Getting subwoofers for the first time

[DimitryZ]

The main choice in sub integration is wether to use them in parallel, filling in the missing octave, or to use the sub's built-in crossover.

I recommend using a passive/parallel approach. This often means a very low crossover frequency on the sub's own crossover, usually below 60 Hz, and experimenting with volume and phase.

If your subs are just behind speakers, 0 degree phase usually works well.

 

[S-Man]

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.

Yep, do it right, or don't bother.

 

[Purité Audio]

Full range loudspeakers are a lot less kerfuffle.
Keith

 

[h.g.]

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.

Yes this would be a reasonable response if you simply add subs in order to make the room boom louder. If you are not going to do anything about the low frequency room response then a steadily falling output with frequency below about 100 Hz seems to be about the best compromise. It won't be high fidelity but it can turn down the boom a bit. Sealed speakers tend to do this better than ported.

On the other hand, if you are interested in high quality sound then competently installed and setup distributed subs are probably the only practical way to get it for low frequencies in the home. This requires separate DSP for each sub, placing the subs largely where they are needed with respect to the room modes rather then where they fit in with the decor, measuring the transfer function of each sub, performing an optimisation study on a PC or dedicated hardware, measuring the result, assessing the weaknesses and the degree to which shifting the subs or buying more will help,... If you are serious about sound quality it is not plug-and-play although various commercial solutions are sold as such and some do an OK job.

 

[dweezil]

The main choice in sub integration is wether to use them in parallel, filling in the missing octave, or to use the sub's built-in crossover.

I recommend using a passive/parallel approach. This often means a very low crossover frequency on the sub's own crossover, usually below 60 Hz, and experimenting with volume and phase.

If your subs are just behind speakers, 0 degree phase usually works well.

I ended up doing just that, crossover set to 60 and ran test tones through to achieve a similar volume to the mains.

Mains are full range though whereas the OP's speakers don't do much in that bottom 8ve.

 

[Tony L]

On the other hand, if you are interested in high quality sound then competently installed and setup distributed subs are probably the only practical way to get it for low frequencies in the home. This requires separate DSP for each sub, placing the subs largely where they are needed with respect to the room modes rather then where they fit in with the decor, measuring the transfer function of each sub, performing an optimisation study on a PC or dedicated hardware, measuring the result, assessing the weaknesses and the degree to which shifting the subs or buying more will help,... If you are serious about sound quality it is not plug-and-play although various commercial solutions are sold as such and some do an OK job.

I consider myself sufficiently “serious” about sound reproduction not to want to add any DSP anywhere in a purist high-end analogue system! ;-)

To be honest even though I have a pair of full-range Tannoy studio monitors large enough to store most people’s whole systems I will take timing and the coherence one gets from a point-source (or close to it) speaker over extended frequency response every single time. I could very happily live with a good near-field mini-monitor system and want nothing more. That sense of coherence is my top priority.

I’ll be very interested to see how Rob gets on. The LS50 are a very good, very coherent speaker and they certainly have enough bass as-is to satisfy me (assuming a damn good amp upstream). If I were a gambling man my money would on Rob keeping the LS50s far longer than he keeps the subs! FWIW I consider the LS50 good enough to hang on the end of any high end system, they are not outclassed by Conrad Johnson, Krell, Accuphase etc. They really are very good, and much of their strengths come from their being a true point-source. That is an aspect I would not alter!

 

[ToTo Man]

I’ll be very interested to see how Rob gets on. The LS50 are a very good, very coherent speaker and they certainly have enough bass as-is to satisfy me (assuming a damn good amp upstream)...

I didn't think you liked small, ported monitors, Tony. Is the LS50 the exception to the rule?

 

[Robert]

I consider myself sufficiently “serious” about sound reproduction not to want to add any DSP anywhere in a purist high-end analogue system! ;-)

To be honest even though I have a pair of full-range Tannoy studio monitors large enough to store most people’s whole systems I will take timing and the coherence one gets from a point-source (or close to it) speaker over extended frequency response every single time. I could very happily live with a good near-field mini-monitor system and want nothing more. That sense of coherence is my top priority.

I’ll be very interested to see how Rob gets on. The LS50 are a very good, very coherent speaker and they certainly have enough bass as-is to satisfy me (assuming a damn good amp upstream). If I were a gambling man my money would on Rob keeping the LS50s far longer than he keeps the subs! FWIW I consider the LS50 good enough to hang on the end of any high end system, they are not outclassed by Conrad Johnson, Krell, Accuphase etc. They really are very good, and much of their strengths come from their being a true point-source. That is an aspect I would not alter!

Could well happen - but I'm giving it a good chance, hence the decision to go with multiple sealed subs both with independent onboard PEQ and variable phase.
The LS50s are fantastic and I agree capable of challenging things far higher up the 'speaker food chain. My issue is that I'm using them nearfield - I mean really nearfield - pulled well into the room in a tight triangular formation to maximise the capability of that driver. With no boundaries close by the low end does thin out somewhat.
If I sit further back in the room and push the LS50s forward, yes the bottom end fills out nicely but that feeling of being direct-coupled to the music, the immediacy is reduced. I want both!

