As much as I enjoy new adventures, it is just such a can o worms. So we have been looking for awhile to revamp the Rat Sound web site which is in dire need of a face lift. We actually have started the project twice with two different web designers and I guess a combination of cumbersome and bad luck have us still in limbo. So frustrated as I am I decide "hey, I will just catch up a bit on web site skills and dial in something till we can get her done right." Heck, just deciding what we want is a major challenge.

Anyway, so I buy a few books yesterday and dive into the sore eye screen stare while fumbling pages both paper and web. Wow, I don't know if I am happy stunned happy or just so lost in the ether world that it no longer matters. Either way, I have been using the daverat.com page as a test bed and there is some really cool stuff out there, though I am not sure I really know how a lot of it works.

What I think I know is that I was able to copy bits of code and embed my twitter site using a profile widget so that my last 4 tweets are shown. Using Feedburner's BuzzBoost I was able to embed this blog, and the Rat Sound Message Board such that the most recent posts are shown and automatically updated. I found that I could create a custom Youtube video player that auto updates and drop it into the page as well. 

If all works as precariously planned there is a bucket brigade of events all now interlinked where soon after I post this blog, feedburner will grab it and generate a tweet which should be grabbed by myspace and facebook updating my status as well as send off stuff to various unknown locations related to whatever those little check boxes I was having a party clicking upon. Why you wonder, or maybe that is me wondering. I can honestly say I do not really know other than the nerdiness of seeing if it all works. To spend massive amounts of time in order to save barely any. Or perhaps I just like opening big cans of worms just to see where they go.

And I am sure that all this is just elemental kids stuff but none the less, it bends my mind in knots and I am only on day 1 though not sure how long I will last. Oh I so crave the relaxing peaceful sensation of mixing a great big giant rock show.

The Mighty Headphone Quest

Is winding down as I settle in on three so far. I have a few more still coming in but for now the Denon AH-D5000 and Denon AH-D2000

are my favorites. Big, no folding expensive headphones that truly do sound impressive. Ha, isn't that just my luck, figures that the best headphones I can find are in the Denon consumer line that Rat Sound does not even have a dealership for. Oh well, I never would let that bias the testing anyway so it is actually kind of cool. In second slot and a bit more reasonably priced are the The Ultrasone HFI-680's

and they scored really high with clean HF, solid LF and they fold up as well. And darn it, Rat did not sell those either, but the folks at Ultrasone are super cool and we worked it out a to be an Ultrasone dealer now. The Shure SRH-840's came up well as well. Spare earmuffs, removable cable and foldable, they are a bit dark sounding but robustly built and solid.

I also did stumble across something I thought was interesting. If I turn up sound in one ear and leave the other ear off on some headphones I hear some sound in the ear that is of and in other headphones I do not. Furthermore, the sound I do hear, though low volume, it is not great sounding and tends to be distant and resonant. I hope to do a test and measure it. I am thinking possible factors are with whether they use 3 or 4 wires from the connector, wire length and wire thickness used in relation to driver impedance.

Ok, so what next. Oh, here is a video I put up a while ago and what is really whacky is if you look at the comments people leave me.

Ok, I am soooo curious to see if this whole posting thing works like a domino chain or a house of cards. Oh and if you have comments or suggestions, love to hear them!

Dave Rat

So I am listening to the news and all this hullabaloo about issues the instantly undrivable Toyota cars and as the story unravels it seems to be steering in the direction of two primary issues. First, there are cars that are doing something that the driver does not want, I.E. accelerating without being told to do so. The second issue arising is related to the cars not doing as they are in instructed, I.E. continuing forward when instructed to stop.

Now answer me this. We keep hearing reports that the acceleration issue is related to throttle linkage. Hmmm, does that make sense? How does a mechanical connection decide on its own to accelerate and tell the car to move faster? Hmmm. Now there are reports of a computer processor causing delayed braking on Prius models that actually do make sense and it is beginning to sound a bit familiar. Something about software and glitch and delay. Hmmmm, that has never happened before, oh wait, except everyday on just about everything computery I own. Could it be that cars are finally catching up to where our laptops have already gone and our digi live sound boards are deep into going? That wonderful digi ether world where our actions are analyzed and what actually occurs is some mathematical processed interpretation that we cross our fingers will actually occur in a timely manner? It is true that no longer does stepping on a gas pedal actually move a mechanical butterfly in a carburetor but instead initiates whole series of calculations and e-decisions which arrange a multitude of things in such a way as to hopefully inspire the car to move in a forwardly direction. Not unlike our new world of audio where the actual audio signals no longer need to even enter the knob and fader units we use to control them. Boot-up times and turning a knob results in stair steps of audible gradations after waiting that awkward fraction of a second for the console to get done calculating what it is you asked it to do.

Don't get me wrong, I love my laptop and rely on my cell phone with a smile. But would I use either of them to control the brakes or accelerator in my car? Perhaps I would but that would indeed add a new dynamic of cautious awareness to get my head around. And what about our non life and death world of audio? I must admit that as one who still is holding on to enjoying the fading world of analog mixing, I smile knowing that arbitrary acceleration and braking while awaiting a software update are two issues I do not have to worry about happening mid rock show.

