Cal, you like those Altec's don't you. I will go and take a picture of mine and post them after I get back from walking my dog.
For the audio-nutters amongst us.
Try tri-amping a three driver speaker.
The difference in power and detail required by each speaker has been threaded to death.
Drive the LOW frequency WOOFER with a High Power but quality is not too important.
Drive the MID frequency MIDRANGE with a Medium Power V.High quality amp.
Drive the HIGH frequency TWEETER with a Low Power V.High quality amp.
If you use a passive crossover before the amplifiers - i.e. at pre-amp level you will negate any of the drawbacks of Speaker X-Overs. Just watch phase change.
Simply put. Most Sub-Woofers act in MONO because there is very little detail in the SUB frequencies.
The detail is normally in the audio range 5KHz to 20Khz with the power being at the lower end of the spectrum.
In this instance a Class A MID and another Class A HIGH of only 10W RMS can be used. The WOOFER can be tailored to your enjoyment or the tolerance of your neigbours.
Try tri-amping a three driver speaker.
The difference in power and detail required by each speaker has been threaded to death.
Drive the LOW frequency WOOFER with a High Power but quality is not too important.
Drive the MID frequency MIDRANGE with a Medium Power V.High quality amp.
Drive the HIGH frequency TWEETER with a Low Power V.High quality amp.
If you use a passive crossover before the amplifiers - i.e. at pre-amp level you will negate any of the drawbacks of Speaker X-Overs. Just watch phase change.
Simply put. Most Sub-Woofers act in MONO because there is very little detail in the SUB frequencies.
The detail is normally in the audio range 5KHz to 20Khz with the power being at the lower end of the spectrum.
In this instance a Class A MID and another Class A HIGH of only 10W RMS can be used. The WOOFER can be tailored to your enjoyment or the tolerance of your neigbours.
I disagree with this part.
It only applies if the three drivers are of different sensitivity, specifically low senstivity Woofer, medium sensitivity Midrange and high sensitivity Tweeter.
If all drivers are of the same sensitivity, then all require the same voltage drive for the same output, whether continuous, or peak, or transient.
I use 4way actives and I have to say most of the detail is in the mid-woofer (250Hz-1.2kHz) region, closely followed by the low-woofer (<250Hz), followed by tweeter (1.2kHz-10kHz) with little detail from the supertweet (>10kHz). In fact IME the woofers always gain the most from active operation as I have yet to hear a passive which can reproduce an electric bass convincingly (I blame series inductors for this).
I also disagree with AndrewT as my drivers are similar in sensitivity but I regularly see the low-woofers drawing 25w or more when the mid-woofers draw less than 10w. The tweeter is quite a bit more sensitive but the supertweeter draws only a tiny fraction of a watt. Just as well as it is a ribbon and only takes 5w before meltdown.
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how are you measuring this?
Are you measuring voltage or peak voltage or current or peak current or power or peak power?
I would agree that the low frequency part of the audio bandwidth contains the most energy and that means one more regularly sees/measures more average voltage to the LF drivers. That does not take any account of peak current demand.
...just read quickly the last page... a few random comments...
reading "current" compared between a woofer and a tweeter one also has to note the reference sensitivity and impedance of each - likely the tweeter is padded in the xover.
The next thing to think about, imo, is that "good" recordings (in digital) have peaks as much or more than 20dB over the "average" level. So what is required to reproduce that?
The poster who mentioned that his system doesn't seem loud but when you try to talk, it's hard to do it, he's on to something imho. What is that system??
If you merely put a scope on your speaker leads and watch for a while you may come to see just how often your amp is being clipped on peaks... a good exercise.
Most live PA/SR has improved incredibly in the last decade or so - before that a majority was awful ratty sound, now only a high percentage is... they not only clip amps, but they run blown drivers, awful electronics and bad EQ... of course it depends on who is running what, but that's no basis for comparison.
Oh yeah, for those peaks there is no substitute for voltage swing - which means that the rails are the hard limit in most cases. I agree, as earlier noted, that current is required to back it up into a reactive load (which is most speakers, unless it is a KEF 😛 ) so this causes another type of clipping and/or distortion. In practice this means that a low power amp (100w and under perhaps) on most normal sensitivity speakers will be running into one of the "walls" of its operating zone/envelope a fair amount of the time...
It's a tough thing to work out all of the compromises that are inherent and come up with a system that sounds good and also measures well, and doesn't run into some important limitation either electronically or acoustically... "...choose wisely, Luke Skywalker..." 😀
_-_-bear
PS. AndrewT is correct for the case where equal SPL is produced by equal sensitivity speakers. But in practice music has less energy in the recording as frequency increases, so unless you have a recording with a flat energy spectrum one does not actually see equal power being used when playing music back.
reading "current" compared between a woofer and a tweeter one also has to note the reference sensitivity and impedance of each - likely the tweeter is padded in the xover.
