Yup but only whit decent meter
There was a tread sumwhere here at diya about measuring speakers output whit a couple of lowish frequency signals
I can't find it any more.
Me think title was sumthink like How much Power You really need....
http://www.diyaudio.com/forums/mult...much-voltage-power-do-your-speakers-need.html
Tanks to Pano found tread that may help deciding how big one F5 need to be
Tanks to Pano found tread that may help deciding how big one F5 need to be
Hikari1, a few things.
First off the "sound" of the F5 is very variable, it's something of a "chameleon" amplifier.
It changes depending on almost all of the possible variations in parts (different mfrs) and types (for resistors, for example) and the power supply. So I'd bet that out of all the F5 amps built that there is a wide spread in subjective sound, ranging from "thin/clean" through "fat/soupy".
Also the match between P and Nch parts changes things too.
I did say soft recovery diodes. Ask others what they think.
You can work out what your max dB/SPL at your listening position. The basic idea is to take the 1w/1m value, increase it by the number of dB up that the max power of your amp has, and then subtract the distance that you are away from the speakers.
So, if you figure that you listen at some given average SPL, like say 93dB, then you can take that figure and work back to how much power that takes. Subtract that wattage from the max wattage and for each doubling of power you get 3dB more SPL. This is then your headroom. Given that some music wants a 20dB over average level for unclipped peaks, this is something to think about... probably covered fully in the aforementioned Pano thread.
_-_-
First off the "sound" of the F5 is very variable, it's something of a "chameleon" amplifier.
It changes depending on almost all of the possible variations in parts (different mfrs) and types (for resistors, for example) and the power supply. So I'd bet that out of all the F5 amps built that there is a wide spread in subjective sound, ranging from "thin/clean" through "fat/soupy".
Also the match between P and Nch parts changes things too.
I did say soft recovery diodes. Ask others what they think.
You can work out what your max dB/SPL at your listening position. The basic idea is to take the 1w/1m value, increase it by the number of dB up that the max power of your amp has, and then subtract the distance that you are away from the speakers.
So, if you figure that you listen at some given average SPL, like say 93dB, then you can take that figure and work back to how much power that takes. Subtract that wattage from the max wattage and for each doubling of power you get 3dB more SPL. This is then your headroom. Given that some music wants a 20dB over average level for unclipped peaks, this is something to think about... probably covered fully in the aforementioned Pano thread.
_-_-
I built dual mono with 2 300VA transformers, using MUR 3060 or maybe 3090 diodes, (whatever Peter Daniels was recommending back then) don't have problems with "reasonable" levels you are speaking of. Even with a 2 way set of only 86 dB or so....using BA-3 FE as Pre REALLY helped in my case.
My F-5 used IRF outputs, which I and others feel sound less "thin" but this really gets into a subjective, possibly imaginary area!
If I remember, you use BA-3 FE as pre? If so, you might try driving the output section of BA-3 (essentially F-4 minus its
front end, as they use the same output section) for a little more umpf, BA-3 is capable of "driving F-4" reasonably well.
Russellc
My F-5 used IRF outputs, which I and others feel sound less "thin" but this really gets into a subjective, possibly imaginary area!
If I remember, you use BA-3 FE as pre? If so, you might try driving the output section of BA-3 (essentially F-4 minus its
front end, as they use the same output section) for a little more umpf, BA-3 is capable of "driving F-4" reasonably well.
Russellc
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Ok, I tried it out. I only had an old shure test record with a frequency sweep for testing but it looks like Iam using 3.5 to 4 volts. So using up about 16watts peak or so. Maybe its my ears that cant take the volume...not the amp.
something I would like to try that would work well with low and med power amplifiers.
Unbenanntes Dokument
Unbenanntes Dokument
This test is based on a digital source that has an absolute maximum peak output of 0dBfs.
analogue sources cannot give this guarantee. They don't have an equivalent to the digital maximum of 0dBfs.
You need to play/reproduce a variety of your music/audio types at the maximum volume you like to use and then leave the vol pot at that fixed setting.
Then use the prescribed CD test signal to allow you to measure the speaker voltage of that test signal with that fixed vol pot setting (remaining unchanged).
There are a couple of test signals on the tread if I remember
U are not the only one that is surprised on how little power U need
I was not surprised...my concern was more about protectinng my speakers than having enough volume, really. Honestly, most of the time I listen to music at about 80 to 85 db, 3m oor so from the speakers.
I may be overstating the soundstage collapse above these levels. It still sound good but I think it is my ears giving up and some room interactions becoming more mnoticeable. On the other hand....this is also the power level where the f5 transistions out of class a into 4 ohms. I believe it is 16 watts class a into 4 ohms. Coincidence?
I may be overstating the soundstage collapse above these levels. It still sound good but I think it is my ears giving up and some room interactions becoming more mnoticeable. On the other hand....this is also the power level where the f5 transistions out of class a into 4 ohms. I believe it is 16 watts class a into 4 ohms. Coincidence?
80dB to 85dB @ a 3m listening distance is usually considered quite high by many.
The equivalent at 1m would be +8dB and if converted to a single speaker (-3dB), you would need 85 to 90dB from each speaker @ 1m
If you now allow transients that are +10dB relative to the average levels, then you have 95dB to 100dB transients coming from each speaker.
If the music/audio you listen to requires a 20dB ratio of average to transient, then your speakers are required to push out 105dB to 110db.
16W into 100dB/W @ 1m speakers would be required to achieve 105dB transients.
My conclusion from your information is that you are listening at much lower levels than 80dB or that you are listening to clipping distortion and that is your "hearing limitation" to maximum volume.
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