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T1 channel imbalance

post #1 of 72
10/1/11 at 10:29am
Thread Starter 

I'm starting a thread on the T1 channel imbalance issue from the "I hated the LCD2 thread".

 

7dd20769_T1L.txt.jpeg cbdb8ab1_T1R.txt.jpeg

 

I'll clarify things more in a bit. I'll also throw in a FR graph to show the differences better.


Edited by purrin - 10/1/11 at 10:30am
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Gear mentioned in this thread:

Beyerdynamic Tesla T1
post #2 of 72
10/1/11 at 10:55am

Hi purrin. Have you contacted Beyer about this issue? What does the warranty say? Btw is this graph from mono source?

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post #3 of 72
10/1/11 at 11:06am
Thread Starter 

 

Quote:
Originally Posted by .Sup View Post

Hi purrin. Have you contacted Beyer about this issue? What does the warranty say? Btw is this graph from mono source?

 

They are not my headphones - they were lent to me. It's my understanding that the owner did not think much of them. The FR below should make things more clear. The output is from a calibrated CLIO measurement setup from the same microphone. 

 

Beyer T1 (early sample - the $999 days)

T1.gif

 

To put things in perspective:

 

HD800 and RS1 (flat pads)

hd800.gif rs1.gif

The RS1 was semi-vintage (probably a few hairs stuck in the driver there).

 

Black = Left Channel

Red = Right Channel

 

There are a couple of questions:

  1. Can the T1 sample as measured above be considered defective? Or are they within Beyer "spec". It should be noted that most lower line headphones measure similarly.
  2. If this sample is within "spec", is this acceptable for a $1200 headphone?
  3. Is this sample atypically, and not representative of the rest? We've heard stories of two different versions or perhaps of some variability with the earlier production samples. The only way to get a better answer is to take measurements of additional samples. Anyone want to send me theirs for measurement?
  4. Typically driver behavior doesn't (and shouldn't) drastically over time. The decade+ old RS1 and HP1000s I've measured demonstrate this. To what recourse does the purchaser have with Beyer to get a "fixed" pair given observation #1 below, even if its after warranty (I don't think it is yet with this pair). Of course this is also dependent on #1 above.

 

There are also observations:

  1. It's very difficult to detect channel imbalances with headphones without measurement equipment. The brain had a tendency of blending in minor differences.
  2. A few Head-Fi'ers who have heard this T1 sample have commented about it's "suckage" for lack of a better term.
  3. I've heard other T1s and I'm pretty sure they didn't sound as bad as this sample. Meaning the overall sound balance was better. One other sample that I've heard sounded like taking the bass from the right channel and the treble of the left channel of this sample.
  4. Tyll's data also shows some driver mismatch from 6kHz to 10kHz on the second pair: http://www.innerfidelity.com/images/BeyerdynamicT1SN3964.pdf

 

So are they defective? Hard to say.

 


Edited by purrin - 10/1/11 at 2:09pm
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post #4 of 72
10/1/11 at 12:02pm
Interesting.

I hope you get the opportunity to measure additional exemplars.
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post #5 of 72
10/1/11 at 1:45pm

Interesting points - but you seem to be heavily biased - saying that the issues with the RS-1 can be attributed to "hairs stuck in the driver there", while the T1 just sounds bad.

 

Also, the T1 was lent to you - how was it treated during that time?  Could the drivers have been damaged?

 

True - I am a Beyer fanboy, but I don't own a T1, and have only heard the T5p (which I didn't like).  I cannot comment on the sound signature of the T1 - you may be 100% right that it does sound like garbage - you just seem incredibly biased in this write up.

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post #6 of 72
10/1/11 at 1:48pm
Quote:
Originally Posted by Anathallo View Post

Interesting points - but you seem to be heavily biased -

 

True - I am a Beyer fanboy

Ummm......
 

 

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post #7 of 72
10/1/11 at 2:07pm

 

Quote:
Originally Posted by Anathallo View Post
True - I am a Beyer fanboy, but I don't own a T1, and have only heard the T5p (which I didn't like).  I cannot comment on the sound signature of the T1 - you may be 100% right that it does sound like garbage - you just seem incredibly biased in this write up.


I heard the DT770 and DT880s before and IMO they both sounded better than the T1 I owned before.

