Tapping rear speakers for sub question

[JerseyMike]

So I bought some Infinity References for the front and back. Rears are 4x6. I was thinking of adding a Rockville 8" sub to the back, and just tapping the rear speaker wires for the high level input on the sub. Question is: if the rear speakers get a little obnoxious and I want to fade them down, does that turn the sub down too? And how would I get around that? This is all for a truck that hasn't been delivered yet. Lol

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[Delbert]

The rear speakers have the base blocked so it is not a good option for running the sub.

 

[JerseyMike]

The rear speakers have the base blocked so it is not a good option for running the sub.

Aw narts. Glad I asked. Thanks

 

[Chris_G]

The rear speakers have the base blocked so it is not a good option for running the sub.

Worked fine for me

 

[MaveRican]

I have the same sub. I tap to the rear speakers, I replace my speakers with DS18 4". Sounds good. I also picked up the remote from the positive of the speaker since the subwoofer is signal sensing.

 

[Piterpi]

I installed a Nakamichi 8" subwoofer behind the rear seat, I took the signal from the rear speakers...the subwoofer didn't even move...no low frequencies. I connected it with the front and everything worked much better...
So the rear speakers DO have their frequencies cut...

 

[Chris_G]

I installed a Nakamichi 8" subwoofer behind the rear seat, I took the signal from the rear speakers...the subwoofer didn't even move...no low frequencies. I connected it with the front and everything worked much better...
So the rear speakers DO have their frequencies cut...

I installed 8" Blaupunkt sub, tapped off rear speakers and it works great.

 

[Piterpi]

I installed 8" Blaupunkt sub, tapped off rear speakers and it works great.

I don't know...in my case, rear speakers sounds without any bass and subwoofer stay flat...

 

[Delbert]

I did do a frequency sweep with a spectrum analyzer and the response did drop off below 150 hz in the rear speakers. Most subs are set to filter out frequencies above 80 hz.

 

[uh50]

So I bought some Infinity References for the front and back. Rears are 4x6. I was thinking of adding a Rockville 8" sub to the back, and just tapping the rear speaker wires for the high level input on the sub. Question is: if the rear speakers get a little obnoxious and I want to fade them down, does that turn the sub down too? And how would I get around that? This is all for a truck that hasn't been delivered yet. Lol

Great question.

The fact that there are different experiences for different people is an interesting conundrum. According to more knowledgeable people than me, the rear speakers are limited. Some say at 250Hz and lower, some say 150Hz and lower and others say 80Hz and lower. Some have said that it is the ACM with a rear channel limitation and others say it is the speaker with a bass block. There is a forum on the Bonco6G website that says the limitation can be removed with Forscan, which I plan on testing one of these days.

I too replaced my factory XL speakers with Infinity Reference and I also purchased a Rockville RW68CA Subwoofer, but I am feeding the sub from a Puzu PZ-C7 DSP Amp (when I get the harness) through the sub RCA output on the Amp which is fed from the front. None-the-less, the DSP Amp is supposed to clean the limitation, but at this writing, I'm not sure how it does that (same with Kicker Key DSP, etc.). From my understanding we can feed the entire DSP Amp setup from the front speaker circuit which eliminates the worry about a bass limitation. When I get the correct harness, I'll learn more when I set up the DSP.

I don't know why Ford is silent about how the limit frequencies to the rear speakers, although I'm sure there are those that read these posts and chuckle at our struggles. Shame on you if you do.

I'll post more when I know more, but according to some I never learn anything.

 

[Delbert]

I think I need to say a a bit more. I'm an amateur audiophile and engineer with 40+ years of experience modifying audio devices to get the sound I want. I have never had a vehicle that I have not tweeked the audio in some way to improve the sound. When I ordered my Maverick over a year ago and waited for it's arrival I made plans for the new audio system.

I'd need a powered sub and all of the speakers would need to be upgraded and sound matting would be added. I had fallen for the Nakamichi DSP amps that had been introduced a few years earlier and never had much success in the US. They have a huge lineup of equipment with integrated line converters and almost no documentation. But they do have a phone interface and app which allows you to control everything . And I mean everything.

Imagine having an equalizer for every channel, control over time delays, choices between crossover types. It's a tinkerer's dream. So much so, that to set it up for optimum car audio you need an audio analyzer with a calibrated microphone positioned where the listener is, a technician and lots of time. There are some great youtube videos showing the process.

When I got the truck I was surprised by the sophistication of the stereo. The head unit was in two parts, the screen and the Audio Control Module (ACM). Each speaker was wired independently back to the ACM and all the wiring was wrapped in this rodent proof tape which is difficult to remove without disturbing the insulation on any of the wires inside. The speakers sounded clear and responsive in their limited volume range. The crossover between the dash tweeters and front door speakers had obviously been thought out and designed. Base was lacking, probably the the most limiting aspect of the system. The controls on the screen were good and the amp seemed powerful enough.

I elected to forgo the DSP for now. To hook it up would require a loopback harness integrated to a pigtail for the DSP. This is a one off product and pricey.

I replaced the door speakers with Infinity Reference which gave me better base response. So good in fact that I worry that I could blow apart the front door if I turned it up to hiphop volumes. I would have to add a sub and decrease the base to the front speakers if I played the stereo loud.

So the question still remains of how to best integrate a sub into the factory base stereo system. I am unwilling to tap into the wires at the back of the ACM. They are too tightly wrapped and the consequences of messing up the harness are big.

On the Bronco forum, someone changed the programming on the ACM using forscan. I tried the codes on my xl hybrid and they did not work. Apparently it is a different ACM module on the Bronco.

I asked on the the stickied forscan thread for someone with the Bose system to publish their codes for the ACM modules. The theory is that part of the Bose implementation is changes in crossover points and the integration of the sub. Specifically, a code that would allow a full spectrum signal to the rear speakers. All done with forscan. Noone has responded and interest in forscan experiments has faded.

I'd still like to check out how much the connected touch radio ACM can be controlled in forscan.

 

[Lordran_Hollow]

Yeah don't go to the rear speakers. Most OEMs nowadays have crossovers (audio filters) set for the rear speakers to filter out the bass that will work pretty poorly for a sub. There may be some signal there that would work, but it wouldn't be the loudest.

Especially with the rear speakers being 4", they wouldn't be able to handle that much bass before bottoming out and buzzing like mad. For every subwoofer I install at my job that uses the OEM radio, I always grab my signal from the front door woofer speakers.

Even with other vehicles that have larger diameter speakers, OEMs tend to have the focus of the bass at the front where the driver will be more likely to feel/hear it than the rears.

 

[uh50]

I think I need to say a a bit more. I'm an amateur audiophile and engineer with 40+ years of experience modifying audio devices to get the sound I want. I have never had a vehicle that I have not tweeked the audio in some way to improve the sound. When I ordered my Maverick over a year ago and waited for it's arrival I made plans for the new audio system.

I'd need a powered sub and all of the speakers would need to be upgraded and sound matting would be added. I had fallen for the Nakamichi DSP amps that had been introduced a few years earlier and never had much success in the US. They have a huge lineup of equipment with integrated line converters and almost no documentation. But they do have a phone interface and app which allows you to control everything . And I mean everything.

Imagine having an equalizer for every channel, control over time delays, choices between crossover types. It's a tinkerer's dream. So much so, that to set it up for optimum car audio you need an audio analyzer with a calibrated microphone positioned where the listener is, a technician and lots of time. There are some great youtube videos showing the process.

When I got the truck I was surprised by the sophistication of the stereo. The head unit was in two parts, the screen and the Audio Control Module (ACM). Each speaker was wired independently back to the ACM and all the wiring was wrapped in this rodent proof tape which is difficult to remove without disturbing the insulation on any of the wires inside. The speakers sounded clear and responsive in their limited volume range. The crossover between the dash tweeters and front door speakers had obviously been thought out and designed. Base was lacking, probably the the most limiting aspect of the system. The controls on the screen were good and the amp seemed powerful enough.

I elected to forgo the DSP for now. To hook it up would require a loopback harness integrated to a pigtail for the DSP. This is a one off product and pricey.

I replaced the door speakers with Infinity Reference which gave me better base response. So good in fact that I worry that I could blow apart the front door if I turned it up to hiphop volumes. I would have to add a sub and decrease the base to the front speakers if I played the stereo loud.

So the question still remains of how to best integrate a sub into the factory base stereo system. I am unwilling to tap into the wires at the back of the ACM. They are too tightly wrapped and the consequences of messing up the harness are big.

On the Bronco forum, someone changed the programming on the ACM using forscan. I tried the codes on my xl hybrid and they did not work. Apparently it is a different ACM module on the Bronco.

I asked on the the stickied forscan thread for someone with the Bose system to publish their codes for the ACM modules. The theory is that part of the Bose implementation is changes in crossover points and the integration of the sub. Specifically, a code that would allow a full spectrum signal to the rear speakers. All done with forscan. Noone has responded and interest in forscan experiments has faded.

I'd still like to check out how much the connected touch radio ACM can be controlled in forscan.

Thanks for the post. It's nice to have knowledgeable people provide valuable information, so again thanks.

Like you, I replaced my speakers with Infinity Reference using their 6.5 REF-6532IX in the front and their 4 x 6 REF-6432CFX in the rear. The limitation on the rear is certainly there because the Infinity 4 x 6 speaker are rated down to 75Hz, which I do not hear with my bass test music (Acoustic Alchemy). However, the front 6.5 Infinity Reference certainly takes advantage of its frequency response of 53Hz - 21kHz and sensitivity of 93db. I like too that the speakers are rated at 3 ohm. It's just one of those little details that help improve the efficiency of the speaker.

My Rockville RW68CA sub is installed but not connected as I want to feed them from a Puzu PZ-C7 DSP Amp with RCA sub outputs fed through the DSP using the front circuit from the ACM. I have received the DSP Amp but it had the wrong loopback harness, but after a few emails, the vendor has ordered a harness specifically for the Maverick. We'll see when I get it if it is truly plug and play. If not, I'm not afraid to correct any wiring issues in the harness.

I ordered the Puzu DSP Amp because of the supplied loopback harness and I was impressed with the quality of the DSP Amp and the supplied harness, and like the factory wiring is cloth wrapped, only they used flannel. The harness even includes REM wiring for the Sub. Again, we'll have to wait until I get it installed to see if indeed it is a quality product. It has a modest output, but as you stated, the Infinity Reference speakers are so very efficient and get loud in a hurry.

I too follow the Bronco6G forum and reviewed their Forscan modifications. there are similar forums for Forscan use on F-150s, but I have not taken the time to review. I'm planning on playing around with Forscan after I get my audio system completed. Can't wait to hear the impact the small sub has. Anyway, planning on adding cruise and delving into the Forscan hacking which I find intriguing.

When I get done, I should have a modest system that pleases my music tastes.

Keep us informed about your Forscan experiences.

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