I've always been pretty satisfied with standard bowls on my RS1s ever since I got them, my first pair came with flats that were so old they were literally disintegrating so I binned them and didn't really look back. I did get some Todd flats some time later, but didn't really take to them, plus on my ears they're much more uncomfortable.
I recently acquired (accidental ebay win) a second pair of RS1s that also came with flats, and in the process of comparing the two pairs I washed and put the flats back on, but either they're much more used or the washing squashed some of the life out of them, as the Todd flats sounded noticeably less dark and veiled.
Putting the bowls back on after a listening session comparing the flats I was hit by how thin and lifeless the RS1s suddenly seemed; I'd been spoiled rotten by the added bass kick of the flats, but missed the more open and airy bowl presentation.
I played around with taping an old pair of bowls, which sounded better, but the condition of the foam was pretty bad and I was picking black bits off my ears after a short while. I noticed, however, that the foam on the back of the bowls (that never touches skin) was still perfectly usable, and thus a plan was hatched...
For this mod you will need one pair of flat pads, a sacrificial pair of bowls, a really sharp knife and some double sided sticky tape. Age of the pads is not a problem, as long as the back side of the bowls is still in good shape since that is the side that will be touching your head (generally when they deteriorate it is the inner bowl part that goes).
Put the bowls somewhere that you can swing the knife without doing any undue damage to anything important, and carefully cut along the line where the dense foam that makes up the back part meets the inner softer foam, as in the pic...
I found it easiest using a sharp kitchen knife, and putting the pads flat on a chopping board, then slicing sideways with my free hand flat on the top to stop it moving. Be patient and you should end up with a neat(ish) circle of dense foam. Set aside and repeat with the other bowl.
Take your sticky tape, and cut out a bunch of little squares and place at regular intervals on the cut side of the foam circles you just created. Once you have peeled off all the backing paper, carefully line them up on the front side of your flat pads and press down firmly. Slip them onto your favourite Grado headphones and have a listen.
Compared to flats and bowls...
I have small ears, so these become practically circumaural for me.
Also, I don't claim to have golden ears or anything of the sort, but hopefully I can convey my impressions in a way that makes sense and is easy to follow.
Youtube links for illustration purposes only, sound quality is outside of my control.
Source: Nad C542
ICs: Van den Hul The Name
Amp: Mapletree Audio Design Ear+ HD2 custom, with 2 matched impedance headphone outputs. This amp was basically built to A/B Grado headphones … The stock version of this amplifier had a high and low impedance output, with this one I can plug in 2 Grado headphones and get matched volume, making it trivial to swap cans in just a few seconds.
Headphones: 2* Grado RS1. One pair came with the later version of the wooden box, the other pair came with the old school flat card box and slide out insert with green foam. Sonically they're close enough that I'll hear the differences in the pads more than the headphones.
Testing methodology was to listen to each track several times with each set of pads, then a/b certain aspects by quickly swapping between headphones to confirm or deny initial impressions. Pads were switched between headphones to rule out one pair sounding better than the other.
Reference Tracks and impressions:
Gomez – Get Miles and Make No Sound from their debut album 'Bring it On'.
This album is a wonderfully quirky example of late '90s British indie rock, with blues, folk and experimental sounds thrown in for good measure. It's beautifully recorded, not suffering from the fallout of the Loudness War, presenting wonderfully detailed and multi layered soundscapes that frequently defy pigeon-holing into accepted genres.
The flats sound somewhat forward and boxy, almost congested with this track, but the low end is wonderfully syrupy and seductive, with the smoky vocals front and centre where they should be. The electric guitars have a raw, vicious edge to them, and drums have a satisfying kick.
The modified flats have better detail and especially more separation, the vocals are a little farther back, but fit in around the other sounds without being quite so in your face. The bass is still ever present, but it's not dominating in the same way. I must admit the electric guitar isn't quite so well pesented.
Make No Sound http://www.youtube.com/watch?v=vh8QatHJY9w
The flats put you inside a smoke filled blues club somewhere in Chicago, the timbre of the acoustic guitar being particularly enjoyable.
The modified flats make the club a little larger, allowing you to place and pick out the various instruments better. The cello in particular has a wonderful, floaty quality that rises above the guitar, with the flats it is a little more in conflict.
