THE LARGEST BMW 2-SERIES FORUM ON THE PLANET
2Addicts
2Addicts
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
2Addicts | BMW 2-Series forum Technical Topics Navigation, iDrive, Audio, Video, Bluetooth, Phone, Cameras, Electronics Stock HiFi amplifier

Post Reply
 
Thread Tools Search this Thread
      10-06-2018, 11:40 AM   #1
jmwilson125
Major
United_States
340
Rep
1,184
Posts

Drives: 2016 M235i
Join Date: Feb 2015
Location: Somerville, Ma

iTrader: (0)

Stock HiFi amplifier

Does anyone know where I can find the specs for the stock HiFi amp?

I am trying to figure out what kind of power it puts to the under seat subwoofers. Rockford Fosgate makes some 8" shallow subwoofers that I want to try to fit. The are available in 2 ohm which is what the factory subs are.

Is there any reason not to try these out, them have the option to amplify them later?
Appreciate 0
      10-08-2018, 10:09 AM   #2
tennisfreak
Second Lieutenant
201
Rep
296
Posts

Drives: M240i
Join Date: Feb 2018
Location: DFW

iTrader: (0)

All I know is the stock HiFi amp puts out 200 watts but dont know the split between channels.
Appreciate 0
      10-08-2018, 01:19 PM   #3
Viffermike
Colonel
Viffermike's Avatar
United_States
1753
Rep
2,942
Posts

Drives: '18 black-n-blue 718 Cayman
Join Date: Jan 2015
Location: Big D

iTrader: (0)

Quote:
Originally Posted by tennisfreak View Post
All I know is the stock HiFi amp puts out 200 watts but dont know the split between channels.
And that's 200 watts split between seven different channels -- That's less than 30 WPC if split evenly, which is unlikely. AND we have no idea if that rating is continuous or peak, and at what THD level the measurement applies to -- heck, we don't even know if that figure applies for all channels driven.

If I had to guess, I'd say the 'conventional' channels are getting about 25 WPC @ 4 ohms so that the underseat drivers can get around 40 WPC @ 2 ohms to reproduce bass decently.
__________________
--Life is a journey made more exciting with a fast car.--
--Helmets are for closers.--
<<Current: "Blackened" '18 NBM Porsche 718 Cayman ... Gone (but not forgotten): "Blackened" MG '15 228i M Sport w/aFe filter/scoop, Hertz drivers, P3Cars multigauge, other goodies>>
Appreciate 0
      10-08-2018, 10:26 PM   #4
jmwilson125
Major
United_States
340
Rep
1,184
Posts

Drives: 2016 M235i
Join Date: Feb 2015
Location: Somerville, Ma

iTrader: (0)

Quote:
Originally Posted by Viffermike View Post
And that's 200 watts split between seven different channels -- That's less than 30 WPC if split evenly, which is unlikely. AND we have no idea if that rating is continuous or peak, and at what THD level the measurement applies to -- heck, we don't even know if that figure applies for all channels driven.

If I had to guess, I'd say the 'conventional' channels are getting about 25 WPC @ 4 ohms so that the underseat drivers can get around 40 WPC @ 2 ohms to reproduce bass decently.
I found a similar stat on an older model somewhere.

Viffermike , do you know if I can use the technic harness to add an amp to power upgraded under seat subs?

Then the sub channels on the stock amplifier would not be used? Would I encounter any issues with that?

I took a shot in the dark and ordered a couple Rockford Fosgate p3 shallows 4 ohm dvc subs that I plan on running at 2 ohm for a direct replacement.

I want to see how they sound on the stock amp, but will likely add an amp to power them assuming I can make them fit.
Appreciate 0
      10-09-2018, 10:01 AM   #5
Viffermike
Colonel
Viffermike's Avatar
United_States
1753
Rep
2,942
Posts

Drives: '18 black-n-blue 718 Cayman
Join Date: Jan 2015
Location: Big D

iTrader: (0)

Quote:
Originally Posted by jmwilson125 View Post
I found a similar stat on an older model somewhere.

Viffermike , do you know if I can use the technic harness to add an amp to power upgraded under seat subs?

Then the sub channels on the stock amplifier would not be used? Would I encounter any issues with that?

I took a shot in the dark and ordered a couple Rockford Fosgate p3 shallows 4 ohm dvc subs that I plan on running at 2 ohm for a direct replacement.