Ok, enough useless but fun babbling, lets get on to the important stuff. There are so many concepts I have wanted to unravel and yet never had a method of documenting and demonstrating them that is enjoyable and easily shareable. In my latest video adventure I figured out a simple way to demonstrate the difference between pickup patterns of some popular vocal mics. I have been using om7's for years on artists that stay on top of the mic (sing with their lips against the mic grill). I have read and heard some pretty interesting and colorful opinions and comments on why one mic is better or worse than another but rarely are these opinions qualified with supporting facts. Also, recently I have spent some time and effort developing and manufacturing an adaptor to mate Audix mic capsules with Shure wireless transmitters. Why? Well, I made a video that answers that question.

Also, I have two more videos up from the Mighty Headphone Quest showing the low frequency volume testing on some of the cans. I have it narrowed down to three pairs so far but new headphones to test are still trickling in.

And oh, thank you Matt and Paul

for taking care of me at the Musicares gig.

I reluctantly forgive you for putting me on a PM5D because as much as I hate to admit it and find them no fun to mix on, it was the right tool for the job with so many bands, it just made sense to roll digi. It was only one song but it was also the first show with Chili Peppers rocking the new guitar player Josh. All good, this is going to be cool, cant wait till the show hits the road though it will be a while.

Finally for today, say hey to my new roommate Bones

Ok, off to ponder my next adventure.

DR

So my headphone testing continues and I actually think I am finding a few pairs that match or beat the Sony CD3000 reference pair. There are many inter-related factors to look at:

• Frequency Response
• Sound quality
• Maximum usable volume
• Isolation
• Fit
• Comfort
• Size
• Cost
• Cable type and length
• Construction quality
• Service-ability
• Any special features and on and on

I am going to do my best to eliminate any opinions and focus on the relevant measurable aspects. So first I started with flat response. Why? Well heck, if you have a pair of super wide response super low distortion headphones but half the frequencies are twice aloud as the others, what good will it do us?

"Oh yes, sir, oooh, you are in the business of accurately reproducing color images for huge crowds? Well take a look at this video projector, It is an amazing, high resolution and very accurate for everything except everything that is the color red will be twice a bright as anything color green and you can barely see blue at all." Crazy business!

So I believe that an even frequency response is the most obvious and basic of requests. I am testing testing with leniency and what I believe to be a sloppy spec of + or - 4 db from 30 to 12K. Furthermore, I do my best to get every pair to pass and whenever possible and give them the benefit of the doubt if they are even close. At this stage it is not about eliminating as much as it is about finding.

I realize my test methods lack many of the high tech perfectionistic angles and that is intentional. I don't know about you but I have personally read some pretty amazing claims about various pieces of audio gear and have seen many accurate and complex test setups constructed to reinforce claims stunning sound quality only to find out that the testing done is focused on a small aspects and offers an incomplete story of the big picture and real world experience. I have also read many profound and ludicrous claims of audio wizardry backed by false logic, pseudo science and blatant lies with no form of testing credibility.

My goal here is to side step both of the overly technical and voodoo magical angles by offering some simple logical and inexpensively repeatable testing that will hopefully allow people to draw useful conclusions as to what to expect from the various headphones.

So first I sought out flat response and thinned the pack a bit and now I am ready to move on to the phase 2 challenge. I am now going to subject all the headphones that meet or are close to the + or - 4 db spec to a low frequency volume test. My experience has been that it is very difficult for headphones to cleanly reproduce very low frequencies. Another issue I often run into is headphones that just do not have enough output and are incapable reaching adequate volume levels without distorting. I guess the question to be pondered is "What is an adequate volume level?" Well, I personally tend to mix around 103db to 105db A-weighted and and 110db to 112db C-weighted or flat weighted. Since I am looking for live sound headphones, I believe it is reasonable to expect the headphones I seek to reach actual show volumes. This way I can PFL the instruments at the same volume I expect to hear them when the PA is on and if they have a reasonable amount of isolation, I will be able to hear the headphones over the PA during the show.

Hmmm, a goal and a test setup. Ok, how about a tone generator on my laptop run into a power amplifier (BGW Model 85) into the headphone under test. Then a mic to measure the output of the headphones, an oscilloscope (HP 1715A) and an RTA (Klark Teknik DN60) to see the waveforms and use the other 1/2 of the power amp to power a speaker (an old Rogers Studio 1 BBC Studio monitor) so I can hear the waveform as well. Simple, easy and I can put it all together with stuff I have laying around the house here.

Here is what I am going to do:

#1) Send a 100 hz tone at a level of 110db flat weighted in the Sony CD3000 headphones. The volume level will be roughly determined by the RTA's overall level meter and the oscilloscope will show the peak to peak voltage. I will them match that peak to peak voltage for all the rest of the headphones I test. I have the oscilloscope set to .5 volts per division and 110db flat weighed shows up as 3 volts peak to peak (6 divisions on the scope screen).

