False cues

May 5, 2022
 by Paul McGowan

REL Speakers make some of the best subwoofers in the world. Owner and chief bass'ifier, John Hunter, is nothing short of a magician when it comes to setting up a system.

John gets the true purpose of a subwoofer. To fill in for the main speaker.

A perfectly set up subwoofer disappears. Only the main speakers seem to be working.

Which can be a bit of a visual struggle when you see a stack of 8 subs (4 per side) next to the main speakers.

One might think the room is going to boom like nothing you've ever heard. Time to nail down the pant legs when when the music starts.

And yet, the sound is perfect. The subs disappear. The main speakers are perfect.

It's why so many folks get the purpose of subwoofers wrong. It's why more subs are typically better than fewer (it's the room we're battling).

Subs give visually false clues. They look like they're ready to overpower the room.

But when set up right, they no longer exist.

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42 comments on “False cues”

  1. Easily seen but rarely heard, till music rides the subterranean bandwidths of audibility! Blend is seamless as my monitors seem to have no bottom to their bottom! The fact that the monitors rarely call attention to themselves (till recorded hard miked L&R channels) fosters on-going listening sessions in suspension of disbelief!! Between 18hz to 28Khz and the subsequently huge and precise 3D live presentation (all behind the speakers), to date I've not found anything missing in playback of my music library!

    Gotta love that old Radio Shack stereo! Wait, we're now in May?...Never Mind! 😉

  2. One important thing they do is fill is for bass nodes, to do that they usually have to be positioned somewhere other than next to the main speakers. If the effect of those bass nodes is not noticeable and the main speakers are OK for bass, then fine. The real downside of subwoofers is their size, ugliness and need for more cabling (signal and power) to a separate location.

    1. According to 'Royal Ascot Mike' his two brand new wireless REL
      subwoofers sound magnificent...the key word here being 'wireless'.

      Also, subwoofers can be hidden behind your sofa or be a base for a
      smoked glass coffee table...a little ingenuity doesn't go astray 🙂

    2. As FR points out, wireless operation for the signal is now a reasonable option. But running power cords to the same dedicated line as your system can be an expensive proposition if the subs are not reasonably close to it. I suppose one could drop down a level or two in power cord for the subwoofers, given their low and narrow bandwidth, without losing too much quality or defeating the purpose. But with wireless signal connection, is it really a problem if the subs are not on the same circuit--aside from the obvious fact that you would be by-passing your power conditioner as well as the high-amperage dedicated line?

  3. If there is very little bass in the recording then it doesn't matter how many
    subwoofers you have in your home-audio rig.
    A lot of 60's, 70's & 80's recordings have minimal bass response...unfortunately.
    And many that have been remastered to bring the bass up to a 'proper' level
    have been compressed to hell.
    A great argument for tone controls.
    Again I will say that home-audio is fraught with compromise.
    Hopefully this will change with labels like Octave, Blue Coast, Stockfisch & the
    like, bringing out new talent & new recordings & the 'correct' amount of bass
    in the recordings.

        1. Ha! I had that won too (King of Loud) back when I had my Kustom Tuck and Roll 200B 3x15” JBL’s & 100W UniVox Jeff Beck tube amp.
          Made me mad when our drummer would get out of his seat and turn it down when we practiced in my dad’s shop.
          That amp was perpetually sticky from beer spilled on it. When the tubes were flashing – and smoke was coming from it... another misplaced and forgotten cigarette was burning the vinyl. LoL

    1. I've been listening to most of Jason Collier. 5 albums, 5 Emmys. Not bad for a kid who wrote, composed, performed, recorded, mixed and mastered all the albums from the back room of his family house with one microphone. Their house is the same size as ours, so I get how small the room is. Makes you remember the sound playback quality only has to be good enough.

    2. That's why the 80s were inundated with woofer-ripper subharmonic synthesizers. Don't you remember the days when you'd rearrange the signal path order of your crossover, tick & pop reduction, DBX range expander, equalizer, BBE, noise reduction and time delay processors to see what sounded best? I still run a DBX 120X-DS in my shop system and an Audio Control Phase Coupled Activator on my PC system. Because .......... well because I have a problem.
      You've SEEN my audio gear list.....

