[Arjisme]

Quote:

Originally Posted by erikzen /img/forum/go_quote.gif Where do I find said volume attenuator? Isn't this adding resistance and isn't that what the P to S adapter does also?

I don't know what the P to S adapter is (just not familiar with Ety stuff). But, yeah, the attenuator is just adding resistance. Mine came with my E500s. I was thinking maybe you had something similar.

 

[schapman]

I used one of
http://www.shure.com/PersonalAudio/P...vel_attenuator

With my UM2s

 

[jinx20001]

Quote:

Originally Posted by kramer5150 /img/forum/go_quote.gif I've always wondered this too... So many of us here suffer from hiss and noise... what kind of OP-amp circuits are in those wireless belt-packs used by gigging musicians? Surely they can't be as hissy as some of the worst amps I have heard... or are they? I think low impedance balanced armatures are carry over from the hearing-aid industry. Where, they use small watch batteries in a very low voltage amp circuit. My dad has a tiny hearing aid, no larger than a UE-10.... its got a mic, volume knob and a small amp inside. So, they are designed to run on miniscule amounts of power. UE and Shure use various knowles armatures.... http://www.knowlesacoustics.com/know...category_id=30

this link is interesting because shure and ue never display or explain the balanced armatures used for thier earphones so we as customers never know wether we get cheap armatures or more interesting and capable armatures,if anybody or in particular kramer can shed light on this it would be an interesting read

 

[Culverin]

well i've tried using one of the variable potentiometer from radioshack and it totally killed the bass.

i should try for that ety cable. maybe that will help.



as for the drivers, i heard these things are dirt cheap. like 8 dollar drivers. so how much could dev costs be to create a new series of higher impedance monitors for stage and audiophiles?

 

[Arjisme]

Quote:

Originally Posted by Culverin /img/forum/go_quote.gif well i've tried using one of the variable potentiometer from radioshack and it totally killed the bass.

My experience from using the level attenuator this afternoon is that it eliminates the hiss and, if anything, makes the bass a tad more punchy. I definitely don't perceive it hurting the bass. It allows me to turn up the output level on my iHP-120. I'm assuming the level attunuator is just a variable resistor.

The level attenuator I'm using is the same one schapman linked to in his post above, btw.

 

[Funk-O-Meter]

They have such a low impedance because their drivers (armatures) were developed originally for hearing aids and such devices that would need to be made as small as possible and with as much usage time as possible between charges. The impedance allows them to be much more efficient and have longer battery times between being recharges/replaced. It works wonderfully for hearing aids but in a situation where armatures have been designed into other audio systems like ours it can cause hiss. Armatures themselves by nature are very efficient. Companies like Ety have addressed this by adding resistance into their designs. I think UE might have done the same thing.

All these armature IEM's we buy are designed around Knowles drivers which are the very same drivers used in hearing aids. They're just designed into more sophisticated systems in an IEM. I've also read that Ety has acquired a proprietary hf driver that they also supply to UE, Sensaphonics and ATS (?). I don't know what they do to change it from stock but it's still a Knowles driver.

 

[kramer5150]

Quote:

Originally Posted by erikzen /img/forum/go_quote.gif Sorry to kick an old post but I thought it was better than starting a new one. This might be a little off topic but I'm coming at the low impedence issue from a slightly different angle. On my normal commute I'm using the UM2s straight out of an iHP-120. I don't really notice any hiss and the sound is pretty good for straight out of a portable. My problem is when I try to beef up my portable rig and add one of my amps. I have a PRII and a Headroom Coda. I guess I could buy another amp that has adjustable gain but I like these amps and don't want to get rid of them and don't want to go out a buy a new amp at this point. Can I add resistence to the UM2 with an Ety adaptor or something?

Certainly, impedance adapters are designed to do just that, match impedance. It will color the sound however, so depending on your sonic preferences or how critical of a listener you are, it may detract for the overall enjoyment.

A better solution would be to switch to a low gain amp. A source with lower line output voltage probably won't hurt either.