Updated Tuning, Improved Bass Response

Last week my JL Sub amp began cutting out intermittently. Since it would be awhile until I could get it back to the shop, I decided to shut it down in the Prima tune for the time being. Once the existing tune was loaded up on the PC I took the sub out and I decide to play around with the overall tune. Mainly I wanted to get more out of the OEM Frontbass speakers to compensate for the missing sub.

It occurred to me that I’d never bothered to push them since the JL sub was a part of the install from day one. Surprisingly, with enough power (I’m bridged on two channels for each speaker) and some very careful EQ they started hitting. In theory there should be an optimum resonant frequency in the Frontbass chamber that takes advantage of it as a bass multiplier, and the idea that by mounting the speakers directly to the car’s inner structure there’s a transducer effect. That frequency is right at the 50hz mark. With some emphasis on 50hz, and a Butterworth filter profile with 6db roll offs on each end, band passed from 125hz to 550hz, suddenly the bass drum hits felt and sounded hard and distinct. They also didn’t seem localized. When the JL sub was handling the bottom end duties, it was obvious the lows were coming from behind. Between the new Frontbass tune and the center dash speaker, the snare drum sound also came alive, with a little “hit” of its own.

Since I was looking to introduce as much midbass as possible, I decided to open up the door 2-ways to full range and gave them a big boost on the bottom end, a little midrange trough and some emphasis on the ultra highs for presence. Surprisingly, not only did the front Focals handle it, even the OEM rear door speakers were game.

In the midst of tuning the JL Sub decided to start playing again, so I gave it a very tight bandpass range. It’s only serving as percussive reinforcement for the Frontbass drivers. If you heard it in isolation you’d have no idea what song was playing.

Here’s the channel by channel tuning. Don’t forget to copy the distance settings as well.

Frontbass:

Front doors:

Rear doors:

Sub:

This tune works well for  Itunes /Apple Music tracks, with the Iphone’s EQ set to Rock. (Settings>Music>EQ), but to really wake it up, try the Aphex Audio Xciter app by Rode Microphones. It will only play files that are resident on your IOS device (not streaming and not ICloud Music Match). Also, it’s buggy as hell with a hard dock connection but perfectly fine over Bluetooth audio. In terms of adding balls and drive to your music, restoring lost harmonics and “decompressing” compressed audio it’s amazing. Once you hear it, it’s impossible to listen to anything else. Highly recommended.

Here are my settings for the Aphex app: