[BroDoze]

RTA’d the car. Know my way around all of that whole thing now.

I used the default house curve. Blech. Too flat in the midrange. Need to come up with my own house curve - take the edge off in the 1k-5k range. That’ll be next step.

Starting to sound like a tuned car now!

[BMW DIY Guy]

Done! All the crossover filters are out!

[BroDoze]

That’s a lot of work right there! ^^

Notice any difference in sound?

[BMW DIY Guy]

Originally Posted by BroDoze

That’s a lot of work right there! ^^

Notice any difference in sound?

Not yet but no testing time either as it was the third car project of the day, and wanted to wrap up.

[kenkamm]

Originally Posted by BroDoze

RTA’d the car. Know my way around all of that whole thing now.

I used the default house curve. Blech. Too flat in the midrange. Need to come up with my own house curve - take the edge off in the 1k-5k range. That’ll be next step.

Starting to sound like a tuned car now!

BroDoze I'm intensely curious to see your curves! Did you notice the same gaping hole between between 80 hz and 160hz?

[kenkamm]

Originally Posted by AdonisP91

No need for the Resonix box. We can achieve digital lossless audio for 20$. There are sacrifices, as always. If you connect a spdif usb to optical adapter to your phone and run an optical cable to the DSP, you now have digital sound but no more system sounds. I am fine with that. I see my blinkers on the dash and other warnings on the idrive display.

See, I am looking at it from the other side of the coin. Having to switch between two source methods depending on what kind of drive I am going on, perhaps not having my "best" sound on shorter drives, missing system sounds on longer drives, all of that has me thinking we could organize a group buy for the Resonix alternative that's like 300 bucks. We only need 3 people to buy in.

If we can't reasonably compensate for this newly discovered -10 dB dip around 100-120 Hz with some EQ (maybe bring it up to -5 or even -3 dB), I would be seriously tempted to buy one of these decoder boxes if we could organize a group buy. The challenge then would be, configuring the DSP PC tool!

[AdonisP91]

Originally Posted by kenkamm

See, I am looking at it from the other side of the coin. Having to switch between two source methods depending on what kind of drive I am going on, perhaps not having my "best" sound on shorter drives, missing system sounds on longer drives, all of that has me thinking we could organize a group buy for the Resonix alternative that's like 300 bucks. We only need 3 people to buy in.

If we can't reasonably compensate for this newly discovered -10 dB dip around 100-120 Hz with some EQ (maybe bring it up to -5 or even -3 dB), I would be seriously tempted to buy one of these decoder boxes if we could organize a group buy. The challenge then would be, configuring the DSP PC tool!

Ok just for the sake of clarity. Why do people want this box? If it is so they hope they can manually change the crossovers, I think I will be able to fix the analog input signal in EQ. So no need on that front. Also the DSP PC tool doesn’t worry me it is extremely nice to work with and integrates with REW seemlessly.

If it is because they want a digital signal to play lossless files from a USB drive while bypassing all the Logic 7 processing, ok fine. If they want to stream lossless directly from the Tidal app in the car without Logic 7 messing things up, fine. That works too.

If you want to stream lossless Apple Music while still connected to CarPlay, we still have to connect the spdif cable to the iPhone.

But yes, having the system sounds while using the digital signal is a massive win. I am definitely down to try a bulk buy with others, but as I mentioned it is untested waters, so we have to all be clear on the risk.

As for the dip, I am extremely skeptical we can fix this just from playing with some crossovers. We might be able to mitigate it a bit, but I think the problem is down to the speaker locations. I don’t think BMW sound engineers are so incompetent they wouldn’t just change the crossovers or filters if they could. The issue is they have to work with the constraints given to them regarding where the subwoofer, midrange speaker, and tweeters go.

That’s also why the Bowers & Wilkins didn’t improve anything, the speakers are under the same constraints. However, that doesn’t mean we don’t have tricks or solutions we can try.

Changing the crossovers, playing with the phase, might help reduce the dip a bit, and if we don’t want to relocate all the speakers, and I certainly don’t, I want to keep the OEM look, there are other tricks we can work with in the EQ.

