Last Call for DIY Cans! Here's the Latest

This story originally appeared at

Editor's Note - A quick reminder here for headphone DIYers: The time is very short for you to send cans in for measurement to enter the contest. Read full details here. The only difference now, relative to that first post, is that it has been opened up to all DIY headphones, not just ortho builders. I will be announcing contest winners on InnerFidelity's anniversary---April 1st.

BUT! I want all the U.S. headphone DIYers to know that my lab door is always open to you for on-going measurements. I didn't do this for the contest, I did this so you guys could put measurements in the loop of your experimentation, and I want to continue to do that. Please feel free to continue to contact me to have your headphones measured. For those of you outside the U.S., I'm very sorry, but it is simply too cost prohibitive to offer this service.

I also want to apologize to those DIYers who didn't get an article written about their cans as they've sent them in this last year. It proved to be too time consuming sometimes when I was trying to get reviews out for the larger public---I need those page-views as well. I really wouldn't have posted this article, but Nick N did such a great job on his write-ups and Kojaku's Grados were so impressive that I just had too.

This time around Nick N sent in four headphones and I'll be using his write-ups on each page, and then adding the measurements. On the last page however, you'll find a very nice pair of modified Grado SR225i by Head-Fi member Kojaku and a comment from me. If you know me, you'll be surprised at my impressions. Do not miss the last page of this article!

Right! Let's get on with Nick N's headphones. I should mention, the first three headphones custom, with a completely transpanted SFI 38mm driver. Nick N's last headphone, the Realistic Pro 30, came stock with the SFI driver.

Right ... let's listen to Nick talk about his cans:

Nick N's Introduction
All 3 customs use brand new 38mm SFI orthodynamic drivers (yep the small guys). I have tried all 3 types (: fully open ( Loops ), semi-open ( Hakamichis ) and closed ( Alder Woodies ) then of course the damping mod on the Realistic Pro30. Overall consensus is that it is difficult coaxing bass out of these SFIs, most likely due to their small diaphragm size and the fact they only have 9 holes in the magnets. These are similar to what the Realistic Pro30, MCS, and Sawafuji branded cans used, and a few other less common ones I may be obviously missing ... maybe Audio Technica.

I seem to be partial to the detailed electrostatish sound signature, but do also like a bit of bass in the mix. No overwhelming or boomy bass though, which, to me, detracts from everything else and I find tiresome after extended listening. Not saying these are anything of the sort, simply what I would prefer to tune towards.

All of these have been tuned using my older silver faced compact integrated amp with tone knob set to high and the volume knob never allowing the amp to leave class A. Realistically ( pun intended, it was a Realistic amp ), after getting a larger receiver, I can see that the amp they were tuned on could be seen as slightly lacking. So, everything from here on will be interesting to see how it all pans out. For the descriptions given here I am listening to them on a personal cd player set to normal E.Q., which seems to be better with louder volume levels than the portable Cowon D2 for listening. Same CDs for all---loungish melodic Fat Jon "Lightweight Heavy," and more orchestral Gungrave Soundtrack, "Uno Lefthead." Of course depending upon your music preferences these impressions may be off the mark, more or less. That, and I'm not particularly excellent at describing things. Bear in mind my descriptions of highs and mids, etc., is a generalization I tried to extract from general impressions. I don't use frequency sweeps or anything, nor do I generally attempt to use that terminology other than very briefly. I just know what I like subjectively. I should find a decent Linux Frequency sweep...

ALDER "WOODIES" ( Closed, 32 ohm SFI driver )
Exterior and a few build details in progress still. Need to readjust/shave down cup mount points to prevent squeaking; spray cups with nitrocellulose laquer used on guitars ( too cold out now ); find identical dimension pad replacements due to the minor soldering iron melts there. Need exact same pad dimensions because they were tuned to these and the distance and air space around the ears.

Western Red Alder is from leftovers I had milled up for furniture. Used it due to it's lightweight and strength, and it's my favourite woodgrain. Chrome headband assembly and padding is from an Audition brand ( Philips OEM model ) old paper-coned 70's thing. All wiring from a Sansui SS-20; earpads from a Superlux HD662F.

CONSTRUCTION DETAILS OF FINAL BUILD (Around 15 different mod attempts)
Alder cups 2 in thick with a center cavity of 1 1/4 inch wide by about the same depth, with a smaller 1/2 - 3/4 inch concave bottom. Top of this has an angled 1-1/2 inch mounting ridge for the driver. Cups wiegh about as much as the driver itself.

Acoustic 3-layer foam ring on ledge above the smaller concave recess; the cavity is filled with slightly teased organic cotton balls; rear of the driver should, if memory is correct, have a disc of the dense white felt used in the other two mods directly on the driver back to increase details and help bring up the mids/highs.

Driver is secured and sealed in completely with the same grey putty, and the outer seams are also sealed up . Wiring entry/exit point holes are sealed using clear silicone. Driver has about a 10 degree (or maybe more) tilt front-to-back to help increase soundstage.

Undamped bass ports are located to the bottom on edge of the cups, and trial and error brought them to their final diameter of 5/32 inch. ( Note to self: don't ever drill things while not disassembled---wires don't like drill bits! ) Any more bass would be too much for my tastes. (TEST THESE TO SEE HOW MUCH IT DROPS OFF by putting you fingers over the bass vent holes during listening.) I placed some black speaker fabric over the drivers on the earside of the cups. Superlux pads attached with double sided tape for proper seal.

GENERAL SOUND (Once the pads warm up)
These definitely have a more closed in/intimate soundstage than the other 3, even with the slight angle on the drivers. I do think that the slight angle does help a little, and they do seem slightly larger than if they were directly facing the ear. After the driver is installed there isn't much room behind it at all. They sound larger than they should given that cavity size. The large space inside the pads may be adding to this effect somewhat. Orthos---at least the older smaller ones like this driver---generally seem to go for small pad openings. I generally wear these with ears slightly towards the back of the cups rather than directly above the drivers, which makes them darker sounding.

The emphasis on these is the bass levels. I find it to still be punchy without being overly boomy or sloppy. It's only on these headphones that at times, in particular songs, I have to take them off to see if somethings's coming from outside in the room due to it's tactile-like bass rumble. Overall detail levels are half decent, maybe not as good as the other 2, hard to say about the mids and highs. Definitely lower than the bass. Nice to have brought that out in a driver that isn't generally known for that; brought out in a reasonable way that still lets you pick out the rest of the music, and not overpower/drown out the mids or highs too much. Details are still present but slightly toned down.

At this point I'd say these are the "darkest" out of the three.


Click on graphs image to download .pdf for closer inspection.