 

 

Just wanted to add that the T1 I had didn't seem to have channel imbalance, but they did sound horrid. Nothing like the raving impressions of the T1's "warmth." The T1 I had was all treble with very recessed mids and bass. Not sure whether what I heard was the intended sound or not. FR measurements still show a recession of upper midrange on the T1s. Measurements show a strong bass response, but FR measurements of bass never seem that reliable to me for semi-closed or closed headphones. I'm not sure if some Head-fiers' idea of warmth is still bright since the T1s definitely are measured to have a treble peak or if the T1 I had was a screw up. Through my previous Woo Audio 6SE, it sounded horrid even with the warmest tubes I could tube roll. I heard another T1 before in a headphone store and it sounded warm. It could have been a warm source it was playing, but it was far too different of an experience considering that my DAC is fairly neutral. The T1 I heard in the store sounded good. The one I owned was probably the worst headphone I ever heard.

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post #8 of 72
10/1/11 at 2:07pm

I think this is something that is very expected when taking measurements.  While you are using the same microphone and setup there are a lot of small parameters that can change when you are taking measurements which can cause differences in this frequency response.  Simple examples are the difference in the distance between your microphone and driver or how reproduceable of a seal you can get on this cup.  If you look at innerfidelity measurements you can very often see a difference in the frequency responses and I don't find this as a surprise due to both manufacturing and measurement tolerances.

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post #9 of 72
10/1/11 at 2:10pm
Thread Starter 

.

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post #10 of 72
10/1/11 at 2:20pm
Thread Starter 

Quote:
Originally Posted by Anathallo View Post

Interesting points - but you seem to be heavily biased - saying that the issues with the RS-1 can be attributed to "hairs stuck in the driver there", while the T1 just sounds bad.

 

Also, the T1 was lent to you - how was it treated during that time?  Could the drivers have been damaged?

 

True - I am a Beyer fanboy, but I don't own a T1, and have only heard the T5p (which I didn't like).  I cannot comment on the sound signature of the T1 - you may be 100% right that it does sound like garbage - you just seem incredibly biased in this write up.

 

I am biased. I admit that I don't like the sound of these. Even the good one I heard a while back I didn't like. They sounded too much like DT880 with a less treble tilt. They extract less low level information than HD650s, although they do sound clearer. On the RS1 comment, even if the RS1 indeed had a hair stuck in it, the left and right channels are still better matched than the T1.


      Quote:


Originally Posted by dazedbus View Post

I think this is something that is very expected when taking measurements.  While you are using the same microphone and setup there are a lot of small parameters that can change when you are taking measurements which can cause differences in this frequency response.  Simple examples are the difference in the distance between your microphone and driver or how reproduceable of a seal you can get on this cup.  If you look at innerfidelity measurements you can very often see a difference in the frequency responses and I don't find this as a surprise due to both manufacturing and measurement tolerances.

 

I agree with what you are saying, but environmental factors, assuming great care is taken to align the microphone, cups, etc. shouldn't alter L and R response at one spot by 3-4db!

 

Consider how the HD800 and SR009 (not shown) FR measurements show extremely good tolerances (as should be expected for very expensive TOTL headphones - and it's my understanding that these manufacturers claim 1 db matching of drivers)? Why do my HD800 and T50RP measurements conducted at different times weeks apart show the same result test after test (not shown, but I would glady post them here)? Maybe 0.25db at most.

 

In the case of the T1 measurements (as with all others I've performed), care was taken to align and adjust pressure applied to the cups. Multiple measurements are also taken to ensure best case results. This aspect isn't too critical because my measuring rig seems to be very consistent with its results.
 


Edited by purrin - 10/1/11 at 4:29pm
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post #11 of 72
10/1/11 at 2:23pm
Quote:
Originally Posted by dazedbus View Post

I think this is something that is very expected when taking measurements.  While you are using the same microphone and setup there are a lot of small parameters that can change when you are taking measurements which can cause differences in this frequency response.  Simple examples are the difference in the distance between your microphone and driver or how reproduceable of a seal you can get on this cup.  If you look at innerfidelity measurements you can very often see a difference in the frequency responses and I don't find this as a surprise due to both manufacturing and measurement tolerances.


That is because Tyll moves the headphones many times (as does Purrin) in order to get an average measurement. Also, Tyll's set-up is a dummy head measurement system while Purrin uses an anechoic and rigid plate measurement system.

 

That said, measurements are one thing but the T1's Purrin has really need to be heard to be...ummm...appreciated.