[kenkamm]

Originally Posted by AdonisP91

Ok just for the sake of clarity. Why do people want this box? If it is so they hope they can manually change the crossovers, I think I will be able to fix the analog input signal in EQ. So no need on that front.

The reason I would want the box is from looking at the input signals from the HK system that were posted earlier and noting that there seemed to be a big hole between the mid bass high-pass and the subwoofer low-pass. If that is real data, then (1) I don't know why BMW would do that, and (2) we can't change it. The solution would then be to get ahead of it.

[AdonisP91]

Originally Posted by kenkamm

The reason I would want the box is from looking at the input signals from the HK system that were posted earlier and noting that there seemed to be a big hole between the mid bass high-pass and the subwoofer low-pass. If that is real data, then (1) I don't know why BMW would do that, and (2) we can't change it. The solution would then be to get ahead of it.

Right on. I agree we might see big improvements just getting back control of the input signal. Let’s see what happens when I run sweeps comparing analog vs digital and how tuneable the analog input signal is. I think Tom mentioned he would try running the Auto EQ in the Advanced Input Analyzer when the weather warms up as well. It’ll be interesting to see how that works too.

[BroDoze]

Well shit. I had an entire wall of text typed out, explaining all my findings about trying to RTA around “the gap” and my iPad decided I didn’t need to share that and closed the f’ing tab on me. Or rather, I accidentally closed it.

TLDR:

“I can’t hear shit around the 125hz range on either the hi-pass or lo-pass, so I’m going to flatline boost those nearest bands to 100% and make RTAing this stupid input signal a pain in the ass for BroDoze.” - Autoset probably

Yes the gap is still there, I hear it and there ain’t much I could do about it. I had to manually soften the surrounding bands nearest the crossover point and even exclude some bands at the crossover points while letting Autoset work, just so the rest of the range (mainly hipass/front stage) wouldn’t also be messed up. So yeah, it’s painfully obvious we need a 6.5” driver in the door. Since BMW didn’t give us that, we need to somehow kill the input crossovers and try to run those underseat woofers up higher. Or live with the gap.

I think a session with Mac would be great to see how he works the RTA around the problem gap bands. I’m no pro and still have a lot to learn about RTAing and crossover points using the PC-Tool. I’m sure my curve looks atrocious around that gap if I were to check it visually.

I may try to redo it today and try a few things I’ve thought of doing differently. Or I already tried those and forgot.

[BroDoze]

Originally Posted by AdonisP91

If it is because they want a digital signal to play lossless files from a USB drive while bypassing all the Logic 7 processing, ok fine.

Yes please. This is my source of choice. FLAC from USB. I’m still not sure how that ResoNix box allows for lossless digital WHILE keeping turn signals, bongs etc… And it’s only 2ch stereo? How does that even work? How do you have surround proximity bongs when it’s only 2ch? Or did I misread something.

[kenkamm]

Originally Posted by BroDoze

Yes please. This is my source of choice. FLAC from USB. I’m still not sure how that ResoNix box allows for lossless digital WHILE keeping turn signals, bongs etc… And it’s only 2ch stereo? How does that even work? How do you have surround proximity bongs when it’s only 2ch? Or did I misread something.

For the GlobalSources one, it says there is front and rear output, ethernet in.

[BroDoze]

Originally Posted by kenkamm

For the GlobalSources one, it says there is front and rear output, ethernet in.

Ah, thanks.

[AdonisP91]

Originally Posted by BroDoze

Well shit. I had an entire wall of text typed out, explaining all my findings about trying to RTA around “the gap” and my iPad decided I didn’t need to share that and closed the f’ing tab on me. Or rather, I accidentally closed it.

TLDR:

“I can’t hear shit around the 125hz range on either the hi-pass or lo-pass, so I’m going to flatline boost those nearest bands to 100% and make RTAing this stupid input signal a pain in the ass for BroDoze.” - Autoset probably

Yes the gap is still there, I hear it and there ain’t much I could do about it. I had to manually soften the surrounding bands nearest the crossover point and even exclude some bands at the crossover points while letting Autoset work, just so the rest of the range (mainly hipass/front stage) wouldn’t also be messed up. So yeah, it’s painfully obvious we need a 6.5” driver in the door. Since BMW didn’t give us that, we need to somehow kill the input crossovers and try to run those underseat woofers up higher. Or live with the gap.

