Aftermarket DSP amp with MIB2STD

[Pipzap]

Yeah, the electrical input levelling is inadequate on the ap series. In your case the tweeters and mid woofers signal overlap and this is not something you can measure or correct with the ap series. Also, the ap has no built in RTA and that makes tuning a real bind. There are other limitations too but I can’t recall them all. The forza dsp series is excellent though. Save up and you won’t be disappointed.

So the issue is actually, that the amp is not able to flatten the input signal (which is the whole reason to get a dsp)??

 

[mathyou78]

So the issue is actually, that the amp is not able to flatten the input signal (which is the whole reason to get a dsp)??

That and the really old and clunky software generally. Get a AF M8.14 and use two of the channels to power the sub.

 

[Chariot]

The capacitor is on the back of the tweeter

If you altered the wiring to the seat sound configuration, you'd be left with 6 channels

Front left high low
Front right high low
Rear left high low
Rear right high low
Subwoofer
Dash speaker

So you may aswell install a 6 channel amp and add an aftermarket subwoofer and a dashboard speaker at the same time. Or just go with Seat Sound

Now I'm getting seriously confused and was wondering if you (or @mathyou78 or anybody could help):

I've pulled the quadlock from the back and have the traditional 8 pins in the brown block (see photo).
But I also have next to that 2 more signals. I was lead to believe this was for the mid speaker and the sub? Can somebody confirm? Yet my car does not have a sub and I would guess, (as I have not opened the dashboard), no mid speaker.

I also don't understand why the tweetets can work, Front and rear, if the brown block only has 4 pairs (I am assuming these 4 pairs, are for the 4 midbass woofers in the doors.

If the tweeters have a filter/resistance/cap, to filter out frequencies it cannot play, does that mean the that cabling duplicates between leaving the quadlock and arriving at the main midbass door speakers? Or is it an inline version where the cable goes to the woofer first and then gets passed to the tweeter?

In case this needed, the multimedia unit is also attached.

The aim is to add a DSP Amp, but I don't understand how to drive the tweeters and what signal/range the tweeters would be fed

 

[mathyou78]

Now I'm getting seriously confused and was wondering if you (or @mathyou78 or anybody could help):

I've pulled the quadlock from the back and have the traditional 8 pins in the brown block (see photo).
But I also have next to that 2 more signals. I was lead to believe this was for the mid speaker and the sub? Can somebody confirm? Yet my car does not have a sub and I would guess, (as I have not opened the dashboard), no mid speaker.

I also don't understand why the tweetets can work, Front and rear, if the brown block only has 4 pairs (I am assuming these 4 pairs, are for the 4 midbass woofers in the doors.

If the tweeters have a filter/resistance/cap, to filter out frequencies it cannot play, does that mean the that cabling duplicates between leaving the quadlock and arriving at the main midbass door speakers? Or is it an inline version where the cable goes to the woofer first and then gets passed to the tweeter?

In case this needed, the multimedia unit is also attached.

The aim is to add a DSP Amp, but I don't understand how to drive the tweeters and what signal/range the tweeters would be fed

Yes and no. It depends on the HU coding basically. The HU has 6 output signals as @East Yorkshire Retrofits has detailed.
As standard, yours has front tweeters and full range rears on the brown 8 pin socket and front mid bass on the 4 pins between the brown socket and the two HU power pins. That’s the same as my car. You can code the HU to Seatsound/ Beats and this will change the output on the mid bass pins to a bass signal and a front centre channel. I assume (perhaps incorrectly) that the physical wiring for the front mid bass is then taken from the front signal (previously tweeter) pins on the brown connector - in which case some amendment to the car’s speaker wiring would be required here.

I terms of the signal output for our set up.; from memory, the tweeter signal is about 1000 hz and up. The tweeter capacitor blocks some of that before it gets to the tweeter but I’m not sure how much. The front woofers play about 2500hz and down. The rears get a full range signal but iirc the overall levels are slightly lower. Anyway, if you route the signals from the HU as you currently have it into an amp or dsp the fronts will sum where they overlap. So in the 1000 to 2500hz range you’ll get a +6db louder signal, which is awful to try and work with. To combat this and achieve a flat input from the front, you let the Forza flatten the eq on each of the 6 inputs as normal and then manually add shelf filters to the front channels so that the front mid bass signals are, say, 2000hz and down and the tweeter signal input are now 2000hz and up. From there you can eq the outputs to the speakers using the dsp and a mic.
Or you could just go the Seatsound route if you want an improved sound over the 8RM set up with less hassle. The results won’t be as good as a well set up aftermarket speaker and dsp arrangement. I suppose it depends on how much time and money you have and how keen you are to learn all this as you go along.

 

[mathyou78]

Now I'm getting seriously confused and was wondering if you (or @mathyou78 or anybody could help):

I've pulled the quadlock from the back and have the traditional 8 pins in the brown block (see photo).
But I also have next to that 2 more signals. I was lead to believe this was for the mid speaker and the sub? Can somebody confirm? Yet my car does not have a sub and I would guess, (as I have not opened the dashboard), no mid speaker.

I also don't understand why the tweetets can work, Front and rear, if the brown block only has 4 pairs (I am assuming these 4 pairs, are for the 4 midbass woofers in the doors.

If the tweeters have a filter/resistance/cap, to filter out frequencies it cannot play, does that mean the that cabling duplicates between leaving the quadlock and arriving at the main midbass door speakers? Or is it an inline version where the cable goes to the woofer first and then gets passed to the tweeter?

In case this needed, the multimedia unit is also attached.

The aim is to add a DSP Amp, but I don't understand how to drive the tweeters and what signal/range the tweeters would be fed

Just spotted your tweeter point.
The front tweeters are driven directly from the HU via the brown plug. The rear signal is also from the brown plug and is full range. The rear tweeters are actually fed from the 6.5 inch rear door speakers and passively filtered, probably by a small internal capacitor. When I upgraded the rear speakers I left my factory rear tweeters disconnected from the 6.5 inch rears. I used coaxial 6.5 inch speakers in the rear doors as they time align better and the rear plays much quieter than the front anyway.

 

[bmnd]

Hi everyone,
I just tried coding bytes 4 to 7 from D70A0000 to FF000000 on a 5QA 035 874 (MIB2 STD) headhunit, but it seems that these values doesn't have any effect on this particular model. Has anyone with this HU successfully got that working ?
Can't get my time alignment right on my DSP as I suspect there is some hardcoded delay between factory tweeters and door speakers...

 

[mathyou78]

Hi everyone,
I just tried coding bytes 4 to 7 from D70A0000 to FF000000 on a 5QA 035 874 (MIB2 STD) headhunit, but it seems that these values doesn't have any effect on this particular model. Has anyone with this HU successfully got that working ?
Can't get my time alignment right on my DSP as I suspect there is some hardcoded delay between factory tweeters and door speakers...

There is definitely delay between the left and right channels. Also front to back. Which DSP do you have? Which aftermarket speakers? Whats the factory channel set up? I’m guessing same as mine; active front mid bass and tweeters plus full range rears? Right?

 

[bmnd]

There is definitely delay between the left and right channels. Also front to back. Which DSP do you have? Which aftermarket speakers? Whats the factory channel set up? I’m guessing same as mine; active front mid bass and tweeters plus full range rears? Right?

I only used the front inputs actually, didn't bother using the rear speakers which are muted.

I'm using 2 Steg MS30 in pillars as full-ranges, Hertz 6.5" drivers in doors as mid-basses and a MTX sub box in the trunk.

My DSP is a Hifonics Medusa M8-DSP, which is cheap, but was enough when I bought it a while ago. Speakers powered by a Pioneer GM-D1004.

I have the factory separated channels in the front (tweets in main 8 pin harness, and bass in pins 9 to 13)

For the channel routing, I did this :
- Left MS30 full-range -> left bass + left tweeter
- Right MS30 full-range -> right bass + right tweeter
- Left mid-bass -> left bass
- Right mid-bass -> right bass
- Sub -> left bass + right bass

Overall, the result is good, everything is time aligned through impulse response with my RTA mic and a loopback on my USB interface.
Bass and mids are great, but it gets messy getting to the crossover region where the sum of the factory tweeter and bass frequencies cross, which completely blurs the imaging. I'm guessing there's delay between the tweeter and the bass channel.
My DSP can only use the raw inputs (no processing like in the Helix DSPs), that's why I wanted to get a clean full-range signal out of the front inputs.
Guess I'm gonna invest some money on a better DSP to compensate this.

 

[mathyou78]

I only used the front inputs actually, didn't bother using the rear speakers which are muted.

I'm using 2 Steg MS30 in pillars as full-ranges, Hertz 6.5" drivers in doors as mid-basses and a MTX sub box in the trunk.

My DSP is a Hifonics Medusa M8-DSP, which is cheap, but was enough when I bought it a while ago. Speakers powered by a Pioneer GM-D1004.

For the channel routing, I did this :
- Left MS30 full-range -> left bass + left tweeter
- Right MS30 full-range -> right bass + right tweeter
- Left mid-bass -> left bass
- Right mid-bass -> right bass
- Sub -> left bass + right bass

Overall, the result is good, everything is time aligned through impulse response with my RTA mic and a loopback on my USB interface.
Bass and mids are great, but it gets messy getting to the crossover region where the sum of the factory tweeter and bass frequencies cross, which completely blurs the imaging. I'm guessing there's delay between the tweeter and the bass channel.
My DSP can only use the raw inputs (no processing like in the Helix DSPs), that's why I wanted to get a clean full-range signal out of the front inputs.
Guess I'm gonna invest some money on a better DSP to compensate this.

I see. Some neat speakers from what I understand. Tbh, after much messing around I ended up putting the MiB settings back to OEM and just using the Audison AF C8.14 bitDrive software to combine the front channel signal using the input crossovers. I then reused the front signal for the rears because I couldn’t get the rear inputs to time align to the fronts, and all the chimes come via the fronts signal. From memory I think one side mid bass + tweeter signal is delayed 0.6ms compared to the opposite side. Hopefully this is helpful

 

[mathyou78]

I see. Some neat speakers from what I understand. Tbh, after much messing around I ended up putting the MiB settings back to OEM and just using the Audison AF C8.14 bitDrive software to combine the front channel signal using the input crossovers. I then reused the front signal for the rears because I couldn’t get the rear inputs to time align to the fronts, and all the chimes come via the fronts signal. From memory I think one side mid bass + tweeter signal is delayed 0.6ms compared to the opposite side. Hopefully this is helpful

These are the automatic delays calculated by my dsp. If not using the rear channel input, I think you can just deduct 2ms delay from each front channel input.

 

[mathyou78]

These are the automatic delays calculated by my dsp. If not using the rear channel input, I think you can just deduct 2ms delay from each front channel input.

My earlier post from today is better, 0.6ms delay on both wf/ tweeter on rhs is best. Note mine is a rhd car. If I go with the Audison de-delay values I get some combing.