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markalroberts
2009-11-21, 08:11
Hi, I've had a duet (with two receivers) for a while now, and, whilst there is a lot to admire about the system, I've never been happy with the sound I get out of it. Finally I've decided to ask the question in the hope that I can do something about it.

I have ripped my CD's using various formats (MP3 192kb and FLAC lossless), and have decided I can tell almost no difference between them, so I don't think it's that.

I have a good 54g wireless network (SqueezeCenter running on QNAP TS-119 NAS), and I'm pretty sure that there is no problem with bandwidth or signal strength.

Each receiver plugs into a different AMP (in different rooms). One plugs into an old Technics midi hi-fi and the other into a Cambridge Audio amp.

In both cases, playing CD's through the systems sounds significantly better to my ears. The Technics midi has its own CD player and the Cambridge Audio Amp has an old (but good quality) external CD player.

To make the test as fair as I can, I've used the same interconnects.

I do have pretty good hearing, but would not consider myself to be unusually picky (as I said, I can't really tell much difference between 192kb MP3 and lossless FLAC!), but the sound out of the Squeezebox Receivers is just dull and uninspiring when compared to native CD playing.

I've invested a lot of money and time in the wireless music setup, and I'd really like to get it to the stage when I can enjoy it as much as the CDs that I own!

Can anyone make any suggestions as to how I can get better sound out of my system?

Thanks very much, Mark.

aubuti
2009-11-21, 08:45
Are you sure that the volume levels are the same when playing the CD players and the SBRs? The analog output on the SBR is only 4.8Vpp, which is lower than the line level output of a lot of other devices (even the SB3/Classic, which is 6.0Vpp). It may well be lower than the output of your CD players. Other things equal, louder always sounds better and less "flat." That could explain why you prefer the CD players' sound, and I would definitely want to rule out that possibility before doing other things like getting an outboard DAC or buying a Transporter.

If the output levels of the SBRs are lower than your CD players, then you should both (1) turn up the SBRs' volume to 100, and (2) adjust the volume on the amp when switching between the CD and the SBR to equalize the volume. If you want to get fancy, you can measure the volume with a sound pressure level (SPL) meter.

Mnyb
2009-11-21, 08:54
1. did you do the comparision with the duets volume at 100%
turn off replay gain while comparing, replay gain is lowering the volume on most tracks .

2. Did u try to level match ? The loudest source will sound "better"
get a cheap spl meter or a volt meter and dail your system so that both the CD and the reciever play at the same level.
level matching is important for a fair comparison you will for example not hear a difference at 2dB as louder, rather as more clear and detailed with more bass defenition or something in that direction.

3. Wait for the Tough to released, the reciever is not expensive after all it would sound ok but not as a top notch cdp.
it is the controller that is the expensive part of the duet package

4. get a 2:nd hand transporter

5. use an external DAC or Home cinema processor, all squeezeboxes has more or less exellent digital outputs, if you have done bitperfect rips EAC or dBpower amp you get a transporter performance no mechanical drive can touch literally .

I tend to like nr 5 in my main hifi i use the SB3 as a digital transport.

markalroberts
2009-11-21, 08:55
Hi. unless I'm missing something, my SBR's are both on 100% (I've synched the volumes through SqueezeCenter and the Duet controller shows 100 for volume, as does the web interface).

I have noticed that I need to crank up the volume of the Amp, when compared with the native Internal/External cd players, but I am still of the opinion that the the sound lacks the punch of the CD player, even when the volume is raised.

markalroberts
2009-11-21, 09:07
Just checked, my replay gain ("Volume Adjustment/Replay Gain") is set to "No volume adjustment", so guess that's not interfering with sound.

I was thinking about whether I needed an external DAC (was thinking about the Cambridge Audio one, which seems to get good ratings). but this is still not cheap, and its a bit frustrating that my old Pioneer CD player gives the sound that I want without needing the additional expense.

aubuti
2009-11-21, 09:33
Hi. unless I'm missing something, my SBR's are both on 100% (I've synched the volumes through SqueezeCenter and the Duet controller shows 100 for volume, as does the web interface).

