I am thinking of building the Troels Gravesen 3 way classic with Scan Speak 21w8550 bass units. The sensitivity is 86 db my amplifier is a Naim Unitilite 50 watts pc into 8 ohms.
My room is 10 ft x 18 ft and I will sit about 8ft away from the speakers.
My question is will the Naim drive the speakers ok to decent levels.
My room is 10 ft x 18 ft and I will sit about 8ft away from the speakers.
My question is will the Naim drive the speakers ok to decent levels.
50 W will give you about 95 dB for 8ft distance.
There is a calculator in the lower third on this site:
Efficiency and sensitivity conversion - loudspeaker percent and dB per watt and meter loudspeaker efficiency versus sensitivity vs speaker sensitivity 1 watt = 2,83 volt box chart - sengpielaudio Sengpiel Berlin
There is a calculator in the lower third on this site:
Efficiency and sensitivity conversion - loudspeaker percent and dB per watt and meter loudspeaker efficiency versus sensitivity vs speaker sensitivity 1 watt = 2,83 volt box chart - sengpielaudio Sengpiel Berlin
To put Fonebones 95dB figure in perspective, regular sustained exposure to 95dB may cause permanent hearing damage!
And remember to get an extra +3 dB, you would need to double the amp power from 50W to 100W.
At average listening levels with speakers of average sensitivity like yours, the amp will be putting out only about 1 watt anyway.
And remember to get an extra +3 dB, you would need to double the amp power from 50W to 100W.
At average listening levels with speakers of average sensitivity like yours, the amp will be putting out only about 1 watt anyway.
And twice as loud needs 10 times the power as the ear is logarithmic.
I listen to a USB DAC powered by the USB bus and it drives a very old Fane 12-50 speaker and it is just a nice level at mid volume pot setting. Its probably not much more than a watt.
I would think so. I find 25W per channel into my 87dB/W/m speakers in a room a little larger than yours produces more volume than I care to listen to!
Hi Nigel!
I know you can take a joke, so allow me to point out that hearing is logarithmic but the ear is a double helix!
P.S. As you know, your Fane 12/50 is super sensitive and would make a portable transistor radio sound loud!
I recall you used four of them in your mobile disco in the 80s, while I did similar with a mixture of Fanes and Goodmans in the 70s.
Regards.
Attachments
All true, but at the same time MISLEADING.
The point is there is a massive difference between the AVERAGE level (which is what the "sustained exposure to..." comment refers to), and the INSTANTANEOUS PEAKS. The ratio between the two is called the CREST FACTOR of a music piece.
Now for some numbers:
A) typical (compressed) POP/ROCK music has a crest factor = 5 - 10dB.
B) JAZZ and CLASSICAL music has a much higher crest factor = 15 - 25dB.
So, it ultimately boils down to what you listen to.
If it's A), then if your amp+speaker combo can achieve a maximum of 95dB at the listening position, then it means that in order to avoid CLIPPING, the maximum AVERAGE level you can listen to is 85-90dB - still pretty loud!
BUT, if it's B), then the same amp+speaker combo can only produce a maximum AVERAGE level = 70-80dB. This is no longer very loud, and may be considered not enough by many.
Of course, if you can tolerate amp clipping on some transients, then you can still turn it up a bit more... but it ain't "high fidelity" anymore.
To sum up: do your amp power / speaker sensitivity calcs first, but remember that what that tells you is how loud the musical PEAKS can be.
THEN, take into account the crest factor of the music you want to listen to, and work out the corresponding AVERAGE level.
M.
As it happens I do listen to classical music a fair bit but I am sure that the peaks are still below 95 db where I sit and listen.
All of the above is so true. Just keep in mind that perceived loudness is a very subjective thing. So it varies wildly between different people.
In my opinion 50W would be nice for 98% of my needs but it would be better if there is a little more headroom than I need. 105dB peak 8ft is nice to have
In my opinion 50W would be nice for 98% of my needs but it would be better if there is a little more headroom than I need. 105dB peak 8ft is nice to have
The key part for me is this:
Keeping the impedance up that high ensures a good match with most amplifiers, assuming it plays loudly enough. Dipping to 3, especially in the bass, and speakers become "discerning." I call it "demanding." Meaning that you can hear any weakness in an amp very easily, probably more than most of us would expect unless you've been looking for it. Audiophiles go nuts, thinking the speaker is somehow more revealing of music and detail.
To sum: I think this is a fine choice for a wide range of amps.
Keeping the impedance up that high ensures a good match with most amplifiers, assuming it plays loudly enough. Dipping to 3, especially in the bass, and speakers become "discerning." I call it "demanding." Meaning that you can hear any weakness in an amp very easily, probably more than most of us would expect unless you've been looking for it. Audiophiles go nuts, thinking the speaker is somehow more revealing of music and detail.
To sum: I think this is a fine choice for a wide range of amps.
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