#2) Without changing the voltage sent to the headphones, proceed to sequentially test with tones at 100, 90, 80, 70, 60, 50, 40, 30 and 20 hz while monitoring the output waveform on the oscilloscope and listening to the speaker. I will be looking for the 6db down point (1/2 peak to peak voltage) and note that as well as any strong distortions in the sound or waveform.

#3) Eliminate the headphones that perform poorly and while contemplating the next round of testing.

For the test setup, I have a mic fitted into a drilled hole in a piece of wood that I wedge against one muff of the headphones. I do my best to form a good seal and move the mic around till I get the best readings I can. To keep this blog post from getting crazy long, I am posting the most relevant waveforms rather than every single one.

Sony MDR-CD3000

Ok, here is a good looking 60hz waveform. 100, 90, 80 and 70 all look and sounds fine. There is a bit of sub harmonics showing up at 30 hz but the sub harmonics tend not to be too intrusive sound wise.

At 40 HZ it starts to drop in level a bit and it is begriming to deform a bit from a clean sine wave.

30 HZ is about the 6db down point and ignore the double traces. The waveform is clearly distorting and you can see the harmonic distortion causing 50 hz (4th from left) to rise on the RTA

and the 20 HZ is at about 1/3 the voltage and the waveform is fairly triangular. For visual consistency, I am not altering the sweep or range on the scope for any of the tests.

As you can see the waveform kind of falls apart but it did make it down to 30 with a reasonable amount of output.

So next lets take a look at the trusty and loved Sony MDR-V6. Since the V6's are pretty much the McDonalds burger of live sound headphones, I will post more read outs so there is a good comparative reference. The 100 hz looked good and here is 90 HZ which also is good but has a slight drop in level of a fraction of a db.

At 80hz we are seeing the waveform begin to distort and become a bit more triangled as the tops curve rightward a bit.

The waveform continues to degrade at 70hz and down from 3 volts to 2 volts PtoP.

And here is 60hz with a significant amount of harmonics showing up on the RTA and quite audible.

50Hz

30hz

and 20HZ

Hmmm, these waveforms are pretty warped as the V6's are not happy with these frequencies at these levels. The sharper the points on those waveforms, the more HF buzz and worse the sound is. Also, look at the RTA. Each tone should be a single or double LED column with the sides dropping off. When you see two peaks with a space between them, that represents harmonic distortion, If the second peak is below the primary, that is not too bad. But when the peak is above like the 40hz harmonic above the 20hz in the pic above, then it is really audible. We were seeing similar issues with the CD3000's as well but it started at a much lower frequency. I am going to cut the V6's out of contending for "The Best Live Headphones" but maybe for a good live headphone for under $100, they could be the way to go.

Ultrasone HFI 680

At 80 they look good

At 60 there is actually a boost of a few db

at 30 there is some triangulation and harmonic distortion at a 50hz but they are holding level quite well

I forgot to shoot the photo of 20HZ but it shows less than a volt down and some triangulation to the wave but nowhere near as severe as the V6's were at a much higher frequency. These continue to be one of the best headphones I have tested so far and they get to carry on to round three.

On the Sennheiser HD25-1 II's at 70hz, you can see they look pretty good. (ignore the double trace)

Here they are at 50hz, down a volt and not looking so good

but I found that some of these headphones are a lot more susceptible to low end variations due to the amount of squeeze against the test setup (or my head). I am sure you have all found that when you squeeze some headphones tight against your head the low end gets louder. Well the headbands on the HD25 are actually quite tight as well so I tested while squeezing the ear muff tighter and dropping the drive voltage level (the scope is on .2 volts per division for this pic,) and re calibrated for the extra volume and now look at 50

Here is 30 at normal pressure

30 at reduced level and more pressure, notice the cleaner sine wave.

And at 20Hz with normal test pressure and level they are just under 2 volts down.

Looking pretty good for over the ear headphones and surprisingly superior lows over the V6's yet not up to par with some of the others. Remember, these had a very flat frequency response so on to round three.

Wow, the Sony MDR-V600 already start to lose shape at 80hz,

Bouncing back in level at 60hz but still asymmetrical rounding on the top of the waveform

Degrading severely through 50 and 40 to a clearly clipped waveform at 30HZ

and I wont even bother showing you 20hz, say by bye to V600's.

Sennheiser MD280 PRO are looked pretty good at 80, But uh oh! Looks like they are not going to fair so well. Check out 70 hz!

But wait, they come back to life if I rest the back of them gently against anything that is rigid with some mass.

My finger does not work but barely touching this little amp or the wall snaps the response back to life. You can feel the slight flexing of the plastic as well when I send a tone to them.

Really strange, it appears the plastic housing is flexing and canceling out the low end. Here they are at 40 when scooted against that amp (ignore the double traces as it is just mis triggering on the old scope.)

and here they are moved and not touching at 40.

With a 3db down point at 20hz while resting against the amp

and a fairly clean sine wave as well, these will have to stay in the mix while I contemplate the whole "has to touch something" oddity.

