BIG Sound on a Budget!

PROS: MP145 – deep textured bass, natural detailed mids, crisp and (depending on eartips selection) non-fatigue treble, big soundstage expansion, and tunable nozzle filters; S9PP – small lightweight design, natural revealing tonality, 3.5mm/4.4mm outputs, physical volume control, selection of digital filters.

CONS: MP145 – strong sound dependency on eartips selection, benefits from the cable upgrade, Golden-Titanium limited edition is more expensive and heavier; S9PP – included OTG cable is unidirectional, draws higher current from a source.

The product was provided to me free of charge for review purposes in exchange for my honest opinion.

Manufacturer/product website:  MP145 and S9 Pro Plus.  Available for sale on Amazon, MP145 and S9 Pro Plus.

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Intro.

While I usually focus on high-end IEMs and DAPs, once in a blue moon I get an itch to try budget IEMs.  After bringing it up to my attention by a few audiophiles who are into mega-kilobuck stuff, the itch returned, and to scratch it I decided to try a set of Hidizs MP145 Planar Magnetic driver IEMs.  Shortly after putting them in my ears, taking them out, and… going straight for the box of eartips to try different combinations, I had to scratch more than just the itch, but my head once I realized how good they sounded.

I remember covering Hidizs AP100 DAP in one of my early write-ups on Head-fi which kickstarted my review journey 10 years ago.  In the last decade, Hidizs continued with portable audio gear releases, trying to stay original, trying to keep it affordable, and trying to focus on mini-DAPs, dongles, and IEMs such as MP145 which come in regular (OG) and limited-edition (LE) Golden Titanium versions.  Both versions made sense for me to test and compare in one review along with their latest S9 Pro Plus (S9PP) dongle.  Here is what I found.

Unboxing and Accessories.

 Hidizs made sure to distinguish the unboxing experience between OG and LE versions of MP145 using the more premium packaging and additional accessories bundled with their limited-edition IEMs.  The OG version comes in a medium-size all-black packaging box, with an external sleeve featuring a glossy 3D-like picture of MP145.  Under the sleeve, you will find a plastic storage box with a secure cutout for IEM shells, a manual, a warranty card, a custom pleather pouch with a spring closure, and 3 sets of silicone eartips in S/M/L sizes.  Each set of eartips has a foam cutout storage and clear labeling of Vocal (white), Balanced (white cap/black core), and Bass (black).  You also get 3 sets of filters in a separate acrylic box with a twist-cover.  By default, you get a 3.5mm SE cable, though my review sample arrived with an upgraded 4.4mm BAL cable which you can select during ordering.

The LE version of MP145 arrived in a bigger cardboard storage box with gold artwork on the cover since these are Golden Titanium shell IEMs.  It includes the same set of Vocal, Balanced, and Bass silicone eartips, a manual, a warranty card, a custom pleather pouch, and 3 sets of filters.  In addition, you will also get both 3.5mm SE and 4.4mm BAL cables, and a unique “souvenir” which looks like a cutout piece of a titanium DAP shell with a volume knob and an engraving to commemorate the 10^th anniversary of the company.  That piece also had a small pinhole so you can attach it to a keychain.

The S9PP dongle arrived inside a very small packaging box, all black, with an outside sleeve featuring a glossy 3D-like picture of the S9PP and a detailed spec on the back.  Under the sleeve, there was a plastic storage box with foam cutout to keep S9PP secure inside, a Type-C to Type-C usb OTG cable, a Type-C to USB-A adapter, a user manual, and a warranty card.  Using plastic storage boxes for MP145 OG and S9PP was an interesting choice.  Not recyclable, but it is very sturdy and convenient to use as a storage box instead of cardboard which people often throw away.

Cable.

The included stock cable is soft, pliable, and comfortable to wear.  It features 4 loosely braided conductors, each one using 6N purity silver-plated single-crystal copper wires.  The headphone plug has a chrome finish housing with a golden ring matching the gold plating of the plug connector.  There is a compact cylindrical y-split and chin slider, all in a matching chrome finish, and a matching IEM connector housing with red/blue rings to id right/left sides, and standard 0.78mm 2pin flush-mount connectors.

Design.

I will go over the design details of the MP145 OG and LE versions and the S9 Pro Plus dongle below.

MP145 OG/LE – Design.

