The Different Types of IEM Connectors
Jul 24, 2020 at 7:06 PM Thread Starter Post #1 of 38

IEMusic

Headphoneus Supremus
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Since this is such a common topic of discussion, and can be quite confusing, I though I’d start a thread solely for discussing the differences between the various types of cable connections for IEMs. I’ll start with some information that I’ve accumulated, then let the real experts provide further clarification (or correction if needed). There are quite a few different types that are currently out there, and some companies like to create their own new proprietary connections, for new technology and features, or perhaps just to make extra money, and annoy us in the process.

Note: I compiled photos primarily from Google searches, a few of my own photos, and photos from fellow head-fi members. Since many of the photos are from various random sources, please forgive me if I don’t credit sources for each photo.

The main different types of connections that I know of include:
1. MMCX -
one of the most common types of connectors. The IEM can typically spin freely around the connection. The main downsides are difficulty connecting and disconnecting cables, and frequent cable swaps can damage the connector. It is generally not considered as convenient or durable in the long run compared to 2 pin variants.

2. Classic 2 pin - maybe the most common type of connector. Regarding the 2 pin outlet on the IEM, there are recessed outlets (probably the best and most durable), flush mounted outlets, and outlets that stick out (but are not meant to be covered by a sleeve, such as qdc or NX7 outlets). **Note: most 2 pin connections are 0.78mm, however, there are also 0.75mm connections. I’m not sure if the qdc and NX7/TFZ connections are all 0.78mm, or if there are 0.75mm variants of those connections as well.

3. qdc 2 pin - the outlet sticks out from the IEM shell, and has rounded edges. The cable plug has a sleeve that covers the IEM outlet. These types of outlets also accept classic 2 pin plugs, and the connection will not be covered, and it is not ”pretty”.

4. NX7 or TFZ 2 pin - the outlet sticks out from the IEM shell, but has squared off corners. The outlet is designed to be covered by a sleeve on the cable plug, like with qdc cables. The NX7 and TFZ outlets do not stick out much, thus the sleeve is shallow. BLON has the same shaped outlet, but it stick out more, and the cable uses a deeper sleeve. These outlets can all also accept classic 2 pin plugs, but the connection will not be covered. It looks better then using a classic 2 pin plug on a qdc outlet though (the shape matches). The BLON BL03 has a unique characteristic, in that there is a vent adjacent to the outlet. The vent should not be obstructed by the cable plug sleeve.

5. IPX connection, with Linum SuperBaX cable - used on current Ultimate Ears IEMs.

6. 4 pin - used on several JH Audio IEMs, and provide the feature of a bass pot on the cable that you use to adjust the bass level of the IEM.

7. 7 pin - newer connection on select JH Audio IEMs.

This list is by no means comprehensive, and there are many other types of connectors out there that I haven‘t mentioned. Other members will likely provide additional information on them.

Note: I’m not familiar with the polarity of the 2 pins on the classic 2 pin vs qdc vs NX7 / TFZ connections, so any additional information would be appreciated.

Okay, now I’m finished with all of my initial postings. I hope it helps.
 
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Jul 24, 2020 at 7:20 PM Post #2 of 38
MMCX Connectors

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Some MMCX outlets are recessed in the IEM, so one needs to make sure the diameter of the plug on the cable is small enough to fit. Otherwise, purchase the corresponding brand of cable (such as Sony).
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MMCX vx classic 2 pin connectors
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Jul 24, 2020 at 7:45 PM Post #3 of 38
Classic 2 pin connectors

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Some 2 pin outlets are recessed, and the connection is at least partly covered. It is more secure this way.
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Some 2 pin plugs are straight, and have a rectangular base that can fit into recessed outlets. Some 2 pin plugs are L-shaped and some have varying lengths of the rectangular base region (not pictured).
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Some 2 pin outlets stick out from the IEM shell. Others are flush with the shell (not pictured).
EA856ED8-24C8-45EA-9D84-7EF78CB5C077.jpeg
 
Jul 24, 2020 at 7:50 PM Post #4 of 38
qdc 2 pin connectors

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An actual qdc IEM, the brand for which the connector was named.
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One can attach a classic 2 pin plug to a qdc outlet. It generally doesn’t look great though.
EB7BAFEF-1255-40FE-9AF2-F455C183CC3F.jpeg
 
Jul 24, 2020 at 8:06 PM Post #5 of 38
NX7 / TFZ 2 pin connectors

The NX7 / TFZ plugs have a sleeve, but it is shallow, and has squared off corners.
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NX7 / TFZ outlet (left) vs qdc outlet (right)
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The FiiO FD1 has a NX7 / TFZ outlet.
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The FiiO FD1 comes with an L- shaped classic 2 pin plug, that doesn’t have a sleeve to cover the connection.
FB7AA690-1D0F-43A7-A0DE-7064C082D68D.jpeg


BLON uses their own variant of the NX7 / TFZ connection. The outlet is shaped the same, with squared off corners, but it sticks out more. The sleeve on the BLON cable plug is deeper.
3BE8B7BE-2129-442E-B1DC-16FC73A82A2D.jpg


When using a TFZ cable on the BL03 (left), the sleeve only covers part of the the outlet, but does over the connection itself, and is actually a good thing (see below).
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Some astute members on head-fi have discovered that a vent is located adjacent to the outlet on the BL03, thus one doesn’t want to cover it with the cable plug sleeve. There is a small notch in the sleeve of the BL03 cables to allow airflow for the vent (not pictured).
69F6D482-2076-4596-A464-9C25BD66E492.jpeg


The BL05 has the same shape of outlet as the BL03, but there is no vent located there (not pictured).
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Jul 24, 2020 at 8:21 PM Post #7 of 38
IPX connectors, with Linum SuperBaX cables
(used on current Ultimate Ears IEMs)


AF5C2C9C-968C-4D2A-AA29-D0C23034F17A.jpeg
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Jul 24, 2020 at 8:25 PM Post #8 of 38
4 pin and 7 pin connectors
(used on various JH Audio IEMs)


4 pin connectors have a bass pot on the cables, used to adjust the bass level of the IEMs.

2 pin vs 4 pin plugs
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The 4 pin plugs screw onto the 4 pin outlets on the IEMs, fully covering and securing the connections.
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Newer 7 pin locking connector, on select JH Audio IEMs
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Jul 24, 2020 at 9:34 PM Post #9 of 38
Now that you're done...


Fyi some MMCX stick out and can use the MFG or any aftermarket MMCX cable. Westone does this on their newer IEM's.

Pic from @twister6's review
westone_w80-41.jpg



Also some newer design MMCX have 'split' male ends that grip better to prevent easy spinning and have a more stable connection.

2039507442-1456864693.jpg

The newer female designs have an internal collar that rises around the tiny split pin to prevent spreading when installing or removing the cables.

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Jul 25, 2020 at 7:34 AM Post #10 of 38
Awesome information here :thumbsup:

Its such a pain that there are so many variants on 2pin connectors...That is the only factor mmcx connectors are better for me. Otherwise I think that 2pins are superior due to their durability.
 
Jul 25, 2020 at 8:29 AM Post #11 of 38
Good info about different connectors :thumbsup:

Common MMCX issue is loose and spinning connections, usually after frequent connect/dis-connect. Is there any method to tighten the connections? I heard putting a washer under the ring on the cable connector can help but have not tried it as I’m not sure how to take out ring.
 
Jul 25, 2020 at 8:54 AM Post #12 of 38
Good info about different connectors :thumbsup:

Common MMCX issue is loose and spinning connections, usually after frequent connect/dis-connect. Is there any method to tighten the connections? I heard putting a washer under the ring on the cable connector can help but have not tried it as I’m not sure how to take out ring.

If it has split type mmcx, you can use a razor blade to open the split a hair wider.

Sometimes a small o-ring can help.
 
Jul 25, 2020 at 12:31 PM Post #13 of 38
I think the new pentaconn ear connector will rectify currently mmcx connector issue, I had recently purchase the acoustune newer batch iem which came with the pentaconn ear connector initially I thought is mmcx but it's not. Heard its a a new connector might replace the mmcx connector who knows.
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Jul 31, 2020 at 11:03 AM Post #15 of 38
This says it all about MMCX, courtesy of Final:
k4jh5.jpg
TL;DR
MMCX ~ fixed cable in long term

Could u translate the japanese words?
 

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