The AKG K271 MkII headphones came in last week. One thing really cool about them is that they actually turn themselves off when you take them off your head. Very cool but drove me crazy trying to test them till I figured it out. They tested up quite well with frequency response on the RTA but rather than backtrack here, I am going to drop them straight into the low end level testing. Here they are at 100

With a bit of a peak at 70 HZ they came back to a pretty good level but some distortion at 50

progressively sloppy down to 30

and 20 is a mess. But, when I lowered the volume 10 db, they really cleaned up and come up quite nice all the way around. I am going to drop them from the top contenders while also recommending them as an awesome set of headphones for lower volume monitoring, especially if the auto off feature is an asset to your application. I will post the frequency response at some point as well.

So I had a pair of Shure SRH 840's and the demo ended before I was done testing and I sent them back. Of course I then get hit with so many requests to test them I have to reorder a pair. Here they are at 100

Getting a few db louder at 80

Still hot at 60 but fairly clean with a bit of sub harmonics rising.

Back to normal level at 50 and 40 and starting to drop at 30 and become more triangular.

With 20hz about 10 db down but reasonably well shaped compared to most

These are looking better than I expected and will have to see how they do on frequency response test.

Next up, the Denon AH D2000. Oh my. Check this out! Here they are at 70

Still holding strong at 50 with a nice sounding sine wave and some sub harmonics coming in at 30hz

A nice sine wave and no drop in level at 30hz yet harmonics at 50hz are up

Barely any level down at 20 and still a clean waveform!

and look! not even 3db down at 15 hz! (Yes, forgot to re label the pic from 20 to 15). These are so impressive I have just ordered a pair of the top of the line of that series, the Denon AH-D5000's that I will test for ya when they come in.

Ok, so that leaves us with five pairs plus the reference Sony CD3000's and the Beyer 770 and Denon D5000's that are on their way to me next week.:

As this test adventure progressed I have reinstated the Shure 840 as I never got a proper RTA reading on the first set that I had to send back when the demo ended.

I have found that I am getting better readings on the Sennheiser HD280 PRO's if I put some pressure on the outer shells so brought those back in the mix.

I wanted to continue testing the Equation Audio RP21 headphones with a removable cable and nice price point but for some reason they rushed me to get their demo pair back faster than I was able to put time into testing them for round 2. I don't think they would have made the "A" list but they do look like they have the potential to beat the V6's in the "under $100 street price" range.

I have been getting requests to test several other pairs from various manufacturers that I will gladly test if someone wants to send me a pair or if I can get some substantial credibility that any of those headphones have a strong chance of beating the top level cans I have already, I will consider purchasing for the test.

Will try and do a video in the next few days or so showing these the test methods and such so you can hear the top contenders as well. Here is a link to the video's so far. Cool cool, till next time rock on!

DR

So as part of the Mighty Headphone Quest, I guess I am going to have the Mighty Headphone Sell Off.

I had to buy several pairs to get them tested and here are the first two and though they did not make the cut for the application I have outlined in this quest, they are still quite good and well loved headphones. A brand new till I opened them pair of Sony MDR-7509's and a brand new till I opened them pair of Grado SR60i open ear. If any bloggery friends buy them, we will toss in a Rat shirt and some stickers as well. They are up on ebay but just send us a note if ya win 'em and we'll hook you up.

Sony MDR-7509HD

Grado SR60i

Ok on to the more mundane. Simplicity, Complexity and Believability. I have been thinking a bit more as I try and hack away the cobwebs of complexity and I think I may be gaining some momentum. The desire to overcomplicate and mask clarity is irresistible, especially when it fills wallets. I do not believe it is tough, though. I believe when accomplishing the purest task is a formidable challenge, that to mask various levels of failure, distractions are introduced in order to overcomplicate something that is easily observed when left in it's simplest state.

So as I dig around in the vast diversity of products available. Each product is claiming to have some group of assets that are superior in some way to the asset group of the other products. Maybe one pair has a certain combination of is cheaper or lighter, more comfy, stylish, durable, louder, flexible, available, socially conscience in the manufacture or whatever and on and on and on and I know that the importance of sound really depends on the application intended, budget allotted and expectations that are set. But unlike price or weight or looks, sound quality opinions have somehow has taken on this supernatural aura that requires elite audio monks from the netherworld of golden ears and fuzzy logic. And ears golden as they may be, maybe, just maybe, at least, at minimum, if the sound that comes out is somewhat close to the sound that goes in, perhaps that may be a good place to start? And when I find perfect sound, I will know it. I will not need magic ears or special wires or voodoo crap of any sort at all. I will merely close my eyes and be completely unable to distinguish between where I am and whatever elsewhere the music has taken me. Everything else is just a feature or preference.

And does anyone know the model # of these Sony mystery headphones?

Dave Rat

Finally we are actually seeing something show up with some potential! As I go through them, one thing keeps coming to mind. How in the heck can all these headphones have these amazing specifications of 20 to 20K, 5 to 30K, 6 to 42K with each one inferring that it is flatter, wider and more accurate than the last when there is almost no relationship whatsoever in the way they sound? Without a +- db spec and some hint as the the measurement methods, those numbers are junk. The state of these audio specifications is so pathetic and deceptive that they are all but useless. I guess that is a subject to address at some future bloggery date.

