ForScan Flat EQ before key200.4?

[colinl]

I took my time when splicing the rear metra connectors to tap the rear speaker signal for my sub amp. I'm not saying it's out of the realm of possibility I am human. Sadly verifying 100% requires me ripping the rear panels off the speakers to check, as I've also wondered if maybe one is wired out of phase.

As I wrapped all my wiring with Tessa tape.

I would just flip the speaker wiring at either the amp or the sub side as a quick test.

Then if it does help, I would probably leave it, but if you really want to find out why we could discuss that.

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[AVC]

I think for now I'm just going to leave it as is with my signal coming from the rear speakers. It's just weird to me how some songs sound great with the kick drums the bass guitar, everything just sounds perfect.

Then a different song sounds okayish, then another song just sounds like trash with horrible bass response if any. I don't know if my expectations are just too high and it's just Ford's doing with the head unit and the EQ of the Maverick.

I just hate jumping further down the rabbit hole spending more money and time running wires buying a harness like the pac lock pro to get my signal from the front speakers as well. Only to find out it didn't make any bit of difference and the bass output is still the same.

Likely because your sub crossover is set too high (above 55Hz or so), exciting a cab resonance around 65 Hz, and because the Forscan "flat eq" setting leaves the the factory speaker acoustical response with a very broad suckout from about 150 to 700Hz. The effect is that the low bass from the sub "suddenly" jumps out when present, but then the whole thing gets thin again. The phenomenon is called "disconnected bass".

Try setting the sub crossover to 55Hz, then using the head unit tone controls set to this:

Which will produce a measured response at the driver seat, head height (where I sit, anyway) of:

These settings significantly (but not perfectly) address the deficiencies of the stock speakers using "flat EQ" in Forscan, and blend the sub in more seamlessly. And don't require modification of the stock head unit/ACM to insert an aftermarket DSP.

Many people will find these settings and curve quite pleasant and punchy. At higher volume the peak at 1.25kHz will begin to bite a bit, but it is vastly prefered over the huge sag in the mid-bass and lower mids. Most will aos find the HF adequate as well, despite the rolloff above 8 KHz.

 

[Toddman45]

I would just flip the speaker wiring at either the amp or the sub side as a quick test.

Then if it does help, I would probably leave it, but if you really want to find out why we could discuss that.

Oh I'm digging into it now.

I flipped it at the sub with no noticeable difference.

 

[AVC]

The curve above is measuring the effective power response, which should NOT be flat but have a smoothly falling response of .5 to 1 dB/oct. I drew the red line to illustrate how well the measured curve fits a smoothly falling line. This represents how you will perceive the overall timbre of the system.

Oh, and for the alert, the mic used for actual measurement was a Denon receiver Audessy mic, using the calibration file some REW member extracted from an Audessy receiver. I used that mic as the calibration is diffuse field, which best simulates what the ear perceives in a car cabin with all speakers operating.

 

[AVC]

interesting that you didn't include or otherwise comment on my statement in this quoted post that some people are noticing no different with flat eq.

it's either that a lot of people are unable to use Forscan properly, or the ACM does not accept flat eq on newer trucks. the value is accepted, no checksum error, but it doesn't change the electronic crossover setting.

Well, I can't speak for what people "notice", and many are notoriously poor at A/B comparisons if the switch is 30 sec to several minutes apart. I know what the MEASURED acoustical response differences are between factory and "flat eq" settings in Forscan.

 

[colinl]

Well, I can't speak for what people "notice", and many are notoriously poor at A/B comparisons if the switch is 30 sec to several minutes apart. I know what the MEASURED acoustical response differences are between factory and "flat eq" settings in Forscan.

technically, you're correct in that RTA shows things that may be difficult to perceive. however, I doubt anyone would fail to notice a 300hz high pass on a sub being present and then removed.

you stated you measured frequency response before and after flat eq. I don't believe I have seen anyone else post that, can you share the 'before' sweep please? ideally with no other settings changed, but I'll still look at whatever you've got.

 

[Darnon]

Also in general the box being in the somewhat enclosed Maverick storage area is going to be less punchy than a box beneath the rear bench of an F-150 if that's what you had previous.

 

[Toddman45]

dumb question, but is your sub out of phase with the door mids? it would take a few seconds to swap the terminals to check.

And I did have my wiring out of phase when connecting the right rear pillar. Rechecking it all now will report back later as for now the first one I checked the right rear pillar wiring was reversed on the passenger side.

