advertisement


Subwoofers and LS3/5As

This is of course dependent on each individuals personal taste with the LS35a’s. If you value base more than the LS35a’s particulars midrange then you may not be happy with a. Bare LS35a but very happy with them on a sub. For some people no bass down to XXhz = no fun

I suspect this is why so many LS3/5A users are similar to me in that they use them as a nearfield counterpoints to a much larger full-range speaker. I honestly think that once you get to the point of wanting to bolt-on bass to an LS3/5A it is time to buy another bigger speaker. To my ears you inevitably bring time and phase error, which is the last thing you want in a little nearfield monitor. I’d also argue much of the LS3/5A magic arrives when partnered with valve amps, and it gets harder to bolt bass onto that scenario.
 
I haven't high-passed my mains for years as I'd need to add another box to my system to do so and haven't taken the plunge into DSP yet. However, back in the mid-2000s when I had a multichannel AV setup I was staggered at the improvement from high-passing my mains. Before they sounded muddy and slow and afterwards they were crisp and dynamic, it really was a night and day difference. The extent of improvement was I'm sure a lot to do with the speakers being of poor quality (they had front AND rear ports FFS! :rolleyes:), so most of the benefit probably came from reducing the ports' output. My AV amp had three hi-pass settings, 80Hz, 100Hz and 120Hz, and the latter definitely sounded the cleanest and most dynamic. I have no idea how it measured as that was long before I had REW, but it sounded great to my 20-year old ears. I'm not sure what I'd think of it now though!... :D

Nice room BTW :).

With all things being equal a subwoofer is the most important component. Ideally frequencies up to 90Hz should be unburdened from the mains and this LF burden passed on to a subwoofer to deal with.

I believe to achieve 'realism' requires power and even if the mains go down to 20Hz a subwoofer should still be incorporated because in my experience a subwoofer can inject power into and energise a system like no other component can.

The goal then is to effectively align, calibrate, dial in a subwoofer so that the subwoofer integrates seamlessly with the mains and disappears into the soundstage with a deep, sharp, tight fisted, fast and powerful punchy sub bass.

Btw, running sub/s below the mains does nothing but WASTE the potential of the sub/s and therefore ultimately comprises the overall performance of the system. It’s like having a Formula 1 car running on Fiesta tyres. Yes, the F1 car will move but ultimately it wastes the potential of the chassis and engine.

No power, no depth. No depth, no body. No body, no soul to the sound. Simple.
 
A sub, no matter how good, would just wreck what I like about the LS3/5A. They are an astonishingly good and coherent little nearfield speaker. No sub is ever going to integrate in the nearfield. Just not possible. For mid/far-field listening I’d buy a larger speaker of similar heritage (e.g. any of the Spendor, Graham, Stirling etc BC1 equivalents). I’ve certainly never liked the AB1s at all, and whenever I’ve heard mono subs in nearfield systems it has taken me less than a couple of seconds to spot their detrimental effect to soundstage, imaging, coherence etc. LS3/5As are special things, but only at being LS3/5As. Try to get them to do anything else and they won’t IME.

Just cogitating on this...
You may well me right for nearfield use.
For mid/far then I think the well integrated bass extender route gives much better results than the "any of the Spendor, Graham, Stirling etc BC1 equivalents".

My pal with the pre-KC62 bass extenders owns:
2 (or 3) sets of JR149s
2 sets of Spendor LS3/5As
ELS63
Gale 401
LS50 Meta

He could easily use any his speakers without the bass extenders.
All are inproved by using the bass extenders, the least improved being the Quads, perhaps due to their lack of 'tuned/box' bass.
His main amp is a KT88 PP, which has no trouble driving the Gales but is not a happy pairing with the wild impedance swings of the LS50M.
The use of the bass extenders doesn't just benefit the speaker by removing the need for high excersions fo the bass unit, it also helps the (valve) amp by it not having to do LF.

We have tried every permutation of everything and probably the best combo was JR149 + bass extenders driven by a pair of Leak TL12.1s.
Sadly the 12.1s were being restored and have gone back to their owner.
 