Ok, so why do we want a flat response from the headphones anyway? And what is flat? Where do we measure flat? Though the frequency responses of these headphones are all over the map I am seeing some potential trends with both bass boost and double dip high frequency responses. Perhaps some manufacturers are imbedding a Fletcher-Munson response, the new standard ISO 226:2003 equal loudness contours or some other form of compensation?

Perhaps it is arbitrary or there is a lot of heavy thinking is going on? Well, well actually there are plenty of mind clustery debates about how to massage the response of headphones to be perceived in certain ways and sound in some form of corrected correct by ears in comparison to some other form of whatever. My friend Ferrit sent me this article which goes into some deep Stereophile depth of some of the whatevers they are trying to figure out. To get a taste of some of that take a gander at this:

http://www.stereophile.com/features/808head/index.html

Ha!, well I am sure that discussion can and will go on forever and never have a definitive winner of rightness, so lets take a slightly different approach and try and keep this a simple, repeatable practical path to a productive outcome.

I set out on this bloggery quest to find some currently manufactured headphones that are close to as accurate, loud and fidelic as the Sony CD3000's I have relied upon for the past decade or so, before they irreparably die. What I did not know when I started the testing is that when I run pink noise and place a measurement mic near my ear inside the CD3000 headphones, that I would see a response that is much flatter than many of the other headphones I am testing. Wow, that is so cool and makes things much easier as I have a simple logical starting point that makes a bit of logical sense.

Another really interesting aspect is that other highly regarded and popular live headphones such as the Sony MDR-V6, Sony MDR-7506, Denon AH D2000, Beyer 770, and Sennheiser HD280 would also measure much flatter responses than many of the headphones that are less favored by live engineers. So it appears that coincidentally many live engineers are naturally attracted to headphones with a response that shows up as relatively flat on my simple measurement method. Or perhaps, just perhaps, it is not a coincidence and the headphones that put out a fairly flat 'equal energy per octave' response are truly a useful reference point for live engineers while headphones with tailored responses are less than optimum.

So armed with the observations that popular live headphones show up fairly flat with my overly simple measurement system, I continue to listen and measure and narrow the field and bang out the rest that I have, first the sad goodbye's:

Oooh, the Grado SR60's are lower line Grado but since they are all open ear and these are the most popular of the line, I bought these just to hear them. They actually do sound quite nice and pretty much like you see below, smooth, a bit top heavy and not much in the sub lows.

May as well dump my old broken MDR 90's or whatever they are. Oooh, they look good and actually beat the spec but are discontinued, are on the ear types, look like tiny little toy headphones and wont get near loud enough to clear the next round. That said, it was sort of cool to find that that flat is not a pipe dream.

Here is my least favorite of the cans that almost meet the +- 4db 30hz to 12.5K spec. If it was not for the dips at 6.3 and 10K, they would make it at least looks wise. These Sony MDR-V600's show up pretty good but do not sound that great. Harsh top end and sub low weak. I am going to drop them as they are not quite up to par sound wise with the V6 and 7506's cans which I am also going to drop. We are not looking at re discovering the average run of the mill utility cans, we want something better.

The Sennheiser MD280's actually showed up better than the Sennheiser MD380's. The sub low on the 380's was more impressive but I really want to hear that smooth midrange. These do fall off a bit in the low mid, and the top end is a few db too much to the dark to make the spec. I have never owned these personally but, based what I see and hear their popularity with live engineers does make sense. But, again, going to drop them, looking for better.

These Equation Audio RP 21's were a pleasant surprise, never heard of them before this test. Yes, bass heavy and they have that spike up top, a bit out of spec but perhaps another option for something with more ULF and UHF than V6's in the $100 street price range that have a removable cable as well.

And now we step up to the true hot shot finalists, now we are talking! Check out these Beyer DT770 (not 770M yet as they are on their way still). They do have a bit of a rounding hump with 1K in the center that just barley puts them outside of the spec at we set at 10K. To be honest, I would like see more low end push and less HF droop, but oooh, can you say "nice cans!"

Take those Beyer's and bump the comfort level up a full notch, add in a the absolute most bad ass cable I have ever seen on headphones and you have these gorgeous Denon home Hi-Fi units. I still have some volume testing to do and yes, they do drop out of our spec at 1.6K due to the solid low end bump from the 50mm drivers that gives the D2000's a bit of that smiley curve home Hi-Fi sound. Ideally they would be a bit more edgy but these are really nice, well built and solid.

And now out of the 29 headphones I have spent the last month or so and maybe a hundred hours testing I have come across some that actually meet the huge gaping hole of sloppy loose +- 4 db from 30hz to 12.5K spec I set long before I knew how challenged the contenders would be. Really? Plus/minus 4db? Think about it, 10 db is twice as loud so our spec says that no frequency can be close to twice as loud as an other frequency. Anyway, these Ultrasone HFI-680 and HFI-780 headphones made it. Imagine my glee after all the time spent to actually have something that not only did not fail what seemed to be such an achievable goal but actually beats it by grabbing 25HZ as well..

