Subjective Listening - Arrrgh!
For audio playback, we use Foobar 2000 alongside Windows Media Player. All music is transferred first to the hard drive in WAV format using Exact Audio Copy at a 4x read speed. Before we continue with subjective listening impressions, let's take a look at the measured room response of both DACs and listen to a couple of tracks without any DRC engaged.
The lowish output voltage of the passive I/V configured TDA1543 means we have to attempt to balance volume as best we can with the 2V output of the tube/transformer output of the Opus DAC for comparison purposes. After some adjustment and re-attempted measurements, we get a close enough match to see how the room responds to the Opus. Microphone gain and placement was kept at exactly the same point throughout the course of taking measurements. Each measurement was taken a number of times to see if any drastic changes could be observed.
Doede DAC Red=Left speaker, Blue=Right. Due to furniture placement, there is a 10dB offset between the channels at around 162Hz. |
The response is of the Transparence speakers with the TDA1543 is pretty much as expected, rolling off sharply under 60Hz and over 13.5k.
Opus |
Unsurprisingly, there's little to divide the two room sweep responses. The question is how both DACs sound when compared subjectively, both with and without DRC.
Listening tests are conducted using tracks from Maxwell's Urban Hang Suite and Embrya albums. Both albums feature music containing deep articulate bass lines, with vocals and instruments that should stress every part of the Bicone Signature frequency response.
Firing up "Til The Cops Come Knocking" on the Doede DAC first, the thing that strikes me is its directness. Soundstage height and depth can be best described as compact with a focused central image. This creates the perception of the vocalist sitting a couple of feet in front of the speakers. Instruments also have a "hang in the air" factor, without any real overemphasis on the finer details or decay of sounds. If "in your face" reproduction of micro details is important to you, you'll find you'll have to concentrate on hearing them with this unit in the loop. Everything's there, but you don't get buckets of spatial information that enhances micro-detail presence. Maybe that's the way it's supposed to be?
Rendition of high frequency sounds such as cymbals is on the smooth side compared to what I can recall from the Legato DACs of the Pioneer. I guess this may be a trait of non-oversampling. Overall, I'm quite impressed by the sound, considering the uncomplicated approach of Doede's implementation of the TDA1543. Subjectively, the sound has a very neutral character yet still manages to present itself without a fatiguing nature.
Now it's time to check out how the Opus fares in comparison. Both DACs are connected to the preamp simultaneously so that I can switch over quickly between the two while memory is still fresh. I spin up the same tracks from Maxwell and I'm amazed to find the perceived difference in presentation is far more apparent than I'd expected. The vocal forwardness of the TDA1543 is gone; the same vocal rendition sits further back between the speakers but has gained the impression of extending past the height of the baffles, and background instruments seem to have shifted back by a good few feet. The compact soundstage impression that the TDA1543 gave has been replaced with something far more expansive and spatial and the focus is now on all the elements of the recording. The finer details are readily apparent with the Opus; everything is projected in its own space and draws your attention. Mid-bass does not sound as prominent as it did on the TDA1543, the notes seem to be a little leaner and perhaps more analytical. Vocals and cymbals are especially alluring, something that we can put down to the sonic traits of the 3A5s on the output of the WM8741 DACs. To confirm the perceived differences I keep switching back and forth between the two units, each time amazed that the change is so apparent.
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phusg - Monday, December 15, 2008 - link
> It'll please you all to know I have no plans to write another audio article.Doesn't please me at all Raja! As I said I'm very grateful for you opening my eyes to the possibilities of DRC. Shame you (or your editor?) don't fancy taking all the criticism and making a kick-arse follow-up article.
All the best,
Pete
Rajinder Gill - Monday, December 15, 2008 - link
I do have some work at hand that I've held back from posting mainly because it opens up another huge can of worms. The testing involved is arduous and takes up copious hours. I am in a position to make spectral measurements, although I need to confirm a few things before I'd even come close to disclosing all of the results. Initial tests show a marked difference between the 2 DAC's used in the article at equivalent levels of gain (between 1-3db at certain freq points). There's a pattern to some of it. Although, I can attribute much of this to noise generated by the amplifier due to the increased gain required by the TDA1543 (ac related hum). I have a few things I can do to cross-correlate those results though, so it's not a complete dead end.Blind testing has shown that human can discern down to .75db of gain. I'm not sure on the consistency of all of that as some of the blind testing involved in the research did show an element of placebo in places. Once I’ve eliminated some of the variables and more importantly tested an internal soundcard output in comparison, I might be in a position to post something worthy of reading.
