Introduction to Grado Modifications

Introduction to Grado Modifications

Contributor:  Trav Wilson

Note:  The bulk of this article is an excerpt from the Symphones V8 Drivers and Shipibo Audio Padded Leather Headbands, Wooden Cups, Aluminum Rod Blocks and Aluminum Gimbals for Grado Review.

Let’s discuss the major Grado sound mods. There are obviously other possible modifications for comfort, appearance, weight, etc, but today we’re going to primarily focus on changing (and hopefully improving) the sound of your Grados.  No other brand of headphone has such an active community of DIY tweakers, modifiers, designers and custom part manufacturers. The abundance of alternative parts and methodologies can, unfortunately, be quite overwhelming for the novice just getting started.

Pictured above:  Shipibo Audio Mahogany wooden cups, prototype aluminum rod blocks and gimbals

Grados are where I began my love of high fidelity headphones, and the DIY modular nature and retro-cool looks still make them one of my favorite brands. From my experience, the modifications that result in the greatest transformations in sound can be listed (in order from most impact to least) as:

Take note: I’m purposely overlooking cables as they fall outside the purview of this article and all testing was done with standardized high-quality copper Mogami cables.

  1. Driver replacement
  2. Shape, size and material of the ear pads
  3. Driver modification
  4. Ear cups material

Driver replacement

Grado has changed their driver design over the years. While the same basic driver is used for multiple models, there are driver differences throughout the current lineup, including closer driver matching on higher-end models.

Grado says the diaphragms are put through a special ‘de-stressing‘ process in order to enhance detail reproduction at lower volumes. Grados are known for having a ‘house sound’ of warm harmonics, rich vocals, excellent dynamics, and lively highs.

Although many models share drivers and or cup construction, there are noticeable performance improvements as you move up the line. The modular design, coupled with the relatively inexpensive Prestige series, has created an unparalleled foundation for the DIY modding community. This has become a business for some, and the manufacture and distribution of high quality replacement drivers, with their own unique sound characteristics, was born.

Replacing the driver with a non-Grado offerings has the greatest influence on the sound and character of the headphone. Popular aftermarket driver manufacturers include Symphones, Nhoord Audio and Elleven Acoustica.

Pictured above:  Symphones v8 replacement drivers

Shape, size and material of the ear pads

For clarity, stock Grado foam pads can be defined as:

  • S-Cushion (‘comfy’ or ‘flat’ pad) is stock on the Grado SR60, SR80, and SR125i.
  • L-Cushion (bowl) is stock on the SR225, SR325, RS1, and RS2.
  • G-Cushion (bagel or salad bowl) is stock on the GS1000 and PS1000.

Pictured above:  S-Cushion (left front), L-Cushion (right front) and L-Cushion (rear)

Typically (depending on ear size) the S- and L-cushion pads are considered on-ear and the G-cushion pads are over-ear.  There are a few companies making alternatives for Grado ear pads from generic foam options from Ebay or Amazon, to the well respected foam options from Todd The Vinyl Junkie or the luxurious merino wool or leather options from Beautiful Audio.  

The size, shape, and material of the pad changes comfort, head interaction and the distance between driver and ear, impacting perceived soundstage, imaging, positioning, space, and volume. Basically, everything you hear. Supra-aural (on-ear) headphones typically are described as having a more forward, intimate, “close to the stage” sound.

However, a downside to drivers being closer to the ear is that it can result in a more congested sound when reproducing complex music.

Driver modification

Opening up (poking holes in) the fabric material covering the holes arranged around the rear circumference of the driver increases the quantity of bass that the driver delivers (although perhaps with a corresponding decrease in quality and control).

Less is more in my opinion and tread carefully before venting your drivers.

The stock Grado line-up has changed over the years and throughout the different models, and varies from no holes to 4 vented holes in their drivers. Modding enthusiasts claim success with anything from 2 to 10 holes vented per driver.

If you are feeling less adventurous, I have a non-destructive hack for you. Adding material to dampen resonances to the rear of the metal center of the driver (anything from Dynamat to Blu-Tack or Sugru) is a safe (and a light-handed) tweak.