And they do sound really good. Would love to see a removable cable, with a straight or coily option. P. S. I hate the coily headphone cables! Break away straight cables that unplug when you step on them are the way to go IMHO). Also of note is that these have offset drivers that do not shoot sound directly down your ear canal. They say in the literature that this is less intrusive to our beloved ears longevity. These babies sound tight, smooth, full range, and were the 'aaaah, I am not crazy' entrants that have made this worthwhile.

Note: I did an edit here.  I originally postsed the HFI 780's a second time in error.

Here is the CD3000 reference pair read out I am seeking to match or beat. Going back to them they do sound a ULF light now that I have the new exposures. The slightly thicker sound of the 680'sand 780's is welcomed though the CD3000's still sound more natural though a bit pushed high end wise now.

And while we are at it, I am going to drop the Sony MDR V6 and MDR 7506's from the running.

Though the Mighty Headphone Test is not done yet, these Ultrasone's have scored high enough to make the Dave Rat Recommends list. Plus I am impressed enough that maybe I should have Rat buy a pile of each and put together bloggery sale of them? What do ya think, anyone interested in a Mighty Top Dog Headphone Sale?

Next blog up, I am going to hit the top level units with some juice and see how they handle being on the back end of a power amp, bypassing those resistors they put on headphone outputs. This will allow us a look at the effect of the headphone resistor on the response, if any and I hopefully will be able to find any weaknesses in power handling.

Rock on and Happy Holidays!

Dave Rat

And on and on we go. I had no idea this would be so time consuming. I also had no idea it would be so interesting to hear how varied headphones can be in side by side comparisons..

So here are few more to gander at. Lets hack away a few more and find a keeper or two as well.

The Koss MV1's has a some dips and is tilted toward vocal inteligeability but we really need a smoother response.

Ohh, and on these Ultrasone HFI-780 we have that double HF dip as well..

This HF dip pattern is showing up in several headphones. My guess is that some of the headphone designers are actually tailoring the responses a bit to account for the percieved loudness effects as described in the Fletcher Munson Curves to provide a sound that is desirable to listen to.

Here as well in the Sony MDR-7509HD cans we see an even more exagerated but similar pattern. I must admit this was a shocker. I really had high hopes for these. Especially with the 50mm drivers, I was hoping to hear something close the Sony CD3000's. The 7509's were both a bit dark and low-end light. Keep in mind I have not really burned in these cans and the burn in could warm the low end up a bit but it is highly that burn-in will fix this huge HF hole. Say bye bye 7509's. Darn!

Another EQ pattern is the 'smiley curve EQ' that tends to be pleasing to listen to and often described as Hi-Fi sounding. While this may be a desirable trait for listenability and offer a sound that is not harsh, for our purpose of having a live sound reference point, we want a flat response. The most 'Smiley Curve' sounding headphones I tested so far were the Ultrasone PRO 900's below:

And just to show another reference point, here is the graph of those same headphones on headphone.com

So while I have been hacking away at thinning I also have been finding some few with potential. Right off the bat it became apperent that the Sony 7506's are popular with live engineers for a good reason. Oooh, look at this: With the exception of the HF rolling off a bit early and a slight droop in the sub lows, these are darn good and flat.

And here is a look at the V6's. Again really flat and I hve heard that the V6 and 7506 have the same 40mm drivers or at least nearly identical and these RTA measurements are within 2 db of each other. Nice cans, not as nice as the CD3000's though. At least we not have a lower end of the spectrum of acceptability.

Now lets take a look at the measurements headphone.com got on the V-6's

Wow, a wide gentle hole at 250 a small peak at 320, gradual dip into slight peak at 3K, dip at 6.3K, peak near 10K and then rolling off from there into a 20K bounce that my RTA cant read.

One of the big hopefuls I had was the Shure SRH-840's

Unfortunately though, the Shure 840 demo ended before I figured out the analyzer snapshot idea and I had already sent the headphones back. But I did get a good amount of time listening to them. So, sorry about no RTA photo but I do have a read out from headphone.com that lines up very well with what I was hearing

Notice how well they emulate the response of the Sony V-6's from 500hz on up! Then notice the 6db bass boost. I can see it beeing a well liked response for DJ's and such but for our accurate live sound reference purposes that bass boost is going to be a considerable issue. In fact it looks like they grabbed the best parts of the Sony V6 and 7506 designs and added a removable cable, spare ear muffs and made a nice set of cans that fold up like the Sony's.

Due to the fact that these Audio Technica's AD700's are open ear design, they will not make it as live cans but they sure do have a nice response. A little low end light and looses top a bit early but they actually do meet our +-4 db spec we set for the CD3000's.

Check out these Koss ESP 950 Electrostatic headphones. Also within our specification though they are also an open ear design.

So, I am going to start putting the headphones that pass the frequency response specification in bold and strikethrough the headphones that for one reason or another will not make it to round 2.

