The stock system is run on software and fiber optics. If anything is changed/swapped, itll screw things up. There is no magic way to upgrade our system, except for GROM system and multimedia tablets. You need to bring all parts to stock first hand.

 

Ok I'm sorry to argue but that's just not true. Have you not read the hundreds of posts on this site where ppl have done exactly this. Only they used aftermarket subs. I'm just using the oem subs. But I'm bypassing the most network and all the things that would screw it up by disconnecting the battery, tapping into the speaker wire, connecting a line out converter and then Amp and then the subs directly to the Amp. So the car shouldn't even know its there. Unless I have my settings wrong and pulls too much if that's even possible.... I'm still wondering are they 4 ohm or two

 

I have done exactly as you have done - used an aftermarket amp with factory subs, with speaker level signals from the front speakers. The factory subs are marked as four ohms each. I ran them in parallel, making a 2 ohm load on the amp. I’m not super happy with the sound quality either, though, I must admit. I have my low pass filter set at 60 Hz. Here is a link showing the 4 ohms.

Pardon Our Interruption...

 

Hi there, right In theory what you have said and done may work, but as you have also said Volvo's are and can be very sensitive, so I'm not sure how to help. I can only offer advice from my own experiences, I am going to face similar issues myself, as I have the Performance System with 8 speaker set-up as well, and my speakers have unfortunately deteriorated with age, so I decided to upgrade to the OEM, Much improved Dynaudio Premium set-up. so I have purchased everything that was installed by the factory, to do a retro-fit, but also all parts were sourced from a parts car which was pretty much identicle to my car as in age and spec, so that the same parts would have been installed in either car. Not much chance of getting slightly different parts this way, but one thing I am acutely aware of is the fact that I will have to plug into Volvo's Vida operating system and or VDash to turn off the "Most Security" Setting otherwise the car won't allow it all to work.

When I say I brought everything for an OEM install I mean everything; I brought all 13 DynAudio speakers which included the two rear seat backrest sub-woofers, Four tweeters, two mid range speakers and four woofers and a central channel speaker with built-in tweeter, two cross overs for the front door and both Amps one for the main set of speakers inside the car and another which is also called a sub-woofer module/control unit etc which powered the two rear sub-woofers, I even got the head-unit with 6 CD multi-changer from the centre stack.

I still haven't got round to installing it all, as the rear speakers are installed with rivets from the factory, so I will have to drill them out, to remove the old speakers and install my DynAudio Woofers and tweeters also two mid range drivers are installed into the front door cards as oppossed to the actual door, like the woofer and tweeter and cross overs are. I am also replacing my interior from Quartz/Umbra to black as it all got very mouldy last winter when the CEM and Battery failed which prevented me from closing the windows properly, when the car was parked up over winter on my drive way due to the sudden break down.

So I am waiting till I have brought and collected the black interior parts and carpet so that I can do it all at once.

So main point is I know that for me to get this in-stall done and working properly it's going take me to DEACTIVATE "THE MOST SETTING" which is switched on from the factory in European C70's, but I did hear somewhere that the setting is not turned on for the C70's that came to North America, in other words It should be all plug in and play!!!! Americans got lucky with this "pain in the ass" issue!!! Also with the over engineered aspect of Volvo with the C70, most of the wiring needed was Pre-installed into our C70's from the factory. I hope this helps any other questions? Below is a few pictures of what you need to buy if you plan on doing the same in-stall, most of it is shown except the 2 sub-woofers and the cross overs!

 

question. is it possible to to replace the stock amp to a more modern 5 chabl amp so i can add subs? found the amp in the rear, but i dont know about the wiring.