Dear friends:
Why it is important the use of subs on our home stereo audio systems ?
Well, for we can hear what is on the recording ( analog / digital / any ) we need a series of links ( audio items ) to build the whole chain for the music/sound reproduction.
All the links on the system chain are important and all of them have their particular distortions that put the " colors " to our " audio pictures ".
In this audio chain, in the analog case , the most imperfect links are at the front end: phono cartridges and the speakers. Here is where we have a lot of distortions ( of any kind ) because these audio music " translators " are truly an imperfect ones against electronics ( for example ). So, for me, these are the " tweak " links on the audio chain.
In this forum all of us already learn how to improve the cartridge link for a better music/sound reproduction ( less distortions ), but not many of us take care about the speakers distortions, other than the room interaction, that really " color " the final sound that we hear.
Why we take care about: VTF, VTA/SRA, Overhang, resonance tonearm/cartridge, SUT or not SUT, unipivot, air bearing, cables, tubes or not tubes, SS, DAC's, CD transports, and the like when all what we do can be corrupted at the end of the audio chain with full of speakers/room distortions.
Where the subs can help us ? :
Intermodulation Distortions: Almost any three ways speaker ( all two ways/one way ) has it's crossover frecuency ( low driver ) between 150Hz and 450Hz. I can assume that any of ours speakers system goes down flat ( at least ) between 60Hz to 20Hz.
What does that means ?, well that a single driver has to reproduce frecuencies/harmonics from 20Hz/60Hz to 150Hz/450Hz. With that kind of frecuency range here exist a great intermodulation distortions that put it's " color " on the sound reproduction.
You have to imagine that that single woofer/driver has to reproduce, at the same " time ", a 30Hz frecuency along a 350Hz frecuency: here is where exist that IM that gives heavy distortions in what we hear ( there is no perfect driver: moving coil, electrostatic, ribbon, etc.. The speaker designers has to choose the best " trade offs ", but the distortions are there. ): less clarity, less resolution, less precision, less natural balance, less pitch, les, less, less......., and this is what we are really hearing: LESS MUSIC.
If you read any manufacturer specifications on their speakers they never " write " the value of the IM or harmonic distortions, they tell us the frecuency range and how is flat on that range but never " talk " about distortions. I think that you know that when we have a speaker frecuency specifications, say: 28Hz to 22kHz +,- 3db, that is a very nice spec, that speaker low driver don't stop at 28hZ it's goes a few hertz below that frecuency with heavy harmonic distortion that increase the IM distortion of the sound reproduction of that driver and these additional distortions have a severe degradation in the reproduction of the MUSIC.
What happen when that low driver is free from those frecuencies ? ( main speakers: monitors or full range, it does not matters. My main speakers are flat to 22Hz and only 5db +.- at 18Hz and I have benefits with the subwoofers integration to my system ), below 80Hz ( this is the crossover frecuency that we find the best point to start to blend a subwoofer. Mines are at around this 80Hz frecuency: 78Hz,yours ( I think ) will be around that frecuency. ):
SUDDENLY the " lights are on ", your music/audio " life " its born: the mid bass is clean, the midrange is clean, the highs are clean: high resolution every where ( the distortions are almost gone ), and now you can really hear for the first time the MUSIC through your home stereo audio system: what a pleasure!!!!!.
This is truly a discovery for all of us that cares about MUSIC. We really discovery what kind ( quality/quantity ) of audio system we really have ( now we can do any evaluation of any audio item, not before. ) and where to work for a future improvements.
Now that we already settle in the subwoofers ( self powered ) with our main speakers ( yes, it is a hard work to do. We need at least: very good ears, love for music, experience with live music, patience, time and good muscles. We have to work with: location of subwoofers and the main speakers too, phase, crossover frecuency, volume/gain. We need two subwoofers not one and this issue is critical. TIP: avoid the common asumption that the crossover point should be at the low frecuency flat response of the main speakers, example: the speakers are flat at 40Hz, then you choose 40Hz for the frecuency crossover between the subs and the speakers, this is a great mistake: remember that we use subwoofers not only for a better and extended low bass but for a better midrange/midbass too. So, the frecuency crossover will be over that 40Hz: not at 40Hz or below 40Hz. ), we have others advantages:
- better quality low bass ( you can have at least one more octave ) and mid bass ( quantity? : you choose it: volume/gain ) ). Now we can heard the " foundation " of the MUSIC ( and its harmonics ) and this single issue is stunning for the pleasure to hear any kind of music. Now, we are nearest to the " real MUSIC ", nothing less.
The first time you can hear the subwoofers right blended on your stereo home audio system: YOU NEVER COULD LIVE WITH OUT THEM AGAIN, ANY ONE CAN, period.
- An improvement in the soundstage reproduction in all parameters: deep, front/side location, wide of the stage, etc...
- the main speakers amplifiers works best ( less distortion, more headroom, less chance of clipping, less amplifier stress, etc...) with out to handle the frecuencies range that now are handle by the dedicated subwoofers amplifiers. This is important for an SS amplifier but for the tubes ones is a must.
- Now the low bass frecuencies are handle for a dedicated driver that was build with specifics characteristics for to work in that frecuency range and this low bass driver is matched with an amplifier ( self powered subwoofers ) that was build with specifications that mates excatly what the low bass drivers needs about: frecuency response, output impedance, damping, power, etc..... You can't ask for more!!!
- Not only the IM distortion goes down but the harmonic distortion of the low driver of your main speakers goes down too, Btw, the whole harmonic distortion goes down, because ( in the case of my Velodyne's less than 0.5%: with's yours? ) ) the harmonic distortion of a well self powered designed subwoofer is usually " very low ". This means ( again ) less coloration: MORE MUSIC.
Btw, and this is not the subject on this thread ( sorry ): We choose Velodyne because after test/research, Velodyne was the only subwoofer manufacturer that answer our questions ( web site, e-mails, reviews ) about harmonic distortion ( and other parameters )on their subwoofers ( no, this was not the only subject for we decide for Velodyne but was an important one ).
I remember ( example ) that I ask to Revel ( three times ) which was the harmonic distortion of their subwoofers at 20Hz and 40Hz at 90db, 100db and 110db of SPL, they give me many answers but never were specifics about, I assume they don't know it.
Check the manufacturer specifications about for: REL, Revel, Aerial, Wilson, etc,... and you can't find it. Who cares about? : You and me that cares about M U S I C , want to hear M U S I C and needs to be nearest to the M U S I C .
All what I post here are my own experiences and that's what I like to share with all of you.
It works for you?, maybe. I think that you have to try if your speakers are not self powered or headphones.
Imagine how could your Wilson's, Dynaudio's, Karma's, Sonus Faber, Dali's, Merlin's, Martin Logan's, Aerial's, Spendor's, Harbeth's, Thiel's, Alon's, Talon's, Paradigm's, JM Labs, Epos, Avalon's, Boston'S, B&W, Magneplanar's, Proac's, Quad's, Revel, Totem's, etc, etc..... sound.
Better than that: don't imagine, try it.
I can tell you that it works for me and that I'm extremely satisfied with the subwoofers integration in my home stereo audio system. Really I'm. !!!!!!
WELL: DO YOU THINK YOU NEED SUBWOOFERS?
Best regards and enjoy the music.
Raul.
