the measurement at the speaker position:

sub in seat mic at speaker by Rob Holt, on Flickr

Not bad, hole at 50Hz which could be why I hear lack of bass oomph.

This next one is interesting, sub down on the floor next to the LS50:

floor nest to main L by Rob Holt, on Flickr

Could work with that, some PEQ would sort it, no major holes.

And finally, sub in the front corner of the room - Yuk!

sub front corner by Rob Holt, on Flickr

What will happen with a pair? - we'll soon see!
 
Arghhh....the upstairs neighbours are having building work done today.
Bloody crashing and banging. I'll get back to this in a couple of days.
 
mansr said:
Are you sure it isn't payback for the racket you've been causing?
Click to expand...

Haha, no we get on okay :)

It's giving me time to read and watch the experience of others so not all bad.

So far it seems you just have to measure, listen and experiment <repeat>

This was interesting and makes the point I hadn't considered whereby the main 'speakers can actually aid LF smoothness when combined with subs if you don't roll them off:

 
Well, here is where they ended up in the room.
They work really well configured to run in mono (both receiving summed R/L) and placed close to the floor along the side wall, in line with the main 'speakers.
This was arrived at via measurement and the positioning is fortuitous since I have Ikea record storage cabinets at those very positions, and the SB1000s are a perfect fit!

Listening for a couple of days my first reaction was, where is the bass? - this is really sounding lean.
Second reaction was that music actually sounded faster paced in many cases - yes faster, not slower. In fact in one case when listening to the PSBs Left to My Own Devices, had this been on vinyl I'd have been checking the motor hadn't drifted!

What's happening of course is better control of room modes, particularly the main 40Hz mode which at some positions in the room peaks at around 10dB above the mid reference level. Now things sit +/- 3dB from 20Hz - 80Hz. Integration with the LS50 running sealed occurs with the crossover on the subs set at 70Hz with 24dB/oct slopes. EQ is minimal - 3dB paramentic cut centred on 35Hz.

The initial sense of leanness was due to acclimatising to the lack of room boom.

There are no negatives. Very happy with the results.

Next up, I'm trying a Marantz HT receiver (on approval so it goes back if not satisfactory) and that thing has built in Audyssey room EQ, the full version accessed via the paid app with manual control.That will allow electrical high passing of the main speakers, so watch this space.

Some pics:

right sub by Rob Holt, on Flickr

PXL_20210430_200011206 by Rob Holt, on Flickr

Room sub by Rob Holt, on Flickr
 
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Here is the gear side of the room for completeness. Yes there is a gap between the cabinet holding the subs and the cabinet on the which sits the TT - a small one :)

More of those record cabinets run end to end along the back of the room behind the listening position (sofa long gone), so I can steal another space for a 3rd sub if we want to really actively smash those room modes.

room by Rob Holt, on Flickr
 
Robert said:
W

Listening for a couple of days my first reaction was, where is the bass? - this is really sounding lean.
Second reaction was that music actually Sounder faster paced in many cases - yes faster, not slower. In fact in one case when listening to the PSBs Left to My Own Devices, had this been on vinyl I'd have been checking the motor hadn't drifted!

What's happening of course is better control of room modes, particularly the main 40Hz mode which at some positions in the room peaks at around 10dB above the mid reference level. Now things sit +/- 3dB from 20Hz - 80Hz. Integration with the LS50 running sealed occurs with the crossover on the subs set at 70Hz with 24dB/oct slopes. EQ is minimal - 3dB paramentic cut centred on 35Hz.

The initial sense of leanness was due to acclimatising to the lack of room boom.

There are no negatives. Very happy with the results.

Next up, 'm trying a Marantz HT receiver (on approval so it goes back if not satisfactory) and that thing has built in Audyssey room EQ, the full version accessed via the paid app with manual control.That will allow electrical high passing of the main speakers, so watch this space.
Click to expand...

Good stuff!

I remember the evening when we got the 1st prototype pair of what has become the KC62 running, about 10 years ago. Our first thought was "where's all the bass"?
Then we realised how easy it was to distinguish bass instruments from drums, and how it all played effortlessly in time and in tune irrespective of musical genre or how it was recorded.
I suspect there is more to come in your situation when you roll the LS50s off (electrically, 12/dB/oct at 70Hz).
 
Seanm said:
Did not know you could tuck them away like that.
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It will vary depending of circumstance but the sub is completely omnidirectional and the room completely model down at those frequencies.
The record cabinets are open at the the back which is where the plate amps sit on the back of the sub cabinet. Class D and cool running but if you had warm running subs you'd have to consider concealed placement more carefully.
 
S-Man said:
Good stuff!

I remember the evening when we got the 1st prototype pair of what has become the KC62 running, about 10 years ago. Our first thought was "where's all the bass"?
Then we realised how easy it was to distinguish bass instruments from drums, and how it all played effortlessly in time and in tune irrespective of musical genre or how it was recorded.
I suspect there is more to come in your situation when you roll the LS50s off (electrically, 12/dB/oct at 70Hz).
Click to expand...

