Good post SY! I kind of sat down expecting to read something that would make the company want to prepare themselves by purchasing a large quantity of KY jelly but instead I was surprised.
Still way too expensive for said function but at least it does something. I am sure I am not the only one that it doesn't sit well that they use so much BS around the product to justify price gouging.
Pftt marketing blah blah blah kill me now.................
Still way too expensive for said function but at least it does something. I am sure I am not the only one that it doesn't sit well that they use so much BS around the product to justify price gouging.
Pftt marketing blah blah blah kill me now.................
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Which headphone is that
Also, how does output impedance seen by the headphone get affected? Asking because earphones like the below exist: Klipsch X10 as measured by innerfidelity. 10 ohm of output R is sufficient to alter the sound greatly.
Or I can probably wait for the teardown.
Also one thing i may suggest - to use the same scaling in all your graphs. It helps to prevent the herp-derp people from finding reasons to be unconvinced.
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Oh, of course I did. I've got about a zillion more measurements yet to post, it's a matter of time for writing and formatting. Depending on Cynthia's plans for me today, I may have some more up by tonight.
Best place for comments is here; moderating blog comments is a pain since 99.9% of them are spammers.
Best place for comments is here; moderating blog comments is a pain since 99.9% of them are spammers.
Okay good so Dennis may still need the lube.
Not sure if people read this little tidbit;
"Hi Everyone. This is Dennis and I am the CTO at REVx Technolgoies.
Full disclosures:
-I just joined this forum as I was alerted to the discussion here and the questions about how the REV33 works
-As such, this is my first post
-I am a healthy skeptic myself (sometimes even a cynic) so I appreciate the questions and desire to understand this a bit better.
I will try to describe how the REV33 works and answer questions I have seen here (as well as common questions I get)
What is inside the REV33?
The REV33 contains a passive circuit inside. We have filed a for a few patents on the architecture and operation of the circuit. We have about 5 different types of REV33s (each with a different color) and a matching data base on our website to match REV33 to earbud type. Each color contains a similar circuit but with values that are tuned to different impedance earbuds.
What does it actually do to reduce distortion and how can it do this without processing the music or trying to differentiate music content from distortion content?
This is one of the most common questions I get. One key objective of the REV33 is to keep the magnetics of the earbud as clean as possible. We do this in a few ways:
1. Reduce high frequency noise generated by amplifiers or other system components. This includes class D amplifier noise that is shaped above 20 kHz as well as spurious tones that can be from high frequency clocks in the system or RF carriers. If you have a spectrum analyzer that goes up to 500 kHz or so, you will be surprised what you see in alot of systems. Now, I concede that the ear cannot hear any of this energy however, this energy does get into your magnetics, reduces some of the capacity of your magnetics and you can measure how this unwanted energy creates intermodulation distortion with the music that you want to hear.
2. Some distortion occurs in the bud itself (as opposed to distortion from the amplifier). This happens simply because the bud is magnetic with moving parts and it doesn't always move perfectly with the audio signal. When this distortion occurs, the electrical characteristics of the distortion make it look like the bud is a generator, sourcing energy and pushing it back to toward the amplifier. To be fair, this energy isn't created out of thin air, it is actually energy that is 'stolen' from the original audio signal sent to the bud. The REV33 resists energy that electrically appears to come from the earbud. Thus, we can resist current (and thus generation) of the distortion energy from the bud.
3. When an earbud moves, its impedance changes dynamically with its position. When its impedance changes dynamically, an amplifier with a small source resistance will produce different currents for the same output. For example, a 5 kHz tone will not render the same if the bud is displaced to a one location vs not displaced at all. The REV33 reduces the sensitivity of the change in position of the bud. This reduces the non-linear current that gets into the magnetics.
All in all, the above 3 work together to keep magnetics in the bud cleaner and reduce distortion. Because none of techniques require trying to analyze the audio signal and differentiate audio from distortion, we don't need to process, equalize or otherwise analyze the music. We just try to keep the magnetics clean.
I hope this helps explain. I am sorry that I was a little long winded. I am happy to follow up with anyone via email or phone to discuss in more detail.
Best Regards,
Dennis"
Flame on
What I find funny is that the advertising makes it sound as if it will clean up the distortion from your amp or whatever. The Effing hilarious part about the device and it's distortion reduction capability is that it only reduces distortion the driver creates, well duh, if you remove the signal from the speaker then the speaker can't distort it. With this logic I can make a -3db attenuator and claim it reduces distortion from the amp by -3db, or even better just disconnect the speaker entirely and poof 100% distortion reduction!
Dennis and any of the marketing gurus from REV33 have officially gone full retard.
Dennis and any of the marketing gurus from REV33 have officially gone full retard.
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Crosstalk measurements.
Based on some correspondence with REV33, the next one up will be source impedance measurements.
Those poor distortion graphs, they keep getting pushed back in the queue!
Based on some correspondence with REV33, the next one up will be source impedance measurements.
Those poor distortion graphs, they keep getting pushed back in the queue!
I can't remember where I have read it but I remember a well respected recording engineer back in the day purposely adding crosstalk into his recordings in the higher frequency domain. I also think he said he did this because he believed that it is one of the reasons why vinyl records sound good.
Mhm
Those poor distortion graphs, they keep getting pushed back in the queue!
Mhm
Yes there isn't enough in the REV33, I was thinking somewhere around 20-30db is audible.
I agree on their explanation being convoluted and breaking things down to the Thevenin equivalent is the best way to understand what's happening.
Thanks again SY, I look forward to seeing more of your data.
I agree on their explanation being convoluted and breaking things down to the Thevenin equivalent is the best way to understand what's happening.
Thanks again SY, I look forward to seeing more of your data.
I have been a member of DIYAudio since '08 but this is my first post.
A quick note to thank SY for the work he's doing on the REV33 box.
Thanks also to the members that contributed with offers to buy the REV33. Unfortunately, I noticed this thread only yesterday but if you need to buy a second REV33, I'll be happy to contribute.
I'm looking forward to seeing more data and info about the REV33.
A quick note to thank SY for the work he's doing on the REV33 box.
Thanks also to the members that contributed with offers to buy the REV33. Unfortunately, I noticed this thread only yesterday but if you need to buy a second REV33, I'll be happy to contribute.
I'm looking forward to seeing more data and info about the REV33.
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