  4. I completely agree with you Paul, your advice and knowledge have utterly transformed my hifi listening experience over the last three years.

    Thank you and please keep it coming!


  5. I could not agree more. I have twin REL S/5 SHO's. Two active 12" and two passive 12" drivers. You do not know they are on until you turn them off. Everything changes drastically. The entire presentation of the imagine shifts and becomes less overall. I would be very unhappy with my system if my subs were removed. I'm using Tannoy Turnberry GR's and other owners of these speakers say it is useless to add subs. Clearly they have never tried the REL approach. In my opinion most speakers can benefit from a properly setup pair of subs. The stacked approach is icing on the cake.

  6. I use an REL G1 in my video system. I have two ATC SCM19 two-way speakers that go down to about 54 Hz ( I have never been a fan of surround sound not even at movie theaters ). The G1 fills in where the SCM19's leave off. While it is large it is also beautiful in its piano black finish.

    It is eleven years old and recently I had to have the circuit board ( which contains the built in subwoofer's amplifier ) repaired. REL USA provided complete support for the repair. Hats off to them! 😀

  7. Heresy alert!
    I predict Paul will sell surprisiingly more FR-midi than his big boys.
    The New Normal for the Rest of UIs:
    Setup of two FR-Minis plus two FRSubs.
    so appealing, such good value.
    and pssst! Even better bass in a real room than Big Brother.

  8. REL recommends a connection method that can cause problems with Class D amps. Paul, would could you explain the best ways of connecting REL subs to your Class D amps?

    Also, REL does not recommend a traditional crossover with a high-pass filter for the main speakers, preferring instead to run the main speakers full range. As you know, a crossover prior to the main amplification for the "full-range" speakers will allow both the amp and speakers to work less hard, often improving dynamic range and lowering distortion. This can have benefits up into the midrange. Does anyone care to comment?

    1. I agree with this comment.
      I run my stratus golds full range. They are a capable full range speaker.
      However, I prefer to run my stand mount speakers crossed over at ~80hz.
      IMO it is beneficial to restrict low frequencies to smaller drivers.
      Especially when the listener enjoys high volume listening sessions.
      Prevents damage. Uses less power from the amplifier.

      I wish PS Audio would build an active crossover for this purpose. There are not too many options available. Only JL and SPL, maybe a couple others.
      Parasound understands this. Active crossovers are built into many of their products.

    2. I’ll take the bait.

      I went round and round with all kinds of subs and placements. With planar speakers it was easy to wash out the highs and upper mids. (Loose details)

      In the end it came down to placement in all 3 axis. Adding an electronic 2way crossover in the main preamp lines helped all the way around. DSP for the subs takes care of the deep end. Finding the right crossover freq and slope was a matter of trial and error. Still is an on going project… sound is extremely good, but you don’t know where best is until you go past it.

      “Your best may not be mine 🙂 “

    3. First, I am aware of the Class D problems with the high level connection method, but I do not use a Class D amp.

      Maybe I just do not listen loud enough to have problems. I use a 200 W/ch Musical Fidelity integrated amp to drive the two SCM19's and the amp remains cool to the touch. If I did not have the G1 all of the sound would go to the SAM19's, so I do not understand what harm is being done by using the high level connection to the G1 and still have 99.99% of all of the sound going to the SCM19's. Why do I need a high pass filter before going to the SCM19's?

      The G1 has a 600 W Class A/B amp which I did have to have repaired after 11 years of use. I find it hard to believe that I was driving it too hard since I am not the kind of person who likes a lot a crash bam when watching TV or movies and everything sounds great when I watch music concert videos.

      1. I have a couple of subs with cheap plate amps (Class D) on the back and both of them have needed replacement after a few years. I suspect that having a built-in amp in a subwoofer is not a healthy environment for the amp from both a heat and vibration standpoint, regardless of the quality of the manufacturer. I don't have a lot of data points though, so this is just a suspicion.