Ear cup material

There are two equally strong and opposite points of view regarding cup material and the impact on sound reproduction (although aren’t there always two passionately differing viewpoints when discussing any hi-fi audio tweak?).  Some popular aftermarket wooden cups manufacturers include Shipibo Audio, SpinAF, Wabi Sabi, Turbulent Labs, Rholupat and Yew Woodworks.

Pictured above: Shipibo Audio Mahogany wooden cups

“Inert” group

The first camp I shall call “inert” group, and they claim that the cups are too solid to vibrate or change the flavor of the sound, regardless of cup material (wood, plastic, metal, etc.). Basically, they assert that if the exact design of cup (shape, thickness etc.) is duplicated, the material used will not make a difference in the perceived sound, that there is simply not enough vibration to create any reverb or interaction with the music reproduction.

Note that it is (more or less) universally accepted that changing the dimension, geometry or driver position in the cup will yield an evident and perceptible (positive or negative) difference in what the user hears.

“Tone wood” group

The second camp is the “tone wood” supporter. Much like a musical instrument, a particular material is selected for its interaction with the driver, in an effort to find a positive synergy, where the final sound produced is greater than the sum of its individual parts. Resonance and reflection of materials are believed to affect the timbre of the music reproduction.

As with most audio tweaks, I believe the difference is noticeable but subtle. As per my list above, I find cup changes to be one of the subtlest of the perceptible Grado sound modifications. This isn’t to say that a change to well made wooden cups isn’t worthwhile. Regardless of the impact on the sound, the humble Grado can be transformed into a work of art aesthetic-wise.

Pictured above:  Shipibo Audio Mahogany cup with Symphones V8 driver

A little throwback from John Grado himself

In 1996, John Grado discussed why he started using mahogany for the cups on the Grado Reference Series One headphone. “The idea of using wood just came to me one night,” explained John Grado. “We went through quite a few species of wood before finding this mahogany—which type, we’ll just keep our secret for the moment. When you’re building speakers, you’re supposed to want a dense, really hard wood—well, that’s not mahogany. But it works really well—I don’t always spend a lot of time figuring out why something works; sometimes I’m just satisfied that it does. Maybe the mahogany has a lower resonant frequency, or maybe its resonance just doesn’t emphasize something in my driver—I’m not saying it would work in all cases, but it seems to work well with our driver.”

So what species of wood sounds the best?

Common cup materials include cherry, cocobolo, ebony, limba, mahogany, maple, oak, padauk, rosewood, and walnut. Users report anything from improved bass, midrange or treble. Some report changes in soundstage and imaging. Typically reports are positive, although some feel that there are perceptible decreases in the treble with particular woods.

Please take all this as a second-hand impression as I have not had the opportunity to try all these cup types (and certainly not in a controlled test environment). I personally feel the differences are quite subtle between what I have tried.

After changing to wooden cups, the users often report a more woody, earthy, warmer tone. Aluminum or metal cups are often described as bright, tinny, cold or sibilant. Notice anything about those descriptive terms for the sound? They seem to be descriptions of the material itself; perhaps the eyes of the user are impacting what they hear? I digress.

Conclusion

I should mention that the other items typically changed on a Grado are the headband, the gimbals (the horseshoe shaped piece that holds the cups) and the rod blocks (the square pieces that attach the gimbals to the band).  

There is one very good reason for changing the band:  comfort.   Grado bands are thin and unpadded.   Especially if you are using the appallingly cheap vinyl headband included on the SR225 and below, replacing it with a well made padded leather band is an immense (and somewhat necessary) upgrade for long listening sessions.  High quality replacement gimbals and rod blocks address the common complaint of free spinning cups that lose your preferred position while annoyingly twisting the cables – the unfortunate reality with the stock units.

Pictured above:  A completed modified Grado build from Shipibo Audio and Symphones

A great DIY headphone build is not simply about function and utility. It should combine style, performance and luxury.  The products pictured in this article make beauty a priority and have infused art into supremely functional objects. With Shipibo Audio’s creations married to the superb sounding Symphones V8 drivers, you have a wearable work of art, with a refined sound quality to rival or better any of Grado’s best. Add the satisfaction of DIY, the unique hand-built style, improved comfort, and durability and it just keeps getting better and better. Factor in the relative bargain cost when comparing them with higher end headphones (with which the quality of sound certainly compares favourably) and it becomes obvious why the Grado modification community keeps growing.