One option was to EQ the LS50 bass in the traditional way but it's a small driver and dual concentric so not a good idea.

All options are on the table from a highly configures DSP solution (I'd need to add something like a miniDSP and additional Cyrus power amp), to using the Subs DSP to match the unfiltered LS50, and positioning the subs anywhere around the periphery the room or even at the base of each LS50 as a stereo pair.

I shall get measuring this afternoon and report the findings, no doubt with some pretty graphs.

 

[Tony L]

I didn't think you liked small, ported monitors, Tony. Is the LS50 the exception to the rule?

There are some exceptions to every rule, the LS50 being one, various small ProAcs (1SC, Tablettes etc) being others, and there are more too. I have very much liked the LS50 whenever I’ve heard them. I wouldn’t personally swap a pair of LS3/5As for them (they are very different in many ways), but they are very, very good indeed. Astonishingly so for the money. I actually think the low-cost Chinese manufacturing distorts their market position, they really compete at twice their retail price and should be viewed as a state of the art mini-monitor for a genuinely high-end system. As stated upthread I view them as a suitable partner for Accuphase, Conrad Johnson, Sugden Masterclass etc. Not especially valve-friendly (I’d likely use a valve pre, solid state power), but a real high-end class A amp would not be wasted on them. Right To Repair politics aside the active ones are very good too. Not heard any of the ‘Meta’ versions yet, I’d be very interested to.

 

[Robert]

I didn't think you liked small, ported monitors, Tony. Is the LS50 the exception to the rule?

I don't either - usually.
The LS50 does it better than most as the alignment is quite dry below 100Hz

There are some exceptions to every rule, the LS50 being one, various small ProAcs (1SC, Tablettes etc) being others, and there are more too. I have very much liked the LS50 whenever I’ve heard it. I wouldn’t personally swap a pair of LS3/5As for them (they are very different in many ways), but they are very, very good indeed. Astonishingly so for the money. I actually think the low-cost Chinese manufacturing distorts their market position, they really compete at twice their retail price and should be viewed as a state of the art mini-monitor for a genuinely high-end system. As stated upthread I view them as a suitable partner for Accuphase, Conrad Johnson, Sugden Masterclass etc. Not especially valve-friendly, but a real high-end class A amp would not be wasted on them. Right To Repair politics aside the active ones are very good too. Not heard any of the ‘Meta’ versions yet, I’d be very interested to.

I recently found a pair of Black Edition LS50 to swap out the standard ones with those rose gold drivers.
Way more aesthetically acceptable to me and it was a choice between jumping on those or trying the Meta.
Meta has the tweeter running 2dB hotter and the upper end of the mid/woofer toned down a tad.
Given I find the overall tonality of the standard LS50 spot-on I decided not to 'upgrade'.

 

[h.g.]

I consider myself sufficiently “serious” about sound reproduction not to want to add any DSP anywhere in a purist high-end analogue system! ;-)

Nothing wrong with knowing what you want but others will be interested in good old fashioned high fidelity.

To be honest even though I have a pair of full-range Tannoy studio monitors large enough to store most people’s whole systems I will take timing and the coherence one gets from a point-source (or close to it) speaker over extended frequency response every single time. I could very happily live with a good near-field mini-monitor system and want nothing more. That sense of coherence is my top priority.

Timing and coherence. Enthusiasts for single driver speakers often bang on about coherence as well but asking them what it means in terms of identifiable measurable quantities has so far failed. Listening to "coherent" speakers at audio shows has also so far failed to produce anything identifiable.

Distributed subs have little to do with extending the frequency response. They are primarily about backing out the room response so one can hear the recording as intended and not the room booming. The system currently sitting in boxes waiting to be put together after I have either refurbished the living room or moved home only uses 8" drivers in small sealed cabinets and will lose adequate clean SPL below about 30-35 Hz. If I was interested in extending the response lower a large single sub tucked away in a corner would do it because such frequencies are below the lowest room resonance.

The system in boxes has a coaxial KEF midrange+tweeter although the wide beamwidth may prove problematic in the asymmetric room (bought for a different room). You will get no argument from me concerning the advantages of coaxials at higher frequencies. The wavelength at 400 Hz or so however is long enough and the room response starting to intrude sufficiently that the pros of a coaxial arrangement tend to be outweighed by the cons like modulation and distortion when it comes to woofer frequencies.

I’ll be very interested to see how Rob gets on.

Likewise. What he uses them to achieve will be interesting. Sticking them under his current speakers to create adequately sized mains while using the DSP to lower a mode or two will bring significant improvements in fidelity if done competently with high and low pass filters. Particularly the former given the high pass filter will remove some of the low frequencies modulating the midrange plus the motor distortion from large deflections. Two subs is not really enough for a good distributed system although he could setup one on the front wall as a source and setup one behind as an absorber which could address some of the axial modes which are often the most problematic.

 

[Robert]

Nothing wrong with knowing what you want but others will be interested in good old fashioned high fidelity.



