Replacement subwoofer for less than 500€

[FurstMan]

Hello music and science lovers,

I own a pair of Kef LS50 (Anniversary Edition) powered by a Cambridge CXA60, an Anti-mode 8033 Cinema DSPeaker and a subwoofer from a Boston Soundware XS kit :
Bass Reflex
Power: 100w RMS
Frequency response: 50 - 150 Hz
20.3 cm driver
Bandwidth: 60 to 180 Hz (24 dB / octave), low-pass filter

The latter has just broken down, so I need to find a replacement. For a budget of €500, I found the SVS SB-1000 (non-pro), which has even more interesting characteristics, capable of going much lower:
Close load
Power : 300w RMS (720W peak)
Frequency response: 24 - 260 Hz +/- 3 dB
30 cm driver
Variable low-pass filter (50 to 160 Hz + LFE)

My entire audio system is used in the near field, at a distance of around 1,2m.

Do you think that replacing my Boston subwoofer with the SVS will bring an audible improvement?
I know that room treatment plays an important role, and that low frequencies are highly dependent on it, but the advantage of a near-field configuration is to take advantage of the speakers' “direct” performance.

What's more, I intend to take advantage of the fact that it has a high-pass filter at 80khz to relieve the LS50s, which aren't the most comfortable in the low frequencies.

What do you think? Thanks in advance and have a nice day.
PS: sorry if I'm not clear, I'm a French speaker.

 

[ZolaIII]

You can use them with crossover @80 Hz without high pass as they are already - 3 dB there and this will be most comfortable regarding pairing. If you want to improve them think about two smaller 10" also close enclosure sub's with suitable DSP or multichannel something and doing the crossover at impedance/phase crossing at 140~150 Hz to easy their burden and improve nasty cabinet refraction they have. It would also be a great for amplifiers sake.
Basically they behave same as Metas.

KEF LS50 Anniversary Model loudspeaker Measurements

Sidebar 3: Measurements I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the KEF LS50's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. My estimate of the KEF's voltage sensitivity was...

www.stereophile.com

Amir's Meta measurements and graphs are much better so stick with them.

KEF LS50 Meta Review (Speaker)

This is a review and detailed measurements of the KEF LS50 Meta bookshelf coaxial speaker. It was kindly purchased new by a member and drop shipped to me and costs US $1,500 for a pair. The LS50 Meta comes in different colors and I must say, it looks stunning in white: You could sell it as...

www.audiosciencereview.com

Room accustic treatment is very not efficient there and good room correction will do more than good enough job there by hand you can do even better (who ever says otherwise wants your money badly).

 

[FurstMan]

Thanks for your reply!

For the high-pass filter, don't you think that frequencies below 80hz will make one less load for the LS50s thanks to this? Even with the -3db, it doesn't mean they don't work, they just have trouble reproducing them. Theoretically, they go down to 45hz. Am I mistaken or have I missed something?

So you think 2 small subwoofers are better than one, even for a near field? Are there any models to recommend?

As for the DSP, I already have an Anti-mode 8033 Cinema, but it only supports one subwoofer. I have no intention of changing amplifiers (I was using them on a Sony DTH-790 AVR where I had placed a crossover at 120hz).

 

[ZolaIII]

Thanks for your reply!

For the high-pass filter, don't you think that frequencies below 80hz will make one less load for the LS50s thanks to this? Even with the -3db, it doesn't mean they don't work, they just have trouble reproducing them. Theoretically, they go down to 45hz. Am I mistaken or have I missed something?

So you think 2 small subwoofers are better than one, even for a near field? Are there any models to recommend?

As for the DSP, I already have an Anti-mode 8033 Cinema, but it only supports one subwoofer. I have no intention of changing amplifiers (I was using them on a Sony DTH-790 AVR where I had placed a crossover at 120hz).

