If you must use the stock head unit then Alpine makes a product that will take the head unit flawed output and flatten it. I am using this in my Mini Cooper system and it works great. It also gives me a 3 band parametric eq and crossover.

 

do you have details on how this alpine unit gets connected to non-alpine sources? any schematics? I saw that sound procesor on alpine web site but it was claimed to work only with alpine sources. plus it says it requires extenal unit and software to get original tune - it would be all nice and doable but i cannot find details on how to mate all that stuff to pcm.

Was it this unit you spoke about?
http://www.alpine-usa.com/product/view/pxa-h100/

 

Yes, and honestly i don't think Bose did it on purpose. Why should they use advanced DSP to control that kind of thing while they don't fix the peak and roll-off ?
I think the weak subwoofer hits his output limits (xmax) before the rest of the transducers, that's it. If it's a 6 inches driver what could possibly be the xmax anyway ? 8mm peak-to-peak ?? It's probably designed so the thermal power handling is higher than xmax, so it won't be damaged when pushed hard but you will hear it bottoming out easily..

Anyway, i believe it's all about; Low cost, Low weight/space, customer's first impression in dealer's showroom (power) and Reliability (for warranty sake)

... not much left for any audiophile consideration!

 

I got massively improved sound by doing something different. I opened up the rear subwoofer, and replaced the stock amp with a Blaupunkt THA-275 PnP amplifier. You will have to open up the amp and use just the innards as the amp with its casing won't fit, but once you remove the amp's side and front and back panels it fits perfectly where the stock sub woofer amp went (cut out the original amp's mounting bracket and just tape the blaupunk amp to the bottom of the subwoofer box using strong double-sided tape.The Blaupunkt THA-275 PnP 2/1 has an auto power on/off sensing feature, and i took power off the fuse box on the circuit that powers the sunroof and ran a power cable under the carpet to the rear. I took the left and right sound signal off the rear left and right speaker inputs. Sounds complicated but I did the whole job in 6 hours. The only fiddly thing was getting the sub woofer level and gain set correctly. You can only tell if it's correct once you close up the subwoofer box, which has about 8,000 screws holding it together. Took three tries to get it right, each time opening up and closing the subwoofer box to get access to the Blaupunkt THA-275 PnP 2/1 amp.

 

I have a complete bose system waiting to get installed. Should I just do some aftermarket stuff and not go with bose?

 

After driving the speakers with a separate amp, and adding a sub, I thought the stock speakers sounded pretty good, that is until I installed the Kevlar Focals, and then it was a completely different level, significant increase in sound quality and dynamics - more than I expected.














As for the head unit, there must be something different about the Bose head units or some DSP processing in the amps. I've had both the CDR and PCM units in the car, both non-bose, and didn't notice any reprocessing of the signal. A RTA with a sound level meter with 1/3 octave pink noise shows a pretty flat output, at other than a boost at the lower octaves with the sub, which you want to be higher anyways to overcome road noise.

 

This is the unit I have in my Mini Cooper
http://www.alpine-usa.com/product/view/pxe-h660/
pluged into the stock head unit harness. I searched some Mini Forums and took the info to my installer who actually already knew all about it. They know I have a Porsche and they use this also in many Porsches. The place I go to is called Blvd Customs whcih is a very high end place that really knows what they are doing. I use this Apline H660 processor to fix the head unit issues and tune the entire system. I use Hertz fronts and JL 10" sub and JL amp. Works for the Mini.

 

Will this work with the Bose as well?

Dave

 

Those Focal speakers are very nice indeed - same design an in my B&W Nautilus 805s.
I have heard B&W started making their own line of car speakers but they do not seem to be available yet nowhere. But most people say those Focals do sound as good as car speaker with no proper casing can sound.

 

It has 8 channels input. more than enough.
You will have to cut off ADC that puts analog signal into optical ring, disconnect all wires from PCM as it was discussed earlier, wire source signal from PCM into trunc and get those 4 channels of analog signal directly from PCM and feed it to this processor, then from processor into 2 new amps and then into existing wiring that used to be connected to old amp. Sound not too complicated, actually.
Again, if it is true that embedded pre-amp in PCM is done so badly that it has completely different distortions at different signal volume - it may present a big challenge as all Audyssey system can compensate for is the environment specific frequency issues.

So, more complicated part will be to put crossovers together, find a best spot for them somewhere in doors and mount speakers properly ensuring that you get no rattles and no echo in the doors.
Or if you decide to mount crossovers in trunk you may need to put completely new wiring from trunk to each speaker - it would be an optimal way but heck knows how difficult it will be to do.

In my doors something reverberates very badly at 60-70hz and I have a feeling that it will be a major pain to locate that element and properly isolate it. Plus what worries me a lot is how to put all that back together with all those plastic thingies that usually are not properly reusable after you pull them out and do not hold panels properly anymore that leads to rattles. In my now rattle-free car it would annoy me like hell.

 

Wow. I love to see people who know their stuff expressing opinion. I like your analysis. I'm not an audiophile, but I love almost all music and have been spoiled by my good old american McIntosh home equipment.

