Mr. Never Happy

Hey fellas, I installed new Alpine speakers in my 2013 regular cab STX, but the rear speakers have no bass. The front speakers rock out, whats the deal with the rear speaker signal?

Does the stock head unit filtering out the bass to the rear? or is there a inline filter I can bypass?

Mr. Never Happy

Well.... Even crutchfield showed my truck doesn't have rear speakers. Maybe they were right?

Mr. Never Happy

No one has ever heard of this?

Heel70

Try swapping the polarity of the cables in the rear speakers, that's about the only suggestion ive got. Don't think the head unit does anything to the signal from the front to rear concern.

jhelrey

Adjust your radio settings so you are playing 100% music to the rears and test your theory out.

Hun Shooter

the same happened to me when I replaced my stock speakers to aftermarket JBL of the same size. The reason why you lost your base because aftermarket speakers take more power to be driven in other words if you want base with aftermarket speakers you need an amp.

BadlilF150

Aftermarket speakers will require more power to get loud and produce lower freq. If you swap polarity the phase will be off and they will cancel each other out and cause less bass as well. Add an amp and sub

joedotmac

Three items. One to check is polarity, confirm its correct.

Second is the specifications on the speakers are what RMS? Using the OEM deck, keeping a low watt RMS speaker is recommended to keep the "fullness" and "low end" of the sound spectrum. Using a high wattage RMS speaker, example 120 RMS with the deck only producing 20 to 40 RMS most of all the low end will be gone because the deck lacks the output to drive the woofer of the speaker.

Ideally you'd want to match the stock deck output RMS to the speakers, or be relatively close.

Third, is you'll want to assure the speaker mounting surface is flush and properly seals with the door frame. A speaker which isn't sealed properly looses some of the ability to use the door cavity as a sound chamber. This has a moderate effect to the "fullness" of the sound produced. I've had to resort to building my own mounts out of partical board and foam tape to assure good sealing on previous vehicles.

Mr. Never Happy

Also = I do have "stock" tweeters in the plastic windshield pillars, I'm very sure they have some kind of filters to cut out the lows.

Heel70 - I did swap the polarity of the cables. Not much difference could be heard.

jhelrey - I adjusted the stock radio to the rear speakers only, and even the rear left and right speakers separately, Still no bass from either of them.

Hun Shooter, BadlilF150, joedotmac - The front speakers are the same exact as the rear speakers, but the front speakers produce 100% full range sound and rock out completely (in or out of the doors) the rear speakers have no bass or lows.

Thank you all for your comments and suggestions! Sooner or later I swap the front speaker wires to the rear speakers to see if there is a change, if no change, I will run new speaker wires to the rear speakers. and let you all know what happens.

Thanks again!

F150_1138

This is normal with the stock head unit. I have a 2012 XL that came with the single CD player. A little over three years ago I installed all new Infinity speakers in the front and rear of my regular cab truck. I also installed a 5-channel amplifier. I converted the stock head unit’s speaker output using a PAC interface. Because the PAC had only the LF outputs for front and rear, I had to split the rear channel output to get a signal for the subwoofer. Then I found that my subwoofer did not work. Ended up having to split the front channel output and then my subwoofer worked as it should. I have seen very few posts that address this issue, but I have found a few. Today I have an aftermarket head unit so this is no longer an issue.