--- product_id: 300776750 title: "Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black)" brand: "alphasonik" price: "$258.60" currency: USD in_stock: true reviews_count: 5 category: "Alphasonik" url: https://www.desertcart.us/products/300776750-polk-audio-db351-3-5-inch-coaxial-speakers-pair-black store_origin: US region: United States of America --- # 700W Power 88dB Clarity 3.5" Coaxial Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) **Brand:** alphasonik **Price:** $258.60 **Availability:** ✅ In Stock ## Summary > 🎉 Elevate Your Sound Game! ## Quick Answers - **What is this?** Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) by alphasonik - **How much does it cost?** $258.60 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/300776750-polk-audio-db351-3-5-inch-coaxial-speakers-pair-black) ## Best For - alphasonik enthusiasts ## Why This Product - Trusted alphasonik brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Durable Build:** Engineered for longevity, ensuring your sound system stands the test of time. - • **Compact Design:** Perfectly fits in any space without compromising on performance. - • **Powerful Output:** 700 Watts of peak power for an immersive sound experience. - • **Easy Connectivity:** Seamlessly connects via auxiliary input for hassle-free setup. - • **Unmatched Sound Quality:** Experience crystal-clear audio that elevates your listening. ## Overview The Polk Audio DB351 3.5-Inch Coaxial Speakers deliver exceptional audio clarity and powerful output in a compact design, making them the perfect addition to any sound system. With a peak power of 700 Watts and an easy auxiliary connection, these speakers are engineered for both performance and durability. ## Description db351 3.5 Inch Coaxial Speaker Review: Not bad 6.5" inch 3-way to replace stock door speakers by Alphasonic which is Polk Audio. - I've always been a fan of Polk Audio so I thought I'd give these sub brand Alphasonic 6.5" inch speakers a try to replace my 2023 Kia Niro EV stock door speakers. The specs on these frequency speakers are phenomenal touting: 92 dB sensitivity, 28 Hz - 22,000 kHz, rivaling other ferrite magnet JBL, Infinity, DS18 and even Hertz. The watts aren't super great at 35w RMS each and 70w peak into 4 ohms. Advertising tries to make them sound bigger by adding the watts together, many speaker companies do this. Being this is what most stock audio systems produce I wasn't too worried about it, plus pair of these were so ridiculous cheap, I figured if they didn't sound good I'd just keep them or donate them and get better speakers. Couldn't be any worse than the stock speakers, it's amazing how cheap and low quality automakers go with their base stock audio, even in the year 2023 ! The new Niro stock speakers are junk. They do offer a premium package with Harmon Kardon + subwoofer but if you get a base model you get weak terrible speakers. There are six speakers in the Niro, two tweeters and two 6.5" inch woofers in the front doors, two 6" inch woofers in the back doors that can fit 6.5" inch with a bracket. The front doors need shallow mount or small magnets as the window glass encroaches into the speaker holes when rolled down. I originally bought Skar neodymium woofers for the front because you gain some volume with neodymium magnets and they tend to be more sensitive with a much smaller footprint than ferrite magnets to save on space. The Skars are also amazing for the price. FIRST INSTALL – I replaced the stock tweeters with Soundstream 1" inch, put the Skar neodymium woofers up front and also installed a powered subwoofer leaving the stock woofers in the back doors. Sound improvement over the stock audio was HUGE, also gained significant volume, more than enough for these old ears, just wish I had better DSP for tuning. Bypassing the 8" inch Kenwood sub definitely makes a massive difference, no matter what speakers you have in the doors a sub makes all the difference with low end, without one there's really no boom or thump. The sub I have isn't enough to rattle your windows, but it does add some low end vibrations. SECOND INSTALL - I later added a pair of Alphasonics to replace the rear door woofers. I will say the ferrite magnets are pretty small and was skeptical if they were true to the specs as most other quality woofers utilize much larger magnets and these are nearly the same small size as the stock woofers. Thought I'd install them in the back doors to make up for not having coaxials or 3-way. Difference was negligent as