Testing two Inkax models: EP33 (aka HiFI) vsR9

 

This is a text piece about my interest in audio engineering and my passion for testing audio equipment. I own a large collection of headphones and earphones including many from the Inkax series. I often purchase these from the local distributor, which offers a wide variety of smartphone products at very affordable prices.

The first I found / bought were so trebly which irritated my ears putting the 5+ kHz range with more than 20 db comparing to the remain audio spectrum. This was a reason I stopped for long time spending in earbuds and finding from competitors. 3 years ago their HIFI model was quite better in it response curve with trebly sound but not so high as their predecessors. A newer addition was replacing their sponge buds with comply type which added more bass than the relatively dull sound of the silicon. That translates into a model with near to real HiFi performance as for example the JBL T500 cabled model , one model I use for about 3 years.

The packing of

The latest model I found is the R9. I bet that it is a very recent fron its series of products with a new slimmer design . Marked as stales steel as the color used for the design of this plastic model separates well from is predecessor HiFi with the half on the rear part with the audio transformer and using a quite good insulated cable that seems to be closer to a higher level to the HIFi or even the Muse (design similar to the R9)

As with most of the Inkax models this includes also a microphone and a splitter/switch which can stop /play the music from the smartphone and still be cheaper than its predecessor

Operation and impressions.

I tested for a very short time with its own buds and immediately replaced them with Comply compatible buds. These buds can offer much better isolation then the typical bud and can keep the earphones better and stiffer inside the ear canal .

The first step was to listen to both using some Malaysian music of the 90s with a middle class DAP called Amoi C10 a brick like mp3 player . Malay recordings are usually more bright than the western counterparts with treble curve shaped as in Dolby cassette recording ,while Dolby is not used while tape is playing . An audio splitter is connected between the DAP and the two earphone sets. At first the R9 was not pushed enough into the air canal making the sound rather poor with low bass. A further press and keeping the tips , finger pressed added much of bass and closer to the HiFI model with identical sound response. Note that the HIfi model uses the 400 model tat is a bit wider than the T300 used on R9

Tested them in parallel and seen that the sound level is the same in both stakes: R/R and R/L modes There was no difference in sound level that can shift the audio point towards the left or right ear(eg R)

All together to listen to the music

Next step is testing their frequency rage. The set is very simple: A audio file is previously prepared with test tones , evenly spaced across the audio band with more emphasis on the higher spectrum total 25 tones WAV format! A lavalier microphone is touched in earbuds foam tip ad the sound is finally driven to the smartphone where a program records and saves the audio. The final stage is made in the computer with audio software for making he spectrogram.

 

The picture is quite clear. This picture joints with two spectrans showing the resulted curves form the above process for HIFi (2014) and R9 (2017)

HiFi shows a linear response on the voice part while the R9 has a steep response. The remain part is nearly similar to both. All recording settings are the sane for both As it clear e R9 is has a lower audio level than HiFi

The final part of the test : Checking microphones

Putting the microphones in front of the DAPs’s speaker and isolating them from outside noises with a ….dry sponge. I adjusted once the audio level because otherwise the result will be garbled. The two files were scanned with the software for spectrum analysis and grouped into one image.

My reflections : There is a hum of 55 Hz from R9 (at right) . R9 produces 12 db lower audio (or 4 times lower volume) than the HiFI with a peak on the upper level of voice and losing some lower notes . I have not tested in practice to the moment

Nothing more to notice .Both earphones have a good and reliable sound. The primary issue with HiFi is its splitter design, which causes the cable to tear after only 8 months and heavy use , rendering it unusable. The connections are lost in the one bud’s cable , in the splitter part , Will the R9, with a similar splitter design, be able to resist this problem? Only time will tell!

Checking a cheap inkax model

First before reading the story please oblige yourself to send your comments below. The writer  needs to know  your opinions good  or bad .This will be a very serious reason to  terminate this free service and show disrespect to the writer who spent a lot of time writing this article.

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The Inkax series model mentioned above is one of the most affordable options available in Salonica, priced at just 3-4 Euros for a small box containing around 10 pieces or more.  These pens are available in three colours. I purchased one to experiment with.

 

The small box contains only what is shown above: a mini plastic bag with earphones and a set of silicone buds. The packaging is simple and straightforward. The small box contains only what is shown above: a mini plastic bag with earphones and a set of silicone buds. There are no additional items included.

 

Here is the set with the cable detached.   The earphones have a nice design with thinner ends and a typical plug with reverse polarity for audio.

 

This may be the best angle to capture the back end of the earphone, which can be pushed comfortably into your ear.

Here is a good shot to show the button for stepping or releasing the playback.

The earphone design is quite good. Regarding the hearing results, I have a few comments and positive aspects to highlight.

The earphones have a good frequency response for both bass and treble, providing a full audio range.

In contrast, the audio provides a strong middle range at 400-700 Hz, which enhances speech clarity but reduces music listening quality by more than 6 dB compared to a 'linear' HiFi model (this is for comparison purposes only).

On the other hand, the microphone performs the opposite as tested with the now-extinct Inax HiFi model: it has relatively poor

bass with no increase in the middle range (which is

good) and higher treble than the other model. Listen to these files to better understand:

https://app.box.com/s/79ohgiunv1wo63us682pjqokvem6zl0l (for the HiFi model) and https://app.box.com/s/kp8mbq7w9yijt170vv7wgke3b7ai05dv

(for the other model).

