B&W Recommended Amplifier Power

[ninja12]

I was looking at the specs of some of B&W Speakers. Some speakers, such as the 803D and 802D, recommends 50W - 500W. What does that really mean? Does it mean I could drive the speakers properly with a 50W amp? Does it mean I really need a 500W amp to really drive the speakers? Driving the speakers with less than a 500W amp mean that the speakers are really under powered? I have never seen a 500W per channel amp. So, I would think someone would need to get a monoblock amp to produce 500W. Anyway, I'm a little confused about what this really means. I would appreciate if you could educate me on this. Thanks in advance for the info.

[Horacio]

To me it doesn't mean much. It's kinda sorta guidance...

An underpowered amp might be easily driven into clipping, putting your tweeters in danger first. However, that's only a piece of the puzzle.

800-series like power, especially 803D / 802D and up. A huge power amp usually is preferred.

Having said that, I have 804S, which are rated 50-250W and used to drive them with a 200W Rotel amp. It was OK, but then changed to a McIntosh MC275, which is 2x75W but tubed, and it sounds a lot better than the Rotel.

Then of course there are Watts and Watts. While the unit of measure is the same, what one manufacturer calls a 200W amp might be a 100W amp by another manufacturer.

So I suggest you check what others usually like with the speakers you are considering, like McIntosh, Classe, Levinson, Rowland, and how much power these are, and then try to listen for yourself.

My 2 cents. Hope it helps!

Cheers,
Horacio

[ninja12]

Horacio, thanks for your response.

I have heard a lot of people say they have been using McIntosh MC205, some use Classe 5200, and many using McIntosh MC501. I would think with a high sensitivity of 90db, it wouldn't take much power to drive the speakers given their efficiency. One poster said they heard the 802Ds with the Anthem P5 and the sound was amazing. His only response was WOW. Anyway, once again, thanks for responding.

[indiebands]

To me it doesn't mean much. It's kinda sorta guidance...

An underpowered amp might be easily driven into clipping, putting your tweeters in danger first. However, that's only a piece of the puzzle.

800-series like power, especially 803D / 802D and up. A huge power amp usually is preferred.

Having said that, I have 804S, which are rated 50-250W and used to drive them with a 200W Rotel amp. It was OK, but then changed to a McIntosh MC275, which is 2x75W but tubed, and it sounds a lot better than the Rotel.

Then of course there are Watts and Watts. While the unit of measure is the same, what one manufacturer calls a 200W amp might be a 100W amp by another manufacturer.

So I suggest you check what others usually like with the speakers you are considering, like McIntosh, Classe, Levinson, Rowland, and how much power these are, and then try to listen for yourself.

My 2 cents. Hope it helps!

Cheers,
Horacio

Hi Horacio,

When you say watts and watts- how would one determine whether the amp is really 100w or 200w if the manufacturer claims are so wildly off?

Thanks.

[Horacio]

ninja: take the math as a starting point. You are right, when you look at the efficiency it would seem you don't need a lot of power. And you would also conclude that say for a 100 dB volume level (loud) you might be using 100W, therefore a 200 or 400 or 500W amp would sound the same. WRONG! People who have tried this report the sound improves. Some say is because of headroom. To me it doesn't matter much why. The point is it usually does improve.
For 802D I wouldn't buy anything smaller than the MC402 in the McIntosh line. You can drive it with MC275, MC252, MC205, etc, but to me it doesn't make a lot of sense. Try tolisten to them.
Can't comment much on other brands except people in general like the ones mentioned in my previous post. I did listen to Classe when I was buying an amp, but it wasn't matched with 802D nor 803D.

Cheers,
Horacio

[Horacio]

Indiebands,

Here's a nice answer I'd like to see posted more often: I don't know.

However, let me elaborate some thoughts to try help you make up your mind.
It is clear the definition of a Watt is a given, and all use the same definition.
Some use the peak instantaneous current their amp can deliver and so you end up with those mass market mini components than weight nothing and claim 500W...
Within serious audio manufacturers there seems to be different approaches too. Say an amp can deliver 200W and starts clipping at 200. It is indeed a 200W amp, but before reaching 200 you can start hearing distortion probably coming from transient passages where the amp is required to deliver more current. So maybe you can't really run that amp above 100W if you want to allow for enough headroom so when such a transient comes it doesn't clip. Maybe other manufacturers are taking that approach to rating their amps.