I have noticed that I need to crank up the volume of the Amp, when compared with the native Internal/External cd players, but I am still of the opinion that the the sound lacks the punch of the CD player, even when the volume is raised.
Without a SPL meter it is hard to know if you have raised the volume level enough. Also, are you testing with only FLAC files? Even if you can't hear the difference between 192kbps MP3s and FLAC, you should compare like with like, ie, FLAC vs CD.

Maybe there's something about the sound of the CD players' internal DACs that you like better than the SBR's DAC, but I wouldn't rule out volume differences yet.

mlsstl
2009-11-21, 09:40
just checked, my replay gain ("Volume Adjustment/Replay Gain") is set to "No volume adjustment", so guess that's not interfering with sound.

While I appreciate that you checked the server settings, you haven't indicated if you've tried doing the listening comparison between the duet and the CD player with the volumes matched. This is a critical point. It has been well established that only a 1 or 2 dB difference in volume between two units will not be perceived as a loudness difference, but rather as a difference in tone, clarity, bass, highs and so on. The higher output unit will always sound a shade better, but that difference will disappear (all other things equal) once the volumes are matched.

I've got a Duet in one of my two systems and it sounds excellent. In my main system I use a SB3 (Classic) with a $1,000 external DAC (Lavry DA-10) that has an output volume control. When the Duet without an external DAC is matched against the SB3 with one, there difference between them lies in fairly subtle territory.

Can you be more precise as to what you find unsatisfactory about the sound quality? That's been a bit vague up to this point.

markalroberts
2009-11-21, 10:12
Ok, bear with me... i'm no expert in this area.

Firstly, just to make it clear, I've been experimenting with CD vs MP3 vs FLAC. I've used various CD's from my collection and a variety of music.

One my better system (Cambridge Audio Amp with Pioneer CD player connected via Cambridge Audio analog cable), I've compared the same music played via the SBR using the same analog cable. I have the SBR playing at 100% volume, and I match the (only other) volume control on the AMP so that they volumes sound the same. I've also experimented with using the same CD input or the AUX input - without noticing any difference.

The sound played from the CD player has brighter highs and more punchy bass. The sound is generally richer, and I find I can pick out the various instruments and voices easily... whereas, the music from the SBR is mushier, sound seem to blend into each other... I find that I tend to compensate for this by raising the volume higher (even than the CD, I would say), but it always leaves me feeling like something is missing. I have to try harder to enjoy it.

Not really sure what you mean about making sure the volume level is raised enough. I've certainly turned up the volume on my Amp pretty high! and I have the SBR at 100%. What else can I raise?

aubuti
2009-11-21, 10:33
First, I would say you should leave the MP3s completely out of the comparison. They are compressed in a lossy format, and are quite simply different from the original CDs. If you want to compare the same source material through different audio components, then MP3s shouldn't be used because they are different source material. A good comparison is to put a CD in the CDP and then put the exact same CD, which you have ripped to FLAC, 'in' the SBR, and start them at the same time. Then you can toggle between the inputs, although you'll need to fiddle with the amp's volume to be sure they are level-matched.

Second, it's not that everything has to be louder. My comment about "raising the volume level enough" was ambiguous; I should have said "raising the volume level enough when playing the SBR." You just need to be sure that the CDs and SBRs are playing at equal volume. This will usually mean turning your amp's volume control up for the SBRs and back down for the the CDPs. Whether this volume levels 3 (for CD) and 4 (for SBR) or 8 and 9 is up to you.

That said, maybe your CD players are better quality (or the SBR is lower quality) than you thought. Just out of curiosity, can you hear a difference between the two CD players?

mlsstl
2009-11-21, 10:44
The point is not sheer loudness, but rather, you want a precise match in volume between the two pieces of equipment you're comparing.

You indicated earlier that you have two SB receivers. Do they sound identical to each other? That would help rule out the chance that one receiver has a defect.

However, if both receivers sound less dramatic than your CD player, I'd venture that the CD player has an intentionally non-neutral frequency response.

You might want to see if you can borrow a different brand of CD player from a friend for some experimentation.

I did a lot of back-to-back comparison a few years ago before I dumped my CD player and made the 100% switch to Squeezebox for playback. I always found the Squeezebox the equal of any player I tried in the system.

