Saturday, June 30, 2012

So, You Want a Great Guitar Sound...

Want a great rock guitar sound? Do everything "wrong". Allow me to explain.

For a variety of reasons - some of them understandable, some of them daft - many aspiring rock guitarists think that a "great guitar sound" means buying a guitar with a "hot" (high output) pickup, a large amp cranked to the max, and maybe a distortion pedal in between. But if a "great guitar sound" is one that sounds more pleasing to the human ear than other possible alternatives, what I just described is not a "great guitar sound". Here's why.

What we hear as a sound is a wave of pressure through the air. The speed, or frequency, of these waves, we measure with a unit called a hertz. A hertz tells us how frequently the wave is cycling per second. So, a wave of 500 hertz means that the sound wave is cycling at a frequency of 500 times per second.

Human beings can hear sounds which range from about 20 to 20,000 hertz, but crucially, we cannot hear all those frequencies with equal ease. In fact, our ears are designed so that there is a bump in our sensitivity to frequencies around 3000 hertz (also known as 3 kilohertz or 3k, a kilohertz being equal to one thousand hertz). This makes sense, as the primary frequency in human voices is around that range. Now, virtually any sound or noise is an array of different frequencies, with some being more audible than others. But the more frequencies in 2 to 4 kilohertz range in any sound, the more we will hear that sound as harsh and unpleasant, simply because our ears are so much more sensitive to frequencies in that range.

Now, back to your guitar sound. The particular wood used to make an electric guitar will have some effect on a guitar's tone, but the primary determinant of a guitar's sound is the pickup. A pickup is the device in an electric guitar which senses, or "picks up", the vibrations of the guitar strings, and converts them to an electric signal, which can then be amplified. Naturally, different kinds of pickups affect the characteristics of that signal in different ways.

One determining factor in how a pickup affects sound is the number of winds that the pickup has. (Pickups are made by winding metal wire around magnets).  Essentially, the more winds a pickup has, the louder (or hotter) the output of the pickup becomes, and the the more the pickup broadcasts "mid-range" frequencies, in the - you guessed it - 2 to 4 kilohertz range. Which means, the harsher it sounds.

Further, as the output from a hot pickup is distorted, the more the signal from the string itself is clouded over by harsh, white noise. This doesn't happen with low output pickups, at least nowhere near as much. In short, up to a certain point, a lower wound pickup gives you a better, "cleaner" guitar sound. Now, obviously there's such a thing as a pickup with too low of an output (like, no winding at all). That's no good, either. But I'm saying there seems to be a sweet spot for the optimal number of pickup windings, and it's not in the "high wind" range. (By the way, if you do have a relatively low output pickup but want a more distorted sound, you simply run your guitar through a volume pedal or volume-boosting EQ pedal. The pedal increases the guitar output without increasing the "noise"that a higher-wind, higher output pickup would have.)

Does this sound too simple, or too good, to be true? It shouldn't. This is just how you get a more pleasing guitar tone, and certainly how you can get a great distorted rhythm sound through which you can still hear string clarity.

Consider one of the greatest power-chord rock songs of all time: "Won't Get Fooled Again", by The Who. Millions of people envision Townshend in the studio playing a Les Paul with souped up pickups, standing in front of a wall of Marshall amps, to get that sound. The truth is that Townshend played the song on a hollowbody Gretsch 6120 which Joe Walsh had given him, fitted with Gretsch's standard (low wind) Filtertron pickups (the same set up Brian Setzer used for his classic Stray Cats material). Townshend then ran the signal through a volume pedal and into a Fender amp, thereby distorting it. Presto - a truly awesome distorted power chord sound, which retains a lot of string clarity.

My dad, on "Takin' Care of Business", used a hollowbody Gretsch with Filtertrons as well, and got another classic dirty rhythm sound. Malcolm Young, of AC/DC, has always used Gretsch guitars with Filtertrons for the same reason. His brother Angus plays a Gibson SG with humbuckers - but the humbuckers are also low, or "vintage", output. Add to this the fact that producer Mutt Lange (who produced "Highway to Hell", "Back in Black", and "For Those About to Rock" for them) regularly twiddles the EQ knobs so as to zap out the 3K range entirely from his mixes, and you have an explanation as to why the classic AC/DC guitars sound so good. (I should add here that while Filtertrons can be great for distorted rhythm, they are less suited to lead work).

