For those of you with aftermarket head units in a Bose system, how did you wire the speakers to the new headunit? I just measure the impedance of the various speakers and the front tweeters and mids are both 2 ohms, but the front bass (in the door) is 1 ohm. And the rear speakers are 2 ohms. The center speaker is 2 ohms.

With most headunits capable of handling 4 ohm loads, I'm just wondering how people are wiring these the most effectively (including the center speaker)

Also, does anyone know if there are passive crossovers in the speaker wiring from the original bose amp? For example, if I just ran the tweeters, mids, and bass from one front side in series, would I get an acceptable 5 ohm load (2+2+1)? If there are passive crossovers in there then I obviously couldn't wire anything in series.

How are people wiring the center channel when no headunits have an amplified center channel out (only pre-outs)

Thanks for the comments!

 

I'm not sure if they are passive or active. But you don't want to wire all of these speakers in series because they are all playing different frequenices. You want them crossed over at their appropriate frequencies or you could damage the speakers (especially the tweeter) and it won't sound right.

Also the speakers need to be playing the same or similar frequencies in order to add their impedence when wired in series. For instance, if you did wire them all in series, the amp at 10kHz would see a 2ohm load from the tweeter because none of the other speakers can reproduce 10kHz. When you get close to the frquencies that both mid and tweeter play, then you can add their respective impedence for the total load on the amp. So the load the amp sees is related to the frequencies being played. In the end you get an impedence curve where impedence (ohms) is plotted against frequency (Hz).

Hope this helps.

 

Yes, they SHOULD be crossed over, but they are not from what I've seen, except for the tweeter which has a capacitor mounted directly on the speaker. I somewhat suspect the lack of crossovers to play a big part in making the speakers sound so muddy.

 

oh, good to know

so the "tweeter-with-roll-off-at-8khz" do have 6db/oct passive xover ?

wow. not even active xover in that superpremium Bose thing ?

 

how did you proceed with measurements ?

I'm surprised the imped is that low on speakers, and i guess if it's passive then it's all wired in // then it's even lower imped ?
what kind of amp is that ? high current type?

Or maybe it's wired in serie ?

 

I sent an email to Bose asking for specs on the p-car system but have not heard anything back yet. I doubt that I will.

 

They are waay too busy doing "Better sound through research".

 

At least not between the mids and tweeters, they are both connected to the same outputs on the amplifier. There MIGHT be a crossover in the amplifier for the door woofers and the mids, but considering how cheaply everything else is made I doubt it.

 

oh, so there is high chances the speakers are series-connected ?

did you check the imped from the amp wiring ?

 

No, I haven't, but in the wiring diagram they are wired in parallel. If you PM me your e-mail adress I'll send you the wiring diagram.

 

Well, I installed the new head unit and ran 4 sets of speaker wire from the head unit (Front L/R, Rear L/R) and a line-level RCA to the front trunk. Used Loi's at Euromotorspeeds Bose harness adapter to tap into the factory wiring for the speakers.

I wired the front speakers (Mid/Tweeter and Door Bass in series on each side) and the rears directly. Despite the impedance worries, I can confirm the headunit drives the speakers just fine, does not get hot, and sounds good. I just need to adjust the fader to be more forward centered because of the increased resistance observed by the series connection.

I did not hook up the center speaker at all.

I'm tempted to try the fronts in parallel instead just to see, but worry about the seriously low impedance that might result. But then again, it may be worth it in case I'm losing some high and low end from filtering in the series connection.

I am a little underwhelmed by the subwoofer. Even with the headunit on max vol for the sub connection, it seems more underpower than with the PCM. The headunit had left and right outputs for subs despite me only having one sub in the car, so I only ran one RCA. I am now wondering if I should have "Y'd" the two headunit outputs together and ran it as a single input into the sub. Not sure what the headunit would do? Would the signal be amplified as a result of the Y or just distorted.

Overall I am happy. The new headunit is sweet (Kenwood DNX9960) but I do have the bug to add a dedicated 6 channel amp and replace the speakers/sub. But at least I have very listenable music right now.

 

I thought most people posting here are using the Bose amp with the subwoofer with good results. I thought the Bose people had dedicated amps at the speakers, but maybe that was other versions of the Bose system - not the one used in the 997. I would think crossovers could/should be used at the speakers themselves. New speakers would probably include crossovers.

 

I sent them email regarding a similar issue and they never replied. this is actually a big problem with Bose since their customer service is not as required to be!

 

if you went over trouble to get proper head unit and amps - get rid of that junk and put in Focals.
and re-wire them as original speakers all do sit on same line with no crossovers and even worse - front dash speakers sit on same signal that gets to amps, so you really need to fix al lthat up if you want to spend some $$$$ on good sound.

 

Just to clarify a couple things regarding bose.

First, they really do use 1 and 2 ohm speakers. I have also heard of 13 ohm bose speakers. These are not one off's, but rather marketing strategy. If you blow a crappy bose paper cone speaker and want to replace...but nobody sells a speaker with the wacky dimensions, connectors and impedence of the one you just pulled...guess what, you are locked into paying 80 bucks for a 50 cent piece of crap.

Second...it isn't bad customer service that keeps them from giving any specifications on their systems, again it is marketing. They sell systems with terrible frequency response, high THD and low power as high end systems...why would you give specifications. Go to a bose store and see if you can get them to give you THD or frequency response (god forbid a frequency response curve) on an acoustamass system. They will do a nice song and dance...

Bose..."Better profits through marketing"