MacBook Pro not as good as MacBook?

[Jim Smith]

Not what I intended for my first post on this forum...

 

I have been enjoying the sound of my two-years old MacBook with my new QB-9. Although I have more exotic (i.e. expensive) CDPs around here at home, I have a specific need to have a system that can travel easily.

 

So I decided to "improve" on the currrent QB-9/MacBook set-up. Bought a MacBook Pro with bigger and faster hard-drive, lots more RAM, dedicated to only this task. Loaded all my music onto it. Plugged it into my already broken-in Transparent 2 meter USB cables & QB-9 and expected great things.

 

Not...

 

I've triple checked all of the settings. For this test, I've been using iTunes, AIFF. I have all of the iTunes settings the same for both laptops and all of the audio midi settings the same.

 

Honestly speaking, it sounds as if the MacBook Pro isn't as loud. It certainly sounds thinner. I could measure this, but I wonder is there is a simple answer that I'm missing?

 

Could it be that the spanking-new MacBook Pro needs to run in? I admit to not thinking it would make a difference, but this is not subtle.

 

[Audio_ELF]

Have you tried swapping to using a different USB port. On some McBooks some of the USB connections are shared internally.

 

Eloise

 

[Jim Smith]

Yes.

 

I determined which USB port wasn't connected to the keyboard and mouse before I ever started. So it's not that.

 

In fact, on my MacBook the front port is the correct one, but on my MacBook Pro, the rear port is correct.

 

[mb9061]

How long have you been running the Pro laptop? Like everything else, it may need burn in time for the power supplies, board, USB ports, etc. Different power supplies (and computers in general) impart different signatures on the sound of a system, not suprising one may sound better than another. That said though, one computer shouldn't sound terrible in comparison to the other if they're setup for the same playback (though one will ultimately sound better in your opinion probably). Hard drive speeds (7200rpm/etc.) may play a hand too, along with numerous other variables that it seems nobody really has a firm grip on, including the experts.

 

I have a simple macbook as well as an IMac. Both bought within the last 18 months, both close in specs (ram, Intel chipsets, hard drives/etc.). I had the IMac paired with some spendy power cords and compared it to the simple macbook, of which the latter sounded better in my opinion (not loads better, but enough to warrant use versus the IMac). I also have a Dell Inspiron that's plenty powerful and was setup with Foobar and full Flac library, sounded different yet again.

 

Sorry, no easy answer here...keep trying different things with each and give it a few weeks of play to see which wins out but don't expect a more expensive computer to sound better than a cheaper one.

 

[Jim Smith]

Could OSX versions make a difference?

 

MacBook:

 

OSX Version 10.5.8 (Leopard); 2G; Intel Core 2 Duo; 250GB 5400-rpm Serial ATA hard disk drive; 1G Ram, loaded with two years of files

 

MacBook Pro:

 

OSX Version 10.6.3 (Snow Leopard); 2.53G; Intel Core i5; 500G 7200 RPM HD; 4G Ram; 3 days old, loaded with nothing but the same music as the MacBook in iTunes.

 

There does seem to be a difference in level, which could affect my judgment. The MacBook seems slightly louder. I'll get that measured soon. The question is, if the iTunes and Midi are set exactly the same, how can there be a level difference through USB?

 

[Jim Smith]

Thanks for your comments, Eloise & mb9061!

 

[ziggyzack]

The question is, if the iTunes and Midi are set exactly the same, how can there be a level difference through USB?

 

Because these aren't really hi-fi devices. They're audio, but not hi-fi. They deliver functional audio, sometimes very good functional audio, but during their design and manufacture, no attention is paid to the feature set that you're concerned with (precision audio).

 

E.g. the manufacturer of a certain part may replace it for some reason during the life of a product - more power efficient, a new contract with a different supplier, they found something cheaper. Apple are perfectly within their rights to, for example, remove some shielding which they calculated they don't actually need. All these things can change without announcement, and the end product would still be a mac book or a mac book pro, but they could have significant effects on sound performance, which (I imagine) is not specified to any level on these devices beyond the bitrate. Apple would say, at a guess, that both your macbook and macbook pro are operating within expected tolerances. I could be wrong, and by the time I hit post, you could have found an incorrect volume setting - but the principle remains.

 

So you can review one macbook, and it may not sound like another macbook 6 months later.

 

To slightly generalise on the topic: I think that expectations for what is achievable from massively multipurpose products, like computers, are unreasonably high. They are great for music storage and management, perfect for manipulation in the digital domain, but when it comes to anything requiring real analogue accuracy (including clocked digital audio signals) then they won't compete with more focussed gear.

 

[wgscott]

10.6 differs less from 10.5 than 10.5 does from 10.4, etc. It was rather more like a big point update in many ways. It is possible they corrupted the sound, but I think it isn't likely.