I'll probably blind test a few of the solutions I have at hand before I add anything else here though. It's very difficult to keep all camps happy, and to keep it interesting enough for me to want to commit more time to it all...lol
later
Raja
DorkMan - Sunday, December 14, 2008 - link
Raja, sorry if I had the Sarcasm dialed up to "11" when I made my previous post. It takes a lot of work to create an article like yours, and you did a great job. My beef was not with the quality of your work but with some of the "religion" that seems to surround this hobby. Whether it's tubes, coaxial speaker wire, or whizzer cone transducers, there seems to exist a group of people with a religious zeal for these things and for whom specs and double-blind tests are irrelevant. Whatever.But I commend you for your article. It was well-written, and I have no issue with your conclusions. I, too, calibrate my video-editing workstation position for response flatness.
If you're not too turned off by all the sniping, why not do a series on audio myths? Double-blind testing of tubes and solid-state, and speaker wires?
Anyway, hope you have a great Christmas season.
audionewbieyao - Wednesday, December 10, 2008 - link
If you're a true PC audiophile, I'll say do you best to stay away from gaming sound cards, 'cause they're just not made for audiophiles.I suggest try out Asus Xonar, Auzentech, Onkyo, and if possible, the new Xonar Essence STX would be the best.
thietavu - Tuesday, December 9, 2008 - link
I have myself tried to solve this "problem" for years: to create a good quality audio system around my computer. Since all my CDs and even a few of my vinyls are now digitized into almost 100 GB of data on the hard disk, the challenge was to get some good sound out.I kind of made a mistake by buying "too high-end" (or too good anyway) headphones (Grado SR-325) and a headphone amplifier (Musical Fidelity X-Can v3). After trying two high quality studio sound cards (M-Audio AP2496 and later AP192), I realized that the sound just wasn't what it should have been. There was always a slight "harshness" in what I heard, making the system sound a bit unpleasantly cold and mechanical.
After a long consideration I then bought Musical Fidelity's X-DAC v3 D/A converter, plugging it to AP192's SP/DIF digital output. That made the change. The slight but disturbing harshness disappeared and some originally cold-sounding albums (like Poco's Inamorata) suddenly became both listenable and even enjoyable. And excellent recordings now sound excellent.
Where did the difference come from? Judging by normal measurements, there should be no audible difference at all, since M-Audio card's analog output is of high quality. To me, it appears like the "magic" happens in digital->analog conversion somehow. In cheaper devices like most sound cards, that conversion seems to be somehow "rough", a bit like using a digital camera with too few real megapixels available (imagine a 10 Mpix camera with bad optics etc, and the result becoming maybe equal to a real resolution of only 3 Mpix or so).
I admit that the differences aren't that big, and only very good quality headphones or loudspeakers etc. can reveal them. But after it is revealed, music simply sounds more like "music" in one system compared with another. After that, it's unpleasant to go back to more "mechanical" sound. But as said, everything is relative. I can enjoy an old, noisy C-cassette in an old car stereo as well, as long as the music is good! That's what it is all about: creating feelings. :)
DorkMan - Monday, December 8, 2008 - link
Sorry guys, I know many of you are really into this nitpicky level of Audio Purity. I've been into audio since the late 1960's, when I, too, was fanatical about specsmanship. Now I see the error of my ways.Bipolar loudspeakers have been around since, say, the 1950's. They're a decent solution as long as you can deal with room resonances, as this article does.
But a whizzer cone speaker? When did we fall off the truck? Please tell me that the whizzer is driven by a separate coil subsystem. If not, you'll get decoupling resonances as various frequencies and these effects can change as the transducer ages.
I went to the manufacturer website. Not embarrassed about selling speaker "ribbon" cable for $1,000? Tells me something about the company--long of PR and a bit short on electrical engineering.
Okay, on to the amps. Tubes! The retro look! I have familiarity with tube amplifier designs and think it's great if you want odd harmonics near clipping, a bulky box that actually glows and a chance to heat a cold room at the same time. Hey, it's okay; odd harmonics sound nice--but they're not an accurate reproduction of the input signal.
