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Subwoofers and LS3/5As

The Kef KC-62 seems to carry a premium price for what it does. SVS, for example, has a similar model for half what the Kef goes for, and other makers do too. At the listening chair, I wonder if 'twice the price' will be audible.

The KC62 has a lot more technology inside. It's smaller and it goes lower. The relevant bit for sound is the LF rolloff - the lower and slower the rolloff the tighter and cleaner the bass will sound... and the better it integrates with the main speakers.

I can program my bass extenders rolloff frequency and despite thinking it would be better to roll off above the main room mode frequency I have found that lower is better. Convincingly better!

This might be worth a look (I'm sure there's a comment somewhere on this site about <14Hz rolloff gives better subjective results):
https://www.rythmikaudio.com/technology.html
 
The use of a subwoofer is of paramount importance. For eg. pic. below shows Bowers & Wilkins 802D2’s which are perfectly capable of good quality low frequencies. However this system features a pair of JL Audio Fathom f112 v2 subwoofers in use with a crossover point to the main speakers set at 80Hz, so the 802D2 speakers are relieved of the need to produce deep bass. It’s a good starting point as it relieves the main speakers of the bottom two octaves (20Hz - 40Hz and 40Hz - 80Hz) which lowers distortion in the main speakers. The Fathom f112 v2’s do a much better job in this region. As a result the system is more transparent and dynamic from bottom to top, at low volumes as well as at higher volumes and the space in the original recording is much better defined than the 802D2’s on their own.

57575297_1209277425893977_4560845369558171648_n.jpg
 
I think you accept what small speakers of this ilk can do - and do extremely well - or you buy a different kind of speaker.
 
The use of a subwoofer is of paramount importance. For eg. pic. below shows Bowers & Wilkins 802D2’s which are perfectly capable of good quality low frequencies. However this system features a pair of JL Audio Fathom f112 v2 subwoofers in use with a crossover point to the main speakers set at 80Hz, so the 802D2 speakers are relieved of the need to produce deep bass. It’s a good starting point as it relieves the main speakers of the bottom two octaves (20Hz - 40Hz and 40Hz - 80Hz) which lowers distortion in the main speakers. The Fathom f112 v2’s do a much better job in this region. As a result the system is more transparent and dynamic from bottom to top, at low volumes as well as at higher volumes and the space in the original recording is much better defined than the 802D2’s on their own.

57575297_1209277425893977_4560845369558171648_n.jpg

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 :).
 
The use of a subwoofer is of paramount importance. For eg. pic. below shows Bowers & Wilkins 802D2’s which are perfectly capable of good quality low frequencies. However this system features a pair of JL Audio Fathom f112 v2 subwoofers in use with a crossover point to the main speakers set at 80Hz, so the 802D2 speakers are relieved of the need to produce deep bass. It’s a good starting point as it relieves the main speakers of the bottom two octaves (20Hz - 40Hz and 40Hz - 80Hz) which lowers distortion in the main speakers. The Fathom f112 v2’s do a much better job in this region. As a result the system is more transparent and dynamic from bottom to top, at low volumes as well as at higher volumes and the space in the original recording is much better defined than the 802D2’s on their own.

57575297_1209277425893977_4560845369558171648_n.jpg
I might be wrong but it always seemed to me it was easier to integrate some subs with speakers that can go low on bass notes rather than tiny bookshelf that are mute from 80hz and below. This set up here would be a good example.
 
My humble opinion.

My speakers go down to 25hz in room so I only ask my sub to cover below 40hz (lowest crossover point on my sub). This means my sub (BK XXLS400) only has to produce 40hz and below. If I had smaller speakers and needed a sub to produce higher frequencies, say 80hz and below I reckon I would need a higher quality sub that could produce mid bass at the speed and depth necessary to blend with smaller speakers.

For 2 channel I would want a sealed sub for speed and would look at something like a SVS SB13 or 16 if funds allowed.
 
I think you accept what small speakers of this ilk can do - and do extremely well - or you buy a different kind of speaker.

in my experience (admit only tried twice) a sub kills the essence and beauty of a good ls3/5a type speaker like very little else, why would one do this to them? yes, just buy bigger speakers rather than ruin them?
 
My speakers go down to 25hz in room so I only ask my sub to cover below 40hz (lowest crossover point on my sub)
Bear in mind that the cross-over is not a hard cut but a slope. If the slope is 12dB per octave then your mains are still trying to pump out quite a bit of audio from the 40 > 25 Hz region. In effect you are using them close to their full range. Have you tried a higher cross-over frequency? It might relieve the strain on the mains / amplifier and improve the overall sound?

Also agree that the quality of the sub needs to be good, no point in having a slow and ponderous driver it will remove the enjoyment in listening. I used to own a ported sub (Monitor audio dual 12") and now use sealed subs (Rythmik). The difference is not subtle, though I would hesitate to say that this is a ported vs sealed point as there are so many differences between the 2 subs and it would be over-simplifying to focus on one aspect.
 
rag987, I have no way of limiting the output to my main speakers.

I agree RE ported VS sealed and would always use sealed for HiFi. I have a really well regarded AV subwoofer which goes super low, it has 3 ports and whilst it’s great for AV it’s not fast enough for HiFi.
 
Also agree that the quality of the sub needs to be good, no point in having a slow and ponderous driver it will remove the enjoyment in listening. I used to own a ported sub (Monitor audio dual 12") and now use sealed subs (Rythmik). The difference is not subtle, though I would hesitate to say that this is a ported vs sealed point as there are so many differences between the 2 subs and it would be over-simplifying to focus on one aspect.

Totally agree.
The only bit I would add is that the difference is subtle until the point when you realise all the stuff that's no longer there (with low group delay subs) should never have been there. Once you grasp the difference it's impossible to go back to bass with overhang.

In summary:
LS3/5A with well integrated high performance subs = excellent
LS3/5A = pretty good
LS3/5A with poorly integrated and/or inadequate perfomance subs = schizzle
 
I have heard LS35a’s sounding superb with a sub on one (1) occasion and a few small bookshelf speakers sound outstanding with a sub. Some will simply say a sub will not work with LS35a’s but this is not a fact. What is a fact however is that they are a challenge to make work well with a sub and in some rooms it might be that they will not work. So while I disagree that it can not work I will agree that it might be a bit like hunting unicorns.

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 work with a talented sales person who has made subs sound excellent with some bookshelf speakers over the years where I have failed to. Experience and knowledge would appear to be the second most important criteria to room acoustics (my guess).
 
Jerry Bloomfield has a view on this (48:00)


Interesting that they considered it and decided against.
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.
 
Am now thoroughly enjoying my 11 ohm LS3/5As.

Has anyone had any joy with integrating a sub with them?

Mine are 2m apart in free space and I was thinking of using a single small sub in between them to add a little bottom.


And now for something completely different......know l will get laughed at ( depending on your budget) when the EWA LS40 cable was doing the rounds, borrowed some and my ProAc Tablette 10 gained a TON more bass which was very well controlled, fluid and all aspects of sound was massively upgraded- they simply sounded like a much larger loudspeaker and of course this made music even more interesting and involving..

l will get me coat.:)
 


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