The definitive stereo and subwoofer upgrade thread

[Nillious]

It is significantly better with the sub but I would upgrade the dash speakers for cleaner highs. Without the signals summed you will be limited on frequency to the sub since the factory sub is already crossed over. You could pretty much turn your crossover on the amp all the way up.

As far as the polarity I'm not sure how the sub is oriented in the avant. The sedan subs are upsidedown so when you definitely have to reverse them for a standard box sub. Yours may be different.

Btw I have a B9 now and Will be removing the lc7i from my b8.5 if you are interested. Send me a PM if so.

[buhler955]

The result is a really boomy and inconsistent sound, not at all what I expected from a sealed box. My SB 1000 at home is super smooth sounding, and even the cheap MTX 2x12 I had in a previous car were smooth and played all of the frequencies they were supposed to relattively flatly. Both very tight and punchy sounding as well.

I listen to metal and some hip hop and have tested with both, both sound bad. Drums and bass a muddy and not defined at all. No punch. In hip hop it's very boomy when there is output, and it sounds like there isn't much output after the peak at 50hz.
It ALMOST sounds like the sub cuts in then disappears with some frequencies but I know it doesn't because I've watched/listened from the trunk.

In case anyone else is having this problem, I got it fixed.
As Nillous recommended, I went with a LC6i to sum the front door midbass with the sub signal.

I had a problem with the install where it sounded good for about 2 minutes, then the volume from the sub would roll off until there was zero output voltage on the LC6i RCAs.
After lots of troubleshooting, I fixed that today by swapping the polarity of the sub input. Most say it sounds better with the sub polarity flipped, so that's what I did at first. I originally used the white/yellow wire as the negative and the blue/yellow wire as the positive. I found the wire colors and polarity for the Audison BitOne thread on here.
My car is a S4 avant, so the stock 6" sub fires downward in the spare tire well. I assumed that meant the phase was swapped and + was - and vice versa.
I guess with the inputs having an opposite phase and using the signal summing the LC6i made the output flat at 0v.
My amp doesn't have a phase switch, so now if I want to try it the other way I know I'll need to swap the phase of the sub input and the door midbass input.
Fingers crossed this was actually the fix, but I've driven about an hour since and the sub worked the whole time. Before I was lucky to get 2 minutes out of it.

[Fresh.S4]

In case anyone else is having this problem, I got it fixed.
As Nillous recommended, I went with a LC6i to sum the front door midbass with the sub signal.

I had a problem with the install where it sounded good for about 2 minutes, then the volume from the sub would roll off until there was zero output voltage on the LC6i RCAs.
After lots of troubleshooting, I fixed that today by swapping the polarity of the sub input. Most say it sounds better with the sub polarity flipped, so that's what I did at first. I originally used the white/yellow wire as the negative and the blue/yellow wire as the positive. I found the wire colors and polarity for the Audison BitOne thread on here.
My car is a S4 avant, so the stock 6" sub fires downward in the spare tire well. I assumed that meant the phase was swapped and + was - and vice versa.
I guess with the inputs having an opposite phase and using the signal summing the LC6i made the output flat at 0v.
My amp doesn't have a phase switch, so now if I want to try it the other way I know I'll need to swap the phase of the sub input and the door midbass input.
Fingers crossed this was actually the fix, but I've driven about an hour since and the sub worked the whole time. Before I was lucky to get 2 minutes out of it.

Where did you tap the front speakers at?, the amp?
And why did you go lci6 vs something smaller like an lci2?

[ThoseRings]

Where did you tap the front speakers at?, the amp?
And why did you go lci6 vs something smaller like an lci2?

To get a wider range than the factory cut off for the sub

In case anyone else is having this problem, I got it fixed.
As Nillous recommended, I went with a LC6i to sum the front door midbass with the sub signal.

