Marantz SR7001 - Enough Power for B&Ws?

[SF_VR6]

I just ordered my Marantz SR7001 (rated 115x7 wpc).

Is this enough power to drive any B&W speakers through the 700 Series?

thoughts?

[corysmith01]

Any of those speakers are going to be fairly effecient at 8 ohms and 88-90dB sensitivity. That Marantz is hefty and should have no trouble driving those. Nice receiver by the way. I had an SR8400, sold it, and have regretted it ever since. :cry:

[SF_VR6]

Any of those speakers are going to be fairly effecient at 8 ohms and 88-90dB sensitivity.

I have no idea what this means but its sounds good!
Having said that, what would be typical specs for a very effecient receiver or a receiver which has poor effeciency?

[Briz vegas]

Corysmith is referring to the efficiency of the speakers.

This is my understanding from a few years in this hobbie

A speaker with 90db efficiency with a nominal impedence of 8 ohms will produce 90db volume when driven by your amp at one watt (yes, just one watt). This is considered to be a relatively efficient speaker. 97db would be very efficient, and 83db is not very efficient at all (relatively). Higher db ratings for speakers can mean they are easier to drive, but this is not the full story.

A speaker may have a nominal impedence of 8 ohms (typical for most speakers these days), but impedence varies with the frequency of the sound (highs, mids, lows) being played. Some speakers impedence varies more than others.

With some B&Ws (703 for example) this can drop to as low as 3 ohms. This is a much more substantial load for you amp to drive and you require a higher current amp to do it well (higher watts RMS generally means more current, but this also varies. A very good high current amp will double its rated power between 8ohms and 4 ohms, ie 100w measured at 8ohms will become 200watts measured at 4 ohms - this is not common but the closer to doubling the better. Few companies provide this information, particularly if their product is not a high current design).

Back to the speakers, the B&W website quotes both the nominal and minimum ohms rating for all their speakers on their web site.


This is probably the useful bit............
My Marantz 7300 OSE is about the equivalent of you new amp and it handled a 705, HTM7 set up fine. I added a power amp for the front 2 channels and a pair of 804s and it sounds great, but take away the power amp and the 7300 OSE does sound a little frail trying to drive 705, HTM7 & 804s.
The 804s impedence drops to 3ohms, meaning it is harder to drive (and I don't go volume crazy with DVDs).

For a movie system the Marantz is pretty much as good as any other receiver out there but if you are considering 703 or similar B&W speaker I recommend saving for a power amp for your 2 front channels.

Have fun with your new system

[pbarach]

For a movie system the Marantz is pretty much as good as any other receiver out there but if you are considering 703 or similar B&W speaker I recommend saving for a power amp for your 2 front channels.

But if you have a powered sub (which most people use for movie systems), then do you really need such a high-current amp, since the most power is needed for the frequencies amplified within the sub?

[hifiguymi]

Just to add to what Briz vegas stated, the effciency is measured at 1 meter from the speaker. As you get farther away from the speaker the number drops.

Eric

[RebelMan]

But if you have a powered sub (which most people use for movie systems), then do you really need such a high-current amp, since the most power is needed for the frequencies amplified within the sub?

Not really but this would largely depend on the choice of bass management settings used to configure the pre/pro and the volume levels you listen to. Distortion creep can occur throughout the audilble band not just at low levels.