Harman kardon 688 e90 subwoofer upgrades?

hasse_231 · 03-15-2016, 03:44 PM

I do have option 688. Iam satisfeid with the audio but not the bass. It seems that all the bas is coming from the speaker below the seats. I usally like to have some fader adjusted to the back. When i do that all the bass disappear.

The indivudual setup is more powerful. Can i buy a set and change all the speakers and code it? I have found a set on ebay.

Also i have read that i can buy a harness that make it possible to install a subwoofer.

What is the best way tn do it?

Pierre26 · 03-16-2016, 03:36 AM

Have upgraded whole parts from HiFi to individual and must say that HiFi had more Bass. And with individual they aren't the same at low or loud level. Take care if you take the individual Ampli you MUST change the Bass (2 ohm HiFi and 4 Ohm with individual) or will heat and burn the Amp. But must say that medium and treble are very clear when I put the power!, details about this retrofit could be found there:
http://www.1addicts.com/forums/showt...php?p=19129247

ctuna · 03-16-2016, 12:11 PM

Most people with a L7 just add a sub and sub amp(10" or larger trunk sub)
for big bass.

subwoofer threads
http://www.e90post.com/forums/showpo...2&postcount=66
http://www.e90post.com/forums/showth...t=Ultimate+Sub
http://www.e90post.com/forums/showth...ight=subwoofer

when you say best do you mean best or most cost effective.

hasse_231 · 03-16-2016, 01:09 PM

The best solution. It can cost more but the result gona be better.

ptpending · 03-16-2016, 02:43 PM

this setup will have problem because factory amplifier is time-aligned in a such way that sound from woofers comes from under the seats
when you put woofer in trunk, sound come bit later and not synchronized with other speakers
this will work only if you remove your harman kardon or individual system and replace it with the following set
most-rca converter, dsp processor or amplifier with dsp, and additional amplifers on channels
after that you have to tune all this system
the budget of such system close to 1500-2000 eur

hasse_231 · 03-20-2016, 04:58 PM

I gona go with individual... Ptpending have helped me out. I gona wait a bit until i have upgraded my ahl thoughts 😀

03-15-2016, 03:44 PM	#1
hasse_231 New Member 2 Rep 16 Posts Drives: Loocking for an M3 Join Date: Nov 2014 Location: Sweden iTrader: (0)	Harman kardon 688 e90 subwoofer upgrades? I do have option 688. Iam satisfeid with the audio but not the bass. It seems that all the bas is coming from the speaker below the seats. I usally like to have some fader adjusted to the back. When i do that all the bass disappear. The indivudual setup is more powerful. Can i buy a set and change all the speakers and code it? I have found a set on ebay. Also i have read that i can buy a harness that make it possible to install a subwoofer. What is the best way tn do it?
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03-16-2016, 03:36 AM	#2
Pierre26 Private First Class 20 Rep 105 Posts Drives: 2009-335D Pack M Join Date: Jun 2014 Location: France iTrader: (0)	Have upgraded whole parts from HiFi to individual and must say that HiFi had more Bass. And with individual they aren't the same at low or loud level. Take care if you take the individual Ampli you MUST change the Bass (2 ohm HiFi and 4 Ohm with individual) or will heat and burn the Amp. But must say that medium and treble are very clear when I put the power!, details about this retrofit could be found there: http://www.1addicts.com/forums/showt...php?p=19129247
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03-16-2016, 12:11 PM	#3
ctuna Lieutenant General 1915 Rep 13,107 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Most people with a L7 just add a sub and sub amp Most people with a L7 just add a sub and sub amp(10" or larger trunk sub) for big bass. subwoofer threads http://www.e90post.com/forums/showpo...2&postcount=66 http://www.e90post.com/forums/showth...t=Ultimate+Sub http://www.e90post.com/forums/showth...ight=subwoofer when you say best do you mean best or most cost effective.
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03-16-2016, 01:09 PM	#4
hasse_231 New Member 2 Rep 16 Posts Drives: Loocking for an M3 Join Date: Nov 2014 Location: Sweden iTrader: (0)	The best solution. It can cost more but the result gona be better.
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03-16-2016, 02:43 PM	#5
ptpending Colonel 458 Rep 2,754 Posts Drives: e91 Join Date: Dec 2013 Location: Poland iTrader: (1)	this setup will have problem because factory amplifier is time-aligned in a such way that sound from woofers comes from under the seats when you put woofer in trunk, sound come bit later and not synchronized with other speakers this will work only if you remove your harman kardon or individual system and replace it with the following set most-rca converter, dsp processor or amplifier with dsp, and additional amplifers on channels after that you have to tune all this system the budget of such system close to 1500-2000 eur __________________ E81 2007 130i 6cylinder Montego blue Retrofits: Harman Kardon, High-beam assistant, Removable tow hitch. Auto-dim folding exterior mirrors. Lumbar support. Perfomance Brakes.
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03-20-2016, 04:58 PM	#6
hasse_231 New Member 2 Rep 16 Posts Drives: Loocking for an M3 Join Date: Nov 2014 Location: Sweden iTrader: (0)	I gona go with individual... Ptpending have helped me out. I gona wait a bit until i have upgraded my ahl thoughts 😀
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