Marantz PM14 SE and Bowers & Wilkins 702 S2

[Mpho]

I have the Marantz TT15 S1 turntable and the SA15 SACD player.

I came to a conclusion to purchase the Bowers and Wilkins 702 floorstands in three months time. I just wanted to find out if anyone has ever tried the above mentioned speakers with the Marantz PM14 S1 Intergrated amplifier.

Will the amp be able to push the 702s?

I am a huge Marantz fan and I doesn't look like they still manufacture stereo pre-amps any more, hence I have opted for the integrated amp. However it doesn't look like the integrated amp has enough power (my thinking) for the 702s.

If the power is not enough as I think, do you think I should add the Rotel RB1582 or RB1590 power amp and use the integrated amp as a pre-amp? Please help!

 

[PENG]

If the power is not enough as I think, do you think I should add the Rotel RB1582 or RB1590 power amp and use the integrated amp as a pre-amp? Please help!

B&W recommended 300 W maximum so you can definitely add a RB1590, but how much power you need depends on your required spl at you sitting distance. So your integrated amp may have more than enough power, or it may in fact need help.

If you want to make an informed decision, you should figure out how much power you really need, based on 4 ohm nominal impedance (B&W says 8 ohm nominal but nobody believes that..), at your favorite listening position. Once you figure that out, get an amp with rated output 2 to 4X of what you need just to be on the safe side. If you just want to have the power on hand whether you need it or not, then get the RB1590.

http://myhometheater.homestead.com/splcalculator.html

 

[Bookmark]

Mimimum impedence for the B&W 702 S2 is 3.1 Ohms. So a good amp capable of sub 4 Ohms loads is all you will likely need to drive these speakers well. The sensitivity is 90 so should go loud easily in a normal sized room, but the triple 6.5" mid/bass drivers will be the cause of it sounding weak if it cannot handle the load. B&W do not specify the crossover but likely in the 100s of Hz.

The Marantz PM14 S! is able to do 90 Watts @ 8 Ohms and 140w @ 4 Ohms according to the specs. The Rotel RB-1582 MkII is 200 Watts per channel, load not specified, but assuming 8 Ohms it does specify a minimum of 4 Ohms (ie not below). Putting more watts in an amp will not make it better if it cannot handle the load properly.

The difference between the two amplifiers mentioned is 3dB SPL at around 12' with both over 100 dB SPL max and being "uncomfortable loud". My Nad @ 175 Wpc comes between the two regarding max SPL but it does handle 2 Ohm loads. I have no problem making reference @ -30dB and anything closer to 0 will just annoy yet more neighbours.

 

[KenM10759]

Curious to know which NAD amp is 175 watts per channel.

Bookmark is spot-on with watts and loudness. It takes enormous power increases to get relatively small bumps in SPL, so know what is needed at the listening position before shopping.

 

[PENG]

Any of the amps mentioned can handle 3 and 4 ohm loads, it really depends on one's need. I wish magazine reviewers would emphasize the "need" as much as they do on the low impedance drive capability.

Take for instance, the NAD C375BEE is rated:
- 150 W into 8 and 4 ohms at <0.009%
- 410 W into 4 ohms IHF dynamic power (Yamaha does something similar)

Note that NAD typically rated their integrated amps (the C series) same for 8 and 4 ohm loads in the past, and they provide IHF dynamic power rating only, for the lower impedance values of 4 and 2 ohms.

If we go by current being the limiting factor, as it usually is, for most solid state class A and AB amplifiers, then the NAD C375BEE can in theory be rated for 75 W and 37.5 W correspondingly for 4 and 2 ohm loads. Obviously, depending on the time duration, it should be able to do significantly more than 150 W into 4 ohms, and obviously 410 W as specified in terms of IHF dynamic power, that is, for short duration, such as 20 milliseconds (Yamaha's example).

So if we apply the same logic to the Rotel 1590, that is rated 350 W into 8 ohm, then it is safe to assume it can be rated 175 W into 4 ohm, continuously (not sure how Rotel defines "continuous").

Again, any of those amps could have been rated for 4 or even 2 ohm load if the manufacturer chooses to, but they don't always do that, for the obviously reasons. NAD's reason could be because they believe dynamic power rating is more meaningful. I agree with that philosophy, but I don't agree with the milliseconds sort of dynamic power, it is just too short (in some cases) for real world applications. For dynamic ratings to be more meaningful even if for uncompressed music only, such as jazz and classical, I would like to see standards that call for duration in the order of seconds (a couple of minutes would be great..), not milliseconds.

 

[Bookmark]

Sorry, just using my M27 as a reference point not a solution. It's a 7 channel amp so not really apple v apples, since we are talking about stereo. The M22 might be a closer approximation. Both are however more expensive options than previous listed for the Rotel and cheaper alternatives are available. In either case the figure was for RMS not the Peak. The dynamic figure is 320 W @8, 700W @ 4. Additionally they are Class D and not AB like the Marantz and the Rotel.

https://www.stereophile.com/content/nad-masters-series-m22-power-amplifier

 

[Bookmark]

Not all amps are created equal, some are more equal than others.

 

[KenM10759]

Not all amps are created equal, some are more equal than others.

And that can be especially true with many NAD amplification products. I'm often shocked. My cousin got an NAD C356BEE to run her Totem Sttaf speakers, and she was shocked at both, how the speakers would come alive with a 1/4 turn of the amp's volume knob, but also how easily it could push the speakers to soaring.

 

[killdozzer]

my M27

Wah wah wee wah...