 

[AVC]

technically, you're correct in that RTA shows things that may be difficult to perceive. however, I doubt anyone would fail to notice a 300hz high pass on a sub being present and then removed.

you stated you measured frequency response before and after flat eq. I don't believe I have seen anyone else post that, can you share the 'before' sweep please? ideally with no other settings changed, but I'll still look at whatever you've got.

I was ignoring the 300 Hz high pass scenario. Only referencing before and after setting of Forscan "flat EQ

I don't have the before snaps at the office to post. Will try and remember to post later or on the weekend. I also used a different app for the "before", as it was right after I bought the truck, and before I considered adding a sub.

 

[AVC]

For those interested, here are the "naked" close-mic'ed curves of the rears, and dash tweets with Forscan in "flat eq" and with head unit tone controls zeroed.

REAR Speaker. GREEN = zeroed head unit tone controls. BLUE = tone controls optimized, as shown in previous image. Notice the sizeable peak at 1.2KHz, which seems largely responsible for the (undesirable) peak in the overall system response. When I have time, might suss out whether the driver is responsible or some interaction with the cavity.

DASH TWEET: tone controls zeroed (I think): The tweet response is somewhat modified from factory, as I pulled them and raised the value of the high pass capacitors to move the cutoff to 2Khz. I have cap value noted at home. Ignore anything below 150Hz in the graphs, as there was some LF influence from the doors speakers when measuring the tweet, and some engine rumble when measuring the rears when the tone controls were zeroed.

 

[AVC]

technically, you're correct in that RTA shows things that may be difficult to perceive.

More specifically, if one uses REW, or another FFT (gated window) system like Smaart, SystTune, etc the desired response target IS approximately flat, as those measurements (typically) exclude the off-axis radiation of a loudspeaker and specifically do NOT represent what your ears perceive.

There's also potential for much error (lying of the test equipment) in a car environment using FFT to measure multiple activated loudspeakers, as they have to be carefully arrival-timed to sum at the microphone correctly.

 

[Toddman45]

Yep that fixed it I had the passenger side wiring out of phase and crossed at the speaker and to the amp once I got that all button back up and turn the amp on everything sounds incredible now as it should.

Glad I found the simple mistake and fixed it but boy do I feel like an idiot cuz I thought I double-checked and triple checked. Sounds incredible as it should now sampling a handful of songs, that previously sounded out of sync .

Thank you @colinl for the suggestion to check the wiring Glad it was that simple. .

I can now confirm that if you use forscan and set the EQ to flat curve that tapping the rear speakers for a signal to your Sub Amp, you lose no bass output when connecting a sub there is plenty of bass with the rear speaker signal.

I swore I had it wired right, but somewhere along the line I had the wires reversed from the truck to the rear pillar speaker harness on the passenger side as well as the wiring from the speaker to my amp. After correcting that silly mistake everything sounds incredible. I now have a big fat smile on my face whenever listening to music in the Maverick.

 

[JetFixxxer]

Does the Mav have a Variable Line Level settings in the ACM? I had to do this on my F150 and Fusion.
http://www.2gfusions.net/showthread.php?tid=3704

 

[Toddman45]

Thank you again @colinl , it's so nice having my sub sound the way it should giving a nice back and butt massage. Along with not being able to see anything out the rearview mirror when the bass hits.

Amen and hallelujah...

 

[rallyshark]

interesting that you didn't include or otherwise comment on my statement in this quoted post that some people are noticing no different with flat eq.

it's either that a lot of people are unable to use Forscan properly, or the ACM does not accept flat eq on newer trucks. the value is accepted, no checksum error, but it doesn't change the electronic crossover setting.

I think a lot of the confusion happens when people are talking about their stereo upgrades, then mix up info found on the forum that may be specific to the B&O or base stereo. I can only comment on personal experience with the base stereo. The Forscan flat EQ setting is in the easy section of Forscan, so I don't know how people could get that wrong unless they clicked it and never told Forscan to actually write the change?

As far as the base stereo goes: If anyone doesn't notice a difference between normal and Flat EQ, probably one of two things is happening. A) They aren't listening to music that they would notice that bottom end very much and don't know what they are listening for, and(or)B) they don't have a sub that really digs deep enough to notice the difference. For me, the difference was blatantly obvious. It wasn't even remotely close. Of course, your average person may not bother running tones to verify what their ears are telling them either.

I completely agree with your comment about no one who used signal from the fronts complaining about lack of bass output. We know with 100% certainty that always works. However, tapping the rears seems to be a grey area depending on whom you ask. I also agree that Crutchfield could very well be wrong. Not that they don't know what they're doing, but they also operate on a lot of generalizations rather than very specific vehicle situations.

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