Avid Mbox Pro Computer Interface - Now with Conclusions

[CT357]

Great review. Got my Mbox 3 Pro as soon they were available at Sweetwater... Sounds cleaner then my 002 and much, much more cleaner then my older mbox. And the damn thing is almost as heavy, maybe even heavier then my 002. LOL.... Defintely built better then the older Mbox's and Digi00 interfaces. Was looking for a review like this for a while to pretty much confirm what I was hearing and see what the inside looked like and started feeling like I was the only one on the planet with one... LOL... I just purchased a Peluso 2247 LE Mic and a Great River ME-1NV Mic-Pre and have it going in to my MBox 3 Pro Running on the latest 17" MacBook Pro fully loaded with Pro Tools 9 and I'm blown away by how it sounds. Avid out did them selves with this interface. With The Mbox 3 Pro being able to handle 24bit/192khz and Pro Tools 9 allows you to record and mix at 24bit/192khz, you basically have a low budget HD rig ($1,000)... Mbox 3 Pro kind of makes the 003 seem pointless and waist of money... (sorry 003 owners) I'm finally getting that "BIG BOY STUDIO" sound i've always wanted with out breaking the bank. This was definitely a great investment for me. And this review definitely made me feel better about buying it.

[Anderton]

Originally Posted by CT357

And this review definitely made me feel better about buying it.

Well the intention of the review is to help people make the right choice, but it sounds like you'd already figured out your needs anyway. I'm glad you agree this is night and day compared to the older models, it certainly seems that way to me. Also one thing I haven't really mentioned is that if you use programs other than Pro Tools, the drivers seem really solid. So far I've tried the Mbox Pro with Sonar and Ableton Live, and it works without a hitch. I'll try it with some other programs too to get more of a feel about its performance, but it seems that Avid is definitely trying to push the Mbox Pro as a solution for whatever DAW you use, not just Pro Tools.

BTW - as to 192kHz - I'd say it's not worth the extra storage aggravation, 96kHz is just fine and anyway, few people can reliably tell the difference between something recorded at 44.1/48kHz and 96kHz - let alone 96 and 192. But hey, it's there if you want it!

[Bob Sykes]

Hi Craig,

Great review. Thanks for the informative photos on build quality and measured specs. This is really good to know. I was blown away when I got an AVID Omni interface for an HD3 rig. I used to use a Benchmark DAC1 for a monitor DAC/level control with a Digi HD192, but no more. The Omni converters and monitoring control (real analog gain attenuation - not digital) so good they arguably beat the DAC1. AVID claims the new mBox use the same circuitry as their new HD units - from your measurements and review that looks to be true! A great option to have for remote work, especially since I can buy the mBox discounted since I don't need to buy the PT application again.

[Richard Keesing]

Thanks for such a great review Anderton; I am one of two Mechanical Engineers that designed the mechanical portion of the MBox3, MBox3 Mini, and the MBox3 Pro. Your review gave me a great feeling of accomplishment for a lot of long hours put into the product design.

[Anderton]

Originally Posted by Richard Keesing

Thanks for such a great review Anderton; I am one of two Mechanical Engineers that designed the mechanical portion of the MBox3, MBox3 Mini, and the MBox3 Pro. Your review gave me a great feeling of accomplishment for a lot of long hours put into the product design.

You're probably just happy that someone noticed the lockwashers

Sometimes people forget that these units don't just happen by themselves, that a Real Human at the other end has to sweat a bunch of design decisions, like "do we use lockwashers or do we save a couple of bucks?" Frankly, I'm aware that a lot of effort goes into this kind of thing, but I'm fuzzy as to the details. If you wouldn't mind, would it be possible to give a few paragraphs on how these products come about? Do you design them all on a computer then get prototypes? You say there were two mechanical engineers - did you each specialize in some aspect of construction, or collaborate? How did you decide which features were important and which features to omit? I'm not expecting you to reveal trade secrets or write a thesis, but it would be cool to get some insights into how these products actually come into the world.

[stingray1122]

Thanks for the review Craig. I really enjoyed the detail you go into with the tear-down and measurements. The team here at Avid put a lot into these new interfaces and we're happy to hear that our hard work is appreciated.

We completely redesigned the Mbox family from the ground up. For example, in the new designs, the preamp signal goes through a high-pass filter, which is controlled in the software by a high-quality relay. By using a relay in the analog domain, we eliminated a lot of potential noise.