Well the thing is from 60 to 90 Hz is splash from a standing wave (partly sum) and upwards it's directional and doesn't sum. It fals down on woofer ther - 3 and under is port so you may plug it and additional autend with DSP but it won't easy their burden. If a little bit of directivity doesn't bother you you might as well proceed with single sub in 2.1 (with high pass filter there and by all means proper crossover of course). Problem in small rooms (which all of our arguably are to reference one) you can't influence decay much in lows especially so something which won't make more time domain problems will also benefit there that it's overall lower and that goes to 10" closed back sub's as ideal regarding it. In near feald it's possible even to anulate room mode by placing the sub 1m (in cuple of cm) directly in front of you and in the middle. Cone size increase will give you more extension but over 10" it won't be able to stop really fast so you make compromises (as always in life). Nothing special to recommend as model and not so much of such. From commercially available as a good designed KH 750 stands out but it's stupid to even think of those without their monitors to pair (for DSP capabilities and well price because you don't want to miss that when you paid...). I use relatively cheap Wharfedale D10's, they aren't anything special but they do the job (to mid 20's 0 dB in my small room and pass calibration to 3 m).

 

[kemmler3D]

Do you think that replacing my Boston subwoofer with the SVS will bring an audible improvement?

Yes.

he advantage of a near-field configuration is to take advantage of the speakers' “direct” performance.

This is less of a factor (almost not at all) when it comes to subs because the wavelengths are so long. In-room it's actually hard to perceive direction at all below 60hz or so, and it starts getting noticeably harder below 100.

What do you think? Thanks in advance and have a nice day.

You can find subwoofers secondhand for not too much money sometimes. I got 2x BIC F12 subs for $250 a while back. They are not nearly as good as the SVS, but in an office at moderate to low SPL, having 2 mediocre subs is better than having one good sub for dealing with modes. So, I would just suggest you look for used subs while you are shopping!

Overall your plan seems fine to me.

 

[Verig]

Sealed Elac 2030 works nicely. Plenty of clean output and goes certainly low enough with room and dsp.

 

[mns3dhm]

I’d also consider the RSL Speedwoofer Mk II at that price point. I have a pair of KEF LS50 meta speakers paired with the RSL in our TV room and enjoy that setup.

 

[FurstMan]

I understand, thank you for your detailed answers.

So to sum up, trying not to say too much nonsense:
- 2 mediocre subwoofers are better than one good one, that's the most visible improvement I can make.
- Subwoofers of 20cm or less are preferable, as anything bigger will be more powerful but also slower.
- Subwoofer power is not important for near-field listening.
- The frequencies produced by the subwoofer are not directional, even in the near field.
- Closed subwoofers are preferable.
- A 120-140Hz crossover is preferable.
- The SVS high-pass filter at 80hz is useless, as LS50s have a frequency response (±3 dB) at 79hz - 28 kHz.

Am I right?

 

[kyuu]

- A 120-140Hz crossover is preferable.
- The SVS high-pass filter at 80hz is useless, as LS50s have a frequency response (±3 dB) at 79hz - 28 kHz.

I don't think this is accurate. Generally you want a lower crossover to avoid being able to locate that the subwoofer is in a different location than the speakers. The general rule-of-thumb is 80Hz, though of course this isn't set in stone and certainly depends on the capabilities of the speakers. In the case of the LS50, it doesn't appear to me that there should be any issue crossing them over at 80Hz or so:

You can see the characteristic bass shelf that Kef uses for many of their speakers. That shelf should get filled in as long as the speakers are somewhat near a room boundary (wall) and easily have adequate bass response through the crossover region.

 

[Verig]

120-140Hz is horribly high, you will hear it. 80Hz is absolutely fine with KEFs, xo is not razor sharp anyway.
I don't agree that a large sub is slower but then again the Elac I recommended is a 10" sealed which works wonderfully in small / medium space. I have one. Quite affordable and good quality. As a down firing design it's kids and pets friendly and quite petite as far as these things go.

 

[ZolaIII]

@FurstMan ask your self what makes a subwoofer a good one? SPL capacity where you need it the most and acceptable THD. For music it's mid 30's to 40's Hz where low bass peaks are and for movie's it goes even mid 20's but you can live without that most definitely. You can cross the speakers or you can do it with benefits. General idea is to use it as a tool so you are able to get most benefits from given drivers you are crossing over. Future more you want to stay on their own (closed box) response while doing so. And so do driver manufacture regarding classification parameters for given enclosure capacity. And don't draw abductive reasoning off the category conclusions.

 

[kemmler3D]

2 mediocre subwoofers are better than one good one, that's the most visible improvement I can make.

This is my opinion but only if you don't care about high SPL.

- Subwoofers of 20cm or less are preferable, as anything bigger will be more powerful but also slower.

Not really, "slowness" is not caused by the size of the speaker cone.

