BeoLab 4 + subwoofer ... which subwoofer should I get?

Hi all,

Recently received a pair of (used) BeoLab 4 as a gift. Would like to keep them but would also like to add a subwoofer for bass. They are in a room of about 12 x 16 feet and I like to listen to electronic music! I have no other B&O gear; I just plug my laptop/phone straight in through a 3.5mm jack.

Any advice? I don't mind getting a different brand - doubt I can afford a B&O subwoofer anyway.

Ideally something relatively unobtrusive physically. And of course needs to complement the BL4 pair, rather than being weirdly separate and bass heavy.

NB these are not the 'PC' version.

Thanks!

J

Free speakers?  Therefore cheap new "sub" woofers: Definitive Technology ProSub 800, $250 on amazon.com.  Maybe Jamo S 808 Sub, $159(!) on amazon.  8-inchers cannot play extremely loud (without distorting) or truly low, but that's perfectly appropriate for mating w/ BL4's.  Both come in white and both have fabric grille covers -- important for unobtrusiveness.  There are many other choices, for example with smoother output but more expensive (e.g. REL), or louder & deeper but more ugly (Monoprice, AudioEngine).  If you have a good hiding place, the cheap Yamaha YST-FSW ones fit under some furniture.  None of these will shake the room, not even 12x16', not for your electronica.  But if they are invisible, they will give you quite a start if all you see is the BL4's, when Dennis de Laat's "Sound of Violence" kicks in...  

[Edit: Caveat: I have actually used the Yamaha and DefTech long-term.  Not the Jamo -- just saw it scanning around and thought "That's cheap even for an 8", and it doesn't look horrible like most!"  The Yamaha is under my desk, used at low volumes for near-field w/computer speakers.  A pair of the DefTech's are offloading the bottom octaves from KEF LS50's.  If you crank them on hardwood floors they will jump around!  But on carpet and for musical purposes rather than movie sound effects, they are fine.  I have heard, but never owned, RELs (various sizes) and AudioEngine.  I have never heard the Monoprice but they have a "cheap but acceptable" reputation, and get OK reviews.]

Hi J,

Welcome to Beoworld!  The good news is that you can use these great little speakers with any brand of active (ie. powered) subwoofer, it doesn't have to be B&O.  The best option is to look for a sub that has red and white RCA Audio Out sockets fitted, then you can connect a pair of Beolab 4 or Beolab 4PC speakers to these sockets with this cable:-

https://soundsheavenly.com/beolab-4-and-4pc/80-54-stereo-rca-to-beolab-4-4pc-variable-level-line-outputs-only.html#/2-length-1m

This method allows the sub to filter out the deeper bass, allowing the Beolab 4s to take just the higher frequencies.  Any questions, please ask!

Kind regards, Steve.

None of the models I mentioned have RCA outputs.  Most take a separate subwoofer "LFE" input, requiring the receiver to do the crossover.  The DefTech also has *speaker-level* inputs & outputs.  Of the inexpensive Monoprice units, only the 12in. 150-Watt has line level outputs, alas it outputs a *full-range* line-level signal, to daisy-chain *subwoofers*, not (so far as I know) to split off at the crossover frequency.  Anybody?

Hi Steve,

Thanks a lot for your guidance, this is really helpful.

I live in Berlin and have been looking at what is available on the local version of eBay. There are literally hundreds of subwoofers. I understand what you mean by a sub that has red and white RCA Audio Out sockets fitted. However, it's hard to know exactly what the other qualities of the sub should be. Your cable product linked says 'Suitable for variable level "pre-out" RCA sockets only.' 

I can find subs which have output RCA sockets, and also ones that have output sockets that are not RCA but seem to require the wire to be inserted and then screwed shut under a knob (not sure the name of this type of socket). Some subs have both. In some cases, the RCA output specifically says 'low level output' and the screw shut ones say 'high level output'. I assume I want to be sending the high level output to the BL4s, but this means it would be coming from a screw shut knob. 

Some other subs are more basic and don't specify so much.

So far I've identified the following, all seem viable. The top one seems the best based on price new and the number of dials on the back of it - in case I need to start adjusting phase and crossover etc. Canton seemed a good brand and it helped narrow the selection a bit.

https://www.ebay-kleinanzeigen.de/s-anzeige/canton-subwoofer-as-85-2/1211317504-172-3404

https://www.ebay-kleinanzeigen.de/s-anzeige/canton-as-200-sc-subwoofer/1209020947-172-3412

https://www.ebay-kleinanzeigen.de/s-anzeige/canton-subwoofer-asd-220-sc-kaum-genutzt/1213024824-172-3480

https://www.ebay-kleinanzeigen.de/s-anzeige/canton-subwoofer-asd-250-sc/1219205257-172-9652

I'd really appreciate your guidance on more specifically what type of sockets I require on the back of the sub. I am willing to pay up to about 200 euros, but I definitely want to get a second hand sub. 

I am also definitely up for using Sounds Heavenly to ensure I get the right cables!

I'm pretty technical and enjoy getting involved with detail on this.

