Yes, I was going the cheaper route and only replaced the two 8 inch woofers. Although it looks like they replaced the 8's with 6.5's for some reason. It's like there is no mid bass. Is that weird that new speakers would be less efficient? I'm not very handy which is why I didn't go the focal route is it looks like you have to make mounting bracket to make them fit which sounds way over my head. I was also very scared to take the door panel off. At his point which way would you guys recommend. Go back to the Bose, or replace the other 4 inch woofers in the door as well as the tweeters?

 

Very important - check the phase of the speakers. If one speaker is out of phase with the other, it will kill the bass as it's sine wave will be opposite.

 

I assume the shop installed them correctly. I found it helps if I move the fader to the rear a little bit to get rid of the harsh highs from the tweeter. I still really don't understand why these sound so much worse. You literally can't hear the kick drum in most music tracks. Any more opinions on if I should just go back to the Bose woofer? I searched the part number but can't find any new? Can you still find them new?

 

Remove the '.' in the part number and search again. Most places that sell OEM parts have them. Try here for example: http://www.porschepartshub.com/oe-porsche/99764555500

 

Don't assume. Have them check it and verify.

 

Hi,

(small explanation)

the problem of all here is, the BOSE door "woofer" has a ~ 1 ohm impedance and is a special driver that match to the BOSE amp.
So if you install an aftermarket speaker (I assume) with 4 ohm your speaker performance goes dramatically down. It will not hurt anything, but the maximum output voltage for a 4 ohm speaker is much too low on the 2.1 BOSE amp.

Example: the "door woofer channel" on the BOSE amp is digital switched (class D) an will produce round about 100 watts.


Bose OEM 1 Ohm Speaker : Output max voltage on the speaker -> 10 Volt / 1 Ohm = 10 Ampere ---> Power = 10 Volt * 10 Ampere = 100 Watt.

"any" Focal 4 Ohm Speaker: Output max voltage on the speaker -> 10 Volt / 4 Ohm = 2.5 Ampere ---> Power = 10 Volt * 2.5 Ampere = 25 Watt.


So in the PCM 2.1 amp environment you can run a 4 Ohm "woofer" speaker only about a quarter of the power.

The reason for this is, the BOSE 2.1 amp is ultra small (design done in the early 2000) and the "door woofer channel" amp has no step up power supply internal and uses direct the 12 volt from the car power. So there is no way the get more the 12 Volts on the speaker. This is a very poor design but it is working. No Highs? No Lows? Must be B...

The only working solutions are, install a OEM 1 ohm (I bought already a set on ebay, $30 and they were fine) speaker or install the nice focals and live with that.
If you go for a "ebay version", check the fotos on the speaker. There is date printed the speakers. If the speaker(s) only of few years old (2011) or so, they should be o.k.


A "modern" class D (Pioneer or what ever ) amp and the 43 pages focal 8/4/1 solution would be interesting.

 

Thanks for the basics here. A lot of people do not realize this.
To the guy who switched out the sub speaker, if you get two aftermarket subs with dual drivers you can wire all four in parallel to drop the ohm from 4x to 1x.

yah996, is this also the case with the PCM 3.0 Bose system? Is it the same 100 watt class D amp and 1 ohm driver setup on each speaker. Ergo, the same issue with 4 ohm aftermarket speakers?