the rear speakers get less power from the stock amp and to hear them you have to change the balance so much you lose a lot of volume up front. So I switched the Alphasonics to the front despite already having nice tweeter separates installed and put the neodymiums in the rear hoping to gain a little volume with the higher output. Only made a slight difference and surprisingly the the 3-way Alphasonics did not sound too shrill or piercing in the high frequency bandwidth. So I've left the speakers this way for a few weeks now. The stock EQ is flat and I only have to use about 3/4 the volume on my sub versus 100% when it was running with wimpy muddy the stock door speakers. Overall I'm pretty satisfied as I'm not looking win any stereo competitions. The stock volume is plenty as I don't want to age my ears more than they already have. I may eventually replace the Alphasonics with Memphis Audio 6.5" neodymium at some point, but for now it's not really needed and the headroom and volume are a hundred times better than stock. Still not sure if the Alphasonics actually meet the specs, but they don't sound bad. Having dampening and doors with good airspace also makes a difference. Review: Incorrect image but correct product. Also very loud - The picture displayed is incorrect but you do receive the actual Polk DB351 is you order it. I love the speakers, they are loud and can reproduce high notes really well. I suggest blocking any frequencies below 130 to have a nice clean and crisp sound. Overall I love them. I installed them on my 2008 NC NC1 Mazda Miata ## Features - Coaxial Speakers -3.5-Inch - Pair, Black - Clear sound ## Technical Specifications | Specification | Value | |---------------|-------| | Brand | Polk Audio | | Manufacturer | Polk Audio | | Model | AS26 | | Model Name | DB351 | | Product Dimensions | 17 x 15 x 8 cm; 1.22 Kilograms | | Batteries | 1 12V batteries required. | | Item model number | AS26 | | Audio input compatible with the item | Auxiliary | | Audio output mode | Surround | | Speakers Maximum Output Power | 700 Watts | | Noise Level | 88 dB | | Speaker connectivity | Coaxial | | Wattage | 350 | | Power Source | ac | | Batteries Included | No | | Batteries Required | Yes | | Mounting Type | Flush Mount | | Does it contain liquid? | No | | Includes Rechargeable Battery | No | | Includes remote | No | | Manufacturer | Polk Audio | | Item Weight | 1 kg 220 g | ## Product Details - **Audio Output Mode:** Stereo - **Brand:** Alphasonik - **Connectivity Technology:** Coaxial - **Frequency Response:** 22000 hertz - **Speaker Maximum Output Power:** 700 watts ## Images ![Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - Image 1](https://m.media-amazon.com/images/I/71EJx9130LL.jpg) ![Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - Image 2](https://m.media-amazon.com/images/I/51E4XOaoAhL.jpg) ![Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - Image 3](https://m.media-amazon.com/images/I/819xt2KdAEL.jpg) ![Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - Image 4](https://m.media-amazon.com/images/I/81va5iN+mSL.jpg) ![Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - Image 5](https://m.media-amazon.com/images/I/811vfXRv1XL.jpg) ## Questions & Answers **Q: Are the bass blockers separate or already built into the speaker line?** A: they are included in the box, but you have to wire them in-line yourself. They are 200muF capacitor. small black cylinder's are in the parts bag in the box under the speakers **Q: What is the frequency range?** A: frequency response: 90hz - 22khz , per box spec. **Q: Will they fit a 2002-06 Toyota Camry front window dash?** A: No idea. I had a 2015 Mazda CX 5. but it might replace many front dash speakers I think ? **Q: Will this fit a Bmw 535xi 2010?** A: I was an owner of a 2015 Mazda CX 5 so I would do some searching around on youtube and Google see if someone else did it. I learnt it that way myself. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Not bad 6.5" inch 3-way to replace stock door speakers by Alphasonic which is Polk Audio. *by S***T on 26 August 2023* I've always been a fan of Polk Audio so I thought I'd give these sub brand Alphasonic 6.5" inch speakers a try to replace my 2023 Kia Niro EV stock door speakers. The specs on these frequency speakers are phenomenal touting: 92 dB sensitivity, 28 Hz - 22,000 kHz, rivaling other ferrite magnet JBL, Infinity, DS18 and even Hertz. The watts aren't super great at 35w RMS each and 70w peak into 4 ohms. Advertising tries to make them sound bigger by adding the watts together, many speaker companies do this. Being this is what most stock audio systems produce I wasn't too worried about it, plus pair of these were so ridiculous cheap, I figured if they didn't sound good I'd just keep them or donate them and get better speakers. Couldn't be any worse than the stock speakers, it's amazing how cheap and low quality automakers go with their base stock audio, even in the year 2023 ! The new Niro stock speakers are junk. They do offer a premium package with Harmon Kardon + subwoofer but if you get a base model you get weak terrible speakers. There are six speakers in the Niro, two tweeters and two 6.5" inch woofers in the front doors, two 6" inch woofers in the back doors that can fit 6.5" inch with a bracket. The front doors need shallow mount or small magnets as the window glass encroaches into the speaker holes when rolled down. I originally bought Skar neodymium woofers for the front because you gain some volume with neodymium magnets and they tend to be more sensitive with a much smaller footprint than ferrite magnets to save on space. The Skars are also amazing for the price. FIRST INSTALL – I replaced the stock tweeters with Soundstream 1" inch, put the Skar neodymium woofers up front and also installed a powered subwoofer leaving the stock woofers in the back doors. Sound improvement over the stock audio was HUGE, also gained significant volume, more than enough for these old ears, just wish I had better DSP for tuning. Bypassing the 8" inch Kenwood sub definitely makes a massive difference, no matter what speakers you have in the doors a sub makes all the difference with low end, without one there's really no boom or thump. The sub I have isn't enough to rattle your windows, but it does add some low end vibrations. SECOND INSTALL - I later added a pair of Alphasonics to replace the rear door woofers. I will say the ferrite magnets are pretty small and was skeptical if they were true to the specs as most other quality woofers utilize much larger magnets and these are nearly the same small size as the stock woofers. Thought I'd install them in the back doors to make up for not having coaxials or 3-way. Difference was negligent as the rear speakers get less power from the stock amp and to hear them you have to change the balance so much you lose a lot of volume up front. So I switched the Alphasonics to the front despite already having nice tweeter separates installed and put the neodymiums in the rear hoping to gain a little volume with the higher output. Only made a slight difference and surprisingly the the 3-way Alphasonics did not sound too shrill or piercing in the high frequency bandwidth. So I've left the speakers this way for a few weeks now. The stock EQ is flat and I only have to use about 3/4 the volume on my sub versus 100% when it was running with wimpy muddy the stock door speakers. Overall I'm pretty satisfied as I'm not looking win any stereo competitions. The stock volume is plenty as I don't want to age my ears more than they already have. I may eventually replace the Alphasonics with Memphis Audio 6.5" neodymium at some point, but for now it's not really needed and the headroom and volume are a hundred times better than stock. Still not sure if the Alphasonics actually meet the specs, but they don't sound bad. Having dampening and doors with good airspace also makes a difference. ### ⭐⭐⭐⭐⭐ Incorrect image but correct product. Also very loud *by D***R on 11 November 2019* The picture displayed is incorrect but you do receive the actual Polk DB351 is you order it. I love the speakers, they are loud and can reproduce high notes really well. I suggest blocking any frequencies below 130 to have a nice clean and crisp sound. Overall I love them. I installed them on my 2008 NC NC1 Mazda Miata ### ⭐⭐⭐⭐ Four Stars *by J***N on 19 August 2016* Good ## Frequently Bought Together - Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) - KabelDirekt – Pure Copper Stereo Audio Speaker Wire & Cable – Made in Germany – 2x2.5mm² – 10m – (For Hifi Speakers and Surround Sound Systems, Pure Copper, with polarity markings) - Amazon Basics RCA Audio Cable for Stereo Speaker or Subwoofer with Gold-Plated Plugs, 2.44 M, Black --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/300776750-polk-audio-db351-3-5-inch-coaxial-speakers-pair-black](https://www.desertcart.us/products/300776750-polk-audio-db351-3-5-inch-coaxial-speakers-pair-black) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-11-13*