    4. [...a crossover prior to the main amplification for the “full-range” speakers will allow both the amp and speakers to work less hard, often improving dynamic range and lowering distortion. This can have benefits up into the midrange...]

      Absolutely, especially with a 2.1 setup that uses 2-way stand monitors (with a 6" mid/woofer)! IME, using the 50Hz HP/LP electronic crossover (built-in to pre amp & adjustable) has added 6db+ of clean output headroom to overall system performance!

      1. Theo, If I understand you correctly by removing the content below 54 Hz the MF amp can put all of its power into the content above 54 Hz and thus have more headroom ( if I need it ). However, I do not see anything changing for the G1. It has its own adjustable crossover which I have adjusted so it only deals with content below 54 Hz at whatever volume setting I have set at.

        As I said above, I do not listen at volume levels that make this pre-crossover necessary.

        1. Correct Tony! By removing monitor response below 50 Hz (they're rated down to 33 Hz), the power amp dedicates all of its muscle toward 50Hz and up! Clarity, timbre, speed and definition in the low/mid/upper bass increased. Tonality, openness and resolution also improved in the midrange! Overall, my monitors now have what seems like unlimited dynamics and room energizing prowess!

          With the 25-50Hz octave response removed from the monitors, a low bass in-room bloom that was present before (monitors playing full range) has now been completely removed! I've always tried the sub xover @50Hz (to create a seamless blend in my listening room), but now the sonic hand off between sub/monitors is totally invisible, leaving a balanced bandwidth bass response that runs flat down below audibility!

  9. I run a vintage ULD15 Velodyne sub. I loved and dreuled over it then and finally got one and it's still all I remember, however, If PSA was to build a sub, I'm in!!! Paul, you have talked about speakers for a very long time and SUBS even longer. Again, if you and Chris build a sub, I'm in! 🙂 🙂 🙂 no questions and I'm saving my bucks with a financing backup plan:)

    Keep Listening

  10. Paul the biggest problem I have is figuring out the method to wiring 4 or 8 Subwoofers in a room. I know you suggest wiring them in parallel rather than in series by using a splitter at the preamp outputs but that only takes care of two subs.

    Also making sure I don't overload the AC wall circuit. I will have to run heavy duty extension cords to outlets that are on separate circuits to avoid the overload problem that will trigger the AC circuit breaker.

    1. Thanks, Joe. Because each of the mutiple subs is handling its portion of the load it's not a problem. Or put another way, the power required to play a single sub at loudness X is the same as 4 subs playing together at the same loudness (each is now only handling 1/4 of the load).

      1. Ok thanks Paul. If I wire 6 or 8 RCA interconnects to 6 or 8 subwoofers where are all the RCA outputs coming from so my preamp volume control controls the subwoofer volume? My preamplifier has only a right and left output. How many times can the signal be split to accommodate that many subwoofers? Will it weaken the signal or harm anything if it's spit too many times?

        1. Well, that's going to have to be through Y connectors which at these low frequencies is probably fine. Your preamp will have no trouble driving all these as the input impedance of a sub is typically 50kΩ or so.

  11. Interesting post to me Paul, I’m currently dialing in a pair of Sceana speakers with 3 stacked 18” woofers per side each with a Crown amp and active EQ. I’m experimenting with the volume of each driver to account for floor bounce effects. The owner had the subs hooked up the approved Arnie way, from the main SET amps, but eliminating that and feeding them the XLR output from the pre really cleaned up the sound.

    1. I had the same result, Kevin. Pulling the signal from my 300B SET amps to the subs was muddy because the 300B tubes were not highly resolved at the bottom end. Taking a line out from my tube preamp to the subs fed them a much cleaner signal.

