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Creative Sound Blaster new series Z, Zx & ZxR - Page 93

post #1381 of 3296
Quote:

Originally Posted by SaLX View Post

 

The 40Ω figure was based off of one Russian site... I've no doubt that they are serious reviewers (for a change), however I'm a bit concerned as to their methodology ie: was it exactly the same test between the two examples below. I've seen many posts from people using headphones under 40Ω and they say they work well with the ZxR; and quite a few of them seem damned well informed about audio. By the normal 1/8 rule, that ratio would make their ZxR/low impedance headphones sound like a huge pile of steaming sh*te.

 

The measurements at the Russian site consistently show ~40 Ω output impedance for the ZxR. But someone who has the card and a simple splitter could measure it to be sure.

 

Exceeding 1/8th of the headphone impedance does not necessarily have a major effect on the sound with many of the commonly used full size headphones. It usually adds some bass boost/resonance (which some people actually prefer), and slightly increases the distortion of the drivers. Also, not all headphones are equally affected. So, 0 Ω output impedance is ideal in theory, but in practice often even the headphone jack of a receiver with 680 Ω output impedance might sound good to many.

post #1382 of 3296

@Xnor/stv

 

Yes - Solarium would've have been using the line-outs.

 

Thank you both very much for your posts. I'm really surprised though - so the 1/8th rule can easily be circumvented as long as the headphone is of good quality - so you get a bit of bloat in the bass, but it's not really anything to worry about in the long run.

 

Again thank you both - funny that that hard and fast rule is quoted incessantly on Head-Fi. We usually discuss decent quality headphones that would seem to be less prone to distortion, not crappy one's that some gamers would use. Still though.. lower impedance is always something to aim for across the board.


Edited by SaLX - 11/22/13 at 3:41pm
post #1383 of 3296

Some headphones, especially planar magnetic ones, have a pretty flat impedance across 20 Hz - 20 kHz so you will not even get frequency response deviation.

 

The 1/8th rule of thumb minimizes that deviation for dynamic headphones with an impedance peak (quite common) in the bass.

 

Btw, some IEMs with multiple drivers and crossovers have crazy impedance curves, so the frequency response can change a lot. There can be large boosts and cuts across the whole frequency range.

 

 

edit:

Quote:
Originally Posted by SaLX View Post
 

Again thank you both - funny that that hard and fast rule is quoted incessantly on Head-Fi. We usually discuss decent quality headphones that would seem to be less prone to distortion, not crappy one's that some gamers would use. Still though.. lower impedance is always something to aim for across the board.

Yeah, Z or DX + O2 amp for example gets you a powerful and clean system with low output impedance.


Edited by xnor - 11/22/13 at 3:49pm
post #1384 of 3296
No I think he literally meant speakers. Not headphones. Which is why I said there shouldn't be a difference. The amp in the speakers would make more of a difference in this case, which is the same for both.
post #1385 of 3296

Xonars - why isn't there an active thread on Head-Fi? The STX modding thread here gets love, but I guess you can find all the info you need on the net by now.

 

Particularly note the complete lack of any love for the Xonar Phoebus (anywhere). The ROG forums are filled with posts from despondent/dead eyed gamers who wished they had purchased something.. anything ......... The actual card looks good but the driver roll out was (and still is) pretty damned poor. 2 years ago and more that was Creative and look at them now. 

post #1386 of 3296
Quote:
Originally Posted by stv014 View Post

The measurements at the Russian site consistently show ~40 Ω output impedance for the ZxR. But someone who has the card and a simple splitter could measure it to be sure.

Exceeding 1/8th of the headphone impedance does not necessarily have a major effect on the sound with many of the commonly used full size headphones. It usually adds some bass boost/resonance (which some people actually prefer), and slightly increases the distortion of the drivers. Also, not all headphones are equally affected. So, 0 Ω output impedance is ideal in theory, but in practice often even the headphone jack of a receiver with 680 Ω output impedance might sound good to many.
I've had someone else tell me similar months ago. There was a certain someone who made the 1/8th "rule" popular a while ago, before releasing the O2 amp. I still cite impedance as something that matters sometimes, but I don't especially ascribe to the 1/8th figure, seems more of a guideline. I HAVE heard better quality sound by hooking up a "nicer" amp, but output impedance may only be part of the story. Generally though, my experience benefits from lowering odd-harmonic distortion however possible, and I've tried several amps that seem to reduce pain from treble without making a headphone sound dark.

Could I quote your post (and xnor's) in my journal thread? I'm trying to gather good knowledge about a wide variety of topics, and I think if I had several posts by different people explaining both sides, it might encourage Head-Fi people to take a harder look and settle possible myths. I can PM you after I post if you'd like to add anything. I can also remove names if you want to be anonymous.

Thanks!
Quote:
Originally Posted by SaLX View Post

Xonars - why isn't there an active thread on Head-Fi? The STX modding thread here gets love, but I guess you can find all the info you need on the net by now.
Driver support is generally neglected in the Xonar line. I wouldn't want to fudge with something where owners recommend using 3rd party drivers hacked by the community to get the card working well. And then, the big one, I just am not very impressed by Dolby Headphone.
post #1387 of 3296

Evs (+1 on your post): I was thinking more on the lines of a general thread like this one for Xonar users - a thread where we could ask questions, answer stuff and tear out our hair.

post #1388 of 3296

Sure, you can quote my posts. Make sure to check by the Sound Science forum if you have any technical questions, like regarding how much power is enough, impedances etc.

 

The 1/8th rule is just a rough guideline, a rule of thumb.

 

I'd really love to see new sound cards / audio interfaces with low output impedance.. Most are 20+ ohm so not the best match for those common 32 ohm dynamic headphones and headsets.


Edited by xnor - 11/23/13 at 1:07am
post #1389 of 3296
Quote:
Originally Posted by Evshrug View Post

Could I quote your post (and xnor's) in my journal thread?

 

Yes. Some other posts that might be relevant:

Measurements of the effects of high output impedance on a dynamic headphone

How to measure output impedance (for more advanced impedance measurement - creating a plot vs. frequency - I also have utilities not discussed at this link)

post #1390 of 3296

Got to ask this - both the STX and ZxR share the exact same headphone amp - why the huge discrepancy in their impedance values? Why add more impedance when we know less is better?

post #1391 of 3296
Quote:
Originally Posted by SaLX View Post
 

Got to ask this - both the STX and ZxR share the exact same headphone amp - why the huge discrepancy in their impedance values? Why add more impedance when we know less is better?


The Essence STX (& ST) and FiiO E9/E09K and ZxR use the same TI 6120A2 chip, both the STX and E9/E09K are 10-Ohms.

So it would be very surprising if the ZxR was not also 10-Ohms.

The SB-Z & SB-Zx use what I'm assuming is a lower costing chip then the TI 6120A2, the SB-Z & SB-Zx are 22-Ohms.

So the claimed 40-Ohms for the ZxR just does not really make sense.

post #1392 of 3296

@  DJ - yeah - that kind of makes sense by what he wrote - but now that the 1/8th rule is so prevalent (and let's face it - we've been pushing it here on Head-Fi), why would Creative effectively lie about this?

post #1393 of 3296
Quote:
Originally Posted by SaLX View Post
 

@  DJ - yeah - that kind of makes sense by what he wrote - but now that the 1/8th rule is so prevalent (and let's face it - we've been pushing it here on Head-Fi), why would Creative effectively lie about this?

 

I do not think the specs released by Creative include the output impedance. If I recall correctly, they do not even include the maximum power, only that the TPA chip is theoretically capable of 80 mW into 600 Ω, but not that this is necessarily also true of Creative's implementation.

 

Quote:
Originally Posted by SaLX View Post
 

Got to ask this - both the STX and ZxR share the exact same headphone amp - why the huge discrepancy in their impedance values? Why add more impedance when we know less is better?

 

The TPA6120 datasheet recommends 10 Ω output resistors as the minimum for stability, but also notes that this can be increased to up to 100 Ω if necessary. There are several possible reasons why Creative could have increased the output impedance to 40 Ω, for example:

- the TPA chip does not have sufficient cooling and/or the power supply on the ZxR cannot handle high currents, so they added the resistors as a simple protection to limit the maximum output current

- the higher impedance is actually needed to make their particular implementation (which is more complex than the one on the STX because of the addition of a real analog gain switch) stable

- the resistors are used to attenuate output into sensitive low impedance headphones (the STX can have audible hiss with some of those)

- high output impedance usually boosts the bass on full size dynamic headphones, which the casual consumer might actually prefer

post #1394 of 3296

I have a question for anyone who may know, on the Creative ZXR which slot is which channel.  They are labeled J1-J4 and I assumed J3 is Center/Sub (I know J1 and J2 are front for sure based on their location) and from what I have listened to I think I was right.  However to get some confirmation would tell me if I am getting a placebo effect or not on J3 vs. J4 being center/sub or rears.

 

http://www1.picturepush.com/photo/a/13877554/img/Computers/ZXR-Op-Amps.jpg


Edited by NCSUZoSo - 11/25/13 at 2:14am
post #1395 of 3296

I have Audigy 2 ZS and just got Marantz PM6004 to which i plan to connect it.

I wonder is it worth it to upgrade to SB Z in terms of sound quality?

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