According to my DB the lowest price is 12.74 USD for RGB Sound (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest coupon and price update (UTC):
Banggood (12.74 USD)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? What about the price? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal 12.07 USD)
Link: Banggood product page
Price: 12.74 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG589b2e
(you can check these old coupons out, but these probably won’t work)
Aliexpress
Click here… to search for RGB Sound Control LED Light 2pcs on Aliexpress
Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for RGB Sound Control LED Light 2pcs.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).