# mObridge BMW MOST25 Logic 7 8.1.1 channel 1KW Amp/DSP Installation and Review



## starfox5194 (Aug 1, 2013)

Hi all,

I am the first buyer of the New 8.1.1 1KW channel Amp/DSP combo offered by mObridge. I promised them I would provide trouble-shooting feedback and I offered to write about my experience using this product on the forum.

This amplifier interfaces directly with the factory proprietary fiber-optic audio signal on many German cars – Includes BMW, Mercedes, Audi, etc… You can retain full factory head unit controls like left/right and front/rear fade, as well as bass and treble adjustments. These are all seamlessly handled by the m0bridge DSP/Amp.

Amplification Specs:

5 – 75 watt RMS channels

2 – 120 watt RMS channels

1 - 300 watt RMS channel

1 – aux output for a separate sub amplifier

The DSP software is pretty kick-ass, download it from their website and check it out yourself.

DSP Highlights (from their website):
1024-point master and channel parametric equalizer.

Time alignment

Crossover link emulation

Direct passthrough

Phase inversion

Mono input channel gain and delay adjustment

Channel muting

Advanced channel filtering algorithms, including:

Butterworth, Bessel, Chebychev, and Linkwitz-Riley filter designs.

Low-pass, high-pass, and band-pass filters

My personal thoughts:
I found the DSP interface very intuitive. As a regular Joe who likes to tinker with car audio, the graphical EQ helped me finally understand what a Q-FACTOR adjustment does. Eliminating peaks is as simple as point and click with this software. Crossover slopes can be as steep as 42db!

Paired with an AudioControl SA-4100i, I was easily able to achieve a flat frequency curve on both speaker setups I will mention later on.











Photos of the unit itself:

















Test fit in the factory amplifier location for my 2007 335xi:


















As you can see, there is plenty of room in the factory amplifier location, and no cutting of factory wires is necessary if you order a Technic PNP harness for your speaker outputs. I did end up running a separate 10 gauge fused power and ground wire from the battery to the amp.



*Testing setup #1:*

Vehicle: 2007 BMW 335xi with Logic 7 factory option.

Speakers: Bavsound stage 1 and bavsound ghost v2 underseat woofers.

I imagine the primary audience for this unit would like to avoid any unnecessary modifications to their vehicle, keeping it as factory as possible – so I figured testing this amp paired with the Bavsound speakers was appropriate. My logic 7 speakers were long gone, and honestly, if you are using the factory speakers, you probably are not too interested in this amp.

Channel mapping:

5 – 75 Watt RMS – Passive crossover front components (4” woofer, 1” tweeter); Center Channel (4” woofer); Passive crossover rear deck components (4” woofer, 2.5” tweeters?)

2 – 120 Watt RMS - underseat 8” bavsound ghost v2s

My Impressions:

With *just the factory logic 7 amplifier powering the BSW speakers*, the sound was a definite improvement over stock. I had two big issues with this setup, though.


At high volumes, the speakers sounded harsh, gave me a head-ache and lacked clarity.
The factory logic 7 speakers had much better staging than the aftermarket BSW speakers when using stock amplification.
The *mObridge DSP/Amp install fixed both issues*, to an extent. Sound was much clearer at high volumes and the DSP time alignment fixed a lot of the staging issues I was having.

I also threw my JL W3V3 in a fitted sealed enclosure into this setup. It provided a nice lower end kick that the bavsound ghosts just cannot reach due to the laws of physics.

Overall, adding the mObridge DSP/Amp is a really nice way to give your speakers more power and a DSP so that you can achieve a great EQ curve without completely butchering your car’s factory audio wiring.

* 

Testing setup #2:*

I ended up going a little wild though. I read some great things about audiofrog GB10s and GB40s. I HAD TO GIVE THEM A TRY. While I was searching for a good deal on the frogs, I stumbled across some audio development W800-NEOs. Oh, yeah, and I ran an extra pair of wires to the front so I can have a 3 way active setup for ultimate tuning ability.

Here are some pics of the install. I did take a few more, so if you have specific questions, please feel free to reach out. Summary: Installing tweeters and AD W800 Neos requires extensive modification, but you can put grills back on and make it look like factory when you are done:
































Full speaker upgrade Impressions:
[email protected] SH!T I have entered a new dimension of audio quality and SPL. I think the best upgrade of all was setting wiring the system with active tweeters. These tweeters by audiofrog are the bees knees.

