[Tip] Tips For Laptop Performers

[Lo-Key Fu]

Hi all,

Now I don't claim to be any kind of expert on these matters - in this case, more of a compiler - but I thought it would be useful to put together a list of tips to help avoid performance issues on a laptop as there seem to be some common ones that vary a little from regular desktop/studio use. This thread is written specifically for those who haven't ventured into the live realm before, but by all means chime in if you have any "power user" tips to offer too; I'm sure we'd all love to hear them!


CROSS-TALK NOISE
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Some combinations of sound-card and laptop AC power-pack can generate unwanted noise. Two common causes of this noise might include: crosstalk between the two devices or a groundloop.

Possible Solutions
- Buy a portable power conditioner (comparatively expensive).
- Run off laptop battery for your set (may not be possible).
- Use the "Earth Lift" on a DI box (may not help in all situations).
- Remove the ground pin out of a power adapter (quick fix only, potentially dangerous!).

* WARNING: REMOVING THE GROUND FROM A PLUG TO STOP A GROUND LOOP CAN BE EFFECTIVE, BUT IT COULD ALSO KILL YOU! IF YOU DON'T HAVE THE ELECTRICAL KNOWLEDGE TO KNOW WHETHER IT IS SAFE TO REMOVE THE GROUND ON A PARTICULAR DEVICE, DON'T!

SUB-BASS VIBRATION
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Bass-heavy venues can provide an environment that will bounce the heads on your hard-drive causing performance issues during your set. Excess vibration can result in audio glitching, audio drop-outs and possibly hard-drive damage.

Possible Solutions
- Make/buy a rubber/foam mat/mount to reduce vibration/shock.
- Play your set from a USB Flash Drive


DATA TRANSFER ISSUES
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Until recently (and even still in the case of some manufacturers), standard laptop hard-drives will often perform a lot slower than their desktop counterparts in terms of data transfer. A lot of hard-drives are around the 5400RPM mark, whilst standard on a desktop is more like 7200RPM. If you are experienced audio drop-outs or glitching, it may be due to the slow data transfer rate of your drive.

Possible Solutions
- Purchase a faster hard-drive for your laptop (external).
- Play your set from a USB Flash Drive


OPTIMISE YOUR LIVE SET
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There are a number of choices you can make in preparing your live set to improve the performance of an older machine (or make a newer one even more capable).

Possible Solutions
- Use fewer channels in constructing your set.
- Reduce the bitrate of your source samples (16bit is not a dirty word!).
- Use mono samples instead of stereo (halves the required transfer rate).
- Use hotkeys to turn off FX that are not in use.
- Use send/return channels for global FX rather than placing a new instance.
- Bounce MIDI tracks down to audio if you don't need to tweak them.


SYSTEM-RELATED PERFORMANCE ISSUES
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Using a computer for audio can be a very different application than usual desktop use. For this reason, there are a number of simple things you can do to ensure you are getting the best possible response from your system at all times.

Possible Solutions (General)
- Keep your system clean, organised and with a bare minimum install.
- Defragment your Hard Drive regularly.
- Make sure relevant power settings are NOT running in "efficiency mode".
- Disable unused background applications (eg. antivirus, bluetooth, wifi).
- Consider using a disk-imaging program for emergency system roll-back.
- Consider rebooting your system before starting a performance.

Possible Solutions (PC Only)
- Visit musicxp.net and use their Tuning Tips (registration required)

Possible Solutions (Mac Only)
- Suggestions welcome!

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Hope this helps some people into their first live sojourn, and looking forward to hearing from others as to some general "Best Practice" type tips.

Kudos to all.

[andydes]

Ah, good thread.

Although I thought cross talk was different to ground loop problems. And definately go for power conditioner and DI box options rather than removing earths. Especially for Macbook pros or other metal cased laptops.

I'd also add in the system performance, turn off unused background applications, such as virus software, bluetooth and wifi.

And when optimising sets, you could bounce instruments tracks down to audio if you don't need realtime tweaking of synth parameters. Obviously you can still add effects.

I've only done a few sets, but I'm sure I'll think of some other issues. I seem to have had enough.

[Lo-Key Fu]

Although I thought cross talk was different to ground loop problems.

I am entirely happy to stand corrected on this one if need be mate, but I was of the opinion that the ground/earth was one of the more common causes of cross-talk. The lift itself simply prevents the current from other devices travelling through cable shielding - which can prevent ground hum (a type of cross-talk?). Any experts out there care to clarify? As mentioned earlier, I certainly don't claim to be one...



Thanks for your input too andydes - all great suggestions - and I have added your thoughts to the top post.

[andydes]

Although I thought cross talk was different to ground loop problems.