Edit: Found this in another thread and might help. Though the ohm rating may be the same, power output increased and it should still be enough as long as you change ALL speakers to a 4 ohm setup:
"Despite the improved standard ICE, the Bose sound system upgrade was another popular option and well worth seeking out for best audio performance. The flagship Bose system (standard on the Turbo, not available on the GT3/RS) was Porsche’s ultimate Hi Fi package. It’s certainly a sought-after extra as the standard system could only be described as adequate. Bose provided superb audio quality tuned to the 997’s interior (the full specification is given below).
This digital surround sound audio system included 13 loudspeakers (12 for the 911 Carrera Cabriolet/911 Targa 4 models) and 7-channel digital amplifier (MOST® bus integrated). The surround sound was enhanced through Centerpoint® signal processing technology and there was continuous compensation for ambient noise using integral AudioPilot® microphone. There was also a special open-top sound programme for Cabriolet models.
Total power output was 325 watts (2 x 100 watt BOSE® TSM switching amplifiers, 5 x 25 watt linear amplifiers). On the dashboard were two 2.5cm (1 inch) Neodym high-range speakers and one 7.0cm (2.76ins) mid-range speaker (centre). In the doors were two 8.0cm (3.15ins) Neodym mid-range speakers plus two 20.0cm (7.88ins) Nd® low-range speakers. In the rear side panels were two 2.5cm (1 inch) Neodym high-range speakers plus two 8.0cm (3.15ins) Neodym midrange speakers and on the Coupé there were two 13.0cm (5.12ins) low-range speakers behind rear seats (active subwoofers in 14-litre bass reflex enclosure). On the Cabriolet/Targa there was one 10.2cm x 15.3cm (4ins x 6ins) low-range speaker in the passenger footwell (active subwoofer in a 6-litre bass reflex enclosure). This was available as factory fitment only.
Note: The Bose system was upgraded for the 2009MY onwards. Power output was increased to 385 watts and now offered full 5.1 Dolby Surround
sound (with five dedicated audio channels - front left, front right, centre, surround left, surround right), while Bose’s patented Centerpoint signal
processing was upgraded to version II, which Porsche claims – “extracts an even more precise and realistic sound from the stereo signal”.

Edit 2: (After yah996 replied). It looks like the info I supplied in my edit is from a 997 book (http://www.porsche997book.co.uk/) and not from the factory. It is also inaccurate because the speaker sizes are definitely wrong. Looks like they just rounded up metric measurements. They are standard 1", 4", 5.25" and 6.5" speakers. Also, the total power output does not match what yah996 has and I'm having trouble finding the actual total peak power. I'll update again if I can find it.

 

YES. BOSE 2.1 and BOSE 3.0 are similar in the power amps.


The PCM 3.0 (997.2/987.2) Bose uses the same speakers as for the PCM 2.1 (997.1/987.1)

To understand it a little bit more, i try to explain.

The bose amp has a lots of amps:

- 2x15 Watt RMS (bridged internal ~ 25 Watts sine wave on 2 Ohm) for front doors speaker (2 ohm) and tweeter in the dash (ohms don't care)

- 2x15 Watt RMS (bridged internal ~ 25 Watts sine wave on 2 Ohm) for rear panel speaker (2 ohm) and tweeter in the dash (ohms don't care)

- 1x15 Watt RMS (bridged internal ~ 25 Watts sine wave on 2 Ohm) middle dash (2 ohms )

I 100% believe there is no different in the analog amps. (You will not hear a big difference here anyway)

These amps are real classic analog stuff, nothing specials, but the can drive 2 ohm load.

Now the special part and the most important one. The "Power amp" in the Bose. The Bose 3.0 amp has here an improvement on power.

PCM 2.1
- 2 x 100 Watt (digital switched class D) for front doors bass speaker (1 ohm) only. Strange thing, the cables resistance is ~ 0.7-1.0 ohm. The cables to the speaker are 2.5mm² and of course not acceptable for any HiFi freak and never ever for high end 1 ohm solution. I did on my 997.1 turbo a measurement. So it is not really a 1 ohm impedance, because the resistance is in series.

PCM 3.0
- 2 x 125 Watt (digital switched class D) for front doors bass speaker (you will almost hear no difference - pls. DON'T kill me)

(so much more power on the datasheet and same speaker in the front door?, autsch....)

Subwoofer panel in the rear is the same.


You wrote:
Edit: Found this in another thread and might help. Though the ohm rating may be the same, power output increased and it should still be enough as long as you change ALL speakers to a 4 ohm setup:



To be correct, there will be a little improvement. A quarter of the gain from 100 to 125 Watt. (You will hear no difference on a 4 Ohm System) b. m.


By the way, last year I drove all OEM BOSE speakers with the one and only working aftermarket amp from GLADEN XS75c6 and my Clarion HU NX720E. This amp can drive 1 ohm loads. This is by far the only amp I found which can handle the OEM speaker set. This amp is a animal, but real old analog stuff and too big and to heavy (and to strong) in these days.

There is a some power reserve in the door speakers, but the whole door was starting to vibrate and i was afraid of blowing the speakers. ( And of course on the 997.1 turbo, the battery was drained after a few minutes). So I found now my best solution. I will wait for a 991.