 


Edited by LFF - 10/1/11 at 2:24pm
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post #12 of 72
10/1/11 at 2:30pm
Thread Starter 

 

Quote:
Originally Posted by wind016 View Post

Just wanted to add that the T1 I had didn't seem to have channel imbalance, but they did sound horrid. Nothing like the raving impressions of the T1's "warmth." The T1 I had was all treble with very recessed mids and bass. Not sure whether what I heard was the intended sound or not. FR measurements still show a recession of upper midrange on the T1s. Measurements show a strong bass response, but FR measurements of bass never seem that reliable to me for semi-closed or closed headphones. I'm not sure if some Head-fiers' idea of warmth is still bright since the T1s definitely are measured to have a treble peak or if the T1 I had was a screw up. Through my previous Woo Audio 6SE, it sounded horrid even with the warmest tubes I could tube roll. I heard another T1 before in a headphone store and it sounded warm. It could have been a warm source it was playing, but it was far too different of an experience considering that my DAC is fairly neutral. The T1 I heard in the store sounded good. The one I owned was probably the worst headphone I ever heard.


Anax, LFF, and my impressions were similar to yours with Anax opining that the bass wasn't all that bad. As with you, one T1 I heard elsewhere sounded decent (but that was a long time ago.)

 

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post #13 of 72
10/1/11 at 3:56pm


 

Quote:
Originally Posted by LFF View Post

Ummm...... 

 


I don't understand why you needed to respond with this - I was trying to be transparent with my response by saying that while I am biased (I'm a fan of the 'beyer sound'), I haven't heard the T1, so I can't comment on this particular headphone.  I simply wanted to clear the air as to whether or not purrin was biased against the beyer house sound himself, as I am very interested in purchasing a T1, and I enjoy reading various opinions expressed about and measurements taken of the flagship.

 

It would have been appreciated if you had actually responded with something worthwhile instead of trying to insult my intelligence with your supposed wit.

 



Quote:
Originally Posted by wind016 View Post

 

I heard the DT770 and DT880s before and IMO they both sounded better than the T1 I owned before.

 

 

Just wanted to add that the T1 I had didn't seem to have channel imbalance, but they did sound horrid. Nothing like the raving impressions of the T1's "warmth." The T1 I had was all treble with very recessed mids and bass. Not sure whether what I heard was the intended sound or not. FR measurements still show a recession of upper midrange on the T1s. Measurements show a strong bass response, but FR measurements of bass never seem that reliable to me for semi-closed or closed headphones. I'm not sure if some Head-fiers' idea of warmth is still bright since the T1s definitely are measured to have a treble peak or if the T1 I had was a screw up. Through my previous Woo Audio 6SE, it sounded horrid even with the warmest tubes I could tube roll. I heard another T1 before in a headphone store and it sounded warm. It could have been a warm source it was playing, but it was far too different of an experience considering that my DAC is fairly neutral. The T1 I heard in the store sounded good. The one I owned was probably the worst headphone I ever heard.


Do you find you're sensitive to other bright cans (like some of the Grado) models as well?

 



Quote:
Originally Posted by purrin View Post

 

I am biased. I admit that I don't like the sound of these. Even the good one I heard a while back I didn't like. They sounded too much like DT880 with a less treble tilt. They extract less low level information than HD650s, although they do sound clearer. On the RS1 comment, even if the RS1 indeed had a hair stuck in it, the left and right channels are still better matched than the T1.

 


Cool, just wanted to get some background information on how you felt about beyer in general - really enjoy reading the threads based around your waterfall graphs - thanks for the work.

 

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post #14 of 72
10/1/11 at 4:26pm
Thread Starter 

 

Quote:
Originally Posted by Anathallo View Post

Cool, just wanted to get some background information on how you felt about beyer in general - really enjoy reading the threads based around your waterfall graphs - thanks for the work.


I do like the Beyer DT990 though, so it's not a brand or fanboy thing. Besides, even if I didn't personally like the T1, it wouldn't cause me to make any less effort to measure them properly or figure out if measurement anomalies were caused by unknown factors. I actually make an extra effort to obtain good results for stuff I don't like. In this case, I shifted the cups around, reinserted and realigned the microphone, played with the pads, and took another measurement the next day. The results were the same.

 

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post #15 of 72
10/1/11 at 4:33pm
Quote:
Originally Posted by Anathallo View Post

 

I don't understand why you needed to respond with this - I was trying to be transparent with my response by saying that while I am biased (I'm a fan of the 'beyer sound'), I haven't heard the T1, so I can't comment on this particular headphone.  I simply wanted to clear the air as to whether or not purrin was biased against the beyer house sound himself, as I am very interested in purchasing a T1, and I enjoy reading various opinions expressed about and measurements taken of the flagship.

 

It would have been appreciated if you had actually responded with something worthwhile instead of trying to insult my intelligence with your supposed wit.

 

Hey...I can be witty! I can also be kind of dick at times, especially if I don't "know" you....so my apologies. Based on this response you did deserve a better response than my "Ummmm". beerchug.gif
 

 

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Gear mentioned in this thread:

Beyerdynamic Tesla T1
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