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Suggestions for Throw-away Low Impedance IEMs

amirm

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Hello everyone. Need some help. I am performing my headphone amplifier tests with real loads, i.e. headphones. I am taking a chance with them getting damaged as they are not my primary listening headphones.

For IEMs though, I only have my good Etymotics and don't want to risk damaging them. One click of the mouse can unleash tremendous power into them from the analyzer+amp.

So are there popular IEMs that have low impedance that don't cost more than say, $50? I say low impedance because I keep hearing there are some that are difficult to drive there but if we can't have that for $50, I will take other options.

Thanks for any suggestions.
 
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amirm

amirm

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amirm

amirm

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mindbomb

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if you are testing just one channel, i think you can find many iems on ebay where one channel is broken, for very cheap.
 

restorer-john

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I understand wanting a 'real world' load on the end, but the impedance curves of various IEMs/ear buds are going to be all over the place. This is for measurement of the headphone amps right?

In that case, why not use a non-inductive resistive dummy load? You can have as many arbitrary values as you choose and also challenge the headphone amp stage with capacitive loads for stability. And you won't burn out anything.

All the same setups as the old FTC amplifier testing regime (except scaled for the rated Headphone amp specs)- third power preconditioning for 1hr, both channels driven, single channel, square wave response, your AP results etc.
 
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amirm

amirm

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I understand wanting a 'real world' load on the end, but the impedance curves of various IEMs/ear buds are going to be all over the place. This is for measurement of the headphone amps right?

In that case, why not use a non-inductive resistive dummy load? You can have as many arbitrary values as you choose and also challenge the headphone amp stage with capacitive loads for stability. And you won't burn out anything.
The reason for testing real headphone is that amps are performing very differently under that complex load than they do with dummy loads (which I also have). See this article from Benchmark: https://benchmarkmedia.com/blogs/application_notes/12838141-headphone-amplifiers-part-1

And results of my testing with Chord Hugo 2 DAC and headphone amp showing the same: https://www.audiosciencereview.com/...hord-hugo-2-dac-and-headphone-amplifier.2349/
 

restorer-john

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Yes, I understand. :) The issue is, which IEM/Headphone should you pick as a reference and what parameters should they possess, so they don't 'play' better with some amp topologies more so than others?

I just ran this on my Audiolab (forgive the blown up image- I can't do a screen grab ATM- different computer) on 5 pairs of headphones (JBL E35, standard Apple and Samsung earbuds (new- unused) and a few pairs of randoms).

IMG_2000 (Large).JPG


I would consider them all 'low impedance' but they are all going to affect any headphone amp's measured response and THD (particularly at the frequency extremes) quite differently. Look at the Apple earbuds (red/purple L/R trace)- they have an off scale peak (>33ohms) at around 300Hz that none of the others do.

Complex loads have been considered and designed for 'typical' loudspeakers for amplifier testing so why wouldn't you/we/us consider a 'typical' load for IEMs based on a decent sample group measured with suitable equipment (your AP?)

The 'typical' load can be easily fabricated by anyone using off the shelf components and used to test heapdphone amps with suitable test gear anywhere. That would enable reasonably consistent results?

JA considered this and uses a 'typical' speaker load for real world amplifier testing (see the attached schematic here page 2) https://www.stereophile.com/reference/60/index.html
 
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I have a lot of experience with cheap iems. In my opinion the best ones I've used have been.

The yersen Fen 2000 but I'm not sure If it's still available.

The memt x5 is amazing for $15. It has outperformed many other iems I've tried. Neautral sound signature.

And the uiisii hm7s are superb for $5. A little too v shaped for me. But they are much nicer than much more expensive gear I've tried.

www.audiobudget.com is a great website dedicated to cheap item. You'd be amazed at how some of these sound.
 
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amirm

amirm

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The issue is, which IEM/Headphone should you pick as a reference and what parameters should they possess, so they don't 'play' better with some amp topologies more so than others?
That is the case unfortunately and hence the reason I like to pick a popular choice so there is at least some applicability to what others do. Actually I have been testing with multiple headphones now so pretty broad coverage. I just didn't have any IEMs at the time that were not my "daily driver" and didn't want them destroyed. :)
 
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amirm

amirm

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I have a lot of experience with cheap iems. In my opinion the best ones I've used have been.

The yersen Fen 2000 but I'm not sure If it's still available.

The memt x5 is amazing for $15. It has outperformed many other iems I've tried. Neautral sound signature.

And the uiisii hm7s are superb for $5. A little too v shaped for me. But they are much nicer than much more expensive gear I've tried.

www.audiobudget.com is a great website dedicated to cheap item. You'd be amazed at how some of these sound.
Thanks a bunch. That is a well done site! We like people/companies that are into budget products. :D

I went ahead and ordered the memt X5.
 

sejarzo

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If the X5's FR graph on the audiobudget.com site is to be believed, the matching between the drivers is incredibly good. I am anxious to hear what you think about the performance.
 

rebbiputzmaker

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Sure, I will report back.
There are many Chi-Fi IEMs that are surprising good. Not all are in the $5 and $10 range but some really nice ones out there for less than $50.
 
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