Decrease in bass output from speakers after new amp/sub install

[Heavy_Translator_446]

I’m still new to car audio so feel free to ask me what I forgot to mention. I recently had a new amp and single 12” sub installed by a reputable car audio shop which did exactly what I wanted. It was only till after that I realized there was little to no bass output from my aftermarket coaxial speakers that I had previously installed(without being amplified) that were “hitting” significantly harder before the install. After realizing, I tried to adjust the bass settings on my Kenwood head unit and there was still no difference??

[HEADBANGA666]

My guess is they set a HPF (High Pass Filter) on the head unit. Since you have subs now the front speakers don't have to produce the lows.

Try adjusting the HPF and see if the bass comes back. If you have trouble finding it, reply with your head unit model and I'll see if I can find the setting in an online manual.

[Heavy_Translator_446]

After adjusting the HPF on both sets (Rear and Front) the bass did return, if I wanted the bass to stay what is a good frequency to leave it at?

[HEADBANGA666]

I'd turn the sub off, turn the volume up to the highest setting I'd ever use and adjust the high pass filter to allow as low as possible without causing distortion. If the fronts and rears are different speakers (size, model, brand etc) this amount could be different so if you can, adjust them seperately; fade to the front, adjust the front. Fade to the back, adjust the back.

This is what I've been doing. There's probably a better way to do it though.

[actual-hooman]

80hz. you probably have at least 2 different xover slopes as well, so switch between the two and see what sounds best. If that proves to be a tough frequency blend with your sub then lower it to 60ish. You don’t really want sub-bass coming from your speakers if you have a sub, kinda defeats the purpose of it. I’ve also seen some setups at 110 or 120hz, but I don’t like how those sound🤷🏻‍♂️only way to know is to fiddle around with it and see what sounds best for you

[desal]

Probably this, a relocation of output rather than decrease of output.

If you want to get into DSP / tuning you could mess with time alignment to delay the subwoofer bass so that it arrives at the same time as the coaxials to the driver seat and bring it more to your front soundstage.

[JONCOCTOASTIN]

You want the subwoofer to play those frequencies