Friday, April 26, 2013

My Happy Ending with Harman Kardon Bluetooth Headphones

After my these and those mods, there were still two problems with the Harman Kardon HarKar-BT Bluetooth headphones: 1) A background noise on the left speaker; 2) Ears hurt by the hard surfaces because the square cups are too shallow. Turned out the fixes were very simple.

For problem #1, I opened the cases again and moved the speaker wire away from the metal box. Also made this wire not so parallel to the other one to reduce interference. The noise is now entirely gone. Very happy.



For problem #2, I used some window/door sealing strips to add about 6 mm depth to the cups. Now my ears won't touch the hard surfaces and I won't get sick after hours of listening. The magnets and three teeth still hold the cups quite well in their positions. Look good too!

You may watch this video for more details:

Now this Harman Kardon is perfect: sounds the best, noise free, comfortable, long battery life and wireless; cannot get any better.

[update]The 6 mm white strips still cannot add enough depth. After few days of use, they were pressed down to 4 mm or so. My ears still hurt. I removed them and used the 5/16" strips. 5/16" is 8 mm, not much thicker than 6 mm, but it is wider and firmer - won't be easily pressed down. I first taped the strips onto the ear pads, then I used several pieces of double-side tape to hold them on to the body. The double-side tape should be very thin and cut to be narrower than the strip so that the strips will still seal well. Without good seal, sound becomes thin and lack of bass.

Abstract in Chinese


Wednesday, April 10, 2013

Tweaking Harman Kardon Bluetooth Headphones

The HarKar-BT is by far the best sounding headphones among my collections including Sennheiser HD-580 and RS160, wireless or wired, significantly better than these Sennheiser's. Its battery life, 12 (>18 in real life) hours, is the longest as a Bluetooth device and it is the thinest as an over-the-ear type.

However, it is not comfortable enough, even after I stretched its band span from 5" to 6.5". After some exam in a mirror, I found the problem. The joints have very little freedom; so the ear pads never settle down evenly around my ears. This video explains it well:

The fix is also shown in the video.

For those who want to open the cases to see what's inside: there are five screws under the seal, use a small magnet to locate them. The speakers are not closed type, there are large holes on the back. This may explain why this BT cannot isolate noise as well as other true closed type cans such as the RS160. Furthermore, there are large holes on the front panel, allowing even more noise in. This is also the main reason for its exceptional good sound, especially as a "closed" type, because it is more like open type, and, with phase-reverse holes like home speakers!

A small square foam was at the wrong location, it did not seat the joint, I moved it to the right place -  bottom center of the circuit board. Without this soft seat in place, the joint makes click noise with the plastic case. The wire to the leather strip was too short, I removed the yellow hot glue and pulled more wire out of the case. The antenna, the small white bar on the top, is very short, I might solder a 30mm wire to it to extend the range even further, but I found that the bottleneck is my other devices (Samsung Note 2 and Sony TX/RX).

The battery is on the right side, quite large indeed, no wonder it can last for more than 18 hours per charge. With such long play time - more than a whole day, lacking of audio during charging is not a big deal. I just need to remember to plug it every night before I sleep and my music won't stop for the next full day. To less the pain further: full charge takes less than 2 hours, not the usual 3.5. When battery is low, sound becomes obviously worse. For the best sound, you really should charge it after about 12 hours, even though it can play much longer than that.

Anyone can explain why these yellow hot glue on the back of the speakers? Seems they block some holes and leave only three (or one, on the metal cover) of them open. The audio engineer seems know what he's doing, the mechanical and electronic engineers don't. I guess you can open or block more holes to tweak the sound style to your like.

I could not find its manual online; so I scanned it for you: HarKar-BT manual, in English and Chinese. The most interesting info is how to know whether it's in APT-X, AAC or A2DP mode based on the flashing pattern of the LED. There is also a flyer on the specs and features, here.

Abstract in Chinese


Monday, April 8, 2013

Harman Kardon Bluetooth Headphones

BestBuy has these HarKar-BT on clearance for $99, so I give them a try. They have over-the-ear cups; on-the-ear type always make me sick after about 1 hour. They support APT-X that's also available on my Note 2. The only alternatives that offer these two features are the Sennheiser MM 500-X and 550-X (NC) for $330 and $500, respectively.

Spoiled by the very comfortable and natural sounding Sennheiser RS160 wireless headphones, the BT was initially way too tight with much more bass. I changed to the included large metal band, still no enough improvement. Then I stretched it from about 5" span to 6", it felt and sounded better. But still too tight to me, because the square cups are not natural and too shallow.

I tried them on a bus ride, engine noise was still too loud; the RS160 does a much better job. I think the squared shape cannot provide an ideal seal. On the other hand, the BT can be turned into flat, much easier to carry in a bag.

Before the BT, I bought a pair of Emerson EM515 bluetooth headphones. There was interference noise on the right side of the EM515. The circuit board is on the right side and it is too close to the drive unit - the coil gets the RF noise. The noise is even louder during battery charging. I opened the EM515 and lifted up the circuit board away from the drive unit and the noise was totally gone but still some during charging.

Harman Kardon says the BT cannot be used during charging. What I found is: it actually works normally - it is still connected over bluetooth and all control buttons work, just no audio coming out of the headphones, they are muted during charge. Why HK would do this? Knowing my above EM515 story, it is not difficult to guess the reason. Yes, indeed, I can hear the interference noise on the left side where there is the circuit board. I guess this noise will become more audible during charging, like the EM515, so that the HK engineer muted the speakers to hide this issue.

To HK, simply cutting off any sound during charge is an easy trick to avoid bad reviews on these $250 headphones; but to me, slightly noisy music is still way better than no music at all.  My $20 Emerson can keep my music flowing like this:

To put salt on the cut, the USB charging port is non-standard. For those who want to make a charging adapter, here is the layout of the 2.5mm 4-pin plug:

One more very annoying thing: the square metal frame always rub against the collar, making horrible resonance.

Final Words:

Bluetooth is finally ready for music, but the Sennheiser MM 500-X and 550-X are currently the only alternatives to this Harman Kardon BT, if you require something that is comfortable and can still provide some noise isolation. If you're a DIY person, you can modify the Emerson EM515 to reach your goal. Otherwise, you either pay over $300 or wait.

Or, you can buy an APT-X receiver such as the Avantree BTTC-200X or Samsung HS3000, to make your favorite headphones wireless. Not so elegant, but doable if you don't want to pay more than $300 nor wait.

Either way, once you go wireless, you'll never want to go back to wired.

Abstract in Chinese

用蓝牙播放高音质的音乐在技术上已经可行了,但是目前除了这里介绍的海尔曼-卡尔丹HarKar-BT,也就只有森海塞尔的MM 500-X和550-X。海尔曼-卡尔丹虽然没有森海塞尔那么贵,但是在电池快耗尽时有很轻微的干扰杂音,而且充电时会更大,为了不让你听到这个杂音,充电时声音被完全切断。人耳朵上神经和经络非常丰富,那种压到耳朵上的耳机都是不行的,不到一个小时就会导致各种不适,必须是罩住耳朵的那种才行。

Thursday, April 4, 2013

Pantech Element for $150

Ebay Daily Deal

This is currently the only tablet worth of buying, for its 4:3 screen and 8" size.

More details about this tablet can be found here.

Verizon Samsung Note II - a true global phone

It does both CDMA and GSM out of box. Like all Verizon LTE phones, it is SIM unlocked, i.e., you can insert any SIM card - AT&T, T-Mobile, China Unicom..., this Note 2 will take them all without complaint.

This phone supports all 4 HSPA bands: 850, 900, 1900 and 2100, which means it can use virtually any 3G network on this planet. Verizon locked one thing though: you have to add manually the APN (see below).

The followings are the tweaks for this great phone - the most powerful phone human has made so far.