Many, many moons ago (back in the 1970s) I sold stereo equipment for several years. Almost all amps and receivers had tone controls in those days. It was almost universal for customers to tilt up both the bass and treble controls to about 1 or 2 o'clock to give the sound an extra bit of highlight when auditioning equipment.

While giving a bit of extra emphasis here and there is more common in speaker design, it is not unheard of for a piece of electronics to have an intentional departure from neutral since that can make for an initially good impression in side-by-side comparisons in the showroom.

It is certainly OK to like what you like, but it is also important to understand that your preference may be for a system that isn't neutral.

c3p0
2009-11-21, 23:13
Just checked, my replay gain ("Volume Adjustment/Replay Gain") is set to "No volume adjustment", so guess that's not interfering with sound.

I was thinking about whether I needed an external DAC (was thinking about the Cambridge Audio one, which seems to get good ratings). but this is still not cheap, and its a bit frustrating that my old Pioneer CD player gives the sound that I want without needing the additional expense.


Even through my decent HiFi, moon cd and amp, sonus faber speakers, the squeezebox reciever sounded great not dull and lifeless but I invested 150 in the V-DAC and the quality just got richer, the vdac has been highly rated recently as out performing some more expensive dacs including the Cambridge one. Getting the volume balance equaled between inputs is important and difficult to do for a proper assesment. At the moment I am comparing different cartridges for my turntable and have to crank up the volume for one and down for another to achieve a level comparison. Interestingly it is the cart with the lowest output that sounds the best.
I have also done 3 way comparisons, flac, cd and vinyl, the cd and flac sound very similar and the vinyl sounds different,tonally and spatially. whereas the cd and flac sound very similar tonally but not poorer quality compared to the vinyl. It's like different flavours, sometimes I want strawberry sometimes vanilla.
So something must be going on volume wise for you to be dissapointed.

It might be worth checking if your ripper has some weird volume switch enabled.

markalroberts
2009-11-22, 04:17
Ok, thanks for all the replies. I shall do some more more investigations.

One thing that I realise I'm not totally clear on is how much should I rely on the Duet controller for volume control?

Would I get better sound quality if I always have the SBR's outputting at 100% (could even use the SqueezeCenter setting to force this), and control volume through the AMP only?

Phil Leigh
2009-11-22, 04:24
Ok, thanks for all the replies. I shall do some more more investigations.

One thing that I realise I'm not totally clear on is how much should I rely on the Duet controller for volume control?

Would I get better sound quality if I always have the SBR's outputting at 100% (could even use the SqueezeCenter setting to force this), and control volume through the AMP only?

Provided you keep the controller volume in the upper 20% or so of its range it's fine. You should set the vol on your amp to allow that to happen.

Pete Fowler
2009-11-22, 09:35
With all due respect to the previous posters - the Duet receiver has a master clock oscillator that was built on a chip which also drives the SP/DIF output and another clock. The result is a ton of self-generated gate noise on the oscillator chip.

The effects you're hearing are primarily due to noise in the master clock (aka jitter). The audible effects are exactly as you describe them - lack of dynamics, transient snap/slam and clarity. I kept turning it up trying to get some juice out of the music. ;-)

Upgrading the clock turned a mediocre playback into something really special. I have done this with my receiver and I'm still shaking my head two weeks later. My guess is the master clock on your CDP is simply cleaner than the stock receiver's, so you're hearing more dynamics and body in the music.

Unfortunately the master clock also degrades the output of the SP/DIF - in order to get the best from a stock receiver as a digital source you need a VERY jitter-resistant external DAC. Do that and you'll have a top-notch playback system. Otherwise you need to upgrade the master clock in the receiver to significantly improve the sound. YMMV, of course.

Cheers,

Pete


Ok, thanks for all the replies. I shall do some more more investigations.

One thing that I realise I'm not totally clear on is how much should I rely on the Duet controller for volume control?

Would I get better sound quality if I always have the SBR's outputting at 100% (could even use the SqueezeCenter setting to force this), and control volume through the AMP only?

mlsstl
2009-11-22, 10:28
It occurred to me that I haven't seen anyone suggest that you check your server side settings to make sure the bit rate limiting is not on and that you're transferring files as FLAC, WAV or PCM.

If you are sending info from the server to the receiver as a MP3 stream or with bitrate limiting turned on, this could have a significant effect on sound quality.