Thanks,

Joseph

 

 

Hi Joseph,

Thanks for your reply.  Any powered subwoofer with red and white RCA output sockets should usually be suitable for connecting to Beolab speakers, as these will have their volume controlled by the music source or TV.

Kind regards, Steve.

josephacthomas:

I can find subs which have output RCA sockets, and also ones that have output sockets that are not RCA but seem to require the wire to be inserted and then screwed shut under a knob (not sure the name of this type of socket). Some subs have both. In some cases, the RCA output specifically says 'low level output' and the screw shut ones say 'high level output'. I assume I want to be sending the high level output to the BL4s, but this means it would be coming from a screw shut knob.

In basic terms, the connector types help to determine how the signals should be routed. The RCA connectors handle line level signals at the preamplifier level of around one volt. These are the most appropriate level for Beolab active speakers. The speaker level connectors are to handle the fully amplified signal needed to drive a passive speaker - much higher level. These are the only choice for Beovox passive speakers.

If we look at your first subwoofer selection, the sub has line level and speaker level ins and outs. It also has selections for crossover frequency and phase adjustments. Even the auto on has selections for which level inputs you are using.

The crossover adjustment sets the frequency the subwoofer will hand off the signal to the Beolabs. Too low, and you miss some of the benefits of a subwoofer and are asking the Beolabs to handle more low frequencies than they can really be expected. Too high and the subwoofer becomes more intrusive and your ears will be able to identify the sounds as coming from the subwoofer. A well configured subwoofer will not call attention to itself.

The phase adjustment is used to ensure the sound launched from the Beolabs and the subwoofer arrive at your ears at the same time. Without this control, you would have to rely solely on subwoofer placement to control phase.

There are probably many sources online to provide directions for setting up your subwoofer, but in the end you are trying to achieve a great blend and balance between the Beolabs and the subwoofer from the lowest to highest frequencies.

DMacri:

If we look at your first subwoofer selection, the sub has line level and speaker level ins and outs. It also has selections for crossover frequency and phase adjustments. Even the auto on has selections for which level inputs you are using.

The crossover adjustment sets the frequency the subwoofer will hand off the signal to the Beolabs.

In general this is a good overview, but in specific, the first subwoofer he listed, it is incorrect: In the Canton AS 85.2 manual, the RCA (cinch) line-level output shown is described as a full-range signal, not filtered by the crossover frequency.  In the Canton parlance, "Low Level Output" means full-frequency, intended for daisy-chaining subwoofers (or full-range speakers).  Only if Canton labels the jacks "Low Level Output Filtered" will the RCA jacks hand off a high-passed signal to the Beolabs.  Also from the manual, the filtered pass-thru frequency is fixed at 80 Hz regardless of the adjustment setting, which controls only the frequency at which the subwoofer starts to roll off its own sound.  The other, later, models they just started labeling the jacks "In" & "Out", so maybe your general advice is correct about those.  But it would pay to verify (somehow?!), given their earlier, simpler designs.  Canton's website is a little weak on the archive models, but it says, "For connecting another subwoofer, the power amplifier is additionally equipped with a low-level output," which supports the description of the outputs as full-frequency.

Hi,

Thank you to all repliers on this thread - extremely helpful advice.

Canton:

In response to this specific information: further research by me into Canton suggests it might not be the best brand to be looking at because a) 'Low Level Output' as you have stated in fact gives a full-range signal and b) "Low Level Output Filtered" is a socket option that I cannot find on any Canton model available online.

I will actually get in touch with Canton to see if their 'Low Level Output' does in fact mean, in some cases, that the output is filtered. If it is, then it opens up the options to buy a Canton.

ELAC:

The only other option I have found is this one:
'ELAC SUB 101 ESP'
https://www.ebay-kleinanzeigen.de/s-anzeige/elac-subwoofer-sub-101-esp-aktiver-subwoofer/1194301212-172-3498 

And going from a 1-page manual I found (http://www.sas-audio.dk/documents/00096.pdf), this ELAC does indeed filter line level out. It says, in this document, 'Outputs Line: active filtered, 1st order; LS: passive LF filtered with 220µF'

I don't know, however, if this means that the output level is filtered at the same Hz as the crossover chosen on the dial. I.e. if 63Hz is chosen on the dial on the sub, does this then mean that the sub outputs everything below 63Hz, and that the line level output is given only frequencies above 63Hz. Would appreciate someone's opinion on that! 

If the advice is to get in touch with ELAC then I am happy to do that too.

Many thanks again,

Joseph

 

Well done!  This may seem cold, especially spending someone else's money, but... at 99 Euros for the ELAC sub: buy it and try it!  Even if it has a fixed line-out crossover frequency, it's still better than the other options you have considered.  (My personal opinion: why say "active" and list the filter, unless it is variable.  But I know nothing...)  ELAC does run their own forum on their website, which is where I would ask...  Then please publish the answer here!

I have 2x pairs of lab 4's ....one pair are p.c the other pair are full active......have used a jamo sub and a linn sub.....none of them can touch the beolab 2 ..which is perfect for my set up, when you set it up.