I had a problem with the install where it sounded good for about 2 minutes, then the volume from the sub would roll off until there was zero output voltage on the LC6i RCAs.
After lots of troubleshooting, I fixed that today by swapping the polarity of the sub input. Most say it sounds better with the sub polarity flipped, so that's what I did at first. I originally used the white/yellow wire as the negative and the blue/yellow wire as the positive. I found the wire colors and polarity for the Audison BitOne thread on here.
My car is a S4 avant, so the stock 6" sub fires downward in the spare tire well. I assumed that meant the phase was swapped and + was - and vice versa.
I guess with the inputs having an opposite phase and using the signal summing the LC6i made the output flat at 0v.
My amp doesn't have a phase switch, so now if I want to try it the other way I know I'll need to swap the phase of the sub input and the door midbass input.
Fingers crossed this was actually the fix, but I've driven about an hour since and the sub worked the whole time. Before I was lucky to get 2 minutes out of it.

[Fresh.S4]

To get a wider range than the factory cut off for the sub

Does the lci2 not have enough inputs to tap multiple sources,?

[Nillious]

You need a summing module. The lc6 can sum different signals and make them one full range signal. So you can tp tweeters mids and subs on cars with factory amps already crossed over to have a full range clean signal.

Here's a good explanation of what the lc6 is doing.

https://m.youtube.com/watch?v=B-zXprRI8XQ

[Fresh.S4]

You need a summing module. The lc6 can sum different signals and make them one full range signal. So you can tp tweeters mids and subs on cars with factory amps already crossed over to have a full range clean signal.

Here's a good explanation of what the lc6 is doing.

https://m.youtube.com/watch?v=B-zXprRI8XQ

5 star car audio dudes are awesome. ive known about them for years.
BUT,, that still doesnt answer my question as to why you chose a 6channel (when you arent using 6 inputs) instead of a 2 channel (when you are in fact using 2 inputs: taking the front speaker AND sub wire)

2nd question, where did you tap from? the amp harness?

[simrag]

Instead of getting a high level converter that can sum inputs and an amp, an alternative that will do both tasks is a Match amplifier from Audiotec Fischer. Accepts high level inputs and is available in 6, 8 or 10 channel versions. More expensive, but provides several benefits beyond the LCi/amp combo:

- You'll get 65W per channel to all but the sub, where it provides 160W to a 2ohm load. Assuming you have the B & O system, it is pretty easy to wire up via the connector to the stock speaker wiring harness in the trunk. (male and female connectors are available from aliexpress that can be soldered to the in/out wiring for the Match)

- It gives you a great DSP with many of the setup features automated if you don't want to spend the time to do it manually. You can time align, set crossover points/slopes/types, parametric EQ with user defined frequency and Q. Properly setup, it will sound much better with stock speakers than the B&O processing as well as do fancier stuff like differential rear fill if you're so inclined.

- It gives you an input signal analyzer, which will EQ the output from the stock amp that is less than flat (which might eliminate the need for summing)

- If you want to eliminate the need for input EQ and bypass the stock amp entirely, you can use a preamp to convert the stock optical head unit output to a TOSLINK signal that the Match amp also accepts.

I've used one on my old B7 and now on my B8.5, and really like it - fantastic product.

[ThoseRings]

5 star car audio dudes are awesome. ive known about them for years.
BUT,, that still doesnt answer my question as to why you chose a 6channel (when you arent using 6 inputs) instead of a 2 channel (when you are in fact using 2 inputs: taking the front speaker AND sub wire)

2nd question, where did you tap from? the amp harness?

He and others ARE using multiple inputs, from the door and from the sub.

This is because the factory sub channel has a pre-defined frequency cut off at 50hz. To get more "range" you need to tap other speakers so the LCI can process/combine them.

They don't make an LCI4 so you need to use something with more channels because that's all they offer -- https://www.audiocontrol.com/car-aud...ystem-upgrade/

Instead of getting a high level converter that can sum inputs and an amp, an alternative that will do both tasks is a Match amplifier from Audiotec Fischer. Accepts high level inputs and is available in 6, 8 or 10 channel versions. More expensive, but provides several benefits beyond the LCi/amp combo:

- You'll get 65W per channel to all but the sub, where it provides 160W to a 2ohm load. Assuming you have the B & O system, it is pretty easy to wire up via the connector to the stock speaker wiring harness in the trunk. (male and female connectors are available from aliexpress that can be soldered to the in/out wiring for the Match)

- It gives you a great DSP with many of the setup features automated if you don't want to spend the time to do it manually. You can time align, set crossover points/slopes/types, parametric EQ with user defined frequency and Q. Properly setup, it will sound much better with stock speakers than the B&O processing as well as do fancier stuff like differential rear fill if you're so inclined.

