Home Theater/Personal audio thread...

[jvincent]

Originally Posted by johan

Volume control inside a computer is done via bit rate control. So when you lower the volume anywhere in the software stack you are effectively decreasing the bit rate of your source media.

Doing some "bored at work" cruising and saw this and did a double take because I can't see how that works.

Are you implying that PCM values are converted to a serial stream somewhere or that by scaling the PCM values you get reduced bit density somehow?

Consumer/computer audio is not my field, but I'm an EE by degree and have worked with ADCs/DACs in other applications.

[johan]

Originally Posted by jvincent

Doing some "bored at work" cruising and saw this and did a double take because I can't see how that works.

Are you implying that PCM values are converted to a serial stream somewhere or that by scaling the PCM values you get reduced bit density somehow?

Consumer/computer audio is not my field, but I'm an EE by degree and have worked with ADCs/DACs in other applications.

This is a bit wordy, but should make it clear:

In digital audio, the signal is split up into distinct samples (taken thousands of times per second), and bit depth is the number of bits that are used to describe each sample. Attenuating a signal is done by multiplying each sample by a number less than one, with the result being that you're no longer using the full resolution to describe the audio, resulting in reduced dynamic range and signal-to-noise ratio. Specifically, every 6 dB of attenuation is equivalent to reducing the bit depth by one. If you started with, say, 16-bit audio and reduced the volume by 12 dB, you'd effectively be listening to 14-bit audio instead. Turn the volume down too much and quality will start to suffer noticeably.

Another issue is that these calculations will often result in rounding errors, due to the original value of the sample not being a multiple of the factor by which you're dividing the samples. This further degrades the audio quality by introducing what's basically quantization noise. Again, this mostly happens at lower volume levels. Different programs might use slightly different algorithms for attenuating the signal and resolving those rounding errors, which means there might be some difference in the resulting audible signal between, say, an audio player and the OS, but that doesn't change the fact that in all cases you're still reducing bit depth and essentially wasting a portion of the bandwidth on transmitting zeroes instead of useful information.

[Clipdat]

Is this the case across all OS? 7/10 and Mac?

I knew to always keep the player volume at 100% but I didn't realize the OS volume control was that destructive on the SQ.

Originally Posted by johan

This is a bit wordy, but should make it clear:

In digital audio, the signal is split up into distinct samples (taken thousands of times per second), and bit depth is the number of bits that are used to describe each sample. Attenuating a signal is done by multiplying each sample by a number less than one, with the result being that you're no longer using the full resolution to describe the audio, resulting in reduced dynamic range and signal-to-noise ratio. Specifically, every 6 dB of attenuation is equivalent to reducing the bit depth by one. If you started with, say, 16-bit audio and reduced the volume by 12 dB, you'd effectively be listening to 14-bit audio instead. Turn the volume down too much and quality will start to suffer noticeably.

Another issue is that these calculations will often result in rounding errors, due to the original value of the sample not being a multiple of the factor by which you're dividing the samples. This further degrades the audio quality by introducing what's basically quantization noise. Again, this mostly happens at lower volume levels. Different programs might use slightly different algorithms for attenuating the signal and resolving those rounding errors, which means there might be some difference in the resulting audible signal between, say, an audio player and the OS, but that doesn't change the fact that in all cases you're still reducing bit depth and essentially wasting a portion of the bandwidth on transmitting zeroes instead of useful information.

[cjd]

Bluetooth sucks for audio quality still... So do phones unless you use with an external dac. Or you have one if the fancy LG's like I do...

Originally Posted by Clipdat

Is this the case across all OS? 7/10 and Mac?

I knew to always keep the player volume at 100% but I didn't realize the OS volume control was that destructive on the SQ.

Yes.

Squeezebox upconverts to 24bit so there is some headroom, but not much. Well, 30% from max. The bigger problem on computers (and evidently the iPhone headphone jack) is often lack of adequate current, resulting in clipping. Far better to get an external dac. They can be quite affordable.

[Vracer111]

Originally Posted by cjd

Bluetooth sucks for audio quality still... So do phones unless you use with an external dac. Or you have one if the fancy LG's like I do...

Bluetooth doesn't really suck though - not quite as good as wired through a DAC/amp, but not far behind and nowhere near a sucking level. At least that is my experience in streaming FLAC through UAPP off my Samsung S2 tablet through the infinity audio system of a coworker's Hyundai Sonata Limited. Hardly any noticeable difference from running through an Audioquest Dragonfly Red DAC/amp in line out mode to the auxiliary input. Just a very slight, hard to perceive difference in detail - clarity and dynamics are basically identical.

