After I had a Bluetooth handsfree connected in my car with my car radio, I realized pretty quickly realized that the connection more bad work by interfering with the alternator as pretty. Making calls via Bluetooth was only possible with very strong beeping. After I got interposed the ACV, a really good music reproduction is now possible. Absolutely no Störgeräuche. Also taking part in any way the bass away (like others here in your reviews write). I use the ACV along with the also purchased in Amazon Kinivo BTC450 Bluetooth handsfree car. The sound and voice quality is just great !! Would give 10 stars if we could. For the combined paid 38.- you have a mad combination that leaves no wish unfulfilled. Also, the playback signal (iphone EU Volume Limit) is apparently reinforced and thus you get a better and louder music playback. Thank you for this 2 great products.