Inkax HiFI model

 Just in short again this time with the hope to do some more response analysis later

This is the inverse of the so famous V monk model by frequency response . The model  can be found very easily in  the local market from the local importer and distributor . Though very cheap at price just 8.5  Eu i is the biggest model in its category. Tested with the Sound magic  10 E (flatshaped reponse  for the type) its curve shows much increase above the 1 kHz without getting too sibilant . The sponges increase the  basses towards the AKG DJ 81 curve giving a much better U shaped  sound response  .

In contrast  the V monk kills the higher frequencies

I have used these Inkax models for more than 1 year and i am very impressed with is operation and the audio quality . The only problem us that the twin line divider can shorten the cable

As in the photo above there is also a pause button . The joints on the twin cable part can be easily broken if there is some higher stress 

The cable can also be shorted on the earbud . Mean time of shortening is around 8-10 months with more than 5 hour per day Sometimes its use with the Degen radio during nights can shift me to sleep! 

Rate 4/5 

 

Addition : after finding the bug with the BLON 3 that was simply the mistaken use of the mid- bud and changed into the widest tips, the sound  was clearly much better and didn't fell from the ear. The buds with the wide 'sponges' offered even bassier sound with near to AKJ  headphones audio quality Checking them with the Inkax model i found them to be quite treblier with both buds: their standard  silicone tips and also with the large 4.5mm tips !

Inkax HP31 Bluetooth headphones

After some time I finally won to replace my Ninsheng BY model with a better model that has not the quasi 3D sound. As noted there the previous model and its 'house siblings '  have the common of "spatializing" the sound into 3D and enhancing the basses and the middles. That means making a head full of low freq sounds and make me crazy !

This new model coded as HP31 comes with very nice design includes the same features: cabled  and wirless connectivity , SD card reader FM radio and microphone.

This is now the nicest model i have. It comes with aluminum blade as armature of ca 3 cm in eash side very nice color a. It is the flagship model of the Bluetooth of the companys headphone models . 

As you can see the blade is around 3 cm and relatively big speaker that is over the ear.  Nice leather like isolation over all the arm and mid heavy for just 200 grams 

 Hmm just 1 gram lower than 200! It doesn't matter so much 

In contrast with the other models the P31 has only 3 buttons with enhanced operations. the middle button powers on and off, stop music , while the two others do 2-3 operations : change the mode of operation , scan the radio, control the volume and jump to the next /previous song 

and the SD card slot 

In order to pick it the seller left me also check between a few company models company before picking it . The sound is quite bassy but with rich trebles and cross checked at the same time with mine AKG81DJ which has a bit narrower sound range(above the 10kHz part )  using the Q3 Tescun player recorder with test songs !!

Sound 

As with most typical Bluetooth models  tested.  HP31 has quite deep basses that extend a bit to the normal voice band with audio range that covers up to 20 kHz A that is an extended U type curve with narrow lows.

Its most important feature excludes 3D sound ! This is the reason i took them! I now feel much better listening for indefinite time.

Interesting to notices  the voices frequencies are more linear than in Bluetooth mode

In SD card mode the sound is very close to the Bluetooth curve 

Bluetooth mode 

Tested with the mini transmitter and the latency is around 0.2 seconds  this is possibly due to the transmitter latency . use also with the digital TV receiver with very good audio.  

Cross Checked with Awei :more trebles NO 3D sound !

With my laptop : the laptop sound is unfortunately quite bassy but the results are OK and can be used for long time listening. Tested  in stream radio and in Youtube and is heard very well The same with remote radios from the Kiwi Net used by radio listeners and radio amateurs. This model can replace my standard headphone Sennheiser HD493 used since mid 2000s in other gear . The HD493 was repaired the last month but the technician damaged its sound linearity and i feel it now as also 3D

 

This is the typical options when he headphones are paired. IN headset mode  the sound is heard monophonic 

IN the bottom of  the control panel there is a typical 3.9mm stereo audio socket. 

 

Zoom to watch the  full photo . as you can see the lower part of the higher band is slightly lower.They re recorded in the same volume 

The above audio by amplitude

Distance range with BT gear
It can connect up to 7 meters with half meter wall
Around 12 meter direct length 

Radio: The only drawback as with other models which produce monophonic  sound and poor reception. I think that if the radio could have a terminal to touch the metallic armature the reception could be quite better for sure! 

SD operation : It plays all standard audio formats : WAV MP3 and WMA .Sound is quite bassy as in Bluetooth mode. Changing files is a bit awkward with continuous use of the next back buttons for 1-2 seconds to select the song in sequence, It does not play songs in the exact sequence.

Battery : this is its worst point . its battery lasts only 3 hours as tested so . Upon that i returned back to the seller the headphone only for a item only change but they denied. This company is bond "to their protocol" or the typical procedure disregarding to adapt to the reality As therte is no space in the house i always litter the box and separate all the accessories just in the case they will be used. I use it alone with  my standard accessories in a bag. its very possible that this battery will be expired very soon.
Its funny that after charging it to the full for 3 times without using it after , it operated for 5.5 hours continuously and still having more in its battery...It finally lasted 6 hours.

Verdict :8/10 it has a very good though bassy sound with the most typical features of its category . Very nice ergonomics  and design Its main use ids for remotely listening various TV programs 

Addition post-21 and 22
using it in another home with irregular shape and a fireplace in the middle reception was very problematic , with self-cancellation of signal while moving the head acrross the  room wall 

Just think a room of ca 6m long x5 m with a space of 2x2 missing in the right part (entrance ) . Inthe left part of the room there is a fireplace of 1.5x1.5 m in the middle of the room. This is  what i can suspect making propagation self cancellations :  the fireplace and the design of the whole saloon