Gennum nXZEN Plus 5500 Bluetooth Headset


My first Bluetooth headset review was of Bluetake’s BT400 G5 Bluetooth headset. Like most products, there were things I liked, and things I didn’t. But now that I have a little experience with headsets, I’m ready to do review #2. This time I’ll be looking at Gennum’s nXZEN 5500 Plus Bluetooth headset. Wow, that was a mouthful! This headset claims to have 4x the noise reduction of other headsets on the market, due to a powerful Digital Sound Processor and a two microphone array. That sounds mighty impressive, but let’s see if those specs really live up to the hype.

Hardware Specs

Bluetooth 1.2

DSP Performance – 120 MIPS

Stereo- 16 kHz audio bandwidth processor

Audio Path: 20-bit end-to-end path

Talk Time: Up to 7 hours

Standby Time: 100 hours

Charge Time: 2 hours

Battery: Lithium Polymer

Four-Button Operation

Multiple Device Pairing

Weight:17 grams (0.54 oz)

Size: Length 59.9mm Height 28.5 mm

Package Contents

nxZEN 5500 Plus Headset

4 ear tips

2 ear hooks

Stereo earbud / music player adapter

AC adapter

USB charge cable

User’s manual (not pictured)

Quick reference card

CD with equalizer software (PC)

The nXZEN (pronounced: nex zen) is available in Silver and Pink. As you can see, I was sent the Silver version to review. The headset is made of light weight plastic and is a size which is not too big and not too small. The style isn’t flashy, so you shouldn’t get too many stares from people while wearing it.

The face of the headset has one large button with a LED ring around it and the dual microphones. The LED lights up and / or blinks during different scenarios such as power on/off, pairing, and during a call. The problem is that the LED does not light up or blink while in standby. This makes it difficult to know if it is powered on or off at any given time. The large side button is used to turn the headset on / off, answer / end calls and to switch between music and call modes.

The back edge of the headset has a black rubber covering. On the top is the Volume Up button and on the bottom is the Volume Down button. In the middle is the socket for the AC adapter, USB charge cable, or secondary earbud. The volume buttons are hard to press, both due to their location and the fact that they are covered in thick rubber. They also have really bad tactile feedback. The only way you know that you’ve increased the volume level is when you hear a beep to let you know that it’s at the max setting.

Near the microphone area at the top edge of the nXZEN is the Pinch button. There appears to be a matching button along the bottom edge, but it actually just a dummy button. The pinch button for different functions including pairing, number redial, voice dial, swap between call waiting and current call, etc.

The nXZEN comes with 2 different sized earhooks and 4 sizes of eartips. The earhook is easily flipped to allow for wearing over either ear. The hook itself is covered in rubber and is not adjustable. I used the smaller hook and found that it was still a bit too large for me. The hook is removable though. So, the headset can be used with it, if used with one of the in ear tips. I’ve never been a fan of cramming something into my ear canal, so I opted for the softest and smallest eartip (the clear one).

As far as comfort is concerned, I would rate the nXZEN as moderately comfortable. I found the Bluetake BT400 to be better in this regard. I like the style of the earphone / eartip better on the Bluetake.

I used this headset for a over a week with my Treo 650 and had quite a bit frustration with it. Pairing was no issue at all, but I found that the headset would take too long to reconnect to the Treo when making or receiving a call. The Treo could ring up to 5 times before the headset would beep in my ear. Or, when making a call, it would finally ‘kick’ in after the person had already answered. This behavior became quite annoying to say the least. Half the time I wondered if the headset had been powered off inadvertently.

There was also the fact that I had problems remembering how many times to press or how long to hold down the pinch button to redial, pair, mute, etc.

Once in a call, the volume level on my side was not as loud (at max volume) as I would have liked. Especially if I was in a noisy environment. I’m sure that if you happen to use one of the in-the-ear-canal tips, it might not be so bad.

People on the receiving end of my calls said that my voice quality was very good. No clipping, static, etc.

Below are three audio clips of nXZEN in action. This will give you an idea of what it sounds like to receive a call from someone using the nXZEN. I used the free voicemail / fax service from for these tests. I
signed up for a free account, got a phone number and called it with the Treo 650, using the headset. The resulting voicemails are then emailed to you. Pretty nifty! These tests had the nXZEN paired with my Unlocked GSM Treo 650. I use Cingular, and at test time had full signal strength. The phone was in my jacket pocket during the wind test and beside me on the car seat for the driving test. Click to listen.

Inside Test (312k .WAV file)

Wind Test (320k .WAV file)

Driving Test (200k .WAV file)

In my opinion, the first clip sounds ok until I start walking away from the phone. That’s to be expected though and I don’t fault the headset for that. I was more anxious to hear the results of the wind test, to see just how well the noise reduction feature really worked. From the recording, you can definitely tell when the wind was blowing directly into the microphone, as my voice sounded like I was talking via a tin can. The driving test sounded pretty good to me, as far as the clarity and volume are concerned.

In addition to being a handsfree headset for your mobile phone, the nXZEN can also be used as a headset for your favorite audio player. Shipping with the nXZEN is a special one earbud. One end plugs into a 3.5mm stereo jack, and the other end plugs into the charger jack on the outside edge of the headset. Once connected, you can press the side button once to go into music mode. Music from the audio device will start flowing through both the headset and the lone earbud. Quality is ok through the earbud, but through the headset, you can hear fuzz / white noise in the background. Bleh! If the white noise wasn’t bad enough, there’s another gotcha with using the headset for your music… you would think that when a call comes in, the headset will stop playing music and allow you to answer the call. Well it does. But the music from the audio device keeps playing through the attached earbud. Grrrrr.

When all is said and done, the nXZEN Bluetooth headset from Gennum does allow you to make calls in very noisy / windy environments. I’m just not so sure that this particular feature is worth the price tag of $159.99, unless you constantly find yourself in noisy situations. I will say that my friend Jeanne was much happier while I was reviewing this headset as opposed to the Bluetake BT400. My voice didn’t clip or cut out during our calls like with the BT. That said, my quest to find the perfect Bluetooth headset continues. The nxZEN isn’t a good fit with my Treo 650, or with my ears.


Product Information

  • Powerful noise reduction
  • Receiving voice sounds good, no clipping
  • Can be used with other audio players as a stero headset
  • Noise reduction can make your voice sound tinny
  • No way to know if the headset is powered on, by looking at it
  • In music mode, there is static from the headset
Posted in: Bluetooth Gear, Wireless
{ 6 comments… add one }
  • Julie March 17, 2006, 2:26 am

    Post your comments on the Gennum nXZEN Plus 5500 Bluetooth Headset review.

    Just click the POST REPLY button on this page.

  • Falcon March 17, 2006, 3:44 am

    Hey there,
    Always enjoy your detailed reviews – excellent work and keep up the good stuff!
    Just wanted to feed back a general comment RE reviews of Bluetooth headsets – one application never considered is the use of such for PC-based voice recognition applications.
    Whereas Bluetooth V1.1 clearly did not allow any adequate provisions for this, V1.2 has the profiles/potential to expand in this direction and I’m watching this space keenly.
    Bluetooth headsets are pretty cool for phone applications, but my Nirvana will be a headset I can not only use for telephony but also use to listen to my emails read to me from my tablet PC and to be able to dictate replies too.
    All the Bluetooth headsets I’ve trialled to date have been found to be wholly inadequate as significant parts of the audible range are just omitted/compressed such as to make them unfit for purpose.
    I’d very much appreciate it if in future reviews you could include some consideration/commentary regarding this particular application (PC-based speech recognition) as to me this would be a “killer feature” (esp. when you consider that any PC with either XP Tablet Edition and/or Office 2003 supports speech recognition out of the box and any PC/notebook with Bluetooth could exploit appropriate hardware and deliver wireless dictation…
    Awaiting the right, innovative product with eager anticipation!

  • Julie March 17, 2006, 12:52 pm


    I’ll have to find a way to do the tests you’re requesting with a Mac. I’ll look into it for the next headset review. I’m going to see if I can get the Scala500. I think I also need to get another Bluetooth capable phone. After posting last night’s review, I found some other reviews that mention how crappy the Treo is as far as Bluetooth. Maybe I’m faulting the nXZEN headset where I should be faulting the Treo instead.

  • palmsolo March 17, 2006, 2:44 pm


    I was sent this headset several months ago and gave the company lots of feedback that very closely matches exactly what you said (very poor button placement and ergonomics, can’t tell if it is paired, etc.). I also thought the wrap around earpiece was very cheap and mine actually broke (the plastic attaching to the headset) after only trying to remove and flip it twice. The earplugs protrude way too far into your ear and without the wrap around earpiece the headset falls out too easily. I tried it with the Treo 650, HTC Wizard, Nokia S60 devices, and WM Smartphones and saw the same performance in all cases so I don’t think it is your Treo. This headset needs some serious work and I don’t understand the high price.

    The Cardo Scala 500 is actually my favorite headset and works very well with the Treo, i-mate SP5m, and Nokia Nseries devices. It is the LOUDEST headset I have ever tried and you can also find it online for less than $40. I was also able to use the Scala 500 to listen to podcasts and music with the HTC Wizard and use Voice Command with this headset.

  • Julie March 17, 2006, 4:05 pm

    I’m glad you posted those comments! It makes me feel better that you had the same experiences with phones other than the Treo. 🙂

  • SQLDba March 17, 2006, 11:10 pm

    I just bought this headset 2 days before you posted the review – figures.

    I would agree that it’s not the best headset I have tried and it’s going back to CompUSA. I expected a lot more from the noise reduction – I drive an hour commute twice a day and rely on a good headset – and noise reduction was the primary reason I bought it. My own testing on my company voicemail, as well as feedback from my callers suggests that when the NR kicks in – my voice quality changes to an almost unacceptable tinny sound.

    I had it connected to a Cingular 8125 and also a 2125 and had the same feedback from both – so it isn’t the phone. That said, I do think that the Treo 650 is a little more bluetooth finicky than some phones out there. At least Palm’s list of “certified” BT headsets is fairly short.

    My next purchase is the Plantronics Discovery 640. About $129 at CompUSA / Cingular stores – but Amazon has it for under $100. Very small w/ a charger that the unit sits in – complete w/ a pentype pocket clip. A lot of other features I won’t describe here. But cNet calls it one of their best.

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