JL XD 600/1 into 3 ohms, so I should be getting about 500W RMS at 14.4V. It's in a fiberglass/wood enclosure that takes up the entire rear shelf and old sub location. No photos, sorry.

Sure. I have a 13W7 in a large reinforced box at home, it sounds really good. I guess I can't really compare.

I would highly recommend dynamat (or other sound deadner) in the doors. Vibrating door panels make your midbass drivers sound terrible. But you'll have to be able to stomach the extra weight.

The rears are a 2-way, midbass and tweet, passive crossover.

People say that the stock Bose drivers are 1 ohm, and very few aftermarket amps can drive that load. So, probably not.

You COULD do that. If you're keeping the stock speakers, adding an extra amp won't do anything for your sound. The stock amp isn't the problem. If you want to replace the loudspeakers, you would need to add the aftermarket amp, and you could definitely add it after the Bose amp. Problem is, the Bose amp equalization is designed for the Bose loudspeakers + cabin, and they have built-in crossovers that probably won't match up with what you want with aftermarket speakers. The stock Bose amp has 4 channels driving 6 speakers. 2 midbass and 2 midrange/tweeter combined (passive crossover). It would be really hard to match that up with anything, the way the Bose amp signals are processed at their speaker outputs. So if you want to leave the PCM and the Bose amp, and add an aftermarket amp and speakers, you'll need some kind of "OEM integration device" to sum the inputs and spit out a nice low-level signal. Examples of that device would be the JBL MS-8, RF 3sixty series, JL Cleansweep, and a whole bunch of others.

 

thanks again for all the valuable input!

I'm just waiting for a couple of days off so I can do the install. I would do the install using a professional installer, but we don't have one in Key West. Wish me luck!

 

I called an installer in Miami that by the Google praise had done a Porsche stereo install. They quoted me "at least two grand" to install the double din, speakers, and processor. I wonder if that is in line nowadays, or they just think Porsche owners are easy to part with their money.

Looks like I'm doing it myself after all. I have the door trim tools, wire snaker thing, bezel, wire harness, and pictures from this forum on removing door trim etc, so although it will take me a while I'm sure it is more than doable.

$2000 to install, really?

 

Yeah, $2,000 is probably about right for them to do a good job, particularly if they're running new wires into the doors and if this includes all the cables/fuses/etc. Labor for car stereo installations is about $75-150/hour.

For safety reasons, if you're not familiar installing amps, I would strongly recommend having the installers do this part for you. Keep in mind that you'll need to custom fabricate some spacer rings for the speakers. And even if you're careful, you'll probably break door panel clips, so you might want to order some of those in advance. Good luck.

 

Well, that makes some sense but still seems awfully high for labor. That would be about 13 to 26 hours for a professional to install. I know that wires can be expensive. I already have the wires for my amp, and I was planning on using the stock speaker wires and even if not, I have plenty of good speaker wire.

Thanks for the heads up on the door clips. I tried to find them online but I can only find them for older Porsche models. Any suggestions?

Where did you put your processor?

 

any good install shop these days charges around 125-150 for labor. especially if they have the tech qualified for your car.

If you guys find a good qualified shop, like mine, we will work a package deal out for labor. People who are willing to work the numbers a little to help you out show good character and a sign of a good shop! also Check YELP!

 

Thanks, I'll try Yelp but it looks like I'll be doing the work. It'll take a while, but there are lots of helpful threads to help me through.

I do have a side question, is it possible to use the microphone already built into the Porsche instead of using an external one? I'm sure it would have to be properly spliced but it would be cool to resuse the one there.

 

I have all my stuff in, the only thing lacking is time. But...I did start with the tweeter install. I figured that if I had to make a custom pod I would rather do that first than have everything in place and do it last.
I will create a separate thread later with pictures of my install. It wound up being super simple. The plates pop right out, and then I pried the old tweeters out easy enough. The new tweeters are too big to fit in as it were, so I had to Frankenstein the plastic on the inside to make it fit. If I were to put the old ones back in, it wouldn't be that hard by putting a simple frame or something back in but I have no intention of doing that. But I have to admit it was a "no turning back" moment to break the plastic in order to put the new ones in. They fit perfectly, and the plastic cover piece just popped right back in, no issues. Here's the funny thing though, I thought it would sound like total crap because the tweeters are not matched up to the bose system. They sound not only awesome, I can turn the volume up much much louder to where it should have been all along, and the rest of the speakers including the sub sounded much better. It's as if the real weak link was the tweeters they installed that start distorting at more than slightly moderate levels. The only change I made were the tweeters and the system already sounds a hundred times better, actually not bad. I'm finishing by putting in the rest of the focals, but if someone wanted to upgrade the sound without messing with much, putting in a real set of tweeters will change the whole sound for the better.