I think a session with Mac would be great to see how he works the RTA around the problem gap bands. I’m no pro and still have a lot to learn about RTAing and crossover points using the PC-Tool. I’m sure my curve looks atrocious around that gap if I were to check it visually.

I may try to redo it today and try a few things I’ve thought of doing differently. Or I already tried those and forgot.

With very small dips one can try in EQ to apply a small boost, starting with 3db. If the dip responds great, you can push a little more, trying 5db and so on. But for big dips like the one we are dealing with between 80-160hz, we are not dealing with a simple phase or polarity issue that could respond to boosts. We are dealing with cancellations and destructive interference. Boosting won’t do anything and just overdrive the speakers making matters worse.

It is great you did the test though, but it confirms my fear.

ETA: I am jealous I want to play with all this stuff for real.

[AdonisP91]

Originally Posted by BroDoze

Yes please. This is my source of choice. FLAC from USB. I’m still not sure how that ResoNix box allows for lossless digital WHILE keeping turn signals, bongs etc… And it’s only 2ch stereo? How does that even work? How do you have surround proximity bongs when it’s only 2ch? Or did I misread something.

I haven’t looked at the stock wiring diagram but my guess is the stock system sends a digital signal with the system sounds in one channel as well as 1 channel each for left and right. Then the factory primary amp/dsp does its processing, amplifies a few channels and sends the rest of the channels to the secondary ram booster for amplification.

If I were designing this intercept device like is being sold, I would intercept the signals and then integrate the system sounds into the left right channels, and send them to the aftermarket DSP for processing.

Pro’s/Con’s: Stock method can send the system sounds only to specific channels. It can selectively send the front left blinker only to the front left channel. It can send voice calls directly to the center channel and only the center channel, Etc.

The intercept device can’t do that since the output is 2 channels. Your left blinker will play on every channel that it was mixed into, presumably the left channel signal. This could be extremely annoying, even your subwoofer would amplify the blinker. Instead of having voice calls only on the center channel, all channels would play it?

Maybe they have some magic wizardry but I don’t see how it is possible.

[BroDoze]

Originally Posted by AdonisP91

I want to play with all this stuff for real.

Selfishly, we want you to be playing with it too! You’ve led the charge here certainly.

[AdonisP91]

Originally Posted by kenkamm

For the GlobalSources one, it says there is front and rear output, ethernet in.

It looks like ResoNix, RDVFL, and GlobalSource are redistributors from: EwayGPS:

https://ewaygps.com/product/optical-...t-description/

I’m not sure I mentioned that upthread. Now we just need to get information how this thing actually works and whether we can fix the input without resorting to it.

[BroDoze]

Originally Posted by AdonisP91

It can send voice calls directly to the center channel and only the center channel, Etc.

…

Maybe they have some magic wizardry but I don’t see how it is possible.

Uh-oh, I have my center disabled. I haven’t tried a hands-free call in the car since I’ve been dicking around with this stuff. I better test to see what I’ve broken, lol. I better not have to turn that center back on.

I’ll report back shortly…

[BroDoze]

Originally Posted by AdonisP91

Now we just need to get information how this thing actually works and whether we can fix the input without resorting to it.

Im going to call Nick this next week and try to get more data points on it. Wish me luck, lol.

[AdonisP91]

Originally Posted by BroDoze

Uh-oh, I have my center disabled. I haven’t tried a hands-free call in the car since I’ve been dicking around with this stuff. I better test to see what I’ve broken, lol. I better not have to turn that center back on.

I’ll report back shortly…

You have no real center channel. AlphaOne chopped it out. The MatchUp 10 DSP only has 8 channel input. Audiotec Fischer recommends installing the MEC Analog In extension card and their wiring harness to add the 9th channel, the center channel, into that Analog In card.

BimmerTech didn’t want to add that extension card. So they cut out the Center channel and recreated a simulation, sending 50% front left 50% front right to that speaker. Who knows what impact that has on voice calls, system sounds, etc. Hopefully there is no loss and BimmerTech was right the Analog In extension card is unnecessary.