[jvincent]

Good explanation.

You confused me in your original post when you said "bit rate".

My brain parsed that as the digital bit rate, i.e. number of 1s and 0s, and I thought you were talking about an actual reduction of the transport bit rate, not the ENOB of the signal.

All good here.

Originally Posted by johan

This is a bit wordy, but should make it clear:

In digital audio, the signal is split up into distinct samples (taken thousands of times per second), and bit depth is the number of bits that are used to describe each sample. Attenuating a signal is done by multiplying each sample by a number less than one, with the result being that you're no longer using the full resolution to describe the audio, resulting in reduced dynamic range and signal-to-noise ratio. Specifically, every 6 dB of attenuation is equivalent to reducing the bit depth by one. If you started with, say, 16-bit audio and reduced the volume by 12 dB, you'd effectively be listening to 14-bit audio instead. Turn the volume down too much and quality will start to suffer noticeably.

Another issue is that these calculations will often result in rounding errors, due to the original value of the sample not being a multiple of the factor by which you're dividing the samples. This further degrades the audio quality by introducing what's basically quantization noise. Again, this mostly happens at lower volume levels. Different programs might use slightly different algorithms for attenuating the signal and resolving those rounding errors, which means there might be some difference in the resulting audible signal between, say, an audio player and the OS, but that doesn't change the fact that in all cases you're still reducing bit depth and essentially wasting a portion of the bandwidth on transmitting zeroes instead of useful information.

[johan]

Originally Posted by Vracer111

Bluetooth doesn't really suck though - not quite as good as wired through a DAC/amp, but not far behind and nowhere near a sucking level. At least that is my experience in streaming FLAC through UAPP off my Samsung S2 tablet through the infinity audio system of a coworker's Hyundai Sonata Limited. Hardly any noticeable difference from running through an Audioquest Dragonfly Red DAC/amp in line out mode to the auxiliary input. Just a very slight, hard to perceive difference in detail - clarity and dynamics are basically identical.

Maybe your devices support aptX on both ends, could explain it. Us dummies on iPhones are not so fortunate.

[Clipdat]

The particular McCormack DNA-125 that I auditioned ended up being a disappointment.

Right away, I noticed a few things that bothered me. It produced an audible hum while it was powered on, as well as a white noise/hiss from the tweeters. The hum did not seem to be coming from the front center where the transformer was located, rather it seemed to be originating roughly half way back on the chassis from both the left and right sides. It couldn't be heard over most music, but it was a strange frequency. You could hear it by putting your head close to the amp, but you could also hear it ~10ft away. It also had a loud turn on transient thump sound that it made through the speakers. Wasn't a fan of that. My NAD integrated produces absolutely no hum and no hiss through the speakers.

Regarding it's performance, it basically sounded no different to me than my NAD. If I really had to stretch, I'd say maybe the stereo imaging was a tiny bit better, and the musicality or "PRaT" was slightly better. We're talking minuscule differences.

I ran some of these observations by a few audio guys and they suggested that something was perhaps not quite right with this unit. I arranged to ship it back to the used music equipment retailer that I purchased it from (tmraudio.com), as they have a 45 day satisfaction policy. I explained that the amp produced a noticeable hum while powered on, and thus that it was not in the condition it was advertised. It was described as this: "Operational condition of this item is excellent, fully tested and no issues found." If it had said instead "Unit produced an audible hum while powered on." I would have never purchased it.

So, the return policy of the retailer states: "Every product purchased at www.tmraudio.com is backed by a best-in-class 45 day satisfaction guaranteed return policy. In the event that you received a product that is shown to be defective or not as advertised, The Music Room will take responsibility for shipping arrangements and all shipping costs. Refunds for any other reason will not include shipping costs."

They provided a prepaid label, but informed me that they would take the return shipping cost out of my refund if they were not able to replicate the issue I described during their testing. I think you know where this is going.

I ship it back to them and get this email: "I received the amplifier today. I've tested it out and I have been unable to find anything defective about the amp. There is an extremely small amount of noise difference between completely unpowered and powered up when I'm pressing my ear against the top. This is 100% consistent with normal operation. I'm not sure if it was different with your system or not but based on what I'm seeing I can't call it defective. I'm still happy to proceed with with the refund but as previously discussed that would be minus the shipping costs."