There were also design considerations unique to each unit. For the line inputs on the Mbox Pro, the signal doesn't pass through the preamp; instead, it connects directly to the converter, ensuring that the sound is not colored in any way. However, on the Mbox, the line input goes through the preamp to ensure variable control over the signal level in a more mobile environment, where you might not have all of your adaptors and tools with you.

Every step of our development was challenged with decisions like you mentioned in your reply to Richard—things like, “Do we use lock washers or do we save a couple of bucks?” We stuck to our guns and insisted that the customer experience and quality be the top priorities. Of course we had cost targets to achieve, but when it came to the audio performance and build quality, we felt higher performance was worth a little more in component costs. This attitude is why we have relays, 8-segment input meters, and lock washers.

There are plenty of great stories from our development, covering things from the mechanical design to the drivers and control panels. I'd be happy to chime in with a couple of these over the next few days or weeks. If there's any area of the development anyone is particularly interested in, please let me know.

We’re thrilled that people are digging the new interfaces and that we could help provide an excellent solution that sounds amazing. I'll try to stop back in to answer questions or comments as they come up.

Thanks again for the detailed review Craig!

RayT
Product Manager
Avid

[Anderton]

Aha! So I was right about the relays

Maybe you could answer a controversy that's being discussed in another thread -how much the "glue" (resistors, circuituit board layout, caps, power supply) influence the final sound compared to the converters themselves. My position is that two devices could use the same converters and preamp chips, yet sound diffferent depending on the components wrapped around them. Some feel the difference is small but noticeable, others feel it's negligible...could you speak to this not so much from Avid's standpoint, but from an engineering standpoint, and which components tend to have the greatest influence on the sound?

I'm not expecting you to divulge any trade secrets, just some general comments so we can all be a little better educated about the subject.

[ith]

hi Craig, that was a real eye opener!

I just got my own box and was very happy with it, but your tests made me real confident about what I'm hearing (-:

Forwarding the link to several frieds right away...

One question though. RME boxes come with a software mixer that allows me to make internal patches and rout audio between different software (for example record a stand-alone synth to my daw). The Mbox does come with a mixer application but I couldn't find any internal routing options. Do you know if it's possible with Mbox?

Thanks again for your review,

ith

[stingray1122]

Maybe you could answer a controversy that's being discussed in another thread -how much the "glue" (resistors, circuit board layout, caps, power supply) influence the final sound compared to the converters themselves. My position is that two devices could use the same converters and preamp chips, yet sound different depending on the components wrapped around them. Some feel the difference is small but noticeable, others feel it's negligible...could you speak to this not so much from Avid's standpoint, but from an engineering standpoint, and which components tend to have the greatest influence on the sound?

Today’s converter chips generally perform pretty well, and in many cases manufacturers are all using the same chips or chip families in their products. But making a great converter takes much more than just the chip itself. The analog design, power supply, and clocking all play critical roles in creating a great-sounding converter.

Power will have a huge impact on everything—especially with analog audio, where your transferring voltage through copper circuits. You need to get the grounding right, manage low amounts of power on bus-powered devices, and keep the “loud” power traces away from the audio traces in the layout (this isn’t easy when you’re dealing with a 4- or 8-layer PCB). The power supply needs to be efficient while providing enough capacitance for good transient response.

Good analog design is critical. Little things can make a big difference, like keeping the audio traces away from digital traces to avoid introducing noise to the circuit. In many cases, a few millimeters one direction or the other can make a big difference. Components such as op amps and resistors need to be high quality. But it’s not just which components you use—it’s where you place them. It’s important to continuously listen to the signal path and various components in series to make sure what you are hearing is just as good as the specs you are seeing. There is definitely an art to good converter design, and the ears are always your ultimate guide.

Finally, there’s clocking. Jitter attenuation is key. Less jitter equals less smearing, giving you a better sound stage and depth. There are many different kinds of clock circuits and crystals, and just like other circuits, implementation is key. How much jitter attenuation do you allow for? How tolerant do you make the clock to incoming jittery signals vs. keeping internal clocking as low jitter as possible? All of these decisions have an impact on the end result, both in terms of sound quality and functionality.

All of these elements of the design play a factor in the final sound quality. If experienced engineers and quality components are involved, the converter will likely sound good—especially compared with what was available 5–10 years ago. When I’m evaluating a design, in the end, I always trust my ears. It doesn’t matter if we've allowed extra space between traces and implemented an excellent clock if it doesn’t sound great in real-world use.