 

Double-check iTunes equalizer and make sure it and all the system sounds and everything in the "Sounds" preference pane is turned off.

 

Solid-state components shouldn't need to burn in.

 

[Jim Smith]

Double-check iTunes equalizer and make sure it and all the system sounds and everything in the "Sounds" preference pane is turned off.

 

Thanks.

 

I did that in the very beginning. All settings are correct (according to everything I know of that has been posted on this site) and all are the same.

 

[mb9061]

I'll find out here this evening if Snow Leopard is any worse than the prior version and let you know (just bought it this morning). I'm hoping it's not worse, as all I've read so far indicates Snow Leopard is an improvement (hopefully more than a marginal one, but anything helps).

 

At the end of the day, you shouldn't be getting horrible sound out of either laptop, but one may sound better than the other. I'd let the new Pro run in for several weeks though, as you're comparing a brand new piece of equipment to one with likely hundreds of hours on it (not a fair comparison). Even cheap power cords sound like crap compared to ones that have had a lot of hours on them.

 

[Jim Smith]

Just finished careful measurements with excellent instruments. MacBook Pro is actually 1 dB louder on a 1kHz tone.

 

But on music, it sounds slightly emasculated, lacking richness and authority in the bass, very noticeable on lower registers of piano.

 

Top end sounds leaner. Has less spatial aspects as well.

 

I'm out 3K, unless something radical turns up. This is a difference that anyone could hear easily. Not saying it sounds bad, but compared to the MacBook, it doesn't sound nearly as involving.

 

Sheesh!!!

 

[The Computer Audiophile]

Hi Jim - This is an anomaly. Do you have any way to check for bit perfect output? I can't remember is you are using Amarra, are you? You don't have any volume set differently do you? Is there any way to connect via optical as a test?

 

Where is the source music stored. internal, external, NAS?

 

I think the big thing is to get that 1kHz tone to be equal on both machines. After that it's down to preference and there's no right or wrong preference.

 

[lazycatken]

That could be possible....

One of my experiences,

I ever tried to check the output of iTunes on my MacBook Pro 15" OS X 10.6.3, default system output is SoundFlower, i.e., iTunes outputs SoundFlower then my program check the stream from SoundFlower.

I found that it's strange, while tracks on hard disk was playing, the tail of every track was not silence as it should (I checked digital data), but this did not happened while tracks on CD was playing.

The signal added onto silence looked like dither(under -80dB, I can't remember actual value)...

 

The above problem happened only when iTunes is launched while OS default output device is a 16bits device. SoundFlower is always 32bits float format, the OS internal format.

 

Perhaps, Gordon could give us more information...

 

 

[Jim Smith]

Do you have any way to check for bit perfect output?

 

Hi Chris,

 

Not at this point.

 

I can't remember is you are using Amarra, are you?

 

No.

 

You don't have any volume set differently do you?

 

No. Carefully checked, ad nauseum.

 

Is there any way to connect via optical as a test?

 

Not that I know of.

 

Where is the source music stored - internal, external, NAS?

 

iTunes, internal HD

 

I think the big thing is to get that 1kHz tone to be equal on both machines.

 

I can't figure out how at this point. I even compared AIFF importing with auto and with 16/44.1 to see if they somehow made a difference in level. Nope. The difference is between machines. In a desperate reach, I also measured absolute polarity. Both are identical.

 

After that it's down to preference and there's no right or wrong preference.

 

I must respectfully disagree, unless a breakthrough occurs. These selections are from my reference collection that I use to voice client's systems, and that I've used at shows to great effect. I have certain expectations for their playback.

 

With the QB-9/MacBook, there were aspects that were at least comparable, if not downright superior to two sophisticated CDPs I have on hand (Ayre C5xe-mp & Zanden 2000/5000). I was planning to write an article about my experience in the next Quarter Notes newsletter that goes to my readers. But not now. The MacBook Pro/QB-9 doesn't compare to any of the three.

 

Honestly speaking there are probably too many variables to track down - HD capacity, HD speed, different versions of OSX, different Intel Cores, on and on.

 

I see now that it was somewhat foolish to automatically expect an improvement. I just didn't dream of going backwards.

 

Also, though I'm a believer in break-in in most components (for example the QB-9), guess I don't expect it in this instance. Anyone have experience with such a change occurring in a computer?

 

[Jim Smith]

Perhaps, Gordon could give us more information...

 

I hope so, although I rarely see him on forums over weekends.

 

I'm wrestling with seeing if I can return the MacBook Pro on Tuesday. I already have five Mac computers, so it's not like I haven't been a good customer.

 

[wgscott]

My experience with Apple is they will do whatever is necessary to keep a reasonable customer happy. It is possible there is something wrong with your laptop. Give them a chance to make it right.

 

But I also just remembered the new MacBookPro's are 16,24 and 32-bit capable, so they definitely changed something hardware-wise.

