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Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 5:50 am
by B3DAWG
Update...

In order to fully rule out the CDR-220 as the culprit to the low frequency clipping, I decided to test the amp in isolation. I wasn't totally positive it still wasn't the amp. Most of the bass popping sound was lower frequencies coming from the door speakers. I don't have a schematic for the Harman amp, but in theory, connecting a 4 ohm speaker to an amp that's producing a constant 2 ohm output is not the best combination unless the speaker is rated at 2 ohms. It's hard to find 2 ohm replacements unless you want to get factory replacements at 2x the money. The HAES speakers from Porsche cost about $50 each. This would follow the same logic that applies to attempting to add a home speaker rated at 8 ohms to a car system that normally operates at 4 ohms. And vice versa, if you put a 2 ohm load on an amp that can't handle lower than 4 ohm, you'll potentially damage the amp. Right?

Therefore, I decided to get a wiring harness and connect my new Blaupunkt amp. Result? The signal is clean! Of course, the little 4" and 5.25" speakers are definitely not high-end sound, but at least they're clean with no bass clipping.

Sometimes, it makes me wonder if these systems had bass clipping from the factory. I read many post about 996 owners turning up the bass range and notice distortion even a low volume levels.

For those that have factory Harman/Becker systems (e.g. CDR-210, CDR-220, CDR-23, PCM1 or PCM2), how many of you notice bass distortion and/or clipping?

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 6:37 am
by 32wildbilly
b3freak wrote: Fri Jul 13, 2018 5:50 am Update...


For those that have factory Harman/Becker systems (e.g. CDR-210, CDR-220, CDR-23, PCM1 or PCM2), how many of you notice bass distortion and/or clipping?
Stock CDR-23, as far as I can tell no distortion or clipping. I'm an old guy who grew in the 60's and 70's when there was a lot of music played loudly much with a strong bass so I grew to love it. I still play stuff loudly with the bass cranked up and I hear nothing objectionable. For instance, I sometimes listen to Mountain, you know famous for "Mississippi Queen", with Felix Pappalardi on a STRONG bass and it sounds AWESOME! Now if I could just get the inside rearview mirror to stop distorting! :lol:

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 7:19 am
by wyovino
I have the CDR-220 with factory Hi Fi option and haven't noticed any bass distortion or clipping.

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 7:29 am
by B3DAWG
wyovino wrote: Fri Jul 13, 2018 7:19 am I have the CDR-220 with factory Hi Fi option and haven't noticed any bass distortion or clipping.
Have you tried turning up the bass (beyond +4) and then slowly turning up the volume level past 25 with bass driving music? I couldn't get mine past 25 without popping in the bass range. :(

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 9:03 am
by 5chn3ll
I think it probably depends greatly on how you listen to music and the type of music being played. My experience with Porsche radios, with the Porsche amps and Porsche speakers, has been consistently abysmal. Bass reproduced fine at low volume, but the low end fell apart completely on bass-heavy tracks at high volume.

The best solution I've found after a LOT of tinkering over the past decade: supplement the factory speakers and amp with a powered subwoofer. The enclosure I'm using, an Infinity Basslink sits in one of the recesses where a rear seat would be if I had rear seats. I used both rear speakers to provide signal to the amp; each rear speaker is connected to the corresponding channel's high-level input on the sub.

The sub has a built-in variable crossover, controls to adjust the bass response, and a remote volume control - the only change to the factory setup would be to ensure the bass level is flat - or even a little lower - to ensure that the CDR and Porsche amp stick to midrange and high frequencies.

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 9:59 am
by 32wildbilly
b3freak wrote: Fri Jul 13, 2018 7:29 am
wyovino wrote: Fri Jul 13, 2018 7:19 am I have the CDR-220 with factory Hi Fi option and haven't noticed any bass distortion or clipping.
Have you tried turning up the bass (beyond +4) and then slowly turning up the volume level past 25 with bass driving music? I couldn't get mine past 25 without popping in the bass range. :(
I didn't know the bass went below 4 nor the volume below 25...so yes, yes and yes. :roll:

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 10:07 am
by B3DAWG
32wildbilly wrote: Fri Jul 13, 2018 9:59 am
b3freak wrote: Fri Jul 13, 2018 7:29 am

Have you tried turning up the bass (beyond +4) and then slowly turning up the volume level past 25 with bass driving music? I couldn't get mine past 25 without popping in the bass range. :(
I didn't know the bass went below 4 nor the volume below 25...so yes, yes and yes. :roll:
bwahahahaah! Did you know the knob on the left was for volume? ha! :lol:

Re: My 2002 996 "renovation" thread

Posted: Fri Jul 13, 2018 10:21 am
by 32wildbilly
b3freak wrote: Fri Jul 13, 2018 10:07 am
32wildbilly wrote: Fri Jul 13, 2018 9:59 am

I didn't know the bass went below 4 nor the volume below 25...so yes, yes and yes. :roll:
bwahahahaah! Did you know the knob on the left was for volume? ha! :lol:
I did know that but it seems mine only turns clockwise! Must be defective... :lol:

Re:The verdict is in...

Posted: Sat Jul 14, 2018 11:43 am
by B3DAWG
My outpost... finally after weeks of scratching' my head on this one, the verdict is in... The Becker CDR-220 is innocent!

Connected the CDR-220 with a wire harness to a 200W Blaupunkt amp and the sound is clean across all 6 speakers even in the bass range. It's easier to push the full range of these Kicker speakers with the Blaupunkt.

IMHO, the Harman/Nokia amps are best matched with the factory HAES speakers. You can get by with standard 4 ohm aftermarket speakers for the dash and rear, but the 5.25 speakers in the doors need to have constant resistance of 2 ohm. I tried two sets of 4 ohm 5.25 speakers and all of them popped when turning up the bass with the factory amp. I swapped out the original Harman amp with another Harman amp and same thing. I then thought it might be the CDR-220 producing a clipped pre-amp signal, but after swapping the Harman amp with the Blaupunkt, it clearly wasn't the CDR-220. Good news is you can still retain the factory CDR-220 radio by using a proper wire harness that provides pre-amp outputs and an amp control signal. The wire harnesses can be purchased on eBay for around $20.00.

Re: Re:The verdict is in...

Posted: Sat Jul 14, 2018 1:31 pm
by 32wildbilly
b3freak wrote: Sat Jul 14, 2018 11:43 am My outpost... finally after weeks of scratching' my head on this one, the verdict is in... The Becker CDR-220 is innocent!

Connected the CDR-220 with a wire harness to a 200W Blaupunkt amp and the sound is clean across all 6 speakers even in the bass range. It's easier to push the full range of these Kicker speakers with the Blaupunkt.

IMHO, the Harman/Nokia amps are best matched with the factory HAES speakers. You can get by with standard 4 ohm aftermarket speakers for the dash and rear, but the 5.25 speakers in the doors need to have constant resistance of 2 ohm. I tried two sets of 4 ohm 5.25 speakers and all of them popped when turning up the bass with the factory amp. I swapped out the original Harman amp with another Harman amp and same thing. I then thought it might be the CDR-220 producing a clipped pre-amp signal, but after swapping the Harman amp with the Blaupunkt, it clearly wasn't the CDR-220. Good news is you can still retain the factory CDR-220 radio by using a proper wire harness that provides pre-amp outputs and an amp control signal. The wire harnesses can be purchased on eBay for around $20.00.
OR...you could leave things alone, race karts for five years and sprint cars for three years, wait until you are 67 years old, play poorly mastered old rock and roll so loud that the rear view mirror looks like it has a bad case of saint vitus dance and be insanely happy with the stock setup. Your choice... :roll: