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What we think
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Updated January 10, 2024·
To decide between the Sennheiser CX300S and the Thieaudio Monarch Mk II, consider how you prioritize price versus sound quality. The Sennheiser CX300S offers a budget-friendly option that is likely to be adequate for everyday use and casual listening. On the other hand, the Thieaudio Monarch Mk II is a premium product, providing a superior audio experience with more detailed sound, which might be appreciated by audiophiles and those seeking top-notch performance for critical listening. If you frequently engage in activities where sound quality is paramount, and the cost is less of a concern, the Thieaudio Monarch Mk II may be the better choice. However, if you're looking for a reliable earbud at a more affordable price, the Sennheiser would be suitable, especially if your listening habits are more casual and non-critical. Give Feedback
this description is based on the product variant with some specs and product variant with some specs. At the time of writing, the variant with some specs cost some dollars and the variant with some specs cost some dollars.
Advantages of the Sennheiser CX300S
- Good for air travel
Advantages of the Thieaudio Monarch Mk II
- Best in class for music
- Very good for TV and video
- Good for podcasts and audiobooks
Key differences
Music
6.9
9.5
The Thieaudio Monarch Mk II is best in class for music, while the Sennheiser CX300S is only fair.
Gaming
6.1
6.7
The Thieaudio Monarch Mk II and Sennheiser CX300S are both only fair for gaming, though the Thieaudio Monarch Mk II is somewhat better.
Phone Calls
3.0
5.1
The Thieaudio Monarch Mk II and Sennheiser CX300S are both poor for phone calls, though the Thieaudio Monarch Mk II is somewhat better.
Podcasts and Audiobooks
4.7
7.9
The Thieaudio Monarch Mk II is good for podcasts and audiobooks, while the Sennheiser CX300S is poor.
TV and Video
7.3
8.8
The Thieaudio Monarch Mk II is very good for TV and video, while the Sennheiser CX300S is good.
Noise Reduction
7.0
6.0
The Sennheiser CX300S is good for noise reduction, while the Thieaudio Monarch Mk II is only fair.
Cost
$50
$999
$0
$100
$200
$300
$400
The Sennheiser CX300S has a price of $50 and the Thieaudio Monarch Mk II costs $999.
Build Quality
8.0
9.0
The Thieaudio Monarch Mk II has excellent build quality, while the Sennheiser CX300S has very good build quality.
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How the Sennheiser CX300S and the Thieaudio Monarch Mk II compare to other earbuds and headphones
Spec Comparison
 |  | |
| Sennheiser CX300S | Thieaudio Monarch Mk II |
GENERAL | |||
|---|---|---|---|
| Price | |||
$50 | $999 | ||
Brand | |||
Brand | Sennheiser | Thieaudio | |
Release Date | |||
Release Date | February 1, 2019 | October 1, 2020 | |
Form Factor | |||
Form Factor | Earbuds | Earbuds | |
Connectivity | |||
Connectivity | Wired | Wired | |
SOUND | |||
|---|---|---|---|
Music Score | |||
Music Score | 7/10 | 9.5/10 | |
Phone Calls Score | |||
Phone Calls Score | 3.1/10 | 5.1/10 | |
Gaming Score | |||
Gaming Score | 6.1/10 | 6.8/10 | |
TV and Video Score | |||
TV and Video Score | 7.4/10 | 8.9/10 | |
Exercise Score | |||
Exercise Score | 4.2/10 | 4.5/10 | |
FEATURES | |||
|---|---|---|---|
Active Noise Cancelling | |||
Active Noise Cancelling | No | No | |
Noise Reduction Score | |||
Noise Reduction Score | 7/10 | 6/10 | |
Virtual Surround | |||
Virtual Surround | No | N/A | |
BUILD AND DESIGN | |||
|---|---|---|---|
Build Quality | |||
Build Quality | 8/10 | 9/10 | |
Comfort score | |||
Comfort score | 7.6/10 | 7.6/10 | |
Size | |||
Size | Small | Large | |
Weight (headset or single earbud) | |||
Weight (headset or single earbud) | 12 Grams | 9 Grams | |
Waterproof Rating | |||
Waterproof Rating | 0 | 0 | |
Shopping
Sennheiser CX300S
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Dig into reviews and images
Major HiFi
Carroll Moore | April 2019
"Sennheiser offers impressive bang for your buck when it comes to the CX 300S. Built like a tank and sounding surprisingly good for such a budget-minded earphone, the CX 300S out-classes many of its would-be competitors. Functional but beautiful, it’s the perfect in-ear listening solution for anyone who wants to hear everything and look good doing it."
Thieaudio Monarch Mk II
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Audiophile On
Audiophile On | August 2021
"No other earphone I have listened to in the past 12 months has given me as much joy as the Thieaduio Monarch MKII. One of those IEMs will make you question where we can go from here. The sound is jaw-dropping, leaving you wanting more and more. It makes you want to run through your entire music library and reevaluate. It makes you not feel bad about paying full price for them, especially in a hobby where buyers' remorse is genuine. For me, it's top tier, rivaled by a few but not surpassed."
Get a great deal on the Sennheiser CX300S or the Thieaudio Monarch Mk II
About Sennheiser
A family-owned company, Sennheiser is a German, high fidelity, audio equipment manufacturer founded in 1945. Their consumer audio division is now owned by the Swiss hearing aid and cochlear implant manufacturer Sonova. Sennheiser offers a wide variety of, very high quality, audio equipment solutions, from headphones to earbuds, full sets of monitoring speakers, amplifiers and microphones. They also make what is widely regarded as the best, and most expensive, headphones in existence, the HE-1 Orpheus, costing a whopping $59,000 dollars.
About Thieaudio
Thieaudio is the in-house brand of Linsoul Audio, a Chinese earbud and headphone retailer specializing in what the community lovingly calls Chi-fi, that is high fidelity brands out of China. Thieaudio was established in 2019 as the creative engineering branch of Linsoul. As of today, they market three different lines of earbuds, Voyager, Legacy and the extremely well-received Monarch.
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This information was produced and vetted by the PerfectRec earbuds & headphones team. We are a product research and recommendation organization that meticulously reviews and evaluates the latest earbuds or headphones information and makes it digestible for you.
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