I am entirely happy to stand corrected on this one if need be mate, but I was of the opinion that the ground/earth was one of the more common causes of cross-talk. The lift itself simply prevents the current from other devices travelling through cable shielding - which can prevent ground hum (a type of cross-talk?). Any experts out there care to clarify? As mentioned earlier, I certainly don't claim to be one...



Thanks for your input too andydes - all great suggestions - and I have added your thoughts to the top post.

No problem.

You could well be right. I always think of cross talk being signals to left and right channels bleeding into one another, but could easily be whatever noise the signal is picking up. I'm no expert either, dispite the post count.

As for other problems, I know the biggest issue I had (other than crap gear in the bar) was from my music sounding completely different on a big system. Really just a problem for sequence sets rather than DJing. Sadly, I don't have any advice other than to expect it coming and try to deal with it.

[Lo-Key Fu]

Although I thought cross talk was different to ground loop problems.

I am entirely happy to stand corrected on this one if need be mate, but I was of the opinion that the ground/earth was one of the more common causes of cross-talk. The lift itself simply prevents the current from other devices travelling through cable shielding - which can prevent ground hum (a type of cross-talk?).

I always think of cross talk being signals to left and right channels bleeding into one another, but could easily be whatever noise the signal is picking up.

Anyone in the know care to clear this one up for us for the sake of reference? I have been a-googling, but little luck in achieving a laymans terms answer so far...

As for other problems, I know the biggest issue I had (other than crap gear in the bar) was from my music sounding completely different on a big system.

I suppose the only way around it would be to try and get yourself a decent pre-show sound check and tweak some levels or EQ loops/sounds through the system itself as required.

I guess two other tips that might be related would be:

Mono or Stereo?
Find out whether the system you are playing through is mono or stereo. A lot of venues in my neck of the woods use trashy mono systems which can really screw any stereo imaging or panning if you're not careful. Two simple workaround solutions would be:

1. Work entirely in mono for live purposes.
You can always add a stereo reverb or the like on the master bus to widen the signal on a decent (stereo) system; OR

2. Drop some Utility FX onto your stereo tracks.
And use the Level control to adjust them accordingly when playing through a mono system.


The Low End
This one is always going to be a little tricky if it is a system you have never played on before. A soundcheck will certainly help, but some other simple tips could include:

* Use low cut EQs on most of your sounds to prevent a muddy live mix. You shouldn't need any sound lower than about 30Hz (as most systems won't reproduce lower than this frequency anyhow); and you could probably be a little more adventurous with other sound groups depending on how you arrange your set. (eg. cut below 80Hz for a Lead bus, 60Hz for a Kit BUS etc).

* Try not to have more than one full bass sound playing at a time unless the sounds have been pre-engineered to work together (or they bounce between one another). For most styles, one solid bass is better than four simultaneous muddy ones.


Perhaps not the most innovative of tips so far, but I hope they help someone at least.

Anyone else got something to share?

[fishmonkey]

Although I thought cross talk was different to ground loop problems.

I am entirely happy to stand corrected on this one if need be mate, but I was of the opinion that the ground/earth was one of the more common causes of cross-talk. The lift itself simply prevents the current from other devices travelling through cable shielding - which can prevent ground hum (a type of cross-talk?).

I always think of cross talk being signals to left and right channels bleeding into one another, but could easily be whatever noise the signal is picking up.

Anyone in the know care to clear this one up for us for the sake of reference? I have been a-googling, but little luck in achieving a laymans terms answer so far...

i'm no super-expert either, but i'm pretty sure the following is true:

in audio systems, crosstalk usually refers to a signal in one cable/device inducing a signal in another cable/device... classic example: when you setup a live sound system, extra lengths of power cable are always (or should be!) laid out in figure-8 loops, rather than left coiled on the ground... coils of cable form inductors (think of the coils of wire in a transformer), which create magnetic fields that can then create electrical currents in other cables nearby... like a mic cable...

however, the most common form of unwanted noise in an audio system is caused by ground loops, which is a different beast... classic ground loops are caused by slightly different potentials between the grounding circuits in different pieces of equipment... this is why it is good practice to have all the devices in an audio system plugged into the same power point, since different power points may be on different power circuits in the building... the main symptom of a ground loop will be a hum at whatever the AC frequency is (usually 50 or 60Hz), maybe with some other harmonics added in just for fun! there are many possible causes of a ground loop, which i won't attempt to describe here...

WARNING: REMOVING THE GROUND FROM A PLUG TO STOP A GROUND LOOP CAN BE EFFECTIVE, BUT IT COULD ALSO KILL YOU! IF YOU DON'T HAVE THE ELECTRICAL KNOWLEDGE TO KNOW WHETHER IT IS SAFE TO REMOVE THE GROUND ON A PARTICULAR DEVICE, DON'T!!!!!!!

apart form anything else, the ground pin on a 3-prong plug is there to shunt potentially lethal currents away to the ground/earth if a short circuit occurs in a device.... AWAY from you, that is....

