does anyone else think the um1's are way too loud. i keep my ipod on the lowest level and it even sounds a little too loud. how many db's do think the um1's have if i put my ipod on this level. also im thinking about getting re0's. if i got re0's would they be louder or quieter than the um1's? thanks

Perhaps an inline volume control or a microamp would be a possible solution.

UM1 are very efficient, although you must have very sensitive hearing if your ipod's lowest level is still too loud. An inline volume control might help. Be careful if you use an amp - if the gain of the amp is too high it can cause clipping and distortion with the UM1. Low-gain amps are fine.

so how many dbs do you think the um1's produce on my ipods lowest level? do u think it could harm my ears? also i tried using mp3gain to lower the volume of a couple of my songs but the um1's dont sound good at all when the volume is lowered

The only way to find out is to use a decibel meter. When I got my Shure E4s they seemed kinda loud, so I tested them and found out that I had to keep the volume of my sansa below 50% to keep it ~safe (under 80dB)

Yeah - there's really no way to know unless you test, because it would vary with the input signal level. And even then a db meter is not very accurate because of the difference between measuring in free air versus inside the ear canal. I'm still having a hard time with the idea that the lowest volume setting from a 30GB ipod video (same as I use) and your UM1s (also the same as I use) is too loud. That's amazing! I wish I had your ears. Maybe I did once, but that was way too many concerts and hunting trips ago!

Slightly off topic: are there decibel meters that use a dummy head?

Quote:



Yes, there are, but AFAIK they are custom units (=$$$) built for a special purpose.

Sure - there are dummy heads specifically made for headphone testing. But, there are different types of dummy heads. Some work well for speaker testing because what you are really measuring is the stereo effect of having ears on opposite sides of your noggin. But with earphones, it's also really important to model the shape and influence of the ear canal - and that's more than just your average dummy head. Here's what the experts say:
How We Measure Headphones - HeadRoom: Stereo Headphones, Amps & DACs, Wireless, Noise Canceling, Ear Canal, Earbud, Audio Cables & Accessories
HEAD acoustics - Head-Related Recording and Playback Technology, Communication Measurement Technology

The UM1 has only one driver - which costs it points in the "How many drivers do YOU have" contest but that also helps make it more efficient. It doesn't have to balance its output with that of another driver, a job that tends to add resistance and reduce output efficiency. As it goes, this IEM has an impedence of only 25 ohms and a sensitivity of 114/mW. That makes it quite easy to drive off an iPod.

Let me give you a couple of points for comparison. Etymotics makes an amazing IEM, the ER4S whose impedence is 100 ohms. To make it more drivable, Etymotics came out with the ER4P with a much lower impedence of 27 ohms. The Phonak Audeo PFE, another single-driver IEM, has an impedence of 32 ohms. The Shure SE530 has an impedence of 36 ohms. The UE Triple Fi 10 Pro has an impedence of 32 ohms. Within Westone's family, as you go up the product line, the impedence increases, at least a little. The UM2's impedence is 27 ohms. The triple-driver UM3X, with its own integrated crossover, has an impedence of 56 ohms. Even the party-animal Westone 3 has an impedence of 30 ohms.

So what can you do? Short of selling what you have and buying something else, you can either purchase an in-line volume control (just an attachment that sells for $5 to $10 on Ebay) or you can buy an adapter that adds impedence to the line (for $10 to $20, $50 if you buy the one Etymotic sells). The great gurus of electrical engineering can correct me on this, but a volume control is basically just a way of introducing variable resistance, so why use an adapter when you can just add a volume control?

With the ER4P, I can understand the desire to maintain a fixed resistance. If you can raise the impedence 73 ohms, you can boost the phone's accuracy from 86% to 92%. That's worth doing. But in your case, you're just trying to cut down the volume so you don't get a nasty surprise from song to song (which is important on the iPod because sound levels on different tracks are not equal). For $10 plus shipping, you could easily fix this.

Quote:



The only reason (that I can think of) to use an inline impedance adapter instead of a volume control is to eliminate any artifacts that come from an extra unit in the chain. The volume control has a potentiometer (unless its digital) and those have a tendency to need cleaning, etc.

My um2 is the exact same way. It's way too loud at the lowest level. Plus the hiss is about as loud as the music and is very distracting. I decided to use my Tomahawk with my nano 3g and it takes care of all my issues.

An impedance adapter would work for you. Be warned though, it will modify the frequency response of a multiple driver iem. Since your um1 is single it should merely decreace volume and hiss.

Quote:



In a document titled, "Earphone Design Guide," Knowles Acoustics - the maker of the drivers used in Westone's product line - has this to say in a sectiont titled, "Effect of Adding Series Resistance."

Quote:



For KA's SR series of balanced armatures, 22 ohms of additional resistance can attenuate the 2.5 kHz spike (from 115 to 124 dB) by 2-3 dB but you'll lose about 5 dB of bass between 100 and 300 Hz. With the ED series, 22 ohms of additional resistance can level out sharp spikes to 118 dB at 2.5 kHz and 6 kHz, tuning them down to about 110 and 112 dB respectively. The downside is that you lose as much as 15 dB of deep bass between 100 and 300 Hz. You also get deeper troughs at 4 kHz and 7 kHz and about 3 dB less output at 8 kHz.

This is where you may want to ask yourself what you mean by "louder." I'm not trying to be coy here. I want you to listen to your earphones and ask yourselves which parts of the presentation seem loudest. At this pricepoint, Westone - like a lot of other manufacturers - doesn't even pretend to construct a crossover circuit to attenuate frequency response. Changing impedence (basic resistance) will have a greater effect on bass than on treble but even there, it just basically kills the volume.

If you want to flatten out the response a bit, to attenuate the spiking, you should consider using a capacitor as a crossover device. Like a lot of other manufacturers, Westone doesn't bother using any crossover with monitors that are further down in the product line. KA doesn't even talk about the effect of crossovers with the less expensive drivers. But even with the TWFK, KA's champion driver, there's an 8 dB spike between 2 and 3 kHz. Adding a .82uF capacitor soothes that spike by about 3 dB. A 1.5uF capacitor soothes that spike by a decibel less but significantly fixes and extends treble at the extreme end, where it otherwise goes wobbly.

Since you're dealing with a single driver, it's easier to adopt this fix with a custom adapter which could actually improve the design of your UM1.

I'm not sure I agree that increasing the impedance of a single driver iem does not affect the response. Just look at the ER4P vs ER4S:

Quote:



What made you think I said increasing impedence didn't affect the response? The quotes from KA specifically said that they do affect the response as well as how. Personally, I prefer the following frequency response graph: http://www.etymotic.com/ephp/er4-wrfy.aspx

As Etymotic's graph shows, impedence is useful in cutting the volume to a more balanced setting. The ER4S does sound better than the ER4P, even if the latter is easier to drive off an iPod.