I want to see how they sound on the stock amp, but will likely add an amp to power them assuming I can make them fit.
If those RFs are drop-in replacements for the underseat drivers, I would NOT power them with a separate amp dedicated only to the underseat drivers. Several reasons for this, all documented in other threads:
- Notice that I'm using the term 'underseat drivers'. They are NOT subwoofers in the traditional sense. They are mid-bass/bass drivers tuned to reproduce some sub-bass frequencies. Even aftermarket speakers tuned to replicate subs such as the RFs and the Earthquake SWS-8 are actually bass drivers, NOT subwoofers.
- Running an amp dedicated only to the underseat drivers will create all sorts of balance and volume issues with the OEM amp's output. Why? Because there is no dedicated subwoofer channel. The HiFi system's head unit only outputs four line-level channels -- LF, RF, LR and RR -- which the OEM amp sums to create three extra speaker-level channels: the two underseat channels and the center channel. The signal that the underseat drivers get is LF and RF, and volume varies as the fader control is moved away from its '0' setting.
- The biggest problem with the 2 Series Audio is clarity across the spectrum. If all you're looking for is bigger bass, the only real solution is a dedicated subwoofer, in a dedicated enclosure, with a dedicated amp and volume control. Technic's Add-an-amp harness for subs makes this possible, as I understand it. But it CANNOT work with the underseat drivers.
__________________
--Life is a journey made more exciting with a fast car.--
--Helmets are for closers.--
<<Current: "Blackened" '18 NBM Porsche 718 Cayman ... Gone (but not forgotten): "Blackened" MG '15 228i M Sport w/aFe filter/scoop, Hertz drivers, P3Cars multigauge, other goodies>>
Appreciate 0
      10-09-2018, 10:17 AM   #6
jmwilson125
Major
United_States
340
Rep
1,184
Posts

Drives: 2016 M235i
Join Date: Feb 2015
Location: Somerville, Ma

iTrader: (0)

Quote:
Originally Posted by Viffermike View Post
If those RFs are drop-in replacements for the underseat drivers, I would NOT power them with a separate amp dedicated only to the underseat drivers. Several reasons for this, all documented in other threads:
- Notice that I'm using the term 'underseat drivers'. They are NOT subwoofers in the traditional sense. They are mid-bass/bass drivers tuned to reproduce some sub-bass frequencies. Even aftermarket speakers tuned to replicate subs such as the RFs and the Earthquake SWS-8 are actually bass drivers, NOT subwoofers.
- Running an amp dedicated only to the underseat drivers will create all sorts of balance and volume issues with the OEM amp's output. Why? Because there is no dedicated subwoofer channel. The HiFi system's head unit only outputs four line-level channels -- LF, RF, LR and RR -- which the OEM amp sums to create three extra speaker-level channels: the two underseat channels and the center channel. The signal that the underseat drivers get is LF and RF, and volume varies as the fader control is moved away from its '0' setting.
- The biggest problem with the 2 Series Audio is clarity across the spectrum. If all you're looking for is bigger bass, the only real solution is a dedicated subwoofer, in a dedicated enclosure, with a dedicated amp and volume control. Technic's Add-an-amp harness for subs makes this possible, as I understand it. But it CANNOT work with the underseat drivers.

Ahhh thank you that clears things up quite a bit. I used to dable in car audio in much simpler time.

I was under the impression then the bavsound ghost subwoofer were a plug and play subwoofer that could be amplified.

I assumed that I could make any other 8" shallow sub fit with some some spacers and fiddling around. Then I would just aplify them down the road. Looks like I should probably cancel that order and rethink the situation.
Appreciate 0
      10-09-2018, 12:54 PM   #7
Viffermike
Colonel
Viffermike's Avatar
United_States
1753
Rep
2,942
Posts

Drives: '18 black-n-blue 718 Cayman
Join Date: Jan 2015
Location: Big D

iTrader: (0)

Quote:
Originally Posted by jmwilson125 View Post
Ahhh thank you that clears things up quite a bit. I used to dable in car audio in much simpler time.

I was under the impression then the bavsound ghost subwoofer were a plug and play subwoofer that could be amplified.

I assumed that I could make any other 8" shallow sub fit with some some spacers and fiddling around. Then I would just aplify them down the road. Looks like I should probably cancel that order and rethink the situation.
Well, they CAN be amplified -- they just need to be amplified in the same way as the other channels so system balance is possible. A multichannel amp setup is the best solution in that situation -- either a six-channel amp (which allows for the use of technic's Add-an-amp harness) or a four-channel amp and a two-channel amp (which can be used with both technic Add-an-amp harnesses; the regular one and the subwoofer one).

With that approach, the underseat drivers can be upgraded, by both hardware and power, to act more like a subwoofer. But even the Bavsound Ghosts aren't going to supply the oomph below 75 Hz or so that dedicated subs provide. The space under the seats is simply not designed for it. For most, that's OK. But if you really need low-down articulation, only a dedicated sub enclosure with proper power will provide that.
__________________
--Life is a journey made more exciting with a fast car.--
--Helmets are for closers.--
<<Current: "Blackened" '18 NBM Porsche 718 Cayman ... Gone (but not forgotten): "Blackened" MG '15 228i M Sport w/aFe filter/scoop, Hertz drivers, P3Cars multigauge, other goodies>>
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:01 AM.




2addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST