Hi,
I am in same position as OP.
If okay to ask - what is the least amount of power to drive either Calpamos or OSMC to good levels and without compromise in a 6x4M room (or 8x5M).. will 8W in either single ended or push pull suffice?..
Camplo - are you the designer of the Calpamos speaker?
Thank you.
I am in same position as OP.
If okay to ask - what is the least amount of power to drive either Calpamos or OSMC to good levels and without compromise in a 6x4M room (or 8x5M).. will 8W in either single ended or push pull suffice?..
Camplo - are you the designer of the Calpamos speaker?
Thank you.
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A back of the envelope estimate of peak power is fairly straightforward based on sufficient power to cleanly reproduce peaks in the music. This will need speaker efficiency, average SPL at listening position, distance of listening position from speakers (not room size since peaks are in the direct sound) and ratio of peaks to average SPL. For 83 dB average SPL (typical standard level), 4 m away (+12 dB compared to 1m) and 20 dB peak:average headroom (typical when recording music) that gives a required peak SPL at 1m of 115 dB. OK one can tweak the numbers a bit but this is the ballpark.
Speaker generating 90-93 dB at 1m with 1 W of power (around the sweet spot for high fidelity) will need an amplifier capable of +22-25 dB or 160-320 W (assuming my maths is OK).
As a check if we look to what is used by professionals in studios where high sound quality is a genunine requirement to do the day job then for typical midfield/main monitors used under conditions close to the above it checks out. A few hundred watts, drivers of 90-93 dBish efficiency, woofers around 10-15", 3-4 ways,...
If we look to home audio then things are rather different but sound quality in a dry technical/studio sense is usually not particularly important compared to having fun with other things like 8W valve amplifiers.
It is only required if you have an interest in sound quality in a technical sense rather than more of an audiophile one as suggested by your use of very low power amplifers. It is perfectly fine for people to have different objectives and to have fun with different things. I personally don't get the appeal of valve amplifers, wide band drivers, expensive 2 ways, exotic cables, over-engineered DACS,... plus many more things that some audiophiles might enjoy but I also don't feel any inclination to be abusive because they have different objectives to me.
Did I miss it or did someone explain why horn loaded compression drivers have such high on axis sensitivity?
If you put a compression driver on a typical 90 x 40 degree horn it is only covering 1/18 of a sphere. That should get you a 12.5 dB boost. For those slightly confused a sphere is 360 degrees by 180 degrees.
If you put a compression driver on a typical 90 x 40 degree horn it is only covering 1/18 of a sphere. That should get you a 12.5 dB boost. For those slightly confused a sphere is 360 degrees by 180 degrees.
Can you explain what you get out of your measurements? I think I see a lot of room-related issues at low frequencies. The 350Hz hump could be a floor reflection. Or a misaligned crossover 😀.
Still, I asked for some backing for the claim that we humans are really sensitive to group delay effects at lower frequencies. Preferably in normal (in room) listening conditions.
You should be familiar enough with the time scale ms...if the bass drum and cymbal hit occur simultaneously...and the bass expression is 20ms behind the crash of the cymbal...as a drummer myself...I will hear it. We had this discussion in my thread a while ago....Tempo of the music is a factor as well. The fact remains that plenty of people have bad timing and will not be able perceptive of the distortion in time...no less than plenty of people have no coordination and cannot dance well, or have terrible pitch recognition and can't sing.... If I hear a person sing off key slightly it causes me mental pain....you might say oh she sounds wonderful...it all depends on where you fall between those lines.
You are pretty smart, If you've never read studies regarding sensitivity to group delay at lower frequencies, you either have avoided them or fall into the group of those who are not able to perceive it...and ignored any study suggesting otherwise
The chart is only to show the connection of group delay to time to peak energy...nothing more....The 350hz bump is the tuning note of the horn, which you know tends to be the peak in group delay regarding all vented designs due to the air mass lagging the the driver.
If you can't hear it. Who cares? I find that it is less concerning the more I study it....yet I will always design towards the lowest amount of it. The best way to expose it is to have a perfect example of the source and a and b it with a source that has a much larger latency...usually headphones vs loudspeakers works well. Your point is that everything is lost in the room....and, maybe...
You are pretty smart, If you've never read studies regarding sensitivity to group delay at lower frequencies, you either have avoided them or fall into the group of those who are not able to perceive it...and ignored any study suggesting otherwise
The chart is only to show the connection of group delay to time to peak energy...nothing more....The 350hz bump is the tuning note of the horn, which you know tends to be the peak in group delay regarding all vented designs due to the air mass lagging the the driver.