 

No the porsche mic is not tuned to a new radio

use the mic provided i have a lot of threads on this forum with some good tips

 

I love this thread, so wanted to correct some information. I've measured the stock speakers and they are not 1 ohm. The rears are 2 ohm and the front tweeters are 3.5 ohm. I expect this results in a sensitivity difference between the fronts and the rears. I'm experimenting with some changes. More to follow.

 

Just wondering, were you measuring DC Resistance or Impedance? If you simply took a multimeter and measured the resistance across the terminals for each speaker, then you measured Resistance, NOT Impedance. DC Resistance (=Impedance @ 0 Hz) is really not a useful value, unless you're designing a passive crossover network. The speakers are not "1 ohm Resistance, they are 1 ohm average impedance."

To be accurate, the "ohms" of the speaker varies with frequency, and is best represented by an "Impedance vs. Frequency" graph.

If you want to confirm the 1 ohm average impedance rating, what you would need to do is measure the voltage drop and current using a frequency generator, plot the data, then perform an averaging calculation. There are also automated software/hardware packages that can produce this graph for you.

In general, the dB/W or dB/V sensitivity of a tweeter tends to be 3-6dB higher than a typical midrange or woofer (this is a generalizaton, there are exceptions).

Also, the dB/W sensitivity of a driver isn't related to its DC resistance or its impedance curve directly. For instance, the same driver can be designed in both 4ohm and 8ohm impedance ratings and have the same dB/W sensitivity. For two drivers with the same dB/W sensitivity, the driver with a lower impedance will have a higher db/V "voltage sensitivity."

Regardless, it's important to level-match all of your drivers so that they match together. This can be accomplished by adjusting the levels of amplification (in an active crossover) or adding series resistance (passive crossover).

 

Gotcha. Yeah, I've been a bit too presumptuous. Of course I did not take a reading of average impedance, just simple resistance. Did you refer to an actual impedance measurement of the Bose speakers? Indeed, I have seen impedance graphs measured across a speaker's frequency response. Anyway, taking some more measurements, the resistance of the Bose rear midranges were exactly 2.0 ohms, while the tweeters were 3.5 ohms after the high pass filter. Same as the 3.5 ohms of the front tweeters.

Measuring the Focal's I'm checking out, they measured pretty close at 3.4 ohms, but are much less efficient than the Bose speakers. Indeed, I know a 4 ohm speaker isn't like every 4 ohm speaker - efficiencies can vary widely. I only wonder if the difference in impedance might have something to do with the difference in efficiency between the fronts and the rears. The impedance is not necessarily related to the efficiency, so this may not be the case.

The Focal's are some of the most efficient at 90 db/W. Surprisingly, they are still much less efficient than the Bose's. After checking out the rears, the only feasible alternative appears to be replacing all of the speakers with ones of similar make, balance and efficiency. I realize this is still a bit of a crap shoot that will take quite a bit of time to check out. The 4" Focals have much better sound quality than the Bose speakers; much more refined highs, and much punchier midrange. Even if ultimate volume level is reduced, I think the reproduction will be vastly improved on the whole system.

One concern I have is that driving the whole system with more power is going to also feed more power to the subwoofer, resulting in overpowering muddy bass from the subwoofer. If I get enough bass from the door woofers, I might do without the subwoofer. However, is there a simple way to attenuate the feed to the subwoofer?

 

Manufacturers often just report the "nominal" impedance, which is a rounding up/down of the average impedance over the intended frequency range. I believe this to be 1 ohm, but hey, I'm just going by what Bose says.

The lighter the speaker cone, the more efficient the speaker (usually). Bose uses paper, which is pretty light, but it's also a lousy material.

Are you sure you can't just actively amplify each channel and adjust the gain for each one individually?

Sure, just stick the subwoofer on a separate amplifier channel - this is what is commonly done. If you want to attenuate a sub passively, you'll need a high wattage L-Pad, which heat up and will degrade your sound quality (I don't recommend this).

BTW, what exactly are you trying to do in terms of your system?

 

Didn't think Bose disclosed impedance of their systems.

Ah yes, it would be nice to run the whole system on separate amplification with an equalizer. Not happening. I'm taking a crap shoot. Straight speaker swap into the Bose system. Crossing my fingers.