Any modifications to older N800 series?

[rodH]

I am currently using the original N804 speakers. I know the easy answer to this question for many on these boards it to always just buy new ones. But sometimes there is a faction of DIYers and tweakers on forums that know how to make a good thing even better.

Anyway, since I can't justify selling my speakers for a couple Gs and buying new ones for $9k, is there any links to people out there that have smoothed out the tweeter just a little on the N804. I use to love it and never understood why some people thought it was too bright. But I have been messing with my system lately and there are times when it seems a little harsh and most of the time I am fine with it (ironically, when I listen to high quality recordings done on FLAC, SACD, DVD-A or Vinyl is when I am fine with the tweeters. And when I listen to more alternative rock, rock, or some other music, I don't like it as much, and I am assuming that a lot of that has to do with the poor recording).

At any rate, it would be cool if one could a few hundred bucks to throw a diamond tweeter on an existing older N800 or 800S series speaker. I am sure I am not the only one who has thought of that, and if it were possible, it would be the thing for a lot of people to do. Is there any other modifications that people have done to change the characteristic a bit without losing that fine detail at the upper end? (resistors or modifying crossovers?)

(Also, as I was typing this I just realized that I recently replaced one of my tweeters because my daughter thought it would be fun to try a summersalt in the room and broke the tweeter and housing, and I am sure that tweeter is not "broken in" just yet, so this might be a little bit of my issue with regards to a recent change in sound)

I do have a McIntosh pre-pro, I guess I could turn the treble down 1-2 db, but normally I don't like to mess with any type of EQ settings as I think it may not sound as "clear" or change the way the recording was supposed to sound.

TIA

currently using:
McIntosh MX132 Pre-Pro
McIntosh MC150 amp (mains)
Mcintosh MC7205 amp (center and surrounds)
B&W N804 Mains
B&W HTM2 Center

[Art Vandelay]

Originally Posted by rodH

Anyway, since I can't justify selling my speakers for a couple Gs and buying new ones for $9k, is there any links to people out there that have smoothed out the tweeter just a little on the N804. I use to love it and never understood why some people thought it was too bright.

TIA

currently using:
McIntosh MX132 Pre-Pro
McIntosh MC150 amp (mains)
Mcintosh MC7205 amp (center and surrounds)
B&W N804 Mains
B&W HTM2 Center

Hi Rod,

Given the high cost of diamond tweeters I wouldn't be inclined to attempt that level of upgrade, but a good compromise might be to replace the tweeter with the upgraded signature 800 version, which is a really outstanding tweeter.

However, before you go down that path it might be simplest to modify the series resistor on the crossover pcb.

R1 is stated in the schematic as a 2.2 ohm 11w ceramic WW resistor, so it might be worth trying 3.3 ohm, and at the same time upgrading the resistor to a non-inductive film type.

Ftr, 3.3 ohms will attenuate by 1dB.

[rodH]

Originally Posted by Art Vandelay

Hi Rod,

Given the high cost of diamond tweeters I wouldn't be inclined to attempt that level of upgrade, but a good compromise might be to replace the tweeter with the upgraded signature 800 version, which is a really outstanding tweeter.

However, before you go down that path it might be simplest to modify the series resistor on the crossover pcb.

R1 is stated in the schematic as a 2.2 ohm 11w ceramic WW resistor, so it might be worth trying 3.3 ohm, and at the same time upgrading the resistor to a non-inductive film type.

Ftr, 3.3 ohms will attenuate by 1dB.

Interesting. I wonder if anyone has done this with the resistor and what the results were.

I totally forgot the Signature lineup. Has anyone else done this upgrade? I can't remember what the difference was supposed to be as far as sound characteristics and dynamics with the tweeter. Anyone know? Also wonder if this would require the replacement of the complete tweeter and housing or just the tweeter using the existing housing? Are the crossover points the same so this would be a direct upgrade/replacement?

TIA

[Art Vandelay]

Originally Posted by rodH

Interesting. I wonder if anyone has done this with the resistor and what the results were.

I totally forgot the Signature lineup. Has anyone else done this upgrade? I can't remember what the difference was supposed to be as far as sound characteristics and dynamics with the tweeter. Anyone know? Also wonder if this would require the replacement of the complete tweeter and housing or just the tweeter using the existing housing? Are the crossover points the same so this would be a direct upgrade/replacement?

TIA

The signature tweeter was an improved version of the nautilus tweeter, with lower distortion and the first break-up point is moved up to 31kHz.

My guess is that you'll need to use the same (N804) tweeter housing, because the crossover values are not the same as the 800 / 802 etc, and thus the absolute phase at the crossover point necessitates a specific time alignment of the tweeter in order to achieve phase alignment with the FST mid at the crossover frequency.

Fwiw, there are a couple of people I know of who have added resistors in series with the tweeters in the 800 Diamond series to pad the treble by a db and they are very happy with the outcome.

[rodH]

Originally Posted by Art Vandelay

The signature tweeter was an improved version of the nautilus tweeter, with lower distortion and the first break-up point is moved up to 31kHz.

My guess is that you'll need to use the same (N804) tweeter housing, because the crossover values are not the same as the 800 / 802 etc, and thus the absolute phase at the crossover point necessitates a specific time alignment of the tweeter in order to achieve phase alignment with the FST mid at the crossover frequency. .

So could I just install the tweeter in the housing and be good? It is only about $165 per tweeter. After doing some research it appears the S tweeter is much preferred since it is a slightly softer sound. Is the crossover the same in both of them?

Any idea where I can learn more about the crossovers that are used and at which frequencies, etc?

[rodH]

btw, Art. Thank you for sharing your knowledge, I am limited to what I know and kind of thought it would be easier to find info on this modification stuff since we see so many people building their own speakers, subwoofers, amps, etc.... But the information is very sparce in my extensive searching.

[Art Vandelay]

Originally Posted by rodH

So could I just install the tweeter in the housing and be good? It is only about $165 per tweeter. After doing some research it appears the S tweeter is much preferred since it is a slightly softer sound. Is the crossover the same in both of them?

Any idea where I can learn more about the crossovers that are used and at which frequencies, etc?

You should be right to install the Sig tweeter into the N housing. The M-T crossover frequency is basically the same for all 800 series post Nautilus series but values are slightly different between models with a marlan head Vs those without.

The only issue might be a slight difference in sensitivity, which might necessitate a change to the R1 resistor value on the crossover board, but that's a relatively easy thing to do.

In answer to the last question, loudspeaker crossover design is often more complex that it appears on face value and can be as much an art as a feat of engineering, ultimately determined by a few sets of golden ears.


If you want to look at B&W schematics, try this link ...http://bwgroupsupport.com/manuals/service

[rodH]

Originally Posted by Art Vandelay

You should be right to install the Sig tweeter into the N housing. The M-T crossover frequency is basically the same for all 800 series post Nautilus series but values are slightly different between models with a marlan head Vs those without.

The only issue might be a slight difference in sensitivity, which might necessitate a change to the R1 resistor value on the crossover board, but that's a relatively easy thing to do.

In answer to the last question, loudspeaker crossover design is often more complex that it appears on face value and can be as much an art as a feat of engineering, ultimately determined by a few sets of golden ears.


If you want to look at B&W schematics, try this link ...http://bwgroupsupport.com/manuals/service

Dang, looking at the diagrams, it looks like they are different shape/design than the S enclosure and the whole tweeter enclosure appears totally different. I guess it all else fails, I could just purchase the complete tweeter with housing and make sure I figure out a way to mount it in the exact same position. But it would be nice if just the driver was a direct replacement/fit.

Interesting that you mention the R1 resistor. Some of the limited info out there suggests that the R and possibly others are less than ideal for that particular tweeter, causing it to be overly bright and even grainy. It does sound like it is a bit of an "art" as you say, and it doesn't sound like every resistor, even if using the same values, is going to have the same sound signature. Here is what someone else mentioned on a different forum to help this "issue"..

"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"

sure wish I knew more about this stuff and there was an obvious tried and tested "fix" that has been well documented.

[Art Vandelay]

Originally Posted by rodH

Dang, looking at the diagrams, it looks like they are different shape/design than the S enclosure and the whole tweeter enclosure appears totally different..

Are you comparing the N804 with the sig800?

I'm 99.9% sure that the tweeter assemblies are interchangeable.

It should be as simple as replacing 'A3578' with 'A4907' but if in doubt I'm sure that a BW service support tech would be able to verify it.

[rodH]

Originally Posted by Art Vandelay

Are you comparing the N804 with the sig800?

I'm 99.9% sure that the tweeter assemblies are interchangeable.

It should be as simple as replacing 'A3578' with 'A4907' but if in doubt I'm sure that a BW service support tech would be able to verify it.

It appears we must have been talking about 2 different things. I was talking about the tweeter from the 804s (which dose appear to be a direct replacement based on the shape of the inside) on the N804. I just looked at thrndetsils on the service manual and it appears that the 800 signature IS the exact same shape and should be a direct replacement.

Ok, now that we are on the same page, does the 800 signature (prestige line) have a better tweeter that is slightly smoother and less harsh than the N804? My guess is yes. I don't remember all the details back then but I seem to remember that the signature line was much more money, only came in the 800 and 805 and used some really nice alternative finishes. Slightly better drivers and maybe even Xover.