Anyway to reset Bose amp?

Hey, I have a 2005 Boxster S with the Bose system . Unfortunately the previous owner swapped the factory head unit with a very cheap android unit that sounded terrible. I recently upgraded to a kenwood DMX8710s that sounds way better, but the volume is very low still. It seems like there is no sound until the radio reaches 20 or so. I suspect that the previous owner removed the radio when the volume was at a lower level, and from what I understand, the Bose system keeps the last volume as its peek volume. I’m seeing that the old radio has to be reinstalled and turned 75% all the way up, then the new radio can be put back in, but I don’t have the old radio. Does anyone know of a different way to reset it? I don’t want to buy a Bose oem radio just for this task. thanks!

Hi, welcome to Planet-9, the Friendly Porsche Forum - for frustrated audiophiles with low volume. So far - I haven't seen or heard of any way to changing the Bose amp gain aside from using an original headunit. Maybe you have a really good friend with a 987 that still has the factory Bose radio ? And he'd let you borrow it for 15 minutes?

thank you, I need better friends 🤣

I ended up replacing the Bose amp with a CT 4 channel amp I purchased off of facebook. It sounds a million times better. I’m really getting this car sorted out.

I am piggybacking on this dormant thread because I feel my situation is too specific for its own. I just picked up a 2007 S that is rocking a Kenwood HU of indeterminate age. I get no sound whatsoever. The head unit fires up and all the interfaces work. The car was originally shipped with the Upgraded Bose system . The fuses are all good. Can anyone walk me through some troubleshooting?

I think you first need to find out if the Kenwood is actually working. That's going to require a loudspeaker and some small "clipleads".. you need to look for the loudspeaker outputs from the headunit, hookup a speaker to one of them and see if the thing makes noise/music or not. If it does, then it's time to start looking downsteam (amp and such..) Is the Bose amp still there? If so it probably has a fiber interface since it requires an optical fiber link for it's input, not an electrical input to the amp. With any aftermarket system, one can hope it was plug and play (doubtful if done any time ago) and that the installer didn't hack up the car's wiring harness to install it (they probably did..) If the harness is intact, then it might be a good move to simply buy another inexpensive headunit (AliExpress - several threads on it here) and try to plug and play it. I don't suppose any documentation came with the car? Any idea on a model number for the Kenwood ? (On-line installation manual?)

That’s odd for sure. Did the previous owner say anything about the lack of sound or are you unable to speak with the previous owner? Did you pull the radio out to see how it’s connected? If the MOST interface is connected correctly?

Yeah, I need to pull it and see what's what. The Prev owner thought it needed an Amp....but he has since ghosted me on FB. He even handed me a baggie with some errant screws from the side console panels. Guess he just doesn't want to be bothered. Which I get, but at the same time it was the ONLY post sale question I had. The intertubz points towards the MOST box not waking up the amp. Or else perhaps one of the fiber optics cables is pinched. Idk. There are two USB cables (one male and one female) running out from the dash in separate places....so some wiring chicanery was definitely gotten up to.

Yea I would start at the radio. I think the Most box needs power that’s not available behind the radio and there’s were many people go wrong. If it’s an aftermarket radio, you can always just tap and speaker behind the radio to make sure there is output from the head unit itself, unrelated to the most or Bose amp . I ended up going aftermarket amp and couldn’t be happier.

I think you're correct - the amp must be woken up by a signal over the MOST fiber.. This diagram only shows Connector 1, TERM 30 as receiving power, meaning the transceiver module in the amp must be powered up whenever the ignition is on (MOST is a loop one-way configuration, each device requires a transceiver).. Connector 2, TERM 31 is the ground connection. So if the MOST adaptor isn't working, or the fiber cable going to it is reversed - the amp won't turn on. There is an input and output MOST cable going to each connected device, if they are reversed at any device, it's not going to work. That's what I'd check first. I've played with MOST a bit, and to make sure it's connected correctly you need a small penlight - probably an LED one would be best. You can shine it at the connector when the connector is disconnected. One side will stay dark (the receiver), the other side will light up (the transmitter). And each item has to be wired "transmitter"--"receiver"--"transmitter"-- etc.. if it's plumbed up receiver-to-receiver, or transmitter-to-transmitter - it's not going to work.