- It gives you an input signal analyzer, which will EQ the output from the stock amp that is less than flat (which might eliminate the need for summing)

- If you want to eliminate the need for input EQ and bypass the stock amp entirely, you can use a preamp to convert the stock optical head unit output to a TOSLINK signal that the Match amp also accepts.

I've used one on my old B7 and now on my B8.5, and really like it - fantastic product.

The above conversations are referring to only adding and amp/replacing the subwoofer.

You are better off using something like this if you are replacing the factory amp setup from what I have read.

https://mobridge.us/product/da1-digital-pre-amp-most/

[Fresh.S4]

He and others ARE using multiple inputs, from the door and from the sub.

This is because the factory sub channel has a pre-defined frequency cut off at 50hz. To get more "range" you need to tap other speakers so the LCI can process/combine them.

They don't make an LCI4 so you need to use something with more channels because that's all they offer -- https://www.audiocontrol.com/car-aud...ystem-upgrade/









The above conversations are referring to only adding and amp/replacing the subwoofer.

You are better off using something like this if you are replacing the factory amp setup from what I have read.

https://mobridge.us/product/da1-digital-pre-amp-most/

I know the purpose of the device, I'm not asking what it does, lol.
I'm asking why was the lci6 chosen over the lci2 when ONLY the door speaker AND subwoofer lines are being utilized.

I don't think I missed the part where a 3rd input was being used. I'm just curious if it was personal preference, or?

[Nillious]

5 star car audio dudes are awesome. ive known about them for years.
BUT,, that still doesnt answer my question as to why you chose a 6channel (when you arent using 6 inputs) instead of a 2 channel (when you are in fact using 2 inputs: taking the front speaker AND sub wire)

2nd question, where did you tap from? the amp harness?

The lc2 does not do summing. I wondered the same thing you're thinking. If you're only tapping two channels why not just feed the midbass to one channel and the sub to the other? I messaged them about this and they said it does not simply work like that. They said you will need a summing module for this. I didn't want to go against their advice and fry anything so I just took their word for it. Like rings said. The Factory sub rolls off hard at about 50hz. It does play higher frequencies but they are rolled back drastically. The mids roll off under 60hz. When I had only the sub tapped lows were very peaky below 60 and faded out badly above that. I like my sub up to about 80hz. The only way to get that is to use both signals combined. If you play a song with a continuous low beat it was great. The bass in songs 60-90 range it didn't even sound like there was a sub.

[simrag]

The above conversations are referring to only adding and amp/replacing the subwoofer.

You are better off using something like this if you are replacing the factory amp setup from what I have read.

https://mobridge.us/product/da1-digital-pre-amp-most/

I get that. My point was that rather than buying a LCi and an amp, you could get one device that would accomplish both tasks and also have capabilities well beyond what a line level converter and dedicated sub amp would provide. The LCi/amp combo works too, but doesn't leave you any room for improvement over the rest of the system. The cost is higher, but you get more. I've seen used Match amps going for $500-700 on ebay, so the cost doesn't even have to be that much higher. I'm not positive since I haven't tried it, but I'd bet that the input signal analyzer built into the DSP software would fix the sub 50hz dropoff built into the stock sub signal without summing which could introduce more signal weirdness. If it doesn't, the Match still allows for input summing from speaker inputs.

The preamp you linked to is only needed if you want to bypass the stock amp entirely, which IMO, is the way to go to avoid the processing done by the stock amp you need to undo to get good sound. I used an older version of that device in my system.

[Fresh.S4]

The lc2 does not do summing. I wondered the same thing you're thinking. If you're only tapping two channels why not just feed the midbass to one channel and the sub to the other?

Outstanding. This is the information I was looking for.
I've got to see where my amps settings are at and might consider th device.
For the most part, my sub/ amp work very well. My issue is the shelf rattling I get from time to time. I want to get some plywood and cut it to shape, to get some structural rigidity to reduce the rattle. Albeit it only happens on certain sub bass lines. Other songs, it sounds amazing.
I'm also using a shallow 10" on recommendation from a looooong time ago but feel if I got something with a larger magnet, I'd really induce rattles.