 

[Bookmark]

Borat? Hard to tell if that's a compliment or disparagement

When two or more people agree on an issue, I form on the other side

 

[sterling shoote]

Just get an amp which produces the power the speaker manufacturer recommends.

 

[killdozzer]

Borat? Hard to tell if that's a compliment or disparagement

When two or more people agree on an issue, I form on the other side

I'm glad you found it useful. I also believe it sums it up nicely.

I wrote it as a combination of “lucky you” and “I wanna”.

My father had a beast of a NAD. One of the early THX preamp+amp combos. It lasts forever.

 

[KenM10759]

It didn't seem to translate well. Thanks for clarifying.

 

[PENG]

And that can be especially true with many NAD amplification products. I'm often shocked. My cousin got an NAD C356BEE to run her Totem Sttaf speakers, and she was shocked at both, how the speakers would come alive with a 1/4 turn of the amp's volume knob, but also how easily it could push the speakers to soaring.

Ken, you can't go by the volume knob position. Different amps have different gain structures. Bench tests after bench tests show NAD amps are honest about their output specs, but their AVRs, even some integrated, did not measure better than Denon and Marantz (just examples) in two channel driven outputs, usually worse in terms of THD. I like their products too, and own one, but not because they are more powerful relatively speaker, and will never pay premium for any of them.

 

[KenM10759]

Of course I'm aware of that.

 

[PENG]

Of course I'm aware of that.

I thought so, as that has been pointed out many times on this forum. Just to be clear, I do like NAD and Yamaha's emphasis on the merit of dynamic power. I just wish they could do better on the so called "continuous" especially into 4 ohms as well. S&V don't measure the super short term IHF dynamic power, so my only reference on NAD and Yamaha's IHF DP bench performance is AVtech's, that's unfortunately very limited, and old.

 

[KenM10759]

I thought so, as that has been pointed out many times on this forum. Just to be clear, I do like NAD and Yamaha's emphasis on the merit of dynamic power. I just wish they could do better on the so called "continuous" especially into 4 ohms as well. S&V don't measure the super short term IHF dynamic power, so my only reference on NAD and Yamaha's IHF DP bench performance is AVtech's, that's unfortunately very limited, and old.

The manual for my NAD T758 states "true power" of 60 watts per channel @ 8Ω with all channels driven, and "110 watts per channel (8Ω for two channels within rated distortion.)" Just below that 110 figure it reads "IHF dynamic power; 8 ohms = 137w." but also gives just below that "IHF dynamic power; 4 ohms = 243w."

Here's a bench test of the T758v3:

https://www.soundandvision.com/content/nad-t758-v3-av-receiver-review-test-bench

Given their manual's distortion rating of "<0.08%", I'd say they're being about as honest as we could hope for and certainly better than many who sell a LOT more AVR's. I see what you maen about them not measuring the transient peak performance, though I think you can infer quite a bit by NAD's honesty on what is measured. I can only go by my own ears experience when I say it goes really loud for short bursts when I need it to do that.

 

[PENG]

The manual for my NAD T758 states "true power" of 60 watts per channel @ 8Ω with all channels driven, and "110 watts per channel (8Ω for two channels within rated distortion.)" Just below that 110 figure it reads "IHF dynamic power; 8 ohms = 137w." but also gives just below that "IHF dynamic power; 4 ohms = 243w."

Here's a bench test of the T758v3:

https://www.soundandvision.com/content/nad-t758-v3-av-receiver-review-test-bench

Given their manual's distortion rating of "<0.08%", I'd say they're being about as honest as we could hope for and certainly better than many who sell a LOT more AVR's. I see what you maen about them not measuring the transient peak performance, though I think you can infer quite a bit by NAD's honesty on what is measured. I can only go by my own ears experience when I say it goes really loud for short bursts when I need it to do that.

I have compiled a list of 63 AVRs including the T758. When sorted by 2 channel driven into 4 ohms output at 0.1% THD, the NAD T758 is in the 50th place, just below the $300 less Denon AVR-X3400H. The T757 did better, and took the 47th place on the same list. The 55.6 lbs T787 (7X150W) made it to the 40th, still well below many D&M, Pioneer and Yamaha models rated for 140 WPC or less. So that's my point, they didn't do so well in the 2 channel driven into 4 ohms tests.

Again, in terms of the IHF dynamic power output into 4 ohm and 2 ohm, that both NAD and Yamaha are known for, I believe they would beat comparable D&M models.

Back to the non dynamic output rating, take a look of the T758 vs the $300 (the difference is much greater if street price are used) less AVR-X3400H:

You can see that the THD for the NAD is much higher between 1 and 120 W, two channel driven into 8 ohms.

Imo, for integrated amps, NAD is competitive, but for AVRs they don't make/sell enough to benefit from the economy of scale.

 

[KenM10759]

I can't hear any of that, as far as I know.

For me, the "operability" of a receiver and its remote and/or app matters too, as does the room correction. Here is where the addition of Dirac Live has me optimistic, because NAD's implementation of Audyssey has always sucked.

 

[PENG]

I can't hear any of that, as far as I know.

For me, the "operability" of a receiver and its remote and/or app matters too, as does the room correction. Here is where the addition of Dirac Live has me optimistic, because NAD's implementation of Audyssey has always sucked.

I was only presenting facts and I also can't hear the differences that people claimed they heard either, but I wouldn't argue with them. I have yet to try Dirac, but Audyssey has always done well for me, not so much XT but XT32 for sure. So I have suspect people who didn't get good result could do better if tried harder, and do their research. It is on my to do list to try Dirac, hopefully this month.