EDIT:
To make shure what I am was writing, I checked the PET for a 997.1T and the 997.2T. (Door woofer for example)

997 645 555 00 Tiefton-Lautsprecher 2 I680

The part number is identical.


Please be aware I was writing 25 Watt sine wave . This means "average power" not peak power like RMS. 100 Watts are the peak power in the class D.



Have fun K.

 

Thanks for the great new contributions! Realizing the math of shifting from 1 ohm speakers to 4 ohm ones, one would expect reduced volume from the system. The result is that the volume is slightly reduced, but the stock bose amp has enough power to reach ear splitting volume levels even with the 4 ohm Focal set up. That's the reality.

Wiring a second set of speakers into the bose sub box is effectively impossible as there just isn't any room. Sure, you could drop another amp in there, but then you need to worry about heat and adequate power from the stock wiring. Parts Express does have a Aurum Cantus 5.25" subwoofer that is about $60 each, definitely higher quality than the ones I've used. Could be worth a try.

I think you found that some of the posted "official" measurements are actually wrong. Measurements for all the drivers are in the thread and indeed, the .1 system and .2 system uses the exact same drivers. While there was only a modest improvement in the amp, don't neglect the upgrade of the head unit. I believe that is actually the bigger driver of improved sound in the system.

 

Specs look much better, higher power, more sensitive, freq response down to 35 Hz, but they are 8 Ohm speakers (7 Ohm actually).

http://www.parts-express.com/aurum-c...oofer--296-400

Would love to read your review comparing them to the Dayton Audio ones...

 

I'm not sure you're reading the spec right. 35Hz is the Fs (resonant freq). FS is one of the T/S parameters of the driver. There's no way that a 5" driver can provide usable output down to 35Hz. You have to plug in the parameters into a box design program to get a good estimate of how perform. Fortunately, Aurum Cantus did that for you.

For a small 0.13 ft^3 sealed enclosure, the frequency response extends down to 112Hz (-3dB). For a 0.3 ft^3 simple vented enclosure (no port specs provided), your -3dB point is 71Hz. With some sacrificial port tuning and the cabin response of the Porsche, you can probably get passable bass.

But hey, anything is bound to be an improvement over the stock drivers...assuming similar voltage sensitivity (otherwise you'll need to upgrade the amp).

 

Great you took a look. Question is, do you think it would be better than the Dayton Audio units I installed? They seem to have better specs and are more expensive, but are 8 ohms instead of 4. They also have a different bolt circle than the Dayton ones, which will require some kind of kludge installation or a spacer to drop into the Bose sub box space. Curious for your views. Cool thing about Parts Express is one could always just return them if they don't work. I'm just concerned that the installation will not be very clean.

Actually looks like 35 Hz is not only the Fs, it is the stated lower end of the frequency response. It may or may not reach it, but that is the stated response. (how do they state that given the bass response would be 112Hz in a tuned box?)

 

Short answer:
Stated frequency response ranges on a bare driver are meaningless. You have to plug the T/S parameters into a box calc program to get an idea of how it will perform. Otherwise, it's like comparing the performance of two sports cars based simply on their "maximum speed." Doing box calculations is a PITA. I would suggest just trying the speakers you want and seeing if you like them.


Long answer:
You're right, 35 Hz is the manufacturer's stated lower end of the FR range. Unfortunately, FR is almost always a meaningless specification, particularly when it's describing a woofer. First of all, you're using a range of 2 numbers to describe what is actually an amplitude vs. frequency curve. And it's a curve that can vary wildly just by changing the size of the enclosure, adding or changing ports, changing the room, and even changing the position of the driver in the room. In fact, the driver/enclosure system could be -48dB at 35Hz producing 35% THD (essentially useless and horrible sounding output) but hey, it's still 35Hz. There are a lot of parameters to producing high quality bass. A flat frequency response curve, with low distortion at high volume levels, and a pleasant "Q" alignment of your system, are good starting points.

 

Short question, do you think the Aurum speakers will perform better in this application given the better stated frequency range?

 

Really just wanted to say..I'm loving every minute listening to my Bose sound system with the ryem3 mods