The above pertains especially for solid state amps. Tube amps clip in a "nicer" way, but I guess (I am guessing!) the same is true for manufacturers. I'm not at all familiar with class D amps.

I hope this helps!
Horacio

[SoundEngine355]

Having owned the 803D, they need a minimum of 150W/8ohm and go up from there, don't buy into huge power, it depends on what volume you listen to music or movies at.

I would go middle ground, 200-250W is great.

I ran the 803D's on the Arcam FMJ P7 which is 7x150W/8ohm, sounds fanastic.

[Mark-n-b]

I think of amplifier power output something like car engines - you can have all the horsepower in the world, but you also need lots of torque. In an amp a great indication of this torque is its power output as the ohms half. For example, if an amp is rated at 250w at 8Ω, then the closer to 500w at 4Ω the better. This is a good indicator that the amp will have the muscle to hold a tight grip on all those demanding drivers.

[DM3000 Owner]

I think of amplifier power output something like car engines - you can have all the horsepower in the world, but you also need lots of torque. In an amp a great indication of this torque is its power output as the ohms half. For example, if an amp is rated at 250w at 8Ω, then the closer to 500w at 4Ω the better. This is a good indicator that the amp will have the muscle to hold a tight grip on all those demanding drivers.

While true in theory, don't beieve specs on this. Check ut the Stereophile tests and you will see that amps don't really double as they go down. Most manufacturers under rate the amp at 8 ohms so that it can "double" into four ohms. My amps are rated at 350/700 but test at more than 350 at 8 ohms.

[mjb]

Anyway, I'm a little confused about what this really means. I would appreciate if you could educate me on this.

It means nothing, as there are just far too many variables. It is intended as a guide: ie, smaller than a 50 watt amp will not do them justice, anything much larger than a 500 watt amp and you risk breaking something.

[wettou]

I think of amplifier power output something like car engines - you can have all the horsepower in the world, but you also need lots of torque. In an amp a great indication of this torque is its power output as the ohms half. For example, if an amp is rated at 250w at 8Ω, then the closer to 500w at 4Ω the better. This is a good indicator that the amp will have the muscle to hold a tight grip on all those demanding drivers.

Yes, in addition remember watts are on a logarithmic scale. and you need twice the power for 3db increase.

[emig5m]

I always like getting as much power as I can afford. You're always better off with more clean power than something that might clip and cause damage. I ran my little 685's as front mains just to see how they do and sound as mains and I'm running a Emotiva XPA-5 power amp which when running 2 channels - 8 ohm = 275 watts per channel and the little 685's didn't sweat.

[pixeljedi]

I ran my little 685's as front mains just to see how they do and sound as mains and I'm running a Emotiva XPA-5 power amp which when running 2 channels - 8 ohm = 275 watts per channel and the little 685's didn't sweat.

That's awesome man, and that says alot, considering the specs on the 685s:
25W - 100W into 8Ω on unclipped programme

[indiebands]

Indiebands,

Here's a nice answer I'd like to see posted more often: I don't know.

However, let me elaborate some thoughts to try help you make up your mind.
It is clear the definition of a Watt is a given, and all use the same definition.
Some use the peak instantaneous current their amp can deliver and so you end up with those mass market mini components than weight nothing and claim 500W...
Within serious audio manufacturers there seems to be different approaches too. Say an amp can deliver 200W and starts clipping at 200. It is indeed a 200W amp, but before reaching 200 you can start hearing distortion probably coming from transient passages where the amp is required to deliver more current. So maybe you can't really run that amp above 100W if you want to allow for enough headroom so when such a transient comes it doesn't clip. Maybe other manufacturers are taking that approach to rating their amps.

The above pertains especially for solid state amps. Tube amps clip in a "nicer" way, but I guess (I am guessing!) the same is true for manufacturers. I'm not at all familiar with class D amps.

I hope this helps!
Horacio

Thanks much. Helpful answer and thread.
Cheers!

[wettou]

Has any one listened to Emotiva XP-1 with B&W802D?

[ninja12]

Has anyone heard the 802Ds driven by Anthem's P5 or P2 amp? Also, do you think the P5 or P2 is capable of really driving the 802Ds?