My pal with the pre-KC62 bass extenders owns:2 sets of Spendor LS3/5As
Since you have direct experience of a successful implementation of extra bass with the ls3/5a, would you care to share the details of how you set up the solution in the room and talk about levels, cross over points, perceived sound change etc, with music choices too? Thanks.
 
Question for musicraft,

My understanding is a 7 inch high quality bass driver will move/react faster than a high quality 12 inch sub driver with its associated large magnets etc. If this is the case why would I use a subwoofer to produce 90hz and below if my main speakers perform well down to 35hz? Would they both not be producing 35hz to 90hz with timing differences (no matter how slight)?

Open to being educated if I am mistaken of course.
 
Since you have direct experience of a successful implementation of extra bass with the ls3/5a, would you care to share the details of how you set up the solution in the room and talk about levels, cross over points, perceived sound change etc, with music choices too? Thanks.

My main speakers were designed as ported 2-ways. I blocked the port and measured the acoustic output, which turned out to be a 2nd order rolloff at 80Hz.

V1 of my electronic crossover was a textbook LR4 high and low pass at 120Hz. Results were very good but it occured to me that below 80Hz the sloped didn't match, due to the rolloff of the main speakers. I had two options: a) Add a 2nd order boost to the high pass signal with a corner frequency of 80Hz and continue to use the LR4 or b) Use the 80Hz rolloff of the speaker and a 120Hz 2nd order electronic crossover for the high pass and a corresponding 120Hz 2nd order and 80Hz 2nd order low pass.
V2 of my electronic crossover used option b. Although it's no longer a true LR4, the acoustic response has ideal phase alignment with a modest amplitude variation (<1dB IIRC). The benefit is that it means a reduction in the cmplexity of the high pass part of the crossover.

V2 sounded quite a bit better - tighter and less obvious bass. It really doesn't sound like "subwoofer" bass, just sounds "right".

I don't know if the DSP crossover in the KC62 has any means of correcting for the response of the mains speakers in this way, or if it's just a textbook LR4?

The only adjustment I have is a volume pot on the bass level. It's surprisingly easy to get the level right, with different sensitivities of speakers and power amps. It just sounds right at one particular level.

Of course this method means that any speaker that doesn't have a 2nd order rolloff at 80Hz will not integrate properly :(. The crossover would need some modification for other frequencies. Alternatively one could use something like a Behringer crossover, however the one we tried is far from subectively transparent.

Most small sealed speakers have a rolloff in the right area, however it's possible that the LS3/5A might be less ideal than the JR149 due to the well know bass hump of the former.

Perceived sound change: Much deeper bass (obvs). Much more resolution in the mids and treble. Ablity to play loud without compression, provides much better dynamics even at lower SPLs.

Music: Any. My pal is into jazz and a but of classical. I tend towards rock and vocals etc. It makes everything better. Including "poor" recordings, many of which turn out to be not poor at all!
 
Last edited:
Question for musicraft,

My understanding is a 7 inch high quality bass driver will move/react faster than a high quality 12 inch sub driver with its associated large magnets etc. If this is the case why would I use a subwoofer to produce 90hz and below if my main speakers perform well down to 35hz? Would they both not be producing 35hz to 90hz with timing differences (no matter how slight)?

Open to being educated if I am mistaken of course.
A 7 inch woofer producing a lot of deep bass has to move back and forth a lot with long excursions making it difficult to be accurate on mids at the same time. Even more true when playing out loud.
That said, I'm not a fan of subwoofers in general but my 6 1/2 inch woofer in my floor standers are 87 dB efficient and I never go louder than 95 dB so the result is good enough for me.
I should also mention the moving mass of my small woofer is only 13 grams while the majority is around 20 grams so this also helps.
 
I ran proac tablette 10 SEs with a rel stentor III. Crossed in at 90hz using Lyndorf TDAI 3400 active cross over and room perfect.

The additional 2 octaves on the bottom end make a massive difference, not just those 2 octaves but right through the entire range with improvements to tonal accuracy. Soundstage was bigger too.

You need to integrate the sub or subs with the system and room well though to get the best performance.
 
FWIW, things like AB1 are crap. Just don't bother.

A somewhat strident and frankly offensive statement. LS3 etc's are as room dependent as any speaker and so is the AB1.

I have no personal experience of the AB1 but I wouldn't have thought using a B110 as a subwoofer to be a great idea. For a start it isn't going to provide meaningfully more LF extension, distortion will be high, and its power handling is going to be limited to its relatively small Xmax.

I'd argue it is all about context, by which I mostly mean listening room. We do not all have a small ballroom in which to display our system. True, it doesn't go mega deep, but it extends bass to a reasonable degree, especially where space is an issue.

As it is, I don't have LS3/5A.. I have Rogers Studio 3 which was designed as a replacement. I detailed here, my exerience with them..and with Rogers.

https://pinkfishmedia.net/forum/thr...r-enjoyed-the-most.230080/page-4#post-3720351

And here.. about how Rogers (UK) were promoting an active AB1 two years ago.. though this was at the very start of the pandemic and I don't know what happened since.

https://pinkfishmedia.net/forum/threads/bristol-show-2020.235868/page-6#post-3900494

Finally.. there is a very good reason why I still use my Rogers Studio 3/AB3 combination with LFD amp and Mitchell Orbe etc. Clue. It is not because they are crap.
 
LS3 etc's are as room dependent as any speaker and so is the AB1.
I invested quite a lot in a purchase of the Stirling AB-2 when I owned a pair of ls3/5a V2s. The integration of these bass extenders and my speakers/room was not convincing and the purity of the midband of the ls3/5a was compromised and I sold the lot.
However, I've since purchased Stirling V3s (love them) and most significantly, I treated my room with floor to ceiling bass traps in the two corners behind the speakers. I suspect, (though i have not yet tried) that a pair of ab-2s would be far more successful now. The room treatment had a huge effect on clearing up the room bass frequencies and reduced the significance of the ls3/5a 'bass hump'.
 
A somewhat strident and frankly offensive statement. LS3 etc's are as room dependent as any speaker and so is the AB1.

The AB1 just doesn't make sense. It's a B110 in a ported box.
Why on earth would you want to "augment" the LS3/5As tight and tuneful bass with something that doesn't extend the bass much, adds a load of bass overhang and doesn't low pass the LS3/5A?

No wonder that people get a bad impression about subwoofers!
 
Question for musicraft,

... why would I use a subwoofer to produce 90hz and below if my main speakers perform well down to 35hz? Would they both not be producing 35hz to 90hz with timing differences (no matter how slight)?

Open to being educated if I am mistaken of course.
I'm not @Musicraft but here's my take on that part of the question and is as @Gervais Cote writes.

There's a lot of energy in the bass region of much music. A smaller woofer has to move further to produce the same bass output level as a bigger one. Driver magnetic fields are only constant if you keep this displacement small enough. Operating outside the region of constancy generates distortion - so the smaller driver will distort the bass more. And if that driver also has to produce higher, mid-range, frequencies at the same time, they will get more distorted too when the excursion is high. If you want to reproduce bass down to a reasonable frequency and at high level (for mid-field rather than near-field listening):
  • Low excursion is generally better than high for bass distortion - which favours bigger bass drivers.
  • Separating mid-range frequencies from bass and giving each to separate drivers is better for mid-range distortion too - which favours three drivers over two in main 'speakers for mid-field listening.
  • In the case of adding a sub-woofer, the point above also favours keeping bass frequencies away from small (near-field) main 'speakers by filtering, so getting less mid-range distortion.
However, the above are generalizations and the truth about whether this matters to you depends on a lot more detail including your individual preferences - "generalizations are never true".
 
Question for musicraft,

My understanding is a 7 inch high quality bass driver will move/react faster than a high quality 12 inch sub driver with its associated large magnets etc. If this is the case why would I use a subwoofer to produce 90hz and below if my main speakers perform well down to 35hz? Would they both not be producing 35hz to 90hz with timing differences (no matter how slight)?

Open to being educated if I am mistaken of course.
Proper sub integration requires a processor something for example from the MiniDSP range, and acoustic measurement REW to determine the roll of of your mains.
Keith
 
I invested quite a lot in a purchase of the Stirling AB-2 when I owned a pair of ls3/5a V2s. The integration of these bass extenders and my speakers/room was not convincing and the purity of the midband of the ls3/5a was compromised and I sold the lot.
However, I've since purchased Stirling V3s (love them) and most significantly, I treated my room with floor to ceiling bass traps in the two corners behind the speakers. I suspect, (though i have not yet tried) that a pair of ab-2s would be far more successful now. The room treatment had a huge effect on clearing up the room bass frequencies and reduced the significance of the ls3/5a 'bass hump'.

I like this. You are not generalising as per 'S-Man'. You are describing your own experiences and approach to finding a speaker system which works for your tastes, in your system, in your room, which is all any of us can do.

The AB1 just doesn't make sense. It's a B110 in a ported box.

First off.. I don't have LS3/5As. I have Studio 3s which use the same box with different drivers and are, as several posters here will testify, very capable in their own right.. but that really isn't the issue here..

Yes, I know it's 'a B110 in a ported box'. I have two... And AB1 is NOT a subwoofer, nor was it marketed as such by Rogers, who first produced it. In reality it converts the LS3/5A and in my case the Studio 3, into a tidy and effective floorstander.

Why on earth would you want to "augment" the LS3/5As tight and tuneful bass.

Why on Earth would you want a speaker which only delivers upper bass? IME the strength of the LS3/5A is almost totally in the quality of the mids and highs. Without in any way 'dissing' the LS3 or its designers..any fool can get tight fast tuneful bass if they stay in the 'upper bass' region. So.. having got my Devil's Advocacy out of the way...it comes down to what every audio kit choice comes down to. How does the performance of your speakers, in your room, in your system, interact with your taste? It's the only way to choose kit sensibly.


.with something that doesn't extend the bass much, adds a load of bass overhang.....

Is that experience talking.. or some 'expert' opinion/ received wisdom..? I have had my Rogers since 1996 and the AB3s since 1997. They have seen off many competitors, but never been beaten according to my taste, in my room, in my system.

and doesn't low pass the LS3/5A?

If you are talking absolutes you are incorrect. If you are querying the crossover characteristics, I'd suggest you take that up with Andy Whittle who designed the AB1, the successful 'Studio' series and IIRC correctly another successful more budget oriented series with IIRC the 'LS' prefix. Also IIRC Andy went on to work for Exposure after Rogers closed, and then re-appeared recently with new British designs for the Rogers brand. I think he has a fair idea what he is doing.

But if you want the specs: Here they are direct from my AB1 manual:


Specifications
Type: single driver subwoofer

Frequency Response: 55Hz to 120Hz

Power Handling: 50W

Recommended Amplifier: 25 to 100W

Crossover Frequency: 120Hz

Impedance: 8Ω

Sensitivity: 84dB

Bass: 1 x 125mm cone

Enclosure: band pass

Dimensions: 570 x 190 x 162mm

Weight: 8.2kg

Since I have S3s which are not LS3s, I spoke to Andy way back about an 'AB3'. He told me the design was already worked out and agreed to make me a pair but I can't be bothered typing that story out again. I already posted it above.

No wonder that people get a bad impression about subwoofers!

I repeat. NOT a sub. As with everything else, there are good, bad and indifferent subs, but since the AB1 isn't a sub.. you should maybe look elsewhere for something to blame.
 
I repeat. NOT a sub....but since the AB1 isn't a sub...

Specifications
Type: single driver subwoofer
Enclosure: band pass
These two specs are contradictory IMO. Does the AB1 really have a high-pass filter on it at 55Hz to make it a band-pass or is it a typo? If there is no high-pass on the B110 then by definition it's a subwoofer surely, regardless of how low the B110 is able (or unable) to extend?
 
Is that experience talking.. or some 'expert' opinion/ received wisdom..? I have had my Rogers since 1996 and the AB3s since 1997. They have seen off many competitors, but never been beaten according to my taste, in my room, in my system.

It's just engineering. Ported speakers, with a few exceptions, have a 4th order rolloff which has inherently poor group delay. Some people are sensitve to this, others seemingly not, and some like this effect.

(Continue to) enjoy your system Mull. That's all that matters.
 


advertisement


Back
Top