Finally, I'm all for balancing out a room--as long as the listener sits in the same spot. In a living room, every guest is going to get a different response curve, with some probably getting socked by boost when there should have been cut for that location.
Finally, trust your microphone. If it says the room is flat, you're done. By putting in a slight bass boost, you're making the music sound good to "your" tastes, but be honest--the room then isn't flat. Might as well use tubes as amps.
ackcheng - Monday, December 8, 2008 - link
Not sure if this is mentioned before, other than Audiolense, there are a few other programs we can consider for room correctionThey are DRC which is free http://drc-fir.sourceforge.net/
and Acourate http://www.acourate.com/">http://www.acourate.com/
I myself use Acourate and found it a very good tool for DRC!
But I do not think the so called DRC in Windows Vista a real DRC software!
RagingDragon - Saturday, December 6, 2008 - link
Certainly not what I expected at AT, but I enjoyed the article, and I'm OK with AT expanding it's range of covered topics (i.e. audio, digital photography, and home theatre).The DRC software is certainly interesting, though not really relevant to my setup (headphones). Based on manufacturer specs the TDA1543 isn't very impressive; however, the Wolfson WM8741 looks much more promising. The article's conclusions suggest the WM8741 has a wider dynamic range, flatter frequency response, and is more accurate/precise. Which is exactly what I would expect from the DAC spec sheets. I'd like to see these external DAC's compared to some high quality PC sound cards - like the Asus Xonar series, or even the M-audio revolution/stereophile cards (though if I recall correctly the DAC's in these and equivent cards from Terratec are inferior to the Xonar DAC's).
I was looking at prebuilt external DAC's a couple months ago, and was extremely disappointed in what I found. Despite high prices most of them used cheap DAC chips which would have a hard time beating integrated audio, let alone a discreet sound card with high quality DAC's. The author's Twisted Pear Opus kit has a better DAC (WM8741) than *any* of the prebuilt external DAC's I looked at, and units equalling the Doede Douma kit (TDA1543) were ludicrously expensive.
I'm not conviced that external DAC's and amps sound better than high quality PCI cards - and even if they do, I still don't want the extra clutter.
Since I'm living in an appartment I use headphones rather than speakers to avoid annoying the neighbours, so the upcoming Asus Xonar Essence seems perfectly suited to my needs: stereo only (I'm using stereo headphones so surround sound is irrelevant), an extremely high quality DAC (Burr-Brown 1792A), built in head phone amplifier, swappable opamps, and "professional audio capacitors" (probably snake oil, but they won't make the sound worse).
prd00 - Friday, December 5, 2008 - link
I'd pick Onkyo USB sound card up anytime compared to those stupid creative cards. I've tried all sound cards, but right now, I've ended with onkyo.htgts350monaro - Wednesday, December 3, 2008 - link
Thank you Rajinder for this, and what looks like will be, a great series of articles.Please be aware that despite all those who profess this to be an inappropriate article for this site that I, and I think many others, feel they are incorrect.
Being an amateur audiophile and computer enthusiast myself this is a great mix of both my interests. I have been wondering for a while whether it would be possible to combine these interests and simplify my current combination of source components for my home theater system which I also use for critical 2 channel listening. (not ideal I know but limited space and budget regretfully denies a separate 2 channel system for me unfortunately)
It looks like you may be on the path to solving my problem - please keep going with this. One thing I have gained from this article at least is a new interest in DRC software...
For all thos who say that all audiophile claims are 'snake oil' I ask this - have you actually gone into a high end hifi store and LISTENED to any of the products available and done your own comparisons? Have you ever compared different DAC's/OP-AMP's in the same circuit and system with components of a high enough quality/resolution to expose those differences YOURSELF? I have and the differences can be VERY obvious, to the point that double blind listening is not needed - you would not need to double blind test two LCD's if one had half the contrast range of the other - you would be able to detect it quite easily and this can be true of audio components no matter how many tests say that the components measure the same frequency response/ dynamic range/ s/n ratio etc.
But please go out and try it for yourself BEFORE you claim it is all bogus. (and no - not being able to hear a difference between components on your $300 minisystem or $50 PC speakers does not count!)