Dave Rat

It was recommended to me that I get a second reference point other than my own head to check for any response anomalies. Great idea. Again, super simple, I just stuck the mic inside and held the CD3000's around one of the cases that came wit the Ultrasone 900's. As you can see it is slightly different than the 'on my head reading but still darn close. As with all the readings there is a slight variation with moving the mic a bit and ear pad pressure, but all the reading stay surprisingly close and consistent for each pair of headphones. I tried this with several other pairs and they all too were consistent with the reading while on my head.

So lets have some fun and start elimination round #1 getting rid of some now that I have a good solid selection to pick from. Lets get the reference CD3000's up.

Ok, if you cant read the #'s here they are. I am putting the frequencies with lines down to them in bold

25, 32, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1K, 1.25K, 1.6K, 2K, 2.5K, 3.15K, 4K, 5K, 6.3K, 8K, 10K, 12K, 16K, 20K

There is 8 db between the horizontal lines (2 db per led) so as you can see this reads that the CD3000's are within an 8db range from 25hz to 12.K. Since my setup most likely is not very accurate beyond 12.5K, and for live sound EQ it is not very critical up there as we lose most of that super high stuff to air loss anyway, I am not going worry about 16K and 20K. So as our spec, we can say that we are looking for headphones equal to or better than a +- 4db 25 to 12.5K using my crude but simple measurement system.

First say bye bye to Apple ear buds as clearly they will not work for the desired live sound purpose but they are fairly flat from 125 to 12.5K

No go on the Sony XB700's because they are just not going to cut it the cables too short and their response is way off with the bass boost, big hole at 630-800 and rolling off highs.

Yikes, check out the response of the Pickering vintage OA-3 phones!

These open ear Koss PortaPro open ear phones actually sound quite good, lots of low end and I was duly impressed by the sound versus size and cost. That said, I think I want them for my portable player but they just wont work for live shows.

The Audio Technica Pro 700's had strong low end power but were midrange heavy and lacked a top end.

The extra bass Equation Audio RP22X were smoother sounding but as expected, they were low end heavy. But hey, they are the extended bass version. I think this may be a good DJ headphone at a reasonable price. Plus the 1/4 turn removable cable is a nice feature.

And here drops the first one of the big boys. This was a real surprise for me but what I heard and what I see lined up. Say bye bye to the comfy, nice iso, neatly folding Sennheiser HD380 PRO's. Deep but a bit loose sounding low end, mids a bit subdued and though they sound Hi-Fi, the holes in the upper ranges just pulled all the clarity out. They actually sounded a little similar to the RP22X but with 20 db down at 6.3K and 12 db down at 2.5K, I had to drop them from the list.

It was fun to put on the Koss 4AA cans and brought back fond memories. These durable things have a solid tight fit and some heft and though I do not recommend them for live monitoring cans they do seem optimized for speech intelligibility, so they would make good utility cans in high volume environments.

Finally for today an entry from Ultrasone, the HFI 450 pair show a smooth but gradual roll off towards the HF.

And the culling of the 'heard' has just begun. There are plenty more and some surprises ahead!

Alright, that's it for today.

Dave Rat

The listening test. Since the goal here is to find some headphones that are flat and accurate for live engineers to use as a reference point, lets consider a few factors.

1) Most sound live sound consoles have fairly generic headphone amps so for me to test with some fancy headphone amp would not make much sense.

2) These headphones should not be biased toward any particular music type so the type of music should not be relevant other than purely to highlight issues.

3) Hopefully the only aspect that involves my opinion really is the decision to use the CD3000 and the assumption that the CD3000's are a flat and accurate reference. Though with all the testing I have done on speakers over the years and listening and EQ'ing systems to flat, I am quite confident that the CD3000's are a fairly accurate reference point. Or at least the most accurate I have found yet.

So, what I am doing for the listening phase is is purely comparative. Just out of ease and familiarity I am primarily using a record player as the music source and lackluster stereo receiver. I will shoot a pic for next blog post. This allows me to easily replay the same part of a song and the clicks an pops of my old records allows me to hear how the headphones deal with those sharp spike dynamics. I started out with various tracks from Pink Floyd The Wall and Wish You Were Here albums. Today I am using Van Halen's first record. Did ya know that Jamie's crying, you can't have any pudding and you are gonna make it if you try they're gonna love you. I also give them a listen on an iPod where I have been using Ween, Butthole Surfers (good sub lows) and Why Don't You Do Right from the Roger Rabbit soundtrack (Amy Irving vocals). All that said, what I am really finding is that it makes very little difference what I use for music. The boomy headphones are boomy everywhere on everything. The dull phones are dull on everything and so on. Their was one helpful thing I found for sorting them though. I have a few different phono cartridges for my turntable. One is quite dull sounding and another is very crisp and bright. I find that if I use the dull sounding cartridge it really helps me hear variations in the high mid and higher frequencies between various headphones. Whereas with the tonally bright cartridge it is more difficult to discern, as the variations are masked a bit.

So all I do is play a song, put on the CD3000's, then swap to the headphones I am comparing, go back and forth a few times and take some notes. Really simple and the differences are tending to be so readily noticeable and clear cut that it is really a no brainer. As soon as I put them on, boom, these lack lows, boom, these suck the vocals out, boom highs are dull and so on.