RayT

[CME]

Just wondering if you were gonna get to the other models. I recently sold my 002 to get something smaller and more portable. I'm wanting to get a mh uln-2, or maybe a babyface, but if the d/a on the other mboxes is as good as the pro I might get one of those for now as I save up my pennies.

[Anderton]

 

Originally Posted by stingray1122

Today’s converter chips generally perform pretty well, and in many cases manufacturers are all using the same chips or chip families in their products. But making a great converter takes much more than just the chip itself. The analog design, power supply, and clocking all play critical roles in creating a great-sounding converter.

 

Thanks Ray, I agree. I designed an analog flanger once where there was 2V of RF (from the high-speed bucket-brigade delay clock) on the ground traces! By re-designing the circuit board, it ended up being 20mV. That's quite a difference...

[Anderton]

 

Originally Posted by CME

Just wondering if you were gonna get to the other models.

 

I'll be doing the USB version soon. I have one question here I need to answer, and I also want to see if there are any other comments on the MBox Pro before moving on...I don't want to mix and match products any more than necessary in a single thread, but I do think the USB model is definitely relevant.

[CME]

 

Originally Posted by Anderton

I'll be doing the USB version soon. I have one question here I need to answer, and I also want to see if there are any other comments on the MBox Pro before moving on...I don't want to mix and match products any more than necessary in a single thread, but I do think the USB model is definitely relevant.

 

Cool. And thanks.

[Anderton]

Originally Posted by ith

One question though. RME boxes come with a software mixer that allows me to make internal patches and route audio between different software (for example record a stand-alone synth to my daw). The Mbox does come with a mixer application but I couldn't find any internal routing options. Do you know if it's possible with Mbox?

I get what you're asking, the SCOPE system had this sort of thing and there are a few other systems I've run into that allow creating "virtual ins and outs" to and from different pieces of software. As far as I can tell, this is not possible in the Mbox control panel - Here's a screen shot of the routing matrix (I've also attached the same image), which seems to relate only to the hardware ins and outs.




[Edit by Jon Chappell] And here's the routing matrix of the "regular" Mbox (the one between the Pro, shown above, and the Mini)

[Anderton]

I wondered what the soft limiting option would do to a waveform. So, I grabbed my trusty Phonic PAA6, set it up to generate a 1kHz sine wave, and turned up the levels going into the input.

The picture on the left shows what happens with soft limiting. The peaks become more and more flattened, but retain their roundness, until they start to hit heavy distortion. Meanwhile, the picture on the right shows soft limiting taken out, and we see the familiar characteristic of the waveform staying the same until it butts up against the available headroom, at which point it "flat tops" and eventually turns into more of a square wave.

[Anderton]

A picture may be worth a thousand words, but an audio example is probably worth more than a picture when you're dealing with distortion

So, the attached audio example gives an idea of what Soft Limit does to the sound. I fed in a guitar, and set the Mbox preamp gain to deliberately distort the signal. The first part is the sound with Soft Limit out, and you can hear the nasty high frequency harmonics. The second part has Soft Limit in. Obviously it's still distorted, but the sound quality is definitely more acceptable.

The point of this is not to recommend you use Soft Limit when recording guitar (but hey, whatever floats your boat!), but rather, to give you an idea of how these two processes would affect the occasional overload. Clearly, the soft limit option would do less violence to the signal. In fact, the reason why I used guitar for this example is when I tried drums with sharp transients, you couldn't really hear how soft limit affects the sound; so I felt something more extreme was in order.

[Anderton]

The mixer applet provides zero-latency monitoring, but it also has some other tricks up its sleeve. (Sorry, but for most of these shots you'll need to scroll horizontally to see the whole thing.)

The following shows the basic mixer. The basics are self-explanatory: You have inputs, returns from the DAW, faders, etc. However, we will look at the effects in more detail.



You might have noticed the tuner tab at the top: Yes, there's a built-in guitar tuner, which is really quite convenient - good move! The following shows the Tuner from the MBox USB because it takes up less space onscreen, but the functionality is the same.



Now let's look at the effects. Basically, it's all time-based - two halls, three rooms, plate, echo, and delay. As with the tuner, I'm using a screen shot from the MBox USB to take up less space, but the effects section appear to be identical for both.



And if you want to hear the reverb in action, and listen to an explanation of how it works, I talk about it while fooling around with the reverb controls so you can hear how they affect the sound. Simply play the attached MP3 - it's about a minute and a half.