 

[The Computer Audiophile]

"After that it's down to preference and there's no right or wrong preference."

 

"I must respectfully disagree, unless a breakthrough occurs... "

 

Hi Jim - I should have clarified my statement a bit more. I was assuming both machines were good and the new one was performing up to expectations. When things are not even close preference is a moot point pretty much.

 

This one is really bugging me. If the 1Khz tone is not at the same level on both systems, one of them is likely not bit perfect in my opinion. Can you download the demo of Amarra and measure the tone when using it on both machines? Amarra will output bit perfect.

 

 

 

[Nicholas.Bedworth]

Jim, Chris...

 

If it sounds "thin", could that also be a jitter issue of some kind? And are all the USB ports truly identical in terms of functionality and performance on that particular MBP chassis? To me, most of the S/PDIF coming out of consumer gear has that thin and brittle sound. It's not exactly analogous to your apparent problem with USB, but perhaps one of the transmitters isn't feeling well

 

You've said you've already triple-checked the audio chain settings. Steven Stone in TAS was mentioning a couple of gotchas, which you probably know about already, although these arcanae on Mac are out of my area.

 

My I suggest a 350 Hz test tone? It's a lot easier on your ears. and check the output level (at the output of the DAC) with a DVM.

 

[wgscott]

When messing around with my new mini at work the other day, I figured out two things:

 

1. The USB ports are not all identical

2. They change dynamically, according to what is plugged into them

 

So it might be worth using the "system_profiler" unix command on the command line with the USB to DAC (or whatever) plugged in, to verify that it is being assigned a high-speed connection.

 

 

system_profiler | more

 

will allow you to page through it more readily.

 

[Nicholas.Bedworth]

Jim, you've probably seen the report from the OP on USB ports doing strange things. Does the MPB have FireWire? My impression is that it's more likely to do what it's supposed to do, compared to the vagaries of USB.

 

[Nicholas.Bedworth]

Correct. Apple (and perhaps other vendors) for some time have been doing this and making similar "improvements" to their USB ports. As pointed out earlier, not all of the ports are suitable for audio use, although this situation may have a different cause than what you're observing presently. Making dynamic changes is particularly clever

 

This is the kind of "it's broken and that's because it's really much better than before" feature that comes right out of Dilbert. And how many users know how to get at the UNIX command line, or even know what UNIX is?

 

My experience also is that USB ports on different brands and models of laptops do in fact sound differently, which relates for my lack of enthusiasm for USB as an audio source in general.

 

It seems to me that with IEEE 1394, you tend to get what you're expecting.

 

Based upon what the Jim was mentioning, my thought was to dig into the Mac service bulletins and see if there were any exotic issues. Probably a post to some Apple developer forum would also be useful.

 

[wgscott]

Well, I guess I was a unix geek long before OS X came along. But it really isn't so bad.

 

Open up

 

/Applications/Utilities/Terminal.app

 

and you are set to go. It is helpful to be able to do a few things this way, if you want to carry out system tweaks or even just peak "under the hood" to see how things are running.

 

"About this Mac" essentially runs this command and spits out the output for the GUI user. I didn't actually check to see if it has the same level of detail about the USB ports; it might. (edit: it does)

 

Anyway, if anyone needs it, I have a web page with some links to some basic OS X unix tutorials and other resources here.

 

[barrows]

Barrows here, formally of PS Audio (we met back then).

This is a stumper! The only thing I can think of is that your new MBP has a problem of some kind, corrupting the output data. The level of difference you report seems like it is too big to be explained by small differences between computers, and most have reported that Snow Leopard is at least equal to, if not better than, Leopard.

The other possibility that comes to mind is that the bigger, higher RPM, hard drive might be producing more RFI, and sending this out to the QB-9: but considering the lengths Charles H. went to to try and keep computer borne RFI out of the analog signal I doubt this is the problem.

Three things I would suggest: one, you should do some experimenting with playback engines: try the demo of Pure Music-I think you will find sonic improvement on both machines using it (or Amarra, or both, but the demo of Amarra is kind of annoying with its drop outs).

Explain your situation to Apple, and try to get a new replacement for your MBP.

Contact Gordon Rankin through usbdacs.com and ask for his opinion, he seems very well versed in Macs, and knows the QB-9 as well, he may know more about the new MBPs.

 

[Nicholas.Bedworth]

Now this is useful. Do you have the same level of control from the GUI as from the command line? Sometimes certain (lethal) features are obscured from the GUI version...

 

Can you force the errant USB port to behave in the way you want?

 

[Nicholas.Bedworth]

Doesn't the Mac have a miniature TOSLINK connector somewhere? On PCs, they're usually doubled up inside one of the headphone jacks. Wireworld has a really good glass fiber TOSLINK cable for such situations.