Below is the current list of what is on the headphone test plate. Most of these I already have started evaluating while some are still on their way to me. I am not against adding more but having started, I can tell you that unless the headphones that get recommended are extraordinary and sound bright and clear and they have have super smooth low end without boominess, they will not make it very far. So far my testing is showing that many highly regarded favorites have response curves that make them less than optimum as reference headphones. Yes, many of them do sound quite good but I am finding that the pleasing sound comes from either a gently sloping response, a bass boost and/or a notch in the 1K to 5K region. All of which make those headphones non-ideal reference points.

Code:

• ULF - Ultra low Frequencies, like 20 to 40 or so.
• LF - Low frequencies, like 60 to 150 or so.
• LM - Low mid, like 150 to 400 or so
• M - Mids, like 400 to 1000 or so
• HM - High mid, like 1000 to 3000 or so
• H - Highs, like 3000 to 6000 or so
• UHF - Ultra High Frequencies, like 8000 to 20,000
• The more "+" means the more there is. he more "-" means the less there is.

So that is where listening has taken me so far. I also have devised a stupid simple way to get a rough frequency response measurement for comparative purposes that seems to work surprisingly well! I was thinking, how can I measure what my ear hears? I could:

A) Build a dummy head with a fake ear, an ear canal and then spend endless hours refining and testing to see if it is accurate and try and eliminate any issues. I then could go into depth trying to prove the credibility of my measurement method.

Or

B) I could put the headphones on my own humanly head, shove a measurement mic so it pick up the sound right where is goes in my ear and take some actual readings of what is my ear hears.

Hmmm, I am going to roll with the "B" method and see what happens. Plus, plan B is easily repeatable by anyone who has Smaart, and RTA or any other audio measurement system thus allowing anyone to easily check the results of what I measure on their own gear. Cool! So I am going to run this whole deal old school and simple, the way I like it.

But before we move on, in my e-wanderings I found this cool web site:

http://www.headphone.com/learning-center/build-a-graph.php?graphID[0]=1513&graphID[1]=533&graphID[2]=913&graphID[3]=&graphType=0&buttonSelection=Compare+Headphones

They have already done frequency response curves on quite a few of the headphones I am looking at and the graphs results somewhat match what I am actually hearing. You can actually pull up and overlay graphs. I spent a while there and compared every headphone they have graphs for to the V6. Cool.

Burn In. A few people have brought up burn-in. Burn-in refers to a phenomenon where the sound of a speaker changes over time and that the stable response characteristic is not reached until a transducer is used for some or many hours. I have no doubt the burn-in effects the response of headphones and speakers. We see it all the time with subwoofers where they become floppy and tune at a lower frequency over time. That said, the typical and logical result of burn-in is a slight lowering of the low end tuning frequency as the mechanical compliance loosens. I can tell you right now, there is nothing slight about the differences between the various headphones I am evaluating. The variations are drastic, huge, monumental and tremendous. Giant 5db multi-octave wide holes and peaks. If a pair of headphones is going to have a shift of octave wide 5 db hole or peak due to burn-in, it deserves to be eliminated anyway. Any cans that are doing well, will keep getting tested and naturally burn-in through testing. So say bye bye to burn-in concerns as a relevant factor in this testing.

So I turn on some pink noise, run it through the CD3000 headphones and slide the measurement mic close to where sound enters my ear and...

This is set on 2db scale so the horizontal lines represent 8 db. So here is the response of the reference CD3000 pair of headphones on my humanly head. Looks like + or - 5 db from 25 to 12.5K. Note, I do not think my mic or other gear is grabbing the frequencies above 12k very well, but that is the least of our worries. And after years and years of using these headphones to finally see their response and have them come up relatively flat was quite exciting. Wait till you see what the other cans look like!

Here are the Sony XB 700's and check out that nearly 3 octave, 12 db deep hole from 315 to 1.6K followed by a 6db/octave roll off. That looks like it will sound like standing outside a car cranking stereo with the doors closed, and it does!

Here is how the iPod earbuds showed up. I could not get the mic between my ear and the bud so I just balanced the bud on the mic. These actually should get more low end when in your ear.

Ooooh, look, fairly flat with a gradual roll off below 100 Hz and a smooth hole centered at 2K. That actually looks like it would sound pretty good.

As far as the accuracy of the measurements? Well, first of all, as I move the mic around it really does not change that much. Secondly, I do spend a bit of time trying to get the best reading I can for each headphones. Thirdly, the variations between the differing headphones are so drastic, that a bit of error in the measurement is a low concern. Finally, it is reassuring to my measurements have some parallels to measurements done by headphone.com but more importantly, the RTA readout really does look like what I am hearing so my confidence is quite high.

OK, enough for now, I have lots more and many surprises to come as I will save the good stuff for later!

Dave Rat

PS, I found this while wandering Ebay looking to buy a pair of Grado headphones to test

OMFG! $1100 for a pair of 3 foot long phono cables! This is a real auction seeking a real moron.