N802's: 4 ohms or 8 ohms? - B&W's recommendation

[McGlentosh]

I've read so much info and advice regarding which taps to use when connecting B&W N802's, in this and other forums, that my head was spinning, so I e-mailed B&W to get their recommendation, as follows:

"I am powering, via bi-wiring, my N802's with a McIntosh MC352 amp. The
speaker manual says the 802's impedance is 8 ohms nominal (3.5 ohms
minimal). McIntosh recommends attaching the 802's to the 4 ohm taps on the
amp. What do you recommend, and why?"

And this was their reply:

"Thank you for purchasing B&W! We specify the Nautilus 802s as a nominal 8
ohm impedance loudspeaker, and do recommend that you connect the speakers to the 8 ohm taps for best performance. In the past, consumers with this same scenario have advised upon listening to the speakers using both taps, that the 8 ohm taps do perform better with their N802s.

Best Regards,
Michael Sheehan
B&W / Rotel

Comments?

 

[ron-c]

You can use either one but I would use the 4 ohm taps if they were mine.

Ron-C

 

[mike175gr]

The B&W guy and I have the exact same name, but I would agree with Ron!

 

[qb_1]

Nominally they may be 8 Ohm, but impedance minimum is about 3.6 (I am not sure) and in lower registers they are around 4 ohm. Since most of the power will be demanded to drive woofers I would uggest using 4 ohm taps too.

 

[ron-c]

As long as the MC352 does not get hot and thermally shut down or the speakers are not damaged it is OK to use the 8 Ohm taps.
If the above occurs simply switch over to the 8 ohm from 4 ohm taps.

Ron-C

 

[McGlentosh]

I did try 8 ohm vs. 4 ohms, and I preferred the sound at 8 ohms. The first thing I noticed was a drop in the levels at 4 ohms, so I jacked up the volume via setup on my MX135 to equal the 8 ohm level (80db), using a sound pressure meter. So the quantity of sound wasn't the issue; it was the quality.

At the 8 ohm taps, there was a more open and dynamic character to the sound, with a bigger stage. By contrast, the 4 ohm tap sound was more solid and relaxed in presentation. Although I prefer the sound at the 8 ohm taps, lately I find myself doubting my own ears. Am I the only one who feels this way or hears the difference? There seems to be an overwhelming preference for the 4 ohm taps by those who respond to this forum, so maybe that "relaxed, in-the-box" sound is the way the N802's are supposed to sound.

I guess the bigger question is, WHY is there a sound difference, technically, and which sound is "right"?

 

[Privateer]

There seems to be an overwhelming preference for the 4 ohm taps by those who respond to this forum, so maybe that "relaxed, in-the-box" sound is the way the N802's are supposed to sound.

Just use whatever taps sound right to you.

 

[goldear]

I've used tube amps for many years. When I get a new amp or speaker I intially always hook it up to the 8 ohm tap first. However, I frequently find that in many cases this simply doesn't sound right. If the sound is not up to my expectations when using the 8 ohm tap, then I will try the others. I have found that about 50% of the time, the 8 ohm tap is not the best sounding connection for a given speaker/amp combintation.

So I agree with the guy who said to just use whichever connection sounds best to you. :thmbsp:

 

[Puunda]

I did try 8 ohm vs. 4 ohms, and I preferred the sound at 8 ohms. The first thing I noticed was a drop in the levels at 4 ohms, so I jacked up the volume via setup on my MX135 to equal the 8 ohm level (80db), using a sound pressure meter. So the quantity of sound wasn't the issue; it was the quality.

At the 8 ohm taps, there was a more open and dynamic character to the sound, with a bigger stage. By contrast, the 4 ohm tap sound was more solid and relaxed in presentation. Although I prefer the sound at the 8 ohm taps, lately I find myself doubting my own ears. Am I the only one who feels this way or hears the difference? There seems to be an overwhelming preference for the 4 ohm taps by those who respond to this forum, so maybe that "relaxed, in-the-box" sound is the way the N802's are supposed to sound.

I guess the bigger question is, WHY is there a sound difference, technically, and which sound is "right"?