Alison Krauss – Oh, Atlanta from the album 'Now That I've Found You: A Collection'
I couldn't not include an AKUS track in this list, and Oh, Atlanta is one of my favourites. Like Make No Sound it has that intimate quality that puts you in mind of a small room, that you've been let into to listen to great musicians perform.
Listening with flats I wonder why I'd ever consider anything else; The vocals are seductive, the instruments sound great, in part I think due to the minimal eq and mastering. This song sounds like it was recorded in one take and committed to disc for posterity.
And then I put the modified flats on. Day-um. The lead guitar is there, the rhythm guitar is over here, the double bass is back there and Alison Krauss is sitting just there singing to me. And what a voice, she sounds more precise and better defined, the slight vibrato in certain words that was nearly missing with the flats is much easier to pick out.
Morphine – Top Floor, Bottom Buzzer from their last studio album, 'The Night'
Not Morphine's best recorded album perhaps, a little squashed compared to their earlier work but then this was released in 2000. Still sultry low rock at its best.
The flats sound a bit too veiled here I think, although the entire song is pretty dark, they do nothing to lift it.
The modified flats give the snare drum more definition, and Dana Colley's saxophone has more presence. The subtle distortion surrounds Sandman's Vocals rather than bleeding into the bass line as it tends to with regular flats.
Kate Bush – Nocturn from disc 2 of the album 'Aerial'
This album is a rare treat, a modern recording that makes full use of the dynamic range offered by the CD without smashing into the brick wall. Nocturn is an eight and a half minute epic, the middle track of what is essentially a triptych at the end of the second disc.
This is another song with an infectious bass line that binds the whole composition together, in fact with the flats it can be a bit overpowering, although if you like the singer to sing right in your ear then they're definitely the pads for you.
Put the modified flats on and the whole track becomes so much more 3 dimensional, the cymbal rolls that were slightly flat and confined with flats suddenly sparkle. The bass is taken down a notch which balances everything else out much better to my ears.
Massive Attack – Angel from the album 'Mezzanine'
Mezzanine is the album you want to get test your system's bass performance, and the many layers of sound test detail retrieval and instrument seperation.
I love this track, the way it sucks you in slowly and builds up, then retreats; The bass line ever present. The flats eat it for breakfast, presenting a superb texture, but they tend to pile everything else on with wanton abandon. The high frequencies, such as they are in such a bass heavy track are a tad too subdued for my liking. Switching to the modified flats and you do lose some of the sub bass, but the rest can breathe more, you're able to pick apart the layering much easier to follow a single thread.
Herbie Hancock – Earth Beat from the album 'Future Shock'
Future Shock is not your typical jazz record, featuring lots of electronic sounds, synths and general madness.
The flats have a superb directness that really meshes with this track, notes have killer attack, drums have real punch and that twanging bass riff at 3:54 really kicks you in the butt.
The modified flats again have the edge on separation, but in this case I'm not sure that's such a good thing. Make no mistake, the RS1s nail it with either pads in my opinion, but the less complexity of the track means that the flats have a slight edge.
Seasick Steve – The Banjo Song from the album 'Man From Another Time'
(Live version from Later … with Jools Holland, couldn't find the studio version on youtube but you get the idea)
One man, one banjo. Again, as with Earth Beat the flats have the edge, but with such an intimate recording they should do. Steve's vocals have more expression with the flats that the added soundstage of the modified flats doesn't make up for.
Rage Against The Machine – Bullet in the Head from the album 'Rage Against The Machine'
I don't think this needs much introduction...
This is another song that I was expecting the flats to win hands down, but after listening to both I'm not so sure. The added separation of the modified flats places the individual instruments and vocals very precisely around the soundstage which has merit.
I was hoping to get the bass of flats, more sense of space, more like bowls with oomph, and I think I've managed it. Bowls still sound a thin and weak directly after either of the pads I've compared here, although if one comes to them fresh the lack of bass doesn't manifest itself so much. I don't really have a 'neutral' headphone to line up against these, but I know what I like and these are it. They don't win out on all counts, for absolute bass slam the flats are still king, but these modified pads don't lag behind very far. To me the added separation, and more three dimensional sound/headstage more than make up for it.
Hopefully I have managed to convey a sense of what these pads do for the Grado sound, and would be interested if anyone else who is mad enough to try them finds similar results.
I have to admit that recently I've been favouring my HF2s a little more, but this comparison has made me fall in love my the RS1s all over again.
Thanks for reading!