Enable CDMA Voice

It is a LTE phone, so you cannot use it on, say, PagePlusCellular, without some manual configurations. The followings apply to all LTE phones.
  • First you need to use CDMA Workshop to change "R-UIM only" to "R-UIM if avail" or "NV Only". Otherwise the LTE phone works with a UIM card only. PPC etc. still do not use UIM, so you have to do this.
  • You can activate the phone on PPC etc. with its MEID or the first 14 digits of IMEI.
  • You need to write a Verizon or PPC PRL onto the phone and MDN and MIN with CDMA Workshop or QPST.
Then you can make voice calls over PPC etc.

Phone Utils

In order to do above configurations, first you need two utils.
  • HiddenMenu_No_Root.apk. Use it to enable hidden menu, change USBSetting to DM + MODEM + ADB. Then you can use CDMA Workshop and other CDMA tools. You also need to use it to turn eHRPD off, or it won't (or take a very long time) to connect to EVDO.
  • Phone Info. Use it to switch between CDMA atuo (PRL) and GSM auto (PRL). CDMA mode allows you to use the phone on PPC etc. and GSM mode allows you to use a SIM card.

Root the Phone

You should root the phone and delete /system/app/SamsungSetupWizard.apk, otherwise the phone always complain about non-Verizon SIM even though it uses the SIM fine. You should always insert a SIM card, even any inactive one, otherwise the phone won't show the 3G/4G sign even if it is actually connected to EVDO.

Rooting is very easy, just use the ExynosAbuse-v1.40.apk. If that does not work or you want TWRP recovery, then you need CASUAL-BackAtchaVerizon-Revision311b.jar. Warning: don't use ROM Manager to install CWM recovery, or you'll have to use Odin to flash a stock ROM to get your phone back to life!

TWRP recovery is very good to have. With it you can make full backups. If a bad app messes up your phone, you can use restore back to the backup in few minutes. It is beyond of my understanding why phones do not come with such full backup feature out of box.

Use SIM Cards

When you insert a SIM card into this phone, you should be able to make phone calls immediately. To use data, however, you have to edit the /system/etc/apns-conf.xml file to add the APN. For example, this is what I added for AT&T and T-Mobile data:

<apn carrier="ATT Data"

<apn carrier="T-Mobile Data"

Save the Battery

This phone comes with a whopping 3100mAh battery, but there are still some tweaks to make the huge battery last even longer:
  • Replace the stock GMail (4.1.2) with 4.0.5. 4.1.2 uses CPU constantly. It is quite erratic to do the replacement, I don't remember how exactly I did it. After I replaced it, the phone always got the 4.1.2 back after a reboot. Finally I got 4.0.5 to stick; I think I copied the 4.0.5 directly into /system/app and made it read only.
  • If you use WeChat (WeiXin), use V3.6. The latest version uses CPU constantly like GMail 4.1.2. After you use WeChat, you'd better press back button couple times to make it disappear, or it'll still use CPU sometimes. Don't worry, it'll still run in the background and get your new messages in time.
  • If you use Talkatone and Acrobits, do the same, i.e., press the back button until they disappear, or they use CPU constantly. Acrobits 2.0 and later versions prevent phone from sleep, should not be used.
  • Basically, you press and hold down the home button and select Task Manager to see which apps are using CPU. For those that use CPU, you should exit them after use. You may do the same for GMail 4.1.2, but it is too hassle to do it each and every time a new email arrives, so it's better to replace it with 4.0.5.


iGO works fine on this phone. In case it takes a very long time to get a fix to satellites, use the GPS Test app by Chartcross Limited, it finds the satellites very quickly even if the phone does not have a data connection.

Chinese Input

The phone comes with Chinese as one of the several available languages. So no need to do anything to add that. For typing Chinese, and English too, nothing comes close to Baidu and TouchPal. For Baidu, you need to download v3.5_1000e (v2 does not work on Note 2) and you may use my modified skin for the most perfect soft keyboard.


This is by far the phone that does VO3G perfectly with both Talkatone, Acrobits 1.94 and Nimbuzz. CSipSimple, which I never like, doesn't work. I think the quad-core CPU has plenty of power to do heavily compressed codec like G729 and iLibc, the RF reception is exceptional to keep a steady 3G speed and the MIC processing does a fantastic job to get rid of echo and background noise, resulting into a clean and smooth conversation. I no longer use PPC etc. and I've ported the # to GoogleVoice. I now use VO3G entirely.

I still prefer Acrobits to Talkatone, because it allows me to send and receive direct SIP calls without going through Google Voice and Talkatone's transcoding. If you don't use SipSorcery and you use Google Voice only, then Talkatone is simple and easy, and call quality is good enough most of the time. In my case, Talkatone is not so dependable: sometimes it'll pick up an incoming call but either quit immediately or no audio.

Acrobits actually provides a proxy service:
tls (sip)

When you use this proxy and TLS protocol, you can register to any SIP providers, such as CallCentric, that do not support TCP. Then you no longer need to use etc. for that purpose as described in this article.


Just use FoxFi, as always.

Other Aspects

With a large screen and quad-core CPU, this phone can really do anything that other phones cannot do. For example, editing this blog in Chrome is possible on other phones but a PITA, now a joy on this Note II. Remote Desktop is another job this phone handles extremely well. Typing on the soft keyboard almost never give errors, thanking to the large keys. For the first time on the phone, I feel like to do more typing without reaching for my laptop or tablet. The only other mobile device that offers the same good typing experience is my 7" Samsung Tab for Sprint.

For precise work, the pen comes handy. It is by far the only digital pen, for phones, tablets and computers, that actually works and works well. With its sharp, pressure-sensitive tip, it can do beautiful calligraphy like a Chinese brush. Writing Chinese on this phone with this pen is finally a practical and pleasant input method for those who don't know how to use other IME such as Pinyin.

Websites render extremely fast in Opera Mobile, thanking to the quad-core CPU. 2GB RAM allow far more tabs and apps to open without killing the other. On my other phones, Android always kill Opera whenever I open another app such as a music player.

Wrap up

That's what I can think of at the moment, feel free to ask if any question, as always. HTC DNA is another such global phone with smaller screen and battery. If you don't need CDMA, then the T-Mobile version of Note II is even better, because it can also get TMO 3/4G network and up to 42M speed.

This seems to be my last phone/tablet for years to come, because I have not found a single network it cannot connect to nor a single thing it cannot do well except running Windows applications. Hopefully Intel and Microsoft will come up with a device like this that uses the Clovertrail platform and runs Windows Pro, then it will be my very last phone/tablet/computer.

Intel: no Android on Clovertrail, Okay? MS: no more Windows Phone and RT craps, please! Dear Mr. Ballmer: the stupid RT does not run Windows apps and it does not even have a familiar Windows UI; what made you think people would pay more to buy it instead of the adorable iPad Mini that already runs tons of great apps? You two already have a golden bowl in your hands, why still beg Apple for its market share on phone and tablet while you already have a device does them all plus all Win32 applications? For now this Note II and the X220 serves me well, I cannot see any point of a Clovertrail/Android, WP and RT, but I see huge potential on Clovertrail/WinPro!

Abstract in Chinese

Verizon版的三星Note II是迄今为止最强悍的手机,而且是没上锁的CDMA/EVDO和GSM/HSPA通吃的真正的全球通。在美国可以使用PagePlusCellular等CDMA服务商,也可以使用AT&T(3G)和T-Mobile(2G),在中国可以使用中联通(3G),中移动(2G)和电信(3G)。当然在欧洲等其它国家和地区也都没问题。HTC DNA也是这样的全球通,屏幕和电池都小些。如果不需要CDMA的话,T-Mobile版的Note II更好,因为还可以上T-Mobile的3/4G,而且速度快至42兆。