[Da hand]

DATA TRANSFER ISSUES
-------------------------------------------------------------
Until recently (and even still in the case of some manufacturers), standard laptop hard-drives will often perform a lot slower than their desktop counterparts in terms of data transfer. A lot of hard-drives are around the 5400RPM mark, whilst standard on a desktop is more like 7200RPM. If you are experienced audio drop-outs or glitching, it may be due to the slow data transfer rate of your drive.

Possible Solutions
* Purchase a faster hard-drive for your laptop (internal or external).
* Play your set from a USB Flash Drive

For this one, one has to be aware of where speed bottlenecks occur. If you have an external 7200 rpm hard-drive with a USB 2.0 / firewire 400 connection, the data access will be slower than on an internal 5400 rpm hard-drive.

Also, although similar in theoretical maximum transfer rate, in real-world use, especially for high-bandwidth use such as external hard-drives, FireWire 400 generally, but not always, has a significantly higher throughput than USB 2.0.

The solution for fast data transfer, for now, is to hook up an external SATA drive though a PCMCIA card - or at the least firewire 800.

This is also why desktops still outperform most laptops. The connections between the components offer a much faster data transfer.

USB 3.0 (4.8 GBits/s) and firewire 3200 is forecast to appear on computers in 2009 - can't wait!

[fishmonkey]

here is a good reference about ground loops:

http://www.epanorama.net/documents/groundloop/

[barry tone]

ditch USB for midi where ever possible!

for me connecting my bcr2000 by midi stopped my whole setup crashing whenever it was exposed to a decent level of bass.

[Tuur]

Creating a special Live profile does work: http://www.blackviper.com/WinXP/xpprofiles.htm

After ditching a $#!+load of services and disabling a bunch of hardware (1) in my new profile (2) I'm getting fantastic results on my Dell Latitude.

My ancient EMI 2|6 gives me 2ms latency in Live and my BCD2000 4ms. Both are at the lowest setting of their control panels now. I haven't tested my BCD3000 yet, but I expect the same results.

Before all this I was at 40ms for the EMI and the BCD just stopped working after ~20 secs of playing at the max setting. At lower settings it was drop-outs and crash heaven all over the place.

Go figure.

1) BT/IR/WiFi/network adapters/FireWire/PCMCIA bus/etc

2) boot with new profile > device manager > choose 'disable in this profile'

Also: http://support.microsoft.com/kb/308577

[Kozak]

Is a flash stick really the solution to fast and vibration free performance? No fast external HD's are needed anymore?

In a four track setup playing a simple 2 deck DJ setup how cheap can your machine be? Can I use one that is listed with minimum specs (considering I would only use EQ and some effects on one or two audio files running at the same time) or do I need a more expensive laptop?

I'm looking at a toshiba satellite p300-13j laptop....

[Lo-Key Fu]

@fishmonkey:
Cheers for clearing up the earlier ground/crosstalk discussion mate; an interesting read, and I'll happily stand corrected. Kudos for taking the time to provide the extra link too.


@Da Hand:
Thanks for the extra info mate, I'll adjust the top post accordingly once I have this one dusted.


@barry tone:
Woah! Interesting. Any idea of the cause? Did you have other USB devices connected in your usual uses of it? Just curious more than anything else, but glad you fixed the issue.


Tuur
Great tip mate, I'll add that one to the top post too. Cheers!


@Kozak:

Is a flash stick really the solution to fast and vibration free performance?

It was for me; solved a stack of performance issues in one fell swoop. Everyone works differently though, and the best way to find out would be to get your hands on one and give it a whirl.

In a four track setup playing a simple 2 deck DJ setup how cheap can your machine be?

Comparatively speaking, my answer would be "very".

My own live performance system is 6 years old (P4 2.4, 1GB RAM, 30MB/s transfer speed via USB2) and I comfortably run a live set requiring many times the processing power, transfer speed and resources as the hypothetical set you have outlined.

I would suggest that you would be wise not to skimp on the soundcard though.



EDIT:
After adding in fishmonkey's warning text (re: removing earth pins) and the link to the ground loop page I realised that in this instance editing the top post is going to get pretty messy pretty quickly. I have decided just to leave it be for now as I assume that those interested enough in the topic will read this thread anyhow. Thanks again to all for the contributions so far!

[franklyimshocked]

All good tips.
I decided to play a live set about 2 weeks after getting the program. I'd been using it on the Battery but when I set up in the club I decided to use the mains soi that I didn't shut down mid set. The power outlet I was using was connected to the rest of the system so I got some scary cross talk interference.

Still had to play and blamed the soundsystem the whole night for the hum