      1. Thanks for that Longplayer, the main SE amps are the Ypsilon monsters which don’t use 300Bs, but have probably miles of wire in their multiple transformers. The top line Alnic pre uses those tubes so the subs are still being fed by 300 Bs. I can’t quite get the sound on the drum kits I’m looking for, but if the tubes won’t support it I guess I’m about done. Cheers

  12. I've experienced so many truly bad systems with subwoofers, both audio and video, I couldn't begin to count them.

    The worst example was years ago when wide-screen, panel TVs first became popular. A friend invited several folks over to watch our college team play an important basketball game. But he had the subwoofer turned up so much every dribble sounded like a bass drum stroke. To make it worse he stretched the 4:3 telecast to 16:9 and the players looked more like linebackers than basketball players.

    As Paul says, you should only be aware a subwoofer system was playing by turning it off.

    1. The idea of what a subwoofer is suppose to do changed drastically when the home theater concept was launched. I remember going to audio shows in NYC in 2001/2 and being in one room trying to assess what was then considered a very hi-end sound system ( around $100K ) and the room next to it was displaying their latest home theater system by playing Top Gun ( or something like it ) a 100+ dB sound levels. 😮

      1. Yes, I remember those days, too, Tony. Fortunately at most shows today they space the rooms further apart and often try to stagger the doors to active rooms so they are not right across the hall from each other.

  13. Sounds like my main system. I have used subs for many years, and always had the goal to integrate them perfectly into the room. I will say that had good advice from a good dealer back in the day, so I give that long gone audio store the credit! My subs were custom designed and built by a company here in Knoxville, TN in the early '90's. They consist of 4- 3.5 cubic foot ported chambers with 10inch long travel subs on each side. I borrowed some sound equipment from my company to measure the results of the setup of the subs as I worked to integrate them into my room. The subs were driven by a dedicated amplifier and electronic crossovers for a triamplified system with the MG20's bass and HF sections. I had my home custom built in 1990 with a great room that was 18' x 25' with an inclined ceiling angled from 8' to 23'. this area was open to the entry and dining room. This was my Stereo room, so there was a lot of volume and the sloping ceiling to eliminate reflections in the vertical directions. This left one major sidewall resonance caused by the 18' dimension which occurs at about 60Hz. Unfortunately, this was my initial crossover setting for the subs, so I ordered the 50Hz 24 db cards for my Bryston crossovers. This made a huge improvement, and allowed me to begin to accurately use listening tests to set the sub to MG20 balance. There were no available room tuning tools that I was aware of in 1991 and I was Not going to use an equalizer because they added distortion and killed the imaging of the system. I probably spent the next 2 years enjoying the sound and frequently moving the subs and speakers around to see the effects of the changes. Today the subs are in the mostly in the
    corners and the MG20 are 6' off the wall with the outside edges 3" closer to the listening position. Over the years since then I upgraded the electronic crossovers to Pass Labs XVR1's and the internal passive crossovers inside the MG20's to Janzen silver film caps with Duelund silver foil bypass caps. The inductors were 14 ga. Mundorf copper foil with solid silver wiring for the crossover connections. I removed the stock speaker connections and replaced them with Furutech binding posts. Today the system sounds incredible (if I may say so).

    There have been numerous equipment upgrades and wiring changes over the years. For me the most expensive single change came with the conversion to Synergistic Research cables and power cords. These were spread out over the last 5 years, with many bought used or open box to try to save money. Enjoy the music!

  14. Rel is in a great track with their hi-level setup. (I have a T9/i and have hi-level and line level running to it. I did this when I was evaluating an S300 (class D) power amp.

    I used the Rel-recommended hi-level as I’ve always done. But found the floating the black (common) wire left me with a hum when the system was off and during initialization.
    The low level allowed for a common ground, and I was fortunate to have an XLR output on my preamp, and a sub level on the same.

    I actually preferred the sound with hi-level however.

  15. I remember fondly my first external subwoofer many years ago: an HSU sonotube passive subwoofer that connected with lampcord to one pair of speaker terminals of my stereo amplifier. So simple, so deep, so pure, so uncomplicated. Today's powered external subwoofers are often overkill. I don't need external subwoofers with my current loudspeakers, but if I did, I would explore passive subs.

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