Fascinating to notice just how quiet the subs sound when switching off the LS50s.
In my small room (15x12 with a bay window) even when playing load I can't see the sub driver move.
 
Robert said:
Here we go then, graph overload :)

Just rough measurements to get some understanding of room behaviour. I've applied no filters or tuning.

First the LS50 measured from the listening seat L&R overlayed.

Standard, open ports:

LS50 pair ported by Rob Holt, on Flickr

This surprised me as I didn't expect to see this much LF, though you can clearly see the primary 40Hz room mode lifting the response.

Sealed:

LS50 pair sealed by Rob Holt, on Flickr

Note the low end doesn't collapse it just shelves down - probably why the porting on these sounds better than usual.

This is the sub, wide open, no filters placed on the listening seat with the mic up against the grille:

Raw sub no filter by Rob Holt, on Flickr

I like that - pretty much the raw response of the sub and nicely flat and extended.

Next up, the sub in the listening seat and the measurement at the speaker position:

sub in seat mic at speaker by Rob Holt, on Flickr

Not bad, hole at 50Hz which could be why I hear lack of bass oomph.

This next one is interesting, sub down on the floor next to the LS50:

floor nest to main L by Rob Holt, on Flickr

Could work with that, some PEQ would sort it, no major holes.

And finally, sub in the front corner of the room - Yuk!

sub front corner by Rob Holt, on Flickr

What will happen with a pair? - we'll soon see!
Click to expand...

When you post measurements of the dual sub setup could you adjust vertical scale to a standard 50dB-wide?

Any thing will look flat when the Y is 100dB-wide.
 
Tony L said:
My experience of subs: unbox them, plug them in, turn them on, over the next few months alter the cutoff, phase and level, gradually reducing the impact of each, keep turning them down until you can’t hear the slowness and lack of coherence, realise they are now actually off, box them back up and sell them.
Click to expand...

I wouldn't go as far as to say that. A lot depends on the music being played. If it's music with a lot of fast percussive transients then yes, unless a sub is set up well it can do more harm than good. But something like organ or orchestral music can be enhanced a lot by a decent sub.

I'm sure the OP will take time to set up his sub properly.
 
Tony L said:
My experience of subs: unbox them, plug them in, turn them on, over the next few months alter the cutoff, phase and level, gradually reducing the impact of each, keep turning them down until you can’t hear the slowness and lack of coherence, realise they are now actually off, box them back up and sell them.
Click to expand...

I recently spent a cuple of months with two subs for my Kef R100's. There was bass, no problem, and one could go much louder, no problem. I have measurement capabillities and aren't afraid of using an EQ (digital), lots of tweaking was done. But it never sounded right. Even if measurements didn't say so, it was always boooomy and uncoherent. I gave up.

Sub's where the bass sections of my JBL 4331B's (15" and very large), used full range they have stunning, fast and full bass.

Conclusion (not for the first time): If you want bass, use full range speakers. But feel free to experiment!
 
RJohan said:
Conclusion (not for the first time): If you want bass, use full range speakers. But feel free to experiment!
Click to expand...

That is my viewpoint, though I absolutely love little mini-monitors and could very happily live with nothing more. I was listening to a stack of ECM CDs last night via the recently rebuilt TL12 Plus monos and LS3/5As and it is just staggeringly good within its volume envelope (which is plenty for me in the near-field). I need nothing more than this, though I’m happy to have a huge full-range system downstairs for contrast.

One thing that has been consistent throughout my hi-fi journey is I don’t seem to like speakers with drivers spaced far apart or the bass unit away from the mid & top (e.g. NBLs, some Audio Physics etc). I’m certain it is a timing/phase thing that winds me up as I’m hugely picky about crossovers too. The last octave of bass doesn’t matter to me that much to be honest, I’d certainly not compromise coherence, timing or soundstage depth/resolution to achieve it. The thing I like about proper big speakers (15” Tannoys, huge JBL monitors, Maggies, Khorns etc) is that real ease, effortlessness, scale and heft, and adding a sub to a small speaker never achieves that to my ears. It is a different thing, and one so far I don’t feel any real need for.
 
I tried duel NHT subs with my LS50's (and a single Sunfire sub), both with and without an active crossover, they had more dynamic head room with the subs. Ultimately i thought the LS50 just sounded more satisfying on their own.
Glad you like what they do Rob and you've got them to work well :).

I think Rodney one of the South African members here, had a similar set up for a while then moved onto Dickie designed Giya's, i'm not sure if he's about anymore?
 
@Robert, when you EQ'd the frequency response to achieve +/- 3dB below 80Hz I presume you applied minimal smoothing to the measurements?
 
Getting the bass right ruthlessly exposes any issues elsewhere (or the other way round: bass overhang masks issues).
Most subwoofer installations make everything worse. It takes a lot of luck and/or judgement to get it right.

I am always surprised how much my main power amp influences the sound of the bass, even though it doesn't have to do much below 100Hz. My valve amp still has slightly full and soft bass in comparison my SS amps which have more grip and grunt. So I guess it's how the bass harmonics "fit" with the fundamental that matters.
 
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