Speaking of lead work, consider what most historically-minded rock 'n roll aficionados and guitarists consider the greatest lead sound ever: Eric Clapton's sound on the John Mayall and the Bluesbreaker's "Beano" album. And, guess what? It was a '59 Les Paul, with relatively low output humbuckers, through a small Marshall combo amp. That was a set-up which maximized tone and signal over noise.

Another great lead sound was the solo on "Stairway to Heaven". People think it's a hot-rodded Les Paul through a Marshall stack. It's actually an old '59 Telecaster, outfitted with its standard (relatively low output) single coil pickups, through (by most accounts) a small Supro amplifier. Add in a tiny bit of natural room echo/reverb, and boom, there's another classic sound.

What Townshend, Page, and other pioneers of classic rock guitar sounds had was tone; and they had it, because they weren't using hot-rodded, high-output pickups to play through three different distortion pedals and gigantic stacks, boosting their noise to signal ratio. They were, for the most part, using older guitars, with lower output pickups, to get subtler, sweeter distorted sounds, which paradoxically, make their guitars sound far bigger than most modern distorted guitar sounds. And certainly, those vintage sounds (the analogue tape didn't hurt) were far easier to listen to - not because there is something "magic" about their age, but simply because the set-ups were, in effect, optimized for appealing to the human ear. That those old records were recorded using tube (valve) amps on to analogue tape with vintage compressors helped too, of course.

For those interested in experimenting with achieving better guitar tones, you're in luck: we live in a Golden Age of boutique pickup winders.

Fralin, Lollar, Wolfetone, Bare Knuckle, Seymour Duncan, and many others offer great vintage-sounding pickups (especially humbuckers). There is also the Filtertron, the pickup that Townshend used for the great rhythm sound on "Won't Get Fooled Again". (I suggest going to the TV Jones website if you're interested in that; they make a wide assortment of Filtertron reproductions of varying hotness. (Remember, though, that if you're looking for a lot of sustain for rock leads, a classic Filtertron may not be your best choice). But my favourite pickups for years have been the WCR pickups. Jim Wagner has managed to produce a unique-sounding take on the classic humbucker, which to my ears, sounds even better than many of the original PAFs I've tried (I know, it sounds sacrilegious, but I think in a blind test, you'd agree).

In any case, good luck with your quest to get a great guitar tone. Send me an email if you want to discuss.


Strawman Smith said...

thanks for the info... as a longtime garage band guitarist, this gave me a new perspective...

Strawman Smith said...
This comment has been removed by a blog administrator.
Melissah said...

I am amazed at the information, my dad used to rant about live music being superior due to unheard frequencies and I just tuned him out, but now, your words suggest that he actually knew what he was talking about.

It's actually funny how I tend to give strangers more heed and think their learning is so much more wise when likely the things my father taught me were equally brilliant if not more so.

Marshall B. said...

Overall a really great article. A couple additional points though...

1) While most pickups are described in terms of resistance, the property which has the greatest impact on the characteristics of a pickup is the inductance, which is determined by not only the winding but the magnet(s) and overall pickup design. TV Jones is great for publishing this value on their pickups, as are Bill and Becky Lawrence over at Wilde Pickups. If the inductance is known, there's a lot you can do to tweak the response of the guitar.

2) There are a lot of other factors affecting the frequency response of the guitar sitting between the pickup leads and the amp. The amount of resistance in the volume/tone pots, tone capactitor, etc. One of the most overlooked influences is the guitar cable, specifically its capacitance; even using a 10 foot cable instead of 20 feet can shift the guitar's frequency response by 1000 Hz. This is why some guitarists love the sound of high-capacitance coiled cables; however, used with the wrong guitar, these could push the resonant peak into the harsh 3-4 kHz range or cause you to lose desirable frequencies.

3) Do a web search for "GuitarFreak spreadsheet" and you'll find a link to an excellent spreadsheet someone has created where you can play with a various components in the signal chain to see how it affects a guitar's response and interacts with the other components.

Sallie Ann said...

Do you ever play in Chicago?