My understanding is when you do test, whatever they might be, the one which is louder will usually sound better. Even by 0.5 or 1dB. And it's usally not put down to loudness, it's put down to dynamics, bigger sound stage, smoother, and whatever else audiphiles use to describe the sound.

Another point is that with my 802 Matrix S3, I have found 3 different brochues/manual for it. 2 says 8 ohms, 1 says 4 ohms, 2 say they're 200mm woofers, 1 says they're 180mm woofers.

 

[goldear]

My understanding is when you do test, whatever they might be, the one which is louder will usually sound better. Even by 0.5 or 1dB. And it's usally not put down to loudness, it's put down to dynamics, bigger sound stage, smoother, and whatever else audiphiles use to describe the sound.

Another point is that with my 802 Matrix S3, I have found 3 different brochues/manual for it. 2 says 8 ohms, 1 says 4 ohms, 2 say they're 200mm woofers, 1 says they're 180mm woofers.

When doing A/B comparisons you are right; louder will almost always sound better. But when your are not doing A/B comparisons (as he was not), the volume levels are not nearly as crucial. Besides, I would hazzard a bet that he was compensating by cranking up the gain slighlty anyway.

Speaker's impedances vary widely as a function of frequency. A nominal impecance is just an average of an impedance curve than can go as low as two ohms, to as high as 40 as various frequencies. Often times this average value does not present the optimal impedance match within a large part of the range of frequencies. So it is not uncommon to find that a different tap sometimes will actually work better for a given speaker, simply because a large part of its impedance curve will be a closer match with a different tap.

 

[hassel]

I do have Shahinian Diapason speakers, which have a nominal impedance of 6 ohms. From McIntosh, and from the manual, I got the recommendation to connect them to the 4-ohm-tap of my MC402. The 8-ohm-tap, however, sounded better in every regard - dynamics, slam, bass definition - so I stayed with it. The observation that the 8-ohm-tap sounds better most of the time - even when speakers with a nominallly lower impedance are used - is shared, for example, by Joachim Pfeiffer, editor of German Audio magazine, who has reviewed and owned quite a few Mc-amps over the years.

 

[mc402]

I have an MC402 with B&W 803-S' (newer version of 803B's i believe). I read some on this forum about what taps to use with Biwiring so contacted B&W and had a reply from a Friday email on the following Monday. They suggested 8 ohms regardless of minimum impedance. I know this is a different model but the bottom line is contact B&W for their suggestion. They seem to be good on turnaround for the two questions I had.

 

[kevingnet]

Ok, sorry, this is an ancient thread, but I wanted to share my experience.

B&W 803 s3 <- ST70 <- PAS3 <- MyTek_Brooklyn <- PC_flac

@8 ohms, was loving the sound, though if I upped the volume high enough (not really loud though, about 3 notches, or 8:30) I would hear some nasty bass distortion, I was ok with it, just had to chill on the volume.

@4 ohms, gosh darn it!!! what a difference, I can now listen to high volume, better stage, everything opened up, better sound. What a pleasant surprise, all of a sudden sex became less important, (or maybe I'm getting old...) lol

 

[twiiii]

Because the Quad amps have a higher current output capability they handle varying impedances better than the older amps of the 2000 series. Starting with the 7000 series amps had a higher current capability was inaugurated, So A 7300 will put out close to 900 watts from the 8 ohm tap across 2 ohms. This applies to the 352 also so I would use the 8ohm tap as you will loose at least 3 db in over all out put capability using the 4 ohm tap. The 4 ohm tap givues better woofer control because of the lower internal generating impedance of the amp equaling a higher damping factor. A 352 should put out way over 400 watts if up to snuff so either way that should be enough power cross 8 ohms. Using the 4 ohm driving the higher impedance mis match will lower the volume but 200 to 250 watts across the higher impedances of the speaker midrange and tweeters still ought to be plenty.

This is why I prefer the Mac direct couple amps with out autoformers. Hook up the speakers and go. Just make sure the amps are properly ventilated. MY MC 830's put out more than 600 watts across my 4 ohm XRT 28's. I can peg the meters for over a second before the power guard lights begin to flicker. The amps are rated at 480 watts across 4 ohms.