Personally, I have always shied away from Bose. They seem to apply "science" in order to create a fake virtual sound. Which in my mind is a fancy way of saying they try to cut corners to give you a product that seems better at first impression (like a test drive) than it really is. The enhanced audio option (above the premium audio) on the new M3 is impressive. As is the Burmeister in the Panamera (heard it at the dealer last month - you really can't pinpoint the source of the sound - speaker locations).

As for the 911. My 09' Carrera Bose is okay. I would consider new speakers if that made a significant difference. But my real question to you is in regard to road noise and soundproofing. Are you familiar with any ready-to-install sound deadening kits for the 997? I would think someone would sell a wheel well lining or sound absorbing door insert. I'm not looking to get my car to compete with a lexus for interior noise, I'd just like to reduce tire growl on the highway and prevent the painful noise of rocks hitting the wheel wells.

Any suggestions?

Good work. Keep posting.

Thanks,
David

 

To be honest I don't listen to the music in the 997 that much I wonder if it is even worth the effort.

For my 2004 M3 I went with Bavarian Soundwerks with just upgraded speakers and I was shocked how much the sound improved. I just wish something like this was available for the Porsche. The sound now is just mediocre at best so I just listen to the beautiful music coming out back.

Thanks for the info though..


Dave

 

To me I just want violin to sound like a violin and not like I don`t know what. It is not even a questionable thing that from financial standpoint - it is a waste of money for sure. But, if you like it - why not? I like it.

I downsized my home theater system last spring almost twice down in price after I replaced old Lexicon stuff with new generation pro Onkyo PR-SC886 processor and Rotel RMB-1077 with Oppo DVD player as transport and I can say, you know, progress in this area really exists and works wonders. My old cables all toghether did cost more than this new transport and overall old system sounded worse than that new one. So
I went from complete non-believer into Audyssey and D-class with ICE fan - this stuff really works and does perfectly fix issues that previously would cost you a fortune to fix.
And pretty much alsmost same stuff can be installed in a car now. It is all digital, so, it is not even very expensive and very doable.

Or may be my ears just deteriorate with age, who knows.

 

I think its great that you want to upgrade your sound system. I think many people look at an RTA and feel that its the answer to all measurements in a sound system. It only measures frequency response. It does not take into account the time domain. Its a great tool to use to confirm what you hear but a sound system should not to set up to give a "flat" RTA curve. I've seen people do this and spend lots of time and money doing so, only to be upset that their system sounds horrible. The best tool is your ears. No equipment can give you the info you get from your ears.

I agree that the peak in the 50 Hz region sounds horrible. But you are measuring this without the car on the road. In order to overcome road and engine noise, the Bose engineers had to boost the bass region. I'm not defending their approach; it sucks. I think their engineers use a lot of science and measurements to come up with solutions but fail to spend tiime critically listening to their systems.

Also, regarding this bass peak, we have to also take into consideration the transfer function and cabin gain of the vehicle. I'm sure many are wondering what this is. Its the bass gained by running a system in an enclosed space. Typically there is a certain frequency that resonates the easiest in a given space so those frequencies get boosted relative to the rest of the frequency range. In cars, this is usually in the 30-70 Hz range. What I've seen in vehicles is that the smaller the interior space, the higher the resonant frequency and the higher the peak at that frequency and vice versa. So larger interiors don't get as much boost and peak is at a lower frequency (usually more desirable). I bet that p-cars resonant frequency is in the 50 Hz range.

You can take all the measurements in the world, but the only way to know which speakers sound the best is to literally "throw" them in and listen to them with the car off and running on the road. And listening to a set of speakers on a sound board in a car stereo shop or in your living room will not tell which will sound best in your car. Too many variables at play: you have reflections of all the interior surfaces (leather, glass, plastic, etc), you have the enclosure of speaker (ie. the door, which has its own resonance), the crossover, phase response, distance between speaker locations, separation of midrange and tweeter, the power of the amplifier, etc, etc.

As to the question of setting up a sound system without changing out the head unit, JBL has a very promising unit soon to be released. They are taking pre-orders now. Here's the link:

http://www.harmanaudio.com/search_br...ialNumber=MS-8

The great thing about this product is that it does all of the sound processing for you. So you save time and money on that end. But it still gives you preamp controls and a 31 band equalizer. I'm very interested in seeing the reviews on this unit. For the money, I don't think there is a unit out there that can touch it. And probably a better alternative than spending $1.5k to $2k on a new head unit with navi.

BTW, about the parameters of the factory Bose system, I sent Bose an e-mail about specs; still waiting on a response. Not sure what info they'll share as on their website in FAQs it says:
"Can I get a list of technical specifications?
No, because our custom-engineered, complete system solutions largely supersede conventional audio measurements. Even some basic building blocks have been redefined—including amplifiers, speakers and equalizers. But most importantly, our integrated systems deliver results significantly different from those of conventional systems with individual, unmatched components."

 

Rright. Because it is crap, that`s why.