Finally, here's what the Settings screen looks like, which covers basic utilities and such. Nothing to spectacular here, but we have the bandwidth, so why not show it?

[Anderton]

The middle-of-the-line Mbox (between Mbox Mini and Mbox Pro) isn't the focus of this review, but we'll still give a brief overview. It's very much like a subset of the Mbox Pro, except it's USB 2.0 compatible and can be bus-powered. While smaller, it still has the "built like a tank" construction and many of the same controls and functions (e.g., the SoftLimit option and the Multi button for controlling certain Pro Tools functions). Really, you can just take the opinions on the various Mbox Pro features, overlay them on a smaller feature set, and...there you have it.

However, let's also look at the performance. As you'll see, it's very close to the Pro version, and in some cases, identical.

Let's start with the frequency response. It's essentially flat to 10Hz.



Now, let's look at the noise performance...as you can see, there are no noise components higher than -120dB. Nice.



And here we go with the THD. There's a second harmonic component that's below -110dB, and a third harmonic below -100dB. Everything else is pretty much negligible and lost in the (already low) noise floor.



As to intermodulation distortion, there's the same level of performance as the Pro - in other words, "Where is it?" The only distortion products of the 60Hz and 7kHz tones are at 120Hz and 180Hz, and they're not exactly prominent - both are around -110dB.



Crosstalk is pretty much a copy of the Mbox Pro.



And finally, we have THD levels. As you probably know, with digital technology distortion increases at lower levels due to having less resolution; at -6dB, the THD level is below -84dB and at -15dB, the THD level is around -78dB. These definitely get a thumbs up in the specs department.

http://imgur.com/W5Jpx

So that's the story on the Mbox USB. Suffice it to say that if your needs are more modest than the Mbox Pro, or your finances can't stretch for the Pro version, you basically get the same performance in a smaller device with less I/O.

[Anderton]

As always, let me emphasize that "conclusions" means I feel I know enough about a device to draw conclusions, not that the Pro Review has concluded. Feel free to continue asking questions and posting observations; if I discover anything further in the course of working with the Mbox Pro or Mbox, I'll post my experiences here.

If you've been following this review, you can probably guess my conclusions: The 3rd generation Mbox is light-years ahead of the previous generations, in all respects. The design, construction, features, shielding, mixer application, specs, you name it - everything is a step up. But, it's not just a step up compared to what came before; the Mbox family can pretty much hold its own against anything out there. Even the DSP reverb is quite good, despite not being intended to be recorded into tracks.

One point I haven't emphasized enough is that the Mbox is not for Pro Tools only. Apparently Avid has taken the whole driver thing seriously, because Mbox worked flawlessly with every program I tested. In fact although my intention was to do most of my testing with Pro Tools, Avid told me that wasn't necessary, Mbox worked with everything. Well, I never pass up a chance to see if a manufacturer is blowing smoke, so after making sure it worked with Pro Tools 9 I used nothing but other programs for the rest of the review - and I still couldn't break it.

I don't like the breakout cable for MIDI on the Pro version, especially because the Mbox USB has real, 5-pin MIDI I/O. On the other hand, the Pro has a lot more I/O and it's already not exactly teeny - getting more panel space for audio I/O is a logical tradeoff for not having 5-pin DIN connections.

Other weaknesses of the Mbox Pro include...uh...hmmm...I'll have to get back to you on that. Nothing comes to mind.

I think the biggest problem facing Avid is the less-than-stellar reputation of previous Mboxes; if people think the 3rd generation is more of the same, that would be a shame. Then again, that's probably why they wanted me to do a Pro Review - they weren't afraid of someone getting really down and dirty with the interface, and putting it under the microscope. If so, their confidence was well-placed: Mbox Pro is being marketed as a premium interface, and the bottom line is that it indeed is.

[CME]

Thanks. Good to know the basic versions have the same quality (build and sound) as the Pro. I figured it would but thanks for confirming it.

[Anderton]

 

Originally Posted by CME

Thanks. Good to know the basic versions have the same quality (build and sound) as the Pro. I figured it would but thanks for confirming it.

 

We aim to please I also find it encouraging the level of quality extends across the line, not just the top dog.

[Anderton]

Originally Posted by zephonic

Hi Craig,

thanks for the thorough testing. I have a question about both units, how's the low latency performance?

From the screenshots i see that you were testing the Pro at a 256 buffer....

Actually that's not the case. I did most of my initial testing at 64 and 128 samples, with occasional forays into 96. I lengthened it to 256 when doing the tests as the RightMark version I have doesn't do ASIO, and I felt using MME at 128 was pushing it.

Of course performance at low latencies depends on multiple factors - the complexity of the project, the operating system you're using (I get MUCH better performance with Windows 7 than XP or Vista, even though the hardware's the same), how many plug-ins you're using, etc. That said, I haven't been able to break anything at 128 samples (although I'm not the kind of guy who does projects with 100+ tracks), and 64 samples is what I use when cutting amp sim parts on guitar.

I did not test the units on OS X as I haven't installed Snow Leopard yet, and didn't want to test with an older OS.

[Monte Allums]

Originally Posted by Anderton

Actually that's not the case. I did most of my initial testing at 64 and 128 samples, with occasional forays into 96. I lengthened it to 256 when doing the tests as the RightMark version I have doesn't do ASIO, and I felt using MME at 128 was pushing it.

Of course performance at low latencies depends on multiple factors - the complexity of the project, the operating system you're using (I get MUCH better performance with Windows 7 than XP or Vista, even though the hardware's the same), how many plug-ins you're using, etc. That said, I haven't been able to break anything at 128 samples (although I'm not the kind of guy who does projects with 100+ tracks), and 64 samples is what I use when cutting amp sim parts on guitar.

I did not test the units on OS X as I haven't installed Snow Leopard yet, and didn't want to test with an older OS.

Hi Everyone, and thanx Craig for the review. I wanted to chime in here as a Mac user running Snow Leopard. I recently went on a search to upgrade my recording interface. I was using a very old 16 bit unit from Apogee. I used it for years. But when my G5 died and I bought a new Quad Core Mac Pro I felt it was time to upgrade. I wanted something that would at least do 24/96 and worked well with my Intel Mac. I almost bought the new Apogee Duet but I just felt a little underwhelmed by its features (or lack thereof). I found a great deal on a MBox Pro 3 on eBay and ordered it. It worked for a day and died.

So I returned it for a refund. But even though I was discouraged with the faulty unit I really liked the box so I decided to buy one locally. I have had it now for 2 weeks and so far so good. I use it with a Great River pre and Cubase 6. I have mine set at 128 samples and find it performs excellent and latency is not an issue. There seems to be a few bugs in the software. I often have to reboot the MBox and Mac to resolve them. But I understand it's new to the market and I'm sure these issues will eventually be fixed. I think (from what I've read on some forums) there were some issues with some of the early boxes.

The MBox I purchased locally doesn't seem to have any hardware issues, at least not so far. I think the thing that has most surprised me is the quality of the on-board preamps. I use a Great River ME-1NV and so I had a great preamp already. But in my tests going straight into the MBox the results have been really good. IMO, The MBox Pro 3 with its feature rich specs and stellar sound quality, is the best value out there for its price point. Plus the thing looks as though it could withstand a small nuclear attack. Good job Avid! I am having a blast with this thing..

Thanx,

[Anderton]

 

Originally Posted by Monte Allums

There seems to be a few bugs in the software. I often have to reboot the MBox and Mac to resolve them. But I understand it's new to the market and I'm sure these issues will eventually be fixed.

 

Thanks for chiming in, Monte. Be sure to check the Avid site for new drivers - the current Mac driver rev is 1.0.8. I just upgraded to Snow Leopard (as in, yesterday!) so I'll give the unit a spin at some point, and see what happens.

[jasonsmith]

I was looking at miking my amp with a Shure SM57 to record my guitar playing. I play mostly metal. I haven't done any recording thus far. And a few different people at the big box stores recommended the Mbox. Is the Mbox with Pro Tools 9 probably the best bang for the buck combo pack? I was looking at the regular Mbox since it has more features than the Mini.

And is the Pro Tools 9 that comes with the Mbox the full version? I know some of those combo packs come with a limited version of the software.

I was originally looking at the Line 6 UX2 that has the Pod Farm. As the Pod Farm has virtual instruments, so I could use that to get my clean guitar sounds. But they never got it working with Windows 7.

What laptop requirments with Windows 7 would you recommend be the minimum with the Mbox and Pro Tools 9? I know I've got 4GB of RAM.

Though, some guys online had instead recommended that I spend the most I can on an interface and just get Reaper for the recording software. But Reaper looks rather limiting since it is only $40. Plus since I'm new to all of this. I could at least get a set of DVD's that shows me how to use Pro Tools.