The next thing to think about, imo, is that "good" recordings (in digital) have peaks as much or more than 20dB over the "average" level. So what is required to reproduce that?
The poster who mentioned that his system doesn't seem loud but when you try to talk, it's hard to do it, he's on to something imho. What is that system??
If you merely put a scope on your speaker leads and watch for a while you may come to see just how often your amp is being clipped on peaks... a good exercise.
Most live PA/SR has improved incredibly in the last decade or so - before that a majority was awful ratty sound, now only a high percentage is... they not only clip amps, but they run blown drivers, awful electronics and bad EQ... of course it depends on who is running what, but that's no basis for comparison.
Oh yeah, for those peaks there is no substitute for voltage swing - which means that the rails are the hard limit in most cases. I agree, as earlier noted, that current is required to back it up into a reactive load (which is most speakers, unless it is a KEF 😛 ) so this causes another type of clipping and/or distortion. In practice this means that a low power amp (100w and under perhaps) on most normal sensitivity speakers will be running into one of the "walls" of its operating zone/envelope a fair amount of the time...
It's a tough thing to work out all of the compromises that are inherent and come up with a system that sounds good and also measures well, and doesn't run into some important limitation either electronically or acoustically... "...choose wisely, Luke Skywalker..." 😀
_-_-bear
PS. AndrewT is correct for the case where equal SPL is produced by equal sensitivity speakers. But in practice music has less energy in the recording as frequency increases, so unless you have a recording with a flat energy spectrum one does not actually see equal power being used when playing music back.
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I go by the rather accurate meters on my digitally controlled amps using music as a signal rather than white noise which would kill my supertweeters almost immediately.
I use 400w/channel for the lo woofers, 250w for mid woofer, 175w for tweeters and 60w for supertweeters. I've never managed to get anywhere near clipping but it does go very loud indeed without ever sounding stressed. As somebody previously mentioned it never seems that loud… until you try to talk over it!
I use 400w/channel for the lo woofers, 250w for mid woofer, 175w for tweeters and 60w for supertweeters. I've never managed to get anywhere near clipping but it does go very loud indeed without ever sounding stressed. As somebody previously mentioned it never seems that loud… until you try to talk over it!
"The poster who mentioned that his system doesn't seem loud but when you try to talk, it's hard to do it, he's on to something imho. What is that system??"
This poster would be me.
The system was initially designed for a bigger room than the one it is in now. The listening position is only about 2.5m away from the speakers. The set up is four leach amplifiers (midbass / tweeters) which have been measured to produce 160W each and two mosfet amps running the bass. All active.
Efficiency of the main speakers is approximately 91dB / W and the bass is catered for by two xls10s. The bass speakers are corner loaded with a shelf above. Creates a less than ideal situation for bass with a lumpy response. But have no choice at present. It sounds good enough for listening to my favourite type of music... Trance / Hard Trance.
Maybe it's the power supplies in the amps (3 x 1000Va Toroids)? The system just never sounds stressed. And maybe the fact that the music I listen to is highly compressed. Trance sounds good compressed unlike other types of music. Tricks are used in the tracks to give perceived dynamic range when in fact there is very little (sometimes less than 3dB)
This poster would be me.
The system was initially designed for a bigger room than the one it is in now. The listening position is only about 2.5m away from the speakers. The set up is four leach amplifiers (midbass / tweeters) which have been measured to produce 160W each and two mosfet amps running the bass. All active.
Efficiency of the main speakers is approximately 91dB / W and the bass is catered for by two xls10s. The bass speakers are corner loaded with a shelf above. Creates a less than ideal situation for bass with a lumpy response. But have no choice at present. It sounds good enough for listening to my favourite type of music... Trance / Hard Trance.
Maybe it's the power supplies in the amps (3 x 1000Va Toroids)? The system just never sounds stressed. And maybe the fact that the music I listen to is highly compressed. Trance sounds good compressed unlike other types of music. Tricks are used in the tracks to give perceived dynamic range when in fact there is very little (sometimes less than 3dB)
Just in case you are interested in mine which behave exactly the same I use Volt 3143 in a t/l, Tannoy 3149 dualconcentrics and Fountek JP3.0 ribbons.
The amps are MC2 Audio MC750, MC450, T500 and Omniphonics Footprint 150.
Xovers are modified BSS FDS360 currently directly fed from an EchoAudio AudioFire12 ADDA convertor. Usually I use a Audio Developments Pico mixer as pre-amp but that is being modified at the mo'.
The danger is when I'