[spiritbreaker]

In the market for a plug-play amplifier upgrade (inclined to get used ones) to compliment the SVS 8W woofers. So far looked at Bimmertech and Bav, any others in the market?

Thanks!

[Encanto]

Originally Posted by spiritbreaker

In the market for a plug-play amplifier upgrade (inclined to get used ones) to compliment the SVS 8W woofers. So far looked at Bimmertech and Bav, any others in the market?

Thanks!

mObridge MOST25 8.1.1 AMP

[spiritbreaker]

Originally Posted by Encanto

mObridge MOST25 8.1.1 AMP

that seems to be a very hefty amplifier, anything on the low end?

[Billfitz]

There are no low priced options for BMW amp replacement. The most economical upgrade for use with SWS woofers is to add a separate amp for them. In so doing the H-K amp runs cleaner, as its power supply is no longer taxed by the woofer current draw. This should help: https://f30.bimmerpost.com/forums/sh....php?t=1730058

[spiritbreaker]

Originally Posted by Billfitz

There are no low priced options for BMW amp replacement. The most economical upgrade for use with SWS woofers is to add a separate amp for them. In so doing the H-K amp runs cleaner, as its power supply is no longer taxed by the woofer current draw. This should help: https://f30.bimmerpost.com/forums/sh....php?t=1730058

That's what I've been speculating after going through this thread https://f30.bimmerpost.com/forums/sh....php?t=1311415

I've just ordered the technic's add-a-sub harness (https://technicpnp.com/product/hifi-...sub-harnessloc), now contemplating on what amplifier should I go for?

Since the current woofer setup seems to be stereo, having thoughts on if I should I go mono or stereo amp while reminding myself that I just need more punch and not going bonkers on the budget.

[Billfitz]

There's no such thing as stereo subs. Low frequencies have been summed to mono in the studio on virtually all recordings since subs first came along in the 1970s. I'd say the amp Johnung used works well based on his experience. Where dual channel amps are used to separately power dual subs the signal content is the same to both.

[spiritbreaker]

Originally Posted by Billfitz

There's no such thing as stereo subs. Low frequencies have been summed to mono in the studio on virtually all recordings since subs first came along in the 1970s. I'd say the amp Johnung used works well based on his experience. Where dual channel amps are used to separately power dual subs the signal content is the same to both.

On my way to grab the kicker cxa600.1!!1

Any quick walkthrough on setting these up? Does the harness from technic send the signals back in or should I need to re-wire the SWS 8Xis?

Thanks for clearing things up.

[johnung]

Originally Posted by spiritbreaker

On my way to grab the kicker cxa600.1!!1

Any quick walkthrough on setting these up? Does the harness from technic send the signals back in or should I need to re-wire the SWS 8Xis?

Thanks for clearing things up.

The AudioControl ACM-2.300 that I used was ideal for a few key reasons:

1) Small size. I ended up mounting it on top of my tool kit cover in the right alcove in the trunk. Out of the way. Doesn't take up trunk space and easy access to power and ground near the battery.

2) Contains a built-in LOC so I didn't have to find more space for another box. A LOC is required to take the speaker level outputs from the Technicpnp harness and connect them to the secondary amplifier. The HK amp has no other way to connect a secondary amplifier. Also a cheap LOC cannot be used. The cheap ones can only handle lower voltages. The HK puts out the higher level signals.

3) Has exactly the right amount of power to supply the Earthquake SWS-8Xi (2-ohm) subwoofers. The AudioControl ACM-2.300 puts out two channels of 150watts/channel into 2-ohms which is what the Earthquakes are rated. Turn down the gain on the amplifier slightly because if you go over 150watts per channel, Earthquake tech support warned me that it could blow the subs.

I searched for amplifiers and LOCs for over a month before I found this AudioControl amplifier with these exact features. Be careful if you try another LOC and amplifier, that they meet these requirements. If I was going with a separate LOC I would suggest looking at the AudioControl product line because they make high quality stuff.

Hope this helps!

[johnung]

Originally Posted by spiritbreaker

On my way to grab the kicker cxa600.1!!1

Any quick walkthrough on setting these up? Does the harness from technic send the signals back in or should I need to re-wire the SWS 8Xis?

Thanks for clearing things up.

Photo of AudioControl ACM-2.300

[Encanto]

Originally Posted by Billfitz

There's no such thing as stereo subs. Low frequencies have been summed to mono in the studio on virtually all recordings since subs first came along in the 1970s. I'd say the amp Johnung used works well based on his experience. Where dual channel amps are used to separately power dual subs the signal content is the same to both.

The under seat speakers are woofers, BMW call them "subs" for promotional and not technical reasons.

The woofers are wired and processed in stereo in all BMW OEM audio systems. Play a stereo 50Hz tone and it will sound left and right discrete.

Go.

[spiritbreaker]

Originally Posted by Encanto

The under seat speakers are woofers, BMW call them "subs" for promotional and not technical reasons.

The woofers are wired and processed in stereo in all BMW OEM audio systems. Play a stereo 50Hz tone and it will sound left and right discrete.

Go.

I had the same theory since I was able to isolate the channel when I changed the balance from my media player

[Billfitz]

Read my post again: 'Where dual channel amps are used to separately power dual subs the signal content is the same to both.' Dual amps are often used to power dual drivers when the load impedance of dual drivers parallel wired would be too low for a single amp to handle. The low frequency content sent to both amps is the same. That's because "Low frequencies have been summed to mono in the studio on virtually all recordings since subs first came along in the 1970s." Stereo only exists in the midbass and higher frequencies, where the content of the left/right channels is different.

[spiritbreaker]

Originally Posted by johnung

Photo of AudioControl ACM-2.300

How did you wire the woofers from the amplifier?

[johnung]

Originally Posted by spiritbreaker

How did you wire the woofers from the amplifier?

I ran new speaker wire from the AudioControl in the trunk above the battery to the underseat sub boxes, but the Technicpnp harness can utilize the existing BMW speaker wire to the underseat boxes as well. It should be on the wiring diagram that came with the harness.

[Encanto]

Originally Posted by Billfitz

Read my post again: 'Where dual channel amps are used to separately power dual subs the signal content is the same to both.' Dual amps are often used to power dual drivers when the load impedance of dual drivers parallel wired would be too low for a single amp to handle. The low frequency content sent to both amps is the same. That's because "Low frequencies have been summed to mono in the studio on virtually all recordings since subs first came along in the 1970s." Stereo only exists in the midbass and higher frequencies, where the content of the left/right channels is different.

The under-seat woofers are not subs.

[spiritbreaker]

Woofer: SWS 8Xi
Amplifier: Kicker CXA600.1
Install time: 3hrs
Results: Totally blown away.