If you can't hear it. Who cares? I find that it is less concerning the more I study it....yet I will always design towards the lowest amount of it. The best way to expose it is to have a perfect example of the source and a and b it with a source that has a much larger latency...usually headphones vs loudspeakers works well. Your point is that everything is lost in the room....and, maybe...
I've got two pairs of speakers here (both designed from scratch by me). One is sealed with low group delay and the other is ported with higher group delay. The ported speakers sound tighter and more accurate than the sealed.
Both have same driver and identical box size? At the very least same driver. Your report lacks any type of scientific insight...We can find a dozen reports of preference towards sealed or ported...You've said not much.
Driver
Box Size
Dampening
Full Measurements?
Driver
Box Size
Dampening
Full Measurements?
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Hello camplo
The tuning note of the horn?? You have me confused what is that?? Cutoff??
Help me out here just not getting it.
Rob🙂
Cutoff, tuning note, bout the same thing I guess...A horn is tuned to a specific note, at that note it is most resonate, as are all vented designs
All I can tell you is that an Amp Camp Amp is powerful enough to drive an OSMC so loud that you want to leave the room. Thats more than 10x less than the power levels quotes above.
I had a pair of original Klipsch Fortes and yes, crossover design and horn/waveguide modeling has improved considerably in the intervening years. After hearing a pair of more-recently designed speakers using the SEOS-15 waveguide I had no reservations about literally giving my Fortes away for nothing. Everything I like about horns for mid-high frequencies is improved with OS-style waveguides.
Hi,
It all depends of the type of music you listen to: sure with 'typical' modern kind of production you'll easily blow your head off with 5w and your design ( low to very low dynamic within the recordings).
But if like in the example Andy gave, you listen to non compressed music ( which is the case in studio control room at tracking, a bit less at mixing) the numbers given are rights.
The approach given by Andy is a worst case scenario ( 4m distance to loudspeakers is 'rare' anyway as this is at the edge regarding stereo- you need a center chanel once you past 3,5m ime) and it doesn't take into consideration some acoustic data too ( in control room there is usually a large amount of absorbsion and the critical distance is usually way bigger than in a domestic room too, all this tends to make power requirements higher than at home too).
It all depends of the type of music you listen to: sure with 'typical' modern kind of production you'll easily blow your head off with 5w and your design ( low to very low dynamic within the recordings).
But if like in the example Andy gave, you listen to non compressed music ( which is the case in studio control room at tracking, a bit less at mixing) the numbers given are rights.
The approach given by Andy is a worst case scenario ( 4m distance to loudspeakers is 'rare' anyway as this is at the edge regarding stereo- you need a center chanel once you past 3,5m ime) and it doesn't take into consideration some acoustic data too ( in control room there is usually a large amount of absorbsion and the critical distance is usually way bigger than in a domestic room too, all this tends to make power requirements higher than at home too).
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Alternative facts?
A resonance is not a cutoff frequency. Most here regard a horn as an acoustic (impedance) transformer (I hope), not as a resonator. Be it that reality is more complex than simple substitution schemes. And horns tend to have some resonances. Do you use a folded horn design maybe?
A resonance is not a cutoff frequency. Most here regard a horn as an acoustic (impedance) transformer (I hope), not as a resonator. Be it that reality is more complex than simple substitution schemes. And horns tend to have some resonances. Do you use a folded horn design maybe?
It is more a best case scenario rather than a worse case one. It assumes that one is able to appreciate high fidelity reproduction at standard levels which in the presence of an uncontrolled room response isn't likely. As mentioned above room boom not only makes music sound loud it makes it sound unpleasant leading to wanting to turn the volume down. It appears to be why so many consider inadequately sized drivers and underpowered amplifers to be sufficient which they are likely to be if one is not particularly interested in sound quality in a technical sense.
I have tended to pick 4m as a listening distance in back of the envelope calculations because it is trivial to calculate. 3.2 m seems to be more common in standards so perhaps it would be better to pick that giving +10 dB rather than +12 dB.
Sure, these are studio monitors, not PA. I have never measured a dome tweeter that goes much beyond 100 dB/m without severe distortion. Please advice if you know of one.
Bass reflex typically has lower distortion but more group delay than sealed on the low end. Port output normally shows low harmonics.
You compare resonators with horns. They differ fundamentally in the way they load a driver diaphragm. In acoustic terms the mouth of a horn is best compared to a comparatively sized piston in the same baffle. They both have about the same radiation impedance (that has an imaginary component, read altering phase and therefore group delay, too).