Fosi Audio HT4S Multi-Channel Bluetooth Power Amplifier for Speakers & Subwoofers
Upgrade your audio setup with the Fosi Audio HT4S, a powerful multi-channel Bluetooth amplifier designed to enhance your listening experience. Whether you're setting up a home theater system, outdoor sound system, or a sim racing rig, this compact yet versatile amplifier delivers high-fidelity sound with deep bass and crystal-clear highs.
The HT4S is a stereo amplifier with an integrated DAC and power amplification, offering up to 5 speaker outputs. With 4.1 and 5.0 channel switchability, it provides flexible sound configurations for any audio environment. Featuring Bluetooth, AUX, and optical digital inputs, as well as pre-out connectivity, it ensures seamless compatibility with multiple devices.
Designed for indoor and outdoor applications, this amplifier is ideal for home theaters, cafes, restaurants, bars, and patios. Whether you want wall-mounted speakers, outdoor speakers, or an immersive desktop HiFi system, the HT4S adapts to your needs with ease.
Take your racing simulation or home theater experience to the next level! The HT4S pairs seamlessly with bass shakers, delivering powerful sound output and bass boost that intensifies racing games and movies, making them feel more immersive than ever.
Equipped with a built-in power supply, remote control, bass and treble adjustments, and a multifunctional central knob, the HT4S ensures effortless operation. The LED mode indicator light enhances its aesthetic appeal, while the all-metal CNC unibody construction guarantees durability and long-lasting performance.
Continuing Fosi Audio's premium craftsmanship, the HT4S features a robust aluminum alloy body with a sandblasted finish, ensuring superior durability. Plus, enjoy peace of mind with Fosi Audio's 12-month warranty.
Input Options: 3.5mm AUX, Optical, Bluetooth
Output Options: 3.5mm Pre-Out, Passive Speakers + Subwoofer
Rated Power Output:
4.1 Channel: 30W x 4 + 60W x 1 @ 4Ω
5.0 Channel: 30W x 5 @ 4Ω
Max Power Output: 50W x 5 @ 4Ω
Note: The HT4S is a stereo amplifier and does not support Dolby, DTS, or other multichannel surround sound formats.
Enhance your audio experience with the Fosi Audio HT4S—your ultimate amplifier for multi-speaker setups, home theaters, and immersive gaming!
Channel : Bluetooth 4.1 CH Amp
Input : Bluetooth + 3.5mm AUX + OPT
Output : 3.5mm Pre-Out + Speaker Out
SNR : ≥88dB
THD : ≤ 0.03%
Terminal Impedance : 4-8Ω
Rated Power Output : 30w*4+60W*1
MAX Power Output : 50Wx5 @4Ω
Work Voltage: AC 110V - 240V
Product Dimensions : 6.1 x 7.2 x 2 inches
In The Box
HT4S*1
Power Cord*1
Bluetooth Antenna*1
3.5mm Auxiliary Cable*1
Remote Control*1
HT4S User Manual*1
Warranty Period: 1 Year from the date of Invoice
Covered: Manufacturing Defects Only
Warranty Form: https://www.theaudiostore.in/pages/warranty-claim-form
Cable: 1-month warranty only for manufacturing defects only
Fosi Audio is a dynamic brand dedicated to providing the most comprehensive range of Hi-Fi audio products in the market. We cater to passionate audiophiles by offering Hi-Fi products, DIY kits, and expert guidance, ensuring an immersive audio experience. Beyond a mere transaction, we foster enduring relationships with our clients, supporting them throughout their audio journey.
Our diverse product lineup includes the Hi-Fi power amplifier, pre-amplifier, headphone amplifier, DAC, music player, Bluetooth receiver, DIY board, DIY chassis, and an array of DIY kits. These meticulously crafted offerings embody our commitment to exceptional sound quality and innovation.
Established in China in 2017, Fosi Audio was founded by a team of devoted audiophiles. Our products have gained significant popularity within the Chinese DIY audio community, amassing a large and dedicated following. To expand our reach beyond borders, we launched this website in 2017 and began offering a selection of products on Amazon under the name "Fosi audio." However, please note that many of our outstanding products are not yet available on this website or Amazon. If you cannot find what you're looking for, simply reach out to us via email, and we will be delighted to assist you in finding the perfect product to meet your needs.
At Fosi Audio, we are not just a brand; we are your partner in achieving audio excellence. Join us on this immersive sonic journey and experience the true essence of Hi-Fi audio.
It provides Awesome sound quality go and buy it m
🎧 KZ Castor Pro IEM – Review
🔊 Sound Quality
The KZ Castor Pro delivers clear and detailed sound with excellent separation across lows, mids, and highs. The decent thumping bass is tight and controlled, giving energy to tracks without overwhelming the vocals or instruments. Its super-balanced tuning ensures a natural, enjoyable listening experience suitable for all genres.
🎚 Unique DIP Switch Equalizer
What sets the Castor Pro apart is its DIP switch physical equalizer. With up to 16 different tuning options, it allows listeners to adjust the sound profile on the go—boosting bass, enhancing treble, or keeping it neutral. This feature gives it a level of flexibility rarely seen in IEMs at this price point.
🔇 Noise Isolation
Although it lacks active noise cancellation, the design offers an excellent passive seal. The snug fit ensures that outside noise is effectively blocked, making the listening experience immersive and ensuring ANC doesn’t feel like a missing feature.
🎼 Hi-Res & DAC Performance
For those using Hi-Res lossless audio, pairing the Castor Pro with a DAC is highly recommended. The extra power and clarity from a DAC enhance the already impressive soundstage, detail retrieval, and overall dynamics, making the listening experience truly premium.
💰 Value for Money
At its smart price, the KZ Castor Pro punches well above its weight. It combines detailed sound, punchy bass, balanced tuning, and innovative features—making it a strong choice for both audiophiles on a budget and everyday music lovers.
Have been using these buds for like an year now, they gave me a great time all that while, only recently the cable started getting green and there was an issue with audio drop on even a slight movement (like every earphone ever), but still a great investment for an year.
Got this as my first iem from audio store.. much much more worth than the price.. the bass!!.. my gawddd, it's something which is gonna surprise you.. I got it paired with the moondrop echo a dac.. and trust me, couldn't have asked for anything better.. and the delivery was done to me in kolkata, just within a day.. remarkable job audio store!♥️
Loved the new gear they sound absolutely phenomenal and mind if say the looks and aesthetic of the KZ Castor Pro is underrated for its price, as a newbie I was a little hesitant to jump in this rabbit hole, but it was worth it. Shoutout to The Audio Store to build up my courage, they were very helpful as I was placing my order I fumbled and they responded very positively and helped me correct my mistake. Thank You
Excellent performance with ANC good mic this song is like heaven
Perfect for beginners to start their audiofile journey
I'm satisfied and convinced of this product
The packaging
The quality
And The performance
Trust he go for this one if you never try this one
Just give it a try you will not regret it
I have manny IEM's I'm my collection
But this one is really fantastic
Thanks to The Audio Store
They have many discount in compar to others in market
And shippment is on the time no worrys
1999 is nothing the engineering is perfect of this IEM,,,
Amzing product
Love the way it sounds rich in every range perfect for beginners but if you're not a bass head go for non bass varient.
This is my first ever IEM that I purchased after research of couple of months. And I can say that this was a good decision on my end. Cable is good. Buds look stylish. Comes with a small carry pouch and 6 pairs of ear tips. Sound quality is awesome. Love the instrument separation. Customisable EQ gives them versatility. You can actually experience how other IEM sound just be playing around with the EQ.
Actually, l'm new to this IEM world. Such an amazing product. If you are new to iem just as me, I would highly recommend his product to try out. The OG. There are 16 types of tuning options to play around and explore your favourite music in a new way and the build quality is also pretty good. Overall a nice product 👍.
Good sound
5/5 Mids and Highs
5/5 Well balanced Bass, doesn't overpower the music
5/5 Design look premium and classy
They are quiet heavy and huge
Its my first time buying an iem and it sounds sooo good the design is good the wire can be improve, the bass is somewhat missing and the app has some glitches regarding equalizer. Otherwise this iem is better than my tws. I really like it.
Good
Brand Warranty
100% Original products with brand warranty
7 Days Replacement
On all orders*
Fast & Free Shipping
Ships in 24 Hours*
Secure Payments
Visa, Mastercard, EMI, Net Banking, UPI, BHIM, Wallet's
It provides Awesome sound quality go and buy it m
🎧 KZ Castor Pro IEM – Review
🔊 Sound Quality
The KZ Castor Pro delivers clear and detailed sound with excellent separation across lows, mids, and highs. The decent thumping bass is tight and controlled, giving energy to tracks without overwhelming the vocals or instruments. Its super-balanced tuning ensures a natural, enjoyable listening experience suitable for all genres.
🎚 Unique DIP Switch Equalizer
What sets the Castor Pro apart is its DIP switch physical equalizer. With up to 16 different tuning options, it allows listeners to adjust the sound profile on the go—boosting bass, enhancing treble, or keeping it neutral. This feature gives it a level of flexibility rarely seen in IEMs at this price point.
🔇 Noise Isolation
Although it lacks active noise cancellation, the design offers an excellent passive seal. The snug fit ensures that outside noise is effectively blocked, making the listening experience immersive and ensuring ANC doesn’t feel like a missing feature.
🎼 Hi-Res & DAC Performance
For those using Hi-Res lossless audio, pairing the Castor Pro with a DAC is highly recommended. The extra power and clarity from a DAC enhance the already impressive soundstage, detail retrieval, and overall dynamics, making the listening experience truly premium.
💰 Value for Money
At its smart price, the KZ Castor Pro punches well above its weight. It combines detailed sound, punchy bass, balanced tuning, and innovative features—making it a strong choice for both audiophiles on a budget and everyday music lovers.
This DAC is performing quite well. No heating or white noise issues for me. I am using it with EDC Pro and Castor Pro Harman Target and noticing a good significant upgrade in overall frequency range. I am loving this DAC so far. Build quality is also good at this price range, let's see how long it lasts.
I ordered my first pair of IEM's through The Audio Store and the service was great. Got my package within 5 days and had some questions and their customer care is really active and I got all my queries solved. Great experience overall and I have already recommended Audio Store to my friends.
Went thorough tons of online reviews for a purchase of Desktop DAC+AMP. FOSI K7 was kickstarter but reviews about it was fantastic.
Grabbed it without Blinking twice from TAS. As usual it was a next day delivery.
Fosi delivers crystal clear sound both on Headphones and IEM . Driving power of it crazy.
No doubt it reached my expectations ! The sound quality is really good and gaming experience is also good ! If convenience doesn't matter and sound quality is your priority, you can choose this, it's all rounder IEMs !
Excellent sound
Have been using these buds for like an year now, they gave me a great time all that while, only recently the cable started getting green and there was an issue with audio drop on even a slight movement (like every earphone ever), but still a great investment for an year.
Its geat, the build quality is nice, the wire is preety hard.And quality is sick
Great IEMs