So, clearly, they have a different opinion of what constitutes "normal operation". I replied and explained again that it was not as advertised, in that there was nothing about a hum mentioned in the original description. But they weren't willing to budge and they deducted the $55 return shipping cost from my refund. I also had to email and nag them after 5 business days had passed asking where my refund was. They said some bullshit about how it had already been processed and how sometimes it takes a while to show up as a credit on the CC. Then 1.5hr later I get an email from Paypal stating that I've received a refund. Nice "coincidence" there. I will never do business with tmraudio.com again.

I decided to get these instead: https://www.audiothesis.com/ampino-monoblocks

Also, I impulse purchased this DAC for my PC audio setup. Should be here in a few days: http://www.hirestech.com/product/?pid=116

Originally Posted by Vracer111

Used or refurbished gear always is great bang for the buck. Interested to hear your impressions of it.

[Vracer111]

Ouch, so it didn't work out. Those Ampino monos should be nice though. What amp are you running for your PC setup, or you just tying it into your HT system or using monitor speakers?

Finally modded my second set of TH-X00PHs, got in the Lawton driver housing acoustic dampening kit on Tuesday and installed it along with the E-MU Palo Santo wood cups:





For sound, the Palo Santo cups seems softer, warmer, and more laid back with more body and a little less bass impact (but more boomy) and precision compared to the Purpleheart cups. Do like better than the Mahogany cups... Going to try and see what kind of smooth tune I can get out of them, have orderded a couple different pads (Mrspeakers Alpha sheepskins and ZMF Ori suede) and will be trying some blu tack on the cups and adding some polyfill to make a more TH610'ish tuned TH-X00.

[Clipdat]

Those wood cups are gorgeous! Nice choice.

On my PC I'm running my vintage circa 1999 Klipsch Promedia v.2-400 powered speakers. (2.1 mode, no surround speakers hooked up) Specs aren't bad. 60w to each satellite and 160w to the subr. BASH® (Bridged Amplifier/ Switching Hybrid) design with high efficiency/ high output power. Discrete MOSFET power section for high current, maximum dynamic headroom.

These are the originals with the dual driver subwoofer enclosure, instead of the single woofer version they sell these days. I actually replaced both woofers a few years ago since the original foam surrounds had rotted out. It was actually cheaper to just replace the drivers versus refoam them. Also upgraded the speaker cables to Blue Jeans Cables.

[dem00n]

Headphones?

Nah, I prefer it in my chest.


(Not mine, but same pair)

I'm a vintage guy, I used to hang around those fancy HI-FI stereo stores in NYC, I've heard some expensive rigs, but nothing gonna beat Altec Model 19's with Mcintosh hardware. That's the new goal.

It seems that vintage is coming back too, anyone saw the JBL L100 at CES? Classic speaker...blows away most new stuff I hear.

[Clipdat]

Wouldn't mind a pair of these: https://www.musicdirect.com/speakers...shelf-Speakers

Originally Posted by dem00n

It seems that vintage is coming back too, anyone saw the JBL L100 at CES? Classic speaker...blows away most new stuff I hear.

[Vracer111]

Originally Posted by dem00n

Headphones?

Nah, I prefer it in my chest.

I'm a vintage guy, I used to hang around those fancy HI-FI stereo stores in NYC, I've heard some expensive rigs, but nothing gonna beat Altec Model 19's with Mcintosh hardware. That's the new goal.

It seems that vintage is coming back too, anyone saw the JBL L100 at CES? Classic speaker...blows away most new stuff I hear.

I've always loved the look of McIntosh gear...very sweet style.

I do like both headphones and speakers (do like my NAD C275BEE amp driving the Polk RTi-A5s), but generally listen to music through my phones, it's just easier for me. The TH-X00PH have a 5Hz - 45kHz frequency response and really bring low end to your head you can feel (when properly DAC and amped) - intense bass presence (enough to vibrate the cup screws loose at high volume from listening on a high power amp.) But when modded they are also extremely detailed and clear in the low end at the same time, with organic and lush detailed mids and energetic and precise highs. Love them like no other phone when modded, they are decent stock.

I'm more of a details and dynamics type of listener but also like it smooth and a little warmish. So if I sold my FR-S and wanted some really nice towers it would probably be these babies:



JBL Synthesis S3900

[dem00n]

I can understand for the call of Dynamics, however I find that with speakers I can get the right amount of detail. Headphones are a more personal experience, but I can't sit down and listen to music, I like to move around.

I have a pair of JVC HA-AX900, I think they still sell them today. Great buy for under $100, one of the last great JVC products they sold....