[size=10pt]They are the same drivers. Doesn’t mean I’m wrong and doesn’t mean she’s fibbing. For the last couple years the tolerance had been only within 2dB for average response volume matching on the ER4. That was direct from their mouth over the phone when I called about the warranty replacement pair's imbalance. That's not as tiny as it looks. There might be technically no physical difference in the drivers if you want to phrase it that way, but it makes a difference how closely you pick the drivers from the data base of available drivers. She's not explicitly denying the technicians more closely match the "T" or that for the last few years they were using lower tolerances compared to a decade ago. Either I luckily got a perfectly matched pair just randomly back then in 1999/2000, or their driver matching tolerance were relaxed lately due to increased consumer demand and a need to move more product and not be so stringent. And I highly doubt this printed and signed paper on the "T" is only showing a 2dB tolerance for the average pair and that they've ALWAYS used that tolerance range. Not with how spot-on the old ones always were for people (never heard problems with that before), how many units they’ve been moving in recent years, and how common this issue became. You're insinuating her email is saying they're charging an extra hundred for a piece of paper confirming something they are already doing and have always done on the ER4 and a bonus airline adapter. I'm saying they're giving a very political response so as to not undercut sales of the standard “new & common” ER4, and they're doing so in a way you will have a hard time empirically disproving (for the benefit of others) without Tyll’s or headphoneinfo.com's dummy heads.[/size]
[size=10pt]But one’s hearing does not have to be perfect or centered in every band to determine this subjectively (i.e. in non-empirical way you can have personal certitude in but can’t prove to anyone else). If the spot a mono signal in a particular band (or even complex mono sounds) settles at (its relative center to your hearing) moves around when you flip-flop earpieces, then you know either the source gear, the jack, or the earphones are imbalanced. Assuming the earphones do not have a front and are universal fit in the case of IEMs, you can quickly determine this. It is true that with IEMs you have to do it quite a few times flip-flopping earpieces to really confirm this and find out what the average is you're getting since depths can be a little different each individual attempt. But you can pretty easily do this blind and without bias by not looking at the earpieces, put them in, and judge where the centering is. Flip them around, and then listen again. You're listening for which direction the mono signal MOVES TOWARDS after the flip-flop; preferably it doesn't. Take them out post-flip-flop and look at the drivers to see which was which. That reveals which was in each ear before and after the flip. Do it again by mixing them up without looking and see if the sound shifts towards the same driver again. If after a few attempts, on average, the center tends to shift towards one particular driver, then you know it's the driver imbalance. Yes, you need to use a variety of sources and jacks to rule them out. Pretty simple. Flip-flopping the drivers around rules out your own hearing imperfections. Not knowing which driver is which when you put them in until after the flip-flop is even better at avoiding placebo effect. In the case of the warrantied ER4S, there was ALWAYS a shifting slightly to the right driver as long as the seals and depths didn't feel completely different on both ears (by feel inside the ear and by checking the lip of the flange tips with me finger). So it wasn't just some super tiny amount that shifted 7 out of 10 tries. It was 5 for 5 flip-flops and on and on when they were the same depth each time. A few times I've accidentally put them in the wrong ear and wondered why the sound was shifted more to the left than I know is my natural hearing center plus this ER4’s own right imbalance. I look in the mirror and, oops, blue side's on the right. That explains it.[/size]
[size=10pt]I’m not dissing Etymotic. I love the ER4. I paid a lot for my original ER4. I’m thrilled they covered a 10 year old pair at all. But companies grow. Their defect or tolerance rates get relaxed. I understand that. My best estimate is they want you to pay a premium for their old quality standards. We get to gripe a little about the lack of openness when our new stuff isn’t quite as good as the old stuff or they come out with some obvious marketing-spin to advertise their old quality standards back to us. That doesn’t mean we stop going back to them. I’m flattered by the veiled assumption here that my original complaint went viral and led Etymotic Research to start cashing-in on professionals’ need to be reassured they’re getting a closely matched pair… when in fact they already were. I just think that’s unlikely. I think they saw a real inadequacy pointed out by a variety of complaints like mine (not mine in particular) and their marketing people came up with a strategy in-line with newer trends in customer responsiveness to capitalize on this and appease us. And hey, I prefer these new customer-focused marketing trends over the old ones, I just don’t like marketing so much in general. If Etymotic Research was still a small engineer-centric company with a close transparent relationship to consumers like they’d always had, they wouldn’t have a gazillion different product lines, hot Asian chicks wearing their earphones in advertisements, the tolerances would never seemingly have been relaxed, and/or there would be no “T” version of the ER4. If they really are trying to sell people an adapter and a piece of worthless paper for a hundred bucks, then they’ve grown even bigger for their britches then I’d assumed. [/size]