The MP145 model is part of the Hidizs Mermaid series of earphones, and this particular model features a 14.5mm ultra-large Planar Magnetic driver, so the “MP145” name is not random.  Inside, according to Hidizs, there is a symmetrical 7+7 array of N52H magnets.  The driver itself has ultra-wide bandwidth, supporting a broad 20Hz-40kHz frequency range, with a Sensitivity of 104dB and an Impedance of 30ohm making it relatively easy to drive, just needing a few extra clicks of volume since its sensitivity is slightly below the average.

OG model shell uses aviation-quality Aluminum Alloy material in 3 different finishes: blue, silver, and titanium.  LE model has an identical shell design but uses Golden Titanium material.  As a result, OG shells are lighter, only 8g, while LE shells have more heft at 14g.  The extra weight can affect the seal due to shells weighing down, another reason to spend more time with eartips rolling to find the most secure fit and seal.

The inner part of the shell is smooth and has a comfortable fit, while the faceplate has a raised cutout in the shape of a Whale Tail, the inspiration behind the design.  Actually, 1% of every MP145 sale goes directly to support Whale and Dolphin Conservation (WDC) to preserve marine ecosystems.  This whale-tail faceplate design is not the smoothest to the touch, but it doesn’t matter since it is on the outside.  Also, along the edges of the tail outline, there are 2 slit vents on the faceplate and another pinhole vent on the inner side of the shell.

The fit

The nozzle has a removable mesh filter at the tip, and MP145 includes 3 different pairs which Hidizs refers to as Pneumatic Sound Tuning filters.  I will cover the difference in sound further in my review.  Both OG and LE versions come with 3 filters of the same sound characteristics, but they are not interchangeable between models since the pitch of the thread is different as I learned later after mixing them up.

S9 Pro Plus – Design.

The updated S9PP model now features 3.5mm SE and 4.4mm BAL outputs and physical volume buttons with dual functionality to switch between the digital filters, while the previous S9/S9P used 2.5mm BAL and no physical volume/function controls.  Inside, you still have an ES9038Q2M DAC chip with PCM support of up to 32bit/768kHz and native DSD up to 512, and you still get a sampling rate indicator light.  The output power is not too far off from previous models, a bit higher from 3.5mm SE (138mW) and a touch lower from 4.4mm BAL (180mW), but still, plenty for most of the IEMs and easy to drive full-size headphones.

The CNC aluminum alloy shell of the S9PP is very compact and lightweight having dimensions of 55mm x 25mm x 11mm and weighing 16g.  At the top, you have 4.4mm and 3.5mm headphone jacks, on the right side you have 2 small round buttons that are used for volume up/down or to switch between the filters when you press both, and at the bottom, there is usb-c port.  Btw, the included usb-c to usb-c OTG cable is unidirectional, the cable side with the Hidizs logo has to be connected to the source while the other side without a logo should be connected to S9PP.  This dongle is compatible with most of the platforms, including Windows, Android, iOS, MacOS, and iPad OS.  Also, per my testing, S9PP draws about 150mA from the source.  As confirmed, it wasn’t an issue with the iPhone while cranking up the MP145 volume.

On the front at the bottom, there is the Hidizs logo which doubles as a status LED to display the sampling rate and to indicate which filter you selected.

Sampling Rate indicator:

• Yellow: DSD 64/128
• Purple: DSD 256/512
• Blue: PCM 176.4/192(kHz)
• Red: PCM 352.8/384(kHz)
• White: PCM 705.6/768(kHz)
• Green: PCM 44.1/48/88.2/96(kHz)

6 Filters are selected by pressing both buttons simultaneously every time you want to switch the filter, then the filter light blinks quickly and goes back to the sampling rate.  Following are the filter names with the sound description as provided by Hidizs:

• Red – Linear phase fast roll-off: Enhanced analytical capabilities, delivering a clean and crisp sound.
• Green – Anodizing fast roll-off (Default Filter): Vocals are slightly forward, and high frequencies are extended with reduced resonance.
• Blue – Linear phase slow roll-off: Enriched harmonics, full low frequencies, and natural reverb.
• Yellow – Minimum phase fast roll-off: Balanced and moderate sound.
• Purple – Minimum phase slow roll-off: Clean sound with a forward position.
• White – Hybrid fast roll-off: Soft and smooth sound with enhanced detail.

Page 2 – Sound Analysis, Eartips selection, and Cable pair up.
Page 3 – Comparison, Source Pair up, and Conclusion.