[lvhung]

Stay away the Anthem they are very bad in sound quality

If you can find 2 or 3 Rotel 1090 to drive the B&W

[Horacio]

Stay away the Anthem they are very bad in sound quality

If you can find 2 or 3 Rotel 1090 to drive the B&W

I have to respectfully disagree. I recommend you do not get Rotel for 802D. In my book that is a NO WAY! I had Rotel 1080 with my 804S and needed to upgrade the amp as the speaker was too revealing for the amp. A great amp for the price, don't get me wrong, but not in the same league as these speakers.

I know the 1090 is said to be significantly better than the 1080. However, I seriously doubt that improvement is enough for them to be a good match with 802D (which is a great, demanding, and very revealing speaker).

My point of view, of course. I do not pressume to have THE answer; just my opinions.

Horacio

[lvhung]

At the price point under 2k Rotel and Audio Refinement amps is very good
Above 2k I may not have enough experience !!

Although I might never buy big speakers in my life
which requires a massive power amplifiers which is not cheap at all
There are a lot good small speakers on the market !

[MikeFL52]

Stay away the Anthem they are very bad in sound quality

And just where do you get this iniformation that Anthem are bad sound quality?? :M

I run 803Ds with the Anthem D1/P5 combination and I take exception with your comment. I have had many people come into my home and they are very impressed by the quality and presence of the sound.

Now everyone is entitled to an opinion, but do not make the statement that Anthem are very bad in sound quality as it is just simply not true.

[lvhung]

I owned Anthem AVM 20 paired with Rotel 1095
When I replaced my Anthem with Proceed AVP2+6 and Audio refinement pre2, all that changed, I now have more lively sound in stereo and movies both
Do yourself a favour and find one of the above two which I am sure will knock out the Anthem D1 in every aspects
Anthem D1 and D2 uses the AKM 4395 DAC but it can extract out very little details
Anthem processor is for movie not for music that is true and I never want to offend anyone here
In audio market, more expensive does not mean higher quality

[lvhung]

truth is sometimes bitter

[MikeFL52]

I owned Anthem AVM 20 paired with Rotel 1095
When I replaced my Anthem with Proceed AVP2+6 and Audio refinement pre2, all that changed, I now have more lively sound in stereo and movies both
Do yourself a favour and find one of the above two which I am sure will knock out the Anthem D1 in every aspects
Anthem D1 and D2 uses the AKM 4395 DAC but it can extract out very little details
Anthem processor is for movie not for music that is true and I never want to offend anyone here
In audio market, more expensive does not mean higher quality

I am going to postulate that you really do not know what you are talkiing about.

There have been many reviews singing the praises of Anthem equipment especially the D1, D2 and now D2V along with the P5 & P2. The one thing that they talk about is the level of detail and low backgraound noise thereby giving it an excellent S/N ratio.

I have listened to Rotel equipment and from my own personal experience would not replace my stuff with it.

To the OP for this thread, my apologies, you can obviously see the different views on this topic. You are going to have to decide for yourself what are meaningful opinions and what is absolute rubbish.

[Relentless]

Has anyone heard the 802Ds driven by Anthem's P5 or P2 amp? Also, do you think the P5 or P2 is capable of really driving the 802Ds?

I ran my 802D's with a P2 for a while and it is surely cappable of driving them but found it to be thin in the midrange. I preferred the Bryston 4BSST over it. The Bryston had better bass and was fuller in the midrange. The highs where close. I like Krell over them both. Krell Evo had the better bass attack and decay and smoother midrange with more detail and cleaner highs. Now these are the findings I experienced in my system, my CDP and Processor and power re-generator and cables.... your mileage may very.

[ninja12]

I would like to thank everyone for their responses. I am really interested in how the P2 would drive the 802Ds because I have the P2 driving my 803S and the P5 driving my remaining 5 speakers. I do know that the P2/P5 are a monster and definitely brought my system to a whole new level. The P2/P5 combo replaced my Rotel 1080/1095 combo. Rotel did ok; but, they are definitely not in the same league with the P2/P5. I can't comment on the new Rotel amps because I have not heard them.

[lvhung]

Sorry we are not in the same way to the end of the games :T

I am going to postulate that you really do not know what you are talkiing about.

There have been many reviews singing the praises of Anthem equipment especially the D1, D2 and now D2V along with the P5 & P2. The one thing that they talk about is the level of detail and low backgraound noise thereby giving it an excellent S/N ratio.

I have listened to Rotel equipment and from my own personal experience would not replace my stuff with it.

To the OP for this thread, my apologies, you can obviously see the different views on this topic. You are going to have to decide for yourself what are meaningful opinions and what is absolute rubbish.