Timing and coherence. Enthusiasts for single driver speakers often bang on about coherence as well but asking them what it means in terms of identifiable measurable quantities has so far failed. Listening to "coherent" speakers at audio shows has also so far failed to produce anything identifiable.

Distributed subs have little to do with extending the frequency response. They are primarily about backing out the room response so one can hear the recording as intended and not the room booming. The system currently sitting in boxes waiting to be put together after I have either refurbished the living room or moved home only uses 8" drivers in small sealed cabinets and will lose adequate clean SPL below about 30-35 Hz. If I was interested in extending the response lower a large single sub tucked away in a corner would do it because such frequencies are below the lowest room resonance.

The system in boxes has a coaxial KEF midrange+tweeter although the wide beamwidth may prove problematic in the asymmetric room (bought for a different room). You will get no argument from me concerning the advantages of coaxials at higher frequencies. The wavelength at 400 Hz or so however is long enough and the room response starting to intrude sufficiently that the pros of a coaxial arrangement tend to be outweighed by the cons like modulation and distortion when it comes to woofer frequencies.



Likewise. What he uses them to achieve will be interesting. Sticking them under his current speakers to create adequately sized mains while using the DSP to lower a mode or two will bring significant improvements in fidelity if done competently with high and low pass filters. Particularly the former given the high pass filter will remove some of the low frequencies modulating the midrange plus the motor distortion from large deflections. Two subs is not really enough for a good distributed system although he could setup one on the front wall as a source and setup one behind as an absorber which could address some of the axial modes which are often the most problematic.

If I get good results with a pair of subs, I'd consider adding a third but that's the budget blown.

Completely agree on the reason for using subs. I'm not looking for sonic fireworks or stunts (well for movies but not 2 channel audio) just better control of the room contribution and a little more low end range and heft when the music demands.

 

[mikechadwick]

Very interesting thread - I'm currently using LS50 Metas with a KC62 sub. These are being used in my home office which is a really awkward shape and a bit of a nightmare tbh. I've always struggled with setting up subs correctly and the LS50/KC62 combo is no exception. Always on the lookout fore helpful tips (including sell the sub @Tony L)!

 

[mandryka]

I'll just mention one thing I picked up from someone using a pair of passive subs with LS3/5As. He said that he got best results from putting the speakers in front of the subs on stands, the subs just behind. The standard way was to mount the speakers on top of the subs. Anyway he thought the position made a significant difference and so it's probably worth experimenting.

(I can see other people have suggested something similar.)

 

[ToTo Man]

Meta has the tweeter running 2dB hotter.

According to JA's measurements the Meta does appear to have more HF output between 5kHz and 12kHz than the original LS50 but less 'air' in the highest octave. The Meta also appears to produce more output between 300Hz and 1kHz, which will arguably balance out its hotter treble and may even make its tonal balance sound warmer than the original. IIRC, folks main complaint of the original model was a slight hardness/forwardness in the upper mids. This region appears to have been lowered in the Meta (according to JA's measurements at least). I haven't heard either model but I'd love to audition both! I'm betting the Meta would sound the 'drier' and more neutral of the two, but not necessarily the most enjoyable to listen to...

 

[Robert]

According to JA's measurements the Meta does appear to have more HF output between 5kHz and 12kHz than the original LS50 but less 'air' in the highest octave. The Meta also appears to produce more output between 300Hz and 1kHz, which will arguably balance out its hotter treble and may even make its tonal balance sound warmer than the original. IIRC, folks main complaint of the original model was a slight hardness/forwardness in the upper mids. This region appears to have been lowered in the Meta (according to JA's measurements at least). I haven't heard either model but I'd love to audition both! I'm betting the Meta would sound the 'drier' and more neutral of the two, but not necessarily the most enjoyable to listen to...

The mid-treble balance on the Meta looks near identical to the R3 - slightly lifted mid, lifted treble but slightly reduced presence area between the two. If I run the R3 next to the LS50 then certainly the R3 sounds sounds more airy and superficially detailed, but it is also not kind to vocal compression and sibilance - it sounds superb on reference recording with good balance but the LS50 flatters more recordings IME. Both superb but depends which balance you prefer.
The original LS50 does have a little mid forwardness (though certainly not harsh) but I like that in a mini monitor. it's mild enough to go unnoticed unless you directly A/B or crank the playback levels way up high.

 

[mansr]

Very solid thing and looks superbly built. Definitely good material value for £630.

So you went for the glossy finish? I didn't think it worth the price premium when I got mine recently. Liking it so far, FWIW.

 

[mansr]

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.

Mine is different: plug them in, turn them on, run the Audyssey setup, and enjoy better bass.

 

[mansr]

I consider myself sufficiently “serious” about sound reproduction not to want to add any DSP anywhere in a purist high-end analogue system! ;-)

Funny. I wouldn't go without DSP for the same reason.

 

[Robert]

So you went for the glossy finish? I didn't think it worth the price premium when I got mine recently. Liking it so far, FWIW.

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.