I test audio for a living — 5 best Bluetooth speakers I'd buy in the Memorial Day sales

Sony ULT Field 1 was $129 now $98 @ Amazon
Sony's power sound series only launched in April, but it's already being discounted. The ULT Field 1 is the smallest speaker in the series and sounded impressive during our hands-on test, with a bigger bass than we expected for its size. It claims up to 12 hours of battery life, is light enough to through into a day sack, and comes in black, off-white, forest gray, and orange color options. It has an IP67 rating, making it capable of withstanding water, dust, shock (from falling), and even rust. Users can pair two ULT Field 1 speakers in stereo or can connect and sync with up to 100 speakers for large music installations. This is the lowest price I've seen on this model so far.
Price check: $99 at Best Buy 

JBL Flip 6: was $129 now $99 @ Amazon
The JBL Flip 6 balances compact size with impressive audio quality, and it's also fully waterproof and dust-resistant. It packs 12 hours of battery on a full charge. Its pleasantly rich bass is one of its biggest advantages, and its Bluetooth 5.1 connectivity shouldn't be overlooked either. Overall, it's an impressive portable speaker with strong durability for life on the road and one of the most popular portable speakers on the market. It's important to note that we have seen the Flip 6 drop as low as $89 in previous sales. 
Price check: $99 @ Best Buy

JBL Xtreme 3: was $379 now $229 @ Amazon
Looking for a top-tier Bluetooth speaker? Then meet the JBL Xtreme 3. Silly name aside, this is a powerful audio device delivering consistently strong sound and 15 hours of playback time. It's also waterproof and dustproof, and comes with an included carrying strap. It's also got a built-in bottle opener, which is rather novel, but handy for parties.
Price check: $229 @ Best Buy

Ultimate Ears EpicBoom: was $349 now $296 @ Amazon
This portable has some useful rugged touches to protect the speaker from routine knocks and scuffs while on the road. Its IP67 rating means that it's protected from dirt and moisture, and a rubberized cap secures the USB-C charging port at the back to protect it from water ingress. Sound quality was impressive during my review, and the battery life claims to deliver 17 hours of playback. This is the lowest price I've found for this speaker so far.
Price check: $299 @ Best Buy

Sony ULT Field 7: was $499 now $398 @ Amazon
Another recent release from Sony's ULT series, the powerful ULT Field 7 is one of the most robust portable speakers for outdoor sounds. From the enhanced low-frequency output that will fill large spaces to the IP67 durability rating, it's an ideal speaker for generating big bass sounds by a pool, say. It goes loud, and bass fiends will love the Sony's output. Audio performance is best when turning on Sound Field Optimization in the companion app, which automatically scans your environment for ambient noise and dynamically adjusts sound. Lastly, it has synchronized LEDs at each end of the cylindrical cabinet, and battery life is rated at 30 hours. Just be aware that this big portable weighs 14 pounds. This is the lowest price I've seen on it so far.
Price check: $399 @ Best Buy