Never pair B&W with Quad - It just doesn't work.
B&W do like the Hi-End Rotel topology.
The Nautilus likes the big Krell.
But whos got £33000 to spend on a second hand pair of B&W Nautilus. ?? NOT ME.
I was so fortunate a few years ago. One of my friends is a London property magnate. He was going on holiday and his house insurance didn't cover his Hi-Fi. I got to borrow a pair of B&W Nautilus that were six amped with KSA500s. NIRVANA but cost more than both my houses and the Jag added together.
B&W do like the Hi-End Rotel topology.
The Nautilus likes the big Krell.
But whos got £33000 to spend on a second hand pair of B&W Nautilus. ?? NOT ME.
I was so fortunate a few years ago. One of my friends is a London property magnate. He was going on holiday and his house insurance didn't cover his Hi-Fi. I got to borrow a pair of B&W Nautilus that were six amped with KSA500s. NIRVANA but cost more than both my houses and the Jag added together.
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No, they are not 90dB/W @ 1m
They state 90dB/2.83Vac @ 1m and they imply their usual tolerance on sensitivity.
If one accepts that these 683 are 8ohms speakers then one will find that many 8ohm capable amplifiers will not perform at their best trying to drive the 683s to highish peak levels on transients.
If one were to instead read the specification and decide they are probably 4ohms to 8ohms speakers and select 4ohms capable amplifiers then you are likely to find that the same peak currents into transients, as demanded by the 683, will not cause as much if any problem.
I would look at 100W and above into 8r0 amplifiers and only select those that are capable of at least 180% of that rated power output into 4r0 and are stated as 4ohms capable as being likely candidates for your 683s.
The Aleph probably, or almost certainly, meets all of those conditions.
They state 90dB/2.83Vac @ 1m and they imply their usual tolerance on sensitivity.
If one accepts that these 683 are 8ohms speakers then one will find that many 8ohm capable amplifiers will not perform at their best trying to drive the 683s to highish peak levels on transients.
If one were to instead read the specification and decide they are probably 4ohms to 8ohms speakers and select 4ohms capable amplifiers then you are likely to find that the same peak currents into transients, as demanded by the 683, will not cause as much if any problem.
I would look at 100W and above into 8r0 amplifiers and only select those that are capable of at least 180% of that rated power output into 4r0 and are stated as 4ohms capable as being likely candidates for your 683s.
The Aleph probably, or almost certainly, meets all of those conditions.
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Yes, he didn't like his, but you must do a bit of reading between the lines with him.
His major complaint was a lack of power. He also says he has 91db speakers. This leads me to come to either of 2 conclusions - Either he built it wrong an it wasn't making full power (which I kind of doubt) or he likes his music really loud, and it just wasn't enough power. (My guess) I have worked in high-end stores. There are guys who like it silly loud.
It's the only negative review of the F5 out there. Don't be put off by it. The F5 is an amazing amp.
that volume control position only gives an indication of system gain for that source into that amplifier/speaker combination.
It is not an indication of too little power, nor of too little SPL.
I've had the 'scope across the speakers at that setting and it looks about 5.8W
Banned
Joined 2002
Sensitivity in an 8-ohm speaker is given at 1W/1m.
4-ohm speakers are shown at 2.83v/1m. This is not actually the same thing.
A rule of thumb is to subtract 3db from the 2.83v/1m reading to make equivalent to 1W/1m. It's close enough for government work.
Your scope reads Vpp, not Watts.
90dB/2.83Vac @ 1m means apply a voltage of 2.83Vac to the 8r0 resistor and without adjusting the source/amplifier transfer the speaker to the set up and measure the SPL at 1m.
If the speaker is accurately equivalent to a 8r0 resistor across the whole audio bandwidth then the source/amplifier is delivering 1W to the speaker and you have a dB/W @ 1m measurement.
if the speaker deviates from that idealised 8r0 equivalent then the power delivered to the speaker using that 2.83Vac is no longer an equivalent in Watts. It is a voltage sensitivity measurement. That is what B&W have stated. A voltage sensitivity measurement.
If however, the tester measures both the rms voltage and the rms current passing into the speaker then the operator can adjust the source/amplifier to input exactly 1W into the test speaker and then measure the SPL at 1m. This answer results in the power sensitivity dB/w @ 1m.
If one knows that the speaker is actually 4ohms equivalent and the manufacturer quotes either the power, or the voltage, sensitivity then you can swap between the two specification by simply adding or subtracting 3dB from the stated figure.
If one does not know the speakers equivalent impedance, then one cannot apply the correction for equivalency.
If the manufacturer is transparent and honest, both the power, or voltage, sensitivity and the actual equivalent speaker impedance will be given. These two measurements allow valid comparisons to be made and for predictions of SPL relative to drive from any amplifier.
eg.
90dB/2.83Vac @ 1m driven with pink noise band limited to 40Hz to 18kHz and showing an equivalent impedance of 6.2ohms, tells all.
90dB/2.83Vac @ 1m means apply a voltage of 2.83Vac to the 8r0 resistor and without adjusting the source/amplifier transfer the speaker to the set up and measure the SPL at 1m.
If the speaker is accurately equivalent to a 8r0 resistor across the whole audio bandwidth then the source/amplifier is delivering 1W to the speaker and you have a dB/W @ 1m measurement.
if the speaker deviates from that idealised 8r0 equivalent then the power delivered to the speaker using that 2.83Vac is no longer an equivalent in Watts. It is a voltage sensitivity measurement. That is what B&W have stated. A voltage sensitivity measurement.
If however, the tester measures both the rms voltage and the rms current passing into the speaker then the operator can adjust the source/amplifier to input exactly 1W into the test speaker and then measure the SPL at 1m. This answer results in the power sensitivity dB/w @ 1m.
If one knows that the speaker is actually 4ohms equivalent and the manufacturer quotes either the power, or the voltage, sensitivity then you can swap between the two specification by simply adding or subtracting 3dB from the stated figure.
If one does not know the speakers equivalent impedance, then one cannot apply the correction for equivalency.
If the manufacturer is transparent and honest, both the power, or voltage, sensitivity and the actual equivalent speaker impedance will be given. These two measurements allow valid comparisons to be made and for predictions of SPL relative to drive from any amplifier.
eg.
90dB/2.83Vac @ 1m driven with pink noise band limited to 40Hz to 18kHz and showing an equivalent impedance of 6.2ohms, tells all.
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