- Subwoofer power is not important for near-field listening.

Yes and no. Subs need a lot of power to produce the very lowest frequencies at audible levels. But as long as you have good output down to 20hz you may not need more watts than that.

- The frequencies produced by the subwoofer are not directional, even in the near field.

Basically yes, but direction is still perceptible, if not very meaningful, below 100hz to an extent.

- Closed subwoofers are preferable.

You get less group delay, but they need more power to do the same output at the lowest frequencies. It's a trade off, one that many choose to make, but it's not a hard and fast rule.

- A 120-140Hz crossover is preferable.

This all depends on your exact goals but I think it's a reasonable choice. Higher crossover can give lower distortion but as others have said you may be able to hear the direction. In my office I have 2 subs in stereo that are symmetrical to the listening position, so a higher crossover is no problem.


If the subs are just in random places in the room then a lower xover is probably better.

 

[FurstMan]

Okay, thanks for your clarification.

In the same price range, I can choose between these two models:
REL Acoustics T-Zero MKIII - €465
ELAC SUB 2030 - €495
SVS SB-1000 - €499

Which one would be a good choice?

I'm thinking of buying one, then a second in a few years when I've moved and have my own listening room/office. But the SVS and ELAC seem to be at the end of their life on the market and hard to find second-hand.

I haven't found anything interesting second-hand apart from a KEF Cube, but the all-fabric covering might please the cat...

I live in Belgium (Europe) and some well-known American brands can't be found here. RSL comes to mind.

Oh, I thought I read here on ASR that the subwoofer enclosure facing the listening position and not the floor could be a good thing for near-field listening. What do you think?

 

[kemmler3D]

Okay, thanks for your clarification.

In the same price range, I can choose between these two models:
REL Acoustics T-Zero MKIII - €465
ELAC SUB 2030 - €495
SVS SB-1000 - €499

Which one would be a good choice?

I'm thinking of buying one, then a second in a few years when I've moved and have my own listening room/office. But the SVS and ELAC seem to be at the end of their life on the market and hard to find second-hand.

I haven't found anything interesting second-hand apart from a KEF Cube, but the all-fabric covering might please the cat...

I live in Belgium (Europe) and some well-known American brands can't be found here. RSL comes to mind.

Oh, I thought I read here on ASR that the subwoofer enclosure facing the listening position and not the floor could be a good thing for near-field listening. What do you think?

@sweetchaos made a large comparison sheet of subwoofers: https://docs.google.com/spreadsheet...mfyBjaxK69dkXte6ZL6anVTW2_M/edit?usp=drivesdk

It should probably be the first reply on threads like this...

There's no data on the ELAC but the SVS is the clear winner over the REL.

 

[Verig]

Oh, I thought I read here on ASR that the subwoofer enclosure facing the listening position and not the floor could be a good thing for near-field listening. What do you think?

I don't know how it would be unless there's some really specific scenario discussed with really high crossover point? And then it's not really a sub anymore.
The sub will be on the floor anyway and in near-field set perhaps even under your desk. How would the direction matter. Just keep the crossover under 100Hz and it'll be fine.

 

[FurstMan]

Thank you very much for your help, I bought the SVS SB-1000 non pro for 499€ new. I couldn't find it second hand.

I can't wait to play with it!

 

[Verig]

Looks nice. A sealed 12" is a simple and functional beast and there's plenty of power for your application. Just take your time with placement and dsp. I think LS50 + sub is one of the most bang for the buck sets you can have in small / medium space with the bonus of great near field ability.

 

[FurstMan]

Thanks, the MiniDSP will certainly be my best friend!
For the moment the subwoofer will temporarily go in the living room, behind the sofa: I haven't found a better place, even if it's not really the best, as for many people here there's the aesthetic constraint of a living room, and then I don't live alone.
But when I have my listening room, the subwoofer will certainly be placed at the same distance from the speakers, in the middle of them and facing me. This is the placement I've seen most often for a small room, and I'd obviously adapt it to my situation.

 

[Verig]

My preamp has Dirac and two sub outputs and I've been thinking about adding a second Elac. They're pretty common around here and used prices are very reasonable. I don't absolutely need it but pretty affordable to just try. This is a living room set but I can place them with the speakers. That said, I have not experienced much problems placing the sub farther, DSPs work nicely.
Have fun.