I max out the volume, and the sound is crisp, clear, and now has a smoothness that was not achieved with the bavsound speakers – this holds true all the way to max volume. Staging is incredible. I could not ask for more. If you want crazy booming bass, you might consider a bigger sub box and amp, but most people are not trying to break world records with a 12” sealed stealth enclosure powered by 300 watts.

Overall thoughts for everything:
If you have a fiber optic signal in your BMW or other German car, and want to have more power, control, and clarity being sent to your aftermarket speakers, this is the way to go. This amp offers incredible value because the fiber signal interpretation is part of the amp. Buying a separate box is $200 at the cheapest. Here you are getting the interpreter, Amp, and DSP ALL IN ONE.

*Any downsides?*

1) Going 3 way active, I lost my rear deck speakers. I wish I could get those back by adding more channels to the DSP…

I may be invoking some premature hearing loss because I like to listen to my music so loud.


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## ATXcyclist (Sep 19, 2020)

Nice review. 

I have the W800-NEO in the factory locations with just a custom 3/4" MDF baffle in my F80 M3 (my build log will be coming soon). It looks like you had to cutout the bottom of the factory enclosure. Those Audio Development speakers freakin' rock! What is your impression of those compared to the Bavsound Ghost v2? I am interested in trying the GB10 and GB40 myself. I currently have Morel Dotech Ovation 4, and they are incredibly smooth, maybe a little too much.


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## starfox5194 (Aug 1, 2013)

Thanks, sorry I forgot to get back to this.

The ghost v2s are really nice speakers. A substantial upgrade from stock logic 7 in terms of clarity and power handling. The W800 NEOs can definitely handle more power and hit harder, though. Even though I had to cut up the enclosure, it was well worth it. I like loud, clear, accurate speakers, and I think the W800 NEOs are superior to the ghosts when considering all three factors.

If you don't want to make any modifications, the ghosts are an excellent drop in upgrade.


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## sobe_death (Jul 31, 2008)

Thanks for sharing this! Can the 4V preout be configured to full-range or is it passed at low frequency only?


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## starfox5194 (Aug 1, 2013)

@sobe_death Good question! When I was testing the amplifier, the 4V pre-out needed a firmware update to be usable (I was testing an early revision of the firmware). I think it may be possible to set it to full range, because all of the other channels appear to be usable as a full range. This 4v pre-out may have been fixed by now. Perhaps @mobridge can chime in?

As a side note, I would like to let you all know that I added a second sealed enclosure 12" JL W3v4-4 ohm. I believe the system is now powering the subs at 2 ohms. The amp has no issue powering these two subs, even playing bass-heavy music for extended play times. So in short, I actually do not think a separate sub amp is necessary except in very extreme cases. The second sub really added a lot of the bass I desired because I felt the single 12" in the trunk was a little too isolated. 

After some more time tuning, I can say I am very happy with my setup now. It plays loud, clear, and my ears give out before the speakers do. I don't just listen to the music, I experience it.


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## mobridge (Oct 5, 2009)

sobe_death said:


> Thanks for sharing this! Can the 4V preout be configured to full-range or is it passed at low frequency only?


The 4V preout is fully configurable. Can be filtered, summed or any other function that is available. It's a full range DSP adjustable channel that can be used for anything.


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## sobe_death (Jul 31, 2008)

Is there currently an MSRP or anywhere to buy this, or do we have to contact MoBridge directly?


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## starfox5194 (Aug 1, 2013)

sobe_death said:


> Is there currently an MSRP or anywhere to buy this, or do we have to contact MoBridge directly?


Try contacting mobridge directly on this forum.
You could also try contacting their suppliers listed on their website.


https://mobridge.us/product/mobridge-most25-amp/


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## Dirtboy (Aug 28, 2010)

starfox5194 said:


> After some more time tuning, I can say I am very happy with my setup now. It plays loud, clear, and my ears give out before the speakers do. I don't just listen to the music, I experience it.


I'm thinking about getting this amp for my 2020 X3. Are you still having good results with this amp? Do you happen to know if this amp has analog inputs as well as the MOST25 inputs?


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## starfox5194 (Aug 1, 2013)

Dirtboy said:


> I'm thinking about getting this amp for my 2020 X3. Are you still having good results with this amp? Do you happen to know if this amp has analog inputs as well as the MOST25 inputs?


Yes, This amp still kicks ass. Plenty of power, reliable, clear sound. Ability to tune each speaker individually. Not much more to say about it. I have no issues.

I've run it at 1 tick below max volume (Because my speakers start to bottom out) for more than an hour and this this is super stable. No perceptible drops in audio quality/volume.

The amp only has a MOST25 input. Not sure why you would want analog input? You can just get a normal amp if that's the case...


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## Dirtboy (Aug 28, 2010)

starfox5194 said:


> Yes, This amp still kicks ass. Plenty of power, reliable, clear sound. Ability to tune each speaker individually. Not much more to say about it. I have no issues.
> 
> I've run it at 1 tick below max volume (Because my speakers start to bottom out) for more than an hour and this this is super stable. No perceptible drops in audio quality/volume.
> 
> The amp only has a MOST25 input. Not sure why you would want analog input? You can just get a normal amp if that's the case...


Thanks. 
I was just wondering about analog inputs if I decide to sell the car down the road and keep the amp.

How did you do the tuning of the DSP? Did you use Room Eq Wizard or something like that? I'm more familiar with using the Audiotec-Fischer (Helix) DSP software.


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## starfox5194 (Aug 1, 2013)

Dirtboy said:


> Thanks.
> I was just wondering about analog inputs if I decide to sell the car down the road and keep the amp.
> 
> How did you do the tuning of the DSP? Did you use Room Eq Wizard or something like that? I'm more familiar with using the Audiotec-Fischer (Helix) DSP software.



Tuning was a manual procedure. Requires a USB cable connected to a laptop with windows or mac. No auto tuning is available.

I borrowed a AudioControl SA-4100i from a friend. And flattened out any high and low spots. Crossovers depend heavily on how your speakers are set up.
If you are not used to manual tuning, I think the interface is simple enough that a more advanced novice/intermediate skilled person can figure it out and get a decent tune.


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## Dirtboy (Aug 28, 2010)

starfox5194 said:


> Tuning was a manual procedure. Requires a USB cable connected to a laptop with windows or mac. No auto tuning is available.
> 
> I borrowed a AudioControl SA-4100i from a friend. And flattened out any high and low spots. Crossovers depend heavily on how your speakers are set up.
> If you are not used to manual tuning, I think the interface is simple enough that a more advanced novice/intermediate skilled person can figure it out and get a decent tune.


Gotcha.
I'll be using my MiniDSP UMIK-1 and REW to do my best at tuning. I don't know REW too well but since this is my wife's car, it doesn't need to be perfect. Plus I don't plan on upgrading the HK speakers yet. I'm sure the DSP in this amp will make a world of difference in the soundstage even with the crappy HK speakers.


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## maw1124 (Nov 25, 2020)

starfox5194 said:


> Yes, This amp still kicks ass. Plenty of power, reliable, clear sound. Ability to tune each speaker individually. Not much more to say about it. I have no issues.
> 
> I've run it at 1 tick below max volume (Because my speakers start to bottom out) for more than an hour and this this is super stable. No perceptible drops in audio quality/volume.
> 
> The amp only has a MOST25 input. Not sure why you would want analog input? You can just get a normal amp if that's the case...


Is the amp still performing to your expectations these days? Long term write up? I would be hooking it up to another Mobridge piece (M2 Pro) and have been trying to decide upon their DSP amp (8.1.1) or an aftermarket amp with a Mobridge DSP converter (DA-G2). Thanks in advance.

maw


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## starfox5194 (Aug 1, 2013)

maw1124 said:


> Is the amp still performing to your expectations these days? Long term write up? I would be hooking it up to another Mobridge piece (M2 Pro) and have been trying to decide upon their DSP amp (8.1.1) or an aftermarket amp with a Mobridge DSP converter (DA-G2). Thanks in advance.
> 
> maw



Honestly there's not much more to write about. The amp is great & stable. The built-in DSP is easy to use. There have been some firmware updates I haven't tried yet. 

