Giuseppe,
here is the link to all B&W service manuals:
B&W Group North America Service & Support Homepage
and this is yours N804:
http://www.bwgroupsupport.com/downloads/techmanuals/bw/N804-TM.pdf
Uunderhill,
With the information just supplied by XJR100, I assume you can find the other speaker to make sure they are the same devices. You can then use the schematic you are looking at. The 804 is using all polypro capacitors so I wouldn't change those unless they were a low voltage rating, and even at that depends on the power you are putting into them. The inductor values are on the schematic and I would just make sure they were air core and use a larger gauge wire for lower Dcr resistance. It sure looks like from the exploded view that the speaker can be taken out from the front and just disconnect a set of jumper wires. Then you could make the best crossover for your speakers. That would be an improvement over the existing schematic. But you have to be able to measure the values and there is where I still say someone local could help you.
With the information just supplied by XJR100, I assume you can find the other speaker to make sure they are the same devices. You can then use the schematic you are looking at. The 804 is using all polypro capacitors so I wouldn't change those unless they were a low voltage rating, and even at that depends on the power you are putting into them. The inductor values are on the schematic and I would just make sure they were air core and use a larger gauge wire for lower Dcr resistance. It sure looks like from the exploded view that the speaker can be taken out from the front and just disconnect a set of jumper wires. Then you could make the best crossover for your speakers. That would be an improvement over the existing schematic. But you have to be able to measure the values and there is where I still say someone local could help you.
xjr100 and Kindhornman,
Wonderful - having the service manual, providing the inductor values on the LF board,
makes life a whole lot easier.
Again - the entire LF board inside the N804's can be by passed,
and entirely new one can be built that goes outside of the speakers.
I've checked and certainly the Rdc of various inductors can be considerably lower
than the Rdc in the ferrous bobbin inductors used in the N804's.
Also, when making a new LF board, its important that the 2 inductors "talk" to each other as little as possible
- typically inductors are placed at right angles to help minimize this.
Here is a discussion on Troel's website concerning this
Placement of coils in crossover networks
.
Wonderful - having the service manual, providing the inductor values on the LF board,
makes life a whole lot easier.
Again - the entire LF board inside the N804's can be by passed,
and entirely new one can be built that goes outside of the speakers.
I've checked and certainly the Rdc of various inductors can be considerably lower
than the Rdc in the ferrous bobbin inductors used in the N804's.
Also, when making a new LF board, its important that the 2 inductors "talk" to each other as little as possible
- typically inductors are placed at right angles to help minimize this.
Here is a discussion on Troel's website concerning this
Placement of coils in crossover networks
.
Is the HF crossover board behind the lower or higher LF driver? Did you have trouble re-tighten the screws for mounting the drivers? Thanks.
I know this is an old thread, but has anyone had any experience modifying the crossover network on the N804 to make the tweeter just a little less "hot" or tizzle down a little bit? Currently not in a position to be able to drop $9k on the 804 diamonds, and am trying to see what I can do to modify my existing speaker. I am competent with a soldering iron, and I have an audiophile buddy who is also an EE (he actually just got done creating and building his own tube amp, so he knows his way around how to put this stuff together). I know that different components have different sound characteristics, so it would be best to copy someone who has been down this path before rather than start from scratch and spend a bunch of time experimenting using the trial and error method.
TIA
TIA
I don't think the diamond's would solve your issue anyway. 
You want the "tame" version of Mundorf caps, not the top end. Replace the tweeter caps with Mundorf MKP ($10 each or so)
and replace R1 with Mills 12 Watt.
If that is still too hot, consider changing R1 to 3 Ohms or more. So may be worth ordering both ahead of time.
You want the "tame" version of Mundorf caps, not the top end. Replace the tweeter caps with Mundorf MKP ($10 each or so)
and replace R1 with Mills 12 Watt.
If that is still too hot, consider changing R1 to 3 Ohms or more. So may be worth ordering both ahead of time.
Just did some more research. Apparently the N804 and the 804S has a much different tweeter housing and the shape of the driver and tubes inside are also different, but in my digging I found that the Signature 805 and Signature 800 tweeter is the exact same shape, and size as well as the housing. The signature also used better XO parts as well. The Signature (prestige line) was considered a significant upgrade to the N series and similar in sound (but not exactly) to the S series (some say the Signature was better). The Signature 805 bookshelves still go for a very high premium on the used market. If they worked with my room and my family arrangement, this would probably be the best solution for me (my N804 sell for about the same price, so it would be a straight across "upgrade"). Unfortunately, I don't think they would work in my living situation.
that being the case, wonder what it would take to install the Signature 800 tweeter as well as how to understand what crossover parts to use to kind of mimic the HF crossover in the 800 to make it work with the N804 (since they both use the same/similar FST midrange, you'd think it would be possible, but are the XO points on the mid the same on both applications and if not, how could that be modified to work as well?
that being the case, wonder what it would take to install the Signature 800 tweeter as well as how to understand what crossover parts to use to kind of mimic the HF crossover in the 800 to make it work with the N804 (since they both use the same/similar FST midrange, you'd think it would be possible, but are the XO points on the mid the same on both applications and if not, how could that be modified to work as well?
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