Some Guidance On Headsets

Sennheiser-PC131-Headset.jpg

Passport_21_OTH_3_QTR_RightA couple of weeks ago, over at the Broadband Reports forum on VoIP Tech, there was a question posed about selecting the best low cost microphone for VoIP applications. This is a topic that I’ve considered at length. It has much in common with my background in recording and broadcasting. On that basis I weighed in with some opinion. As I my way, I probably provided a longer answer than anyone anticipated, or even wanted. After re-reading it a few times I thought it worth sharing here as well.

The original question:

I realize many problems people experience are due to a lousy mic that isn’t noise canceling or picks up sounds from a anywhere in the room. There are many ways to improve this. I like the idea of a pickup pattern that is very isolated in front of the mic and within a finite range so I don’t have to wear the mic but maybe this is asking too much. If the mic only picks up sounds very close to it, wearing it can sure avoid a lot of problems. Don’t know if firewire or USB3 is better than USB2 or if its better to run the mic directly into your mic input of your motherboard or audio card or something else. Latency is not our friend! VOIP is so sensitive to extraneous noise so this needs to be addressed and is dependent on the ambient noise of the user. Any recommendations? Few of us work in a soundproof office.

As a long-time and vocal proponent of headsets for office use this is right in my wheelhouse. For example…. https://www.mgraves.org/2011/07/can-you-hear-me-now-headset-vs-speakerphone-in-the-home-office/

But first, an examination of what’s been said….

If the mic only picks up sounds very close to it, wearing it can sure avoid a lot of problems.

What you’re really getting at here is that the very best pickup of your voice, without other sounds, can only be accomplished with a microphone near to your mouth. To my mind that implies a headset with a boom-mounted microphone.

Manufacturers who make such products typically offer many different models. Some feature a simple microphone, while others may feature a noise cancelling microphone design. In the case of microphone design, noise cancelling can be implemented through acoustical/mechanical means or electronics. Both approaches can be very effective at suppressing background noise.

Sony mobile phone headset

In my opinion, ear-buds with an inline microphone(above), as commonly used with mobile phones, don’t cut it for office application. They are better than nothing, but less than ideal.

Don’t know if firewire or USB3 is better than USB2 or if its better to run the mic directly into your mic input of your motherboard or audio card or something else.

There’s effectively no difference between USB 2.0, USB 3.0 and Firewire for the purposes of audio. I know of no Firewire audio interfaces that are specifically designed for telephony. They tend to be for audio production and music recording.

In my experience, the analog I/O of laptops are not bad. I have a Lenovo X1 Carbon and routinely use it with an analog headset. In the past I’ve used various Dell and HP models, all with equal success.

In contrast, the analog I/O on a desktop motherboard can be very noisy. This is result of very low-level analog signals being handled in the presence of noisy, high-speed digital circuitry. This is why high-end audio interfaces for desktops eventually moved to USB attached external devices. It keeps the sensitive analog microphone pre-amp circuitry away from the RF environment of the computer internals.

USB attached headsets can be very good…but they can be very bad also.

Windows occasionally suffers problems with USB headsets. I’ve seen Windows become so confused about the state of a USB bus that it cannot access an audio device. This seems especially true when hot-plugging devices. When it happens the only solution seems to be a reboot of the system. I’ve even had a few rare cases where they simply can’t be made to work reliably.

Such cases are the exception, as I’ve used a number of USB headsets that work very well indeed. When they work they have the advantage of being easily identifiable in the list of audio devices. A USB headset from a major manufacturer like Jabra/GN, Plantronics or Sennheiser is usually clearly indicated by name and model. Those from lesser known names may be indicated by the make/model of the USB audio chip incorporated into the device.

A word of warning about the cheapest USB attached headsets. The price of the headset encompasses both the electro-acoustic components and the audio interface electronics. The very cheapest models, say those under $30, may be compromised in some fashion to meet the target price point. That could be manifest merely in cheaper plastics, but it’s very likely to impact the the audio performance of the device.

Latency is not our friend!

That’s true, but the amount of delay induced by different “sound cards” (aka analog audio interfaces) is insignificant. In fact, it’s miniscule compared to the delay caused by packetization or other network functions.

VOIP is so sensitive to extraneous noise so this needs to be addressed and is dependent on the ambient noise of the user.

I don’t think that VoIP is any more sensitive to noise than a TDM path, or an analog production audio path. What you describe is like caused by gain manipulation possibly involved in the VoIP path.

For example, if you’re using a soft phone it might well use auto gain control to ramp up your microphone level when you’re not speaking. That makes your typing or ambient noise around the office go up, even as you are being quiet. When next you speak, you explode back into the conversation until the AGC clamps down on your level.

With a soft phone like Jitsi, Bria or X-Lite you can turn the AGC off if desired. If you’re using browser-based service like Google+ Hangouts or Jitsi Video Bridge you may have not have explicit, readily accessible control of the audio gain.

A Recommendation: Quality & Flexibility

While there are many possible solutions to be had, I like flexibility. In my work with ZipDX we’ve been looking for devices that we can recommend that don’t cost a lot, but give you maximum performance and flexibility.

vxi passport 21 headset and QD cord

For the moment, we’ve somewhat settled upon the Passport 21V Headset. It costs around $60. Not cheap, but not outrageous. It’s rugged, comfortable and has a good boom-mounted microphone. It also supports HDVoice.

It terminates in a “QD” quick-disconnect fitting. The quick-disconnect cable means that you must buy a bottom-cable appropriate for the device that you’re going to connect to.

VXI QD cables 1

There are QD bottom-cables that terminate in RJ9, 3.5mm TRS, 3.5mm TRRS, (2) 3.5mm TRS or 2.5mm TRS. There’s even one that has an inline USB audio interface, meaning you can connect it to a USB port.

VXI QD cables 2

That means that, with the right lower cable, you can use the headset with just about anything. Sure, you’ve spent about $80-90 for the headset & cable, but it’s a quality too that will last.  Further, you know that it can be adapted to whatever comes next.

Call center headsets that are designed to last are well worth the price. The very fact that a manufacturer offers a “foam refresher kit” kit, with replacement ear cushions and windscreen, tells you that they’re serious. We’re talking about tools vs toys.

A Recommendation For The Cost-Conscious

Sennheiser PC131 HeadsetIf you require a really low-cost solution then simple may be the way to go, while retaining some flexibility. A decent analog headset from a reputable company (the Sennheiser PC 131 is shown) can be had for around $30.

For another $10-12 you can add a USB audio interface (the Plantronics .Audio 770 is a good one, although there are many cheapies many under $10)

This combination allows you to avoid a a noisy on-board sound card if required, or use the headset with a server that doesn’t have any on-board audio interface. It also supports HDVoice!

The Bottom Line

For optimal audio get the microphone near your mouth! Without optimal mic placement, any kind of noise cancelation is a remedial step. No matter how sophisticated the echo cancellation or background noise reduction, it will never be as good as starting with optimal audio pickup in the first place.