I think the best testament to this amp/setup is that I am not tinkering with it every week. It all works great. Occasionally if I want a little more/less bass, I can adjust that from the factory headunit EQ.

As for amp vs converter, I guess that depends on your power goals. I think for 90% of people, the all in one amp/dsp is what you want. If you are in the 10% with truly extreme power/sq goals, then the converter will probably give you more flexibility.


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## maw1124 (Nov 25, 2020)

That's sensible. Thanks.

maw


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## Mag1c Carp3t (May 3, 2021)

They updated this amp to work with my GR Supra. Definitely interested in this amp.

@starfox5194 couple questions;

Where did you find the RMs numbers and are you certain it's 5 channels not 6 like the site states?



https://mobridge.us/product/mobridge-most25-amp/


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## starfox5194 (Aug 1, 2013)

Mag1c Carp3t said:


> They updated this amp to work with my GR Supra. Definitely interested in this amp.
> 
> @starfox5194 couple questions;
> 
> ...


The RMS numbers were sent to me directly via PM by @mobridge. My model is definitely 5x of the 75 watt RMS channels, but the serial number is literally #1, so the one on the website may be a newer revision? I think we would need @mobridge to chime in here. Sorry I couldn't be more helpful.

I would imagine the supra sounds pretty good from the factory, no? I assume the ability for tuning with this amp/dsp is superior for sure. Also, the ability to add some decent subs.


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## Mag1c Carp3t (May 3, 2021)

@mobridge 

Please chime in on the # of channels.

I am assuming the 1x 300w can be 600w at 2-ohm?


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## Mag1c Carp3t (May 3, 2021)

starfox5194 said:


> The RMS numbers were sent to me directly via PM by @mobridge. My model is definitely 5x of the 75 watt RMS channels, but the serial number is literally #1, so the one on the website may be a newer revision? I think we would need @mobridge to chime in here. Sorry I couldn't be more helpful.
> 
> I would imagine the supra sounds pretty good from the factory, no? I assume the ability for tuning with this amp/dsp is superior for sure. Also, the ability to add some decent subs.


The GR Supra premium audio system is terrible. Major design flaw on the BMW oem subs being relocated into a ported style setup on our deck with the ports BLOCKED causing distortion and rattles throughout the trunk paneling.


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## mobridge (Oct 5, 2009)

Mag1c Carp3t said:


> @mobridge
> 
> Please chime in on the # of channels.
> 
> I am assuming the 1x 300w can be 600w at 2-ohm?


Its 6 channels. Starfox had the first amp and I suspect his unit is missing an opamp that was not factory fitted. These are OEM surplus but need an extra opamp to gain the extra channel and it sits under the DSP so isn't visible. We'll need to swap out Starfox's amp at some point if he needs that extra channel.

We did also understate the power at the time also. For reference it runs an internal 48V rail on all channels that is continually varied depending on power requirement at any given time by what the DSP calculates in terms of power. The rail is varied for thermal control - if it sat permanently at 48V than at idle the energy burn off is considerable.

Yes the 1x300W can be at 600w @ 2ohms. The magnetics on this channel is built for it. The entire amp is over engineered as the OEM timelines were so tight that there was no time to design this for cost. As a result its crazy powerful and bulletproof.

cheers,

mObridge


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## Mag1c Carp3t (May 3, 2021)

@mobridge can any of the channels be ran at 2 ohms, if so safe to say it doubles the wattage as well?


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## mobridge (Oct 5, 2009)

yeah you can. The lower power channels will run to around 140W @ 2ohms RMS. The two other higher power channels are bridged so it would be 280W @ 2ohms RMS.


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## Mag1c Carp3t (May 3, 2021)

@mobridge I remembered a conversion of a Tech Sheet being released. I do not see it on the website. Do you have a copy yet?


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## E92James (Jun 9, 2021)

I'm planning on getting this amp for my E92 the only thing holding me back is figuring out what the RMS watts are. @mobridge What would be the RMS watts of the 6 channels running at 4 ohms?


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## starfox5194 (Aug 1, 2013)

E92James said:


> I'm planning on getting this amp for my E92 the only thing holding me back is figuring out what the RMS watts are. @mobridge What would be the RMS watts of the 6 channels running at 4 ohms?


I'm pretty sure the wattages I mentioned in post #1 are accurate for RMS @4 ohms. 

The specs below sound a little more optimistic making me wonder if they are peak wattage?


https://mobridge.us/product/mobridge-most25-amp/


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## Mag1c Carp3t (May 3, 2021)

starfox5194 said:


> I'm pretty sure the wattages I mentioned in post #1 are accurate for RMS @4 ohms.
> 
> The specs below sound a little more optimistic making me wonder if they are peak wattage?
> 
> ...


"Amplification Specs:

5 – 75 watt RMS channels

2 – 120 watt RMS channels

1 - 300 watt RMS channel"

@mobridge says contrary.

I was told the following.

Amplification Specs:

6 – 100 watt RMS channels

2 – 200 watt RMS channels

1 - 300 watt RMS channel

all at 4 ohms.


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## CBX6 (Jul 30, 2021)

K2 is out has more power. Have questions and since I am new it will not let me PM you Starfox. Did you have to have the extra power and ground to get vehicle to recognize amp? I am using protools to program what did you use? I looked under retrofit but did not see Mobridge at all. Thanks for answers.


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## mobridge (Oct 5, 2009)

CBX6 said:


> K2 is out has more power. Have questions and since I am new it will not let me PM you Starfox. Did you have to have the extra power and ground to get vehicle to recognize amp? I am using protools to program what did you use? I looked under retrofit but did not see Mobridge at all. Thanks for answers.


You don't have to use the extra power and ground to get the vehicle to recognise the unit but you will need the extra power and gnd though as the amp will run out of current otherwise and drop out once volume gets to around 75%. 

The PC app for selecting your vehicle is the mObridge DSP workbench https://mobridge.us/mobridge-dsp-pc-application/

kind regards,

mObridge


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## starfox5194 (Aug 1, 2013)

CBX6 said:


> K2 is out has more power. Have questions and since I am new it will not let me PM you Starfox. Did you have to have the extra power and ground to get vehicle to recognize amp? I am using protools to program what did you use? I looked under retrofit but did not see Mobridge at all. Thanks for answers.



I do not see K2 advertised on their website, who are you buying it from? I found some online documentation here:


https://mobridge.us/wp-content/uploads/documents/K2/mObridge_K2_MOST25_8.1.1_Amplifier.pdf


I am not sure how different it is from my current amp? I think they run the same firmware.

I ran extra 4 gauge wire. One lead fit in the factory battery distribution block. The other I grounded to the factory ground a couple feet away. I think you will probably have issues if you only use the small factory wiring.

There was no coding required. This is not a retrofit.

You will need to buy the speaker wiring breakout adapter harness if you don't want to molest your factory wiring. I can't remember the name of the company that custom makes them right now, sorry. If you google other people's setups you may be able to find the name of them.

EDIT:: HERE IT IS: Technic PnP - BMW OEM Audio and Option Integration Expert

Hope that helps


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## mobridge (Oct 5, 2009)

This is the amp you're after https://mobridge.us/product/mobridge-most25-amp/

If its going into a BMW/Supra then the harness you'll need is this Logic7/HK/EPS/Individual Audio/Bang & Olufsen/Bowers & Wilkins MOST OEM amp replacement hardware kit for MOST Converter applications - Technic PNP

If its going into another car such as a Merc/Porsche/Audi then we supply a mating half connector to patch it together,. We're still working on getting direct plug'n'play harnesses but the BMW part is a restricted TE part.

You can buy direct from us. We only have a limited amount left at this point also before the next production run and we don't know when that will be due to silicon shortages around the world.


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## CBX6 (Jul 30, 2021)

starfox5194 said:


> I do not see K2 advertised on their website, who are you buying it from? I found some online documentation here:
> 
> 
> https://mobridge.us/wp-content/uploads/documents/K2/mObridge_K2_MOST25_8.1.1_Amplifier.pdf
> ...





mobridge said:


> You don't have to use the extra power and ground to get the vehicle to recognise the unit but you will need the extra power and gnd though as the amp will run out of current otherwise and drop out once volume gets to around 75%.
> 
> The PC app for selecting your vehicle is the mObridge DSP workbench https://mobridge.us/mobridge-dsp-pc-application/
> 
> ...


So I set the car up from the Mobridge app, ok thanks.


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## CBX6 (Jul 30, 2021)

CBX6 said:


> So I set the car up from the Mobridge app, ok thanks.


Starfox, I had to go ahead and run power and grd, PNP harness had no power in there harness from car harness. Did you run bandpass or High and low for speakers with built in crossover? Thanks again. FYI new specs

6x 175W Channels @ 4ohms had to give up my center channel
2x 300W Channels @ 4ohms
1x 500W Subwoofer Channel @ 4ohms (or 1000W @ 2 Ohms) technically 2-250W @4
1x 4V RMS pre-out


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## CBX6 (Jul 30, 2021)

CBX6 said:


> So I set the car up from the Mobridge app, ok thanks.


I have all the channels mapped but channel 1 to subs. How do I do it when there are no speakers to select in cap image? No sound from sub out, speakers worked before adding this amp.


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## mobridge (Oct 5, 2009)

Can you just shoot us your rax file so we can double check it for you?


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## starfox5194 (Aug 1, 2013)

CBX6 said:


> Starfox, I had to go ahead and run power and grd, PNP harness had no power in there harness from car harness. Did you run bandpass or High and low for speakers with built in crossover? Thanks again. FYI new specs
> 
> 6x 175W Channels @ 4ohms had to give up my center channel
> 2x 300W Channels @ 4ohms
> ...


I can't really provide crossover advice because mine are set according to my sound system (3 way active + center + Sub).

I hope you can get things sorted out... setting crossovers for the first time can be confusing. A local car audio shop might be willing to help you out.

If you can provide me details on what speakers you have mapped to each channel I might be able to give you some general suggestions.

My system is as follows:

500W sub channel goes to subs in the rear is wired to 2 ohms and low pass crossed over at 100hz with a slope of 24db.
My underseat woofers are on the 300W channels and have a high pass at 80 hz and a low pass at 500 hz
My 4" door speakers are high pass at ~200hz and low pass at 8khz I think
tweets are high pass at 5khz and do not have a low pass.
Center channel I think I have a high pass at like 500hz and that is it because it contains a tweeter with an integrated passive crossover


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## doeboy (May 2, 2012)

Any idea on if this type of product will be made compatible for the latest german cars like porsche?


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## starfox5194 (Aug 1, 2013)

doeboy said:


> Any idea on if this type of product will be made compatible for the latest german cars like porsche?


It probably depends on which porsche you have and what sound system. AFAIK, mobridge put a lot of work into understanding and interfacing with audio and data sent over the MOST bus. If your porsche has a MOST bus for audio, then it may be compatible with their amplifier/DSP.


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## marinerbc (Sep 26, 2021)

Thank you for the information on the mobridge MOST25 8.1.1, great find for me as this is probably the only forum that have such information.
I have Porsche cayenne 2016 with PCM 3.1 with MOST25 i am still using the stock head unit along with the stock main Amplifier
i did replace the Bose surround system speakers onboard with :-

2 front dash tweeters replaced with Morel MD 102
1 center channel (3”) replaced with Hertz Amp 3.0 Pro
2 front door midrange (~3.5”) replaced AudisonV oce Av 30
2 front door woofers (8") replaced with Audison prima Ap 8
2 rear door woofers (6.5”) replaced with
Dynaudio Esotec MW 162 Woofer Kit
2 rear door tweeters replaced with
Dynaudio Esotec MD 102 Tweeter Kit
2 rear surround speakers (3”)
Replaced with Hertz MP 70.3 Pro Surround Kit
Trunk Bose subwoofer with Alpine S-W8D2 8" subwoofer with its own Toro MR2 amp.

I have couple of questions , do i need to replace wiring to feed all speakers or can i use the OE wires as is ? the channels are per the attached screen shot.
secondly @mobridge looking for an installer/tuner in Western Canada , prefer British Columbia .
Thank you


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## Mag1c Carp3t (May 3, 2021)

@starfox5194 I noticed you ran 10 gauge wiring. Has this caused any power supply issues resulting in the amp shutting off or intermittent sound?


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