So after yesterday’s blog on full range, single driver loudspeakers a heated debate broke loose on several forums around the web. The swarm intelligence of everyone who participated was remarkable and I am still in awe by the quality of the debate and the fact that given the level of passion about what we do, neither knives were drawn nor blood was shed.
It seems that at the core of the issue was in part what full range really means to everyone in terms and whether a true full range single driver system is even possible. The good news: yes it is, the bad news, we don´t make one, the other bad news, such drivers apperently cost 25´000 dollars a piece and are called Alnico Monster´s for a reason. The question I started to ask myself was: How much bass is enough bass?
So I went on a quest, albeit a personal one. See, I use my sound system for music exclusively. And I happen to like music that is played on real instruments, by real people. Now if you are the kind of person that enjoys home theater surround sound, much of what I am going to write about might not apply to you, Hollywood is incredibly generous with bass notes in explosions, crashes and other kind of thuds, compared to, say, the Royal Albert Hall.
My quest was this: In real music with real instruments what are the kind of frequencies and notes that are played and what happens below a frequency that can be reasonably expressed by a single driver system, like our SoundSommeliers.
My quest started by looking at different instruments and the lowest note they could express. Luckily there are many people that have done this before, and I will gladly cannibalize on the wisdom of others rather than get out my test microphone and visit the local symphony.
So cathedral grand organ, that was the mother of all, was it? I actually already knew that very well, being raised in Vienna and being dragged to the Musikverein by ambitious parents on Sunday mornings, I remember witnessing one of Leonard Bernstein´s last concerts with the Vienna Philharmonic Orchestra playing Richard Strauss´ ”Also Sprach Zarathustra” also known as as the “2001 Space Odyssey Intro”. What some might not know is that the piece actually starts some 4 bars before most of us think it starts because it consists on a single sustained double low C or roughly 16Hz played by a rather larger pipe organ. Now I was there, a younger man, next to my dad, asking myself why Bernstein was waving his hand but the orchestra was not in fact playing, until my dad pointed at the pipe organ and then I felt the subsonic rumble.
Now if Zarathustra is your thing, or Mahler´s symphonies that are also somwehat hefty on the bass notes, then definitely a huge woofer might be on your shopping list. But what about real people listening to real music?
We do have a wonderful customer called Charles Kegg, by the way, happens to build church organs. He really likes his SoundSommeliers he says but did confess to hooking up a woofer. I am now only mildly offended to hear that.
Well, another more surprising candidate on our range chart is the harp with a lowest frequency only an octave above our Church Organ, or about 32 Hz.
Still: what about the instruments we are really likely to listen to? Not surprising next on our list is the Double Bass.
Well in its garden variety, the lowest note on a double bass is an E1 (on standard four-string basses) at approximately 41Hz . But sometimes just to be a pain on us loudspeaker builders, they are tuned to a C1 (~33 Hz), and perhaps as low as sometimes B0 (~31 Hz).
So I decided to get a recording that I consider audiophile quality that had such a B0 bass and after some research I found a wonderful rendition by Patricia Barber of The Doors “Light my Fire” and decided to put things to the test. The good thing about this piece was that I also happen to like it.
I knew this piece might go below the rated capability of my KVART & BOLGE SoundSommeliers setup so I went and got out my pair of B&W CDM7 that I keep as a reference but store away due to lack of SAF – the letter “S” representing “Self”. (You can check last weeks blog if the term SAF means nothing to you.)
So I did the test. I compiled the results for you to follow if you like. Needless to say you need play this on a sound system capable of expressing low frequencies, your computer speakers won´t kick it here.
If you would like to test for yourself, you can click the image below:
First I listened to the piece in its unadulterated form.
I then ran it into an 48dB / octave High Pass filter aka as a "Brick Wall", to only play anything above 120 HZ. I immediately noticed the lack of warmth and depth of the piece as was expected.
The reason was obvious when filtering out everything above 120Hz: There was still lot´s of music to be heard below that level that I was now missing. Many smaller bluetooth home gimmick type speakers cut off at similar frequencies.
So now that I had prooven the concept, I decided to go lower: I ran the piece through a 42Hz high pass, which corresponds, to the lower end of my SoundSommeliers and on the B&W, CDM7s I noted very little difference. I would be hard pressed to identify these subtleties in double blind testing.
So I thought, what is the difference and did the opposite: I filtered everything above 42Hz. and then I nearly thought my rig was broken until I rather faintly and on occasion heard a very low rumble.
So since I am not a harp and organ pipe kind of guy, love the convenience of a small and pretty rig and I don´t need to be knocked of my feet every time stuff blows up over in Hollywood, I decided that my inner peace was restored. Full range drivers are possible, after all, if we only define "full" as reasobale in the real world. The B&Ws went back into storage, I decided to build myself a freshly designed pair of SoundSommeliers to match the décor in a different way and go back to what really counts for me. The music.
My conclusion was that the overall lowest frequency of a loudspeaker might be more a marketing parameter than anything transcendent in the real world. What counts more than absolute depth, perhaps, are the quality of the bass: a smooth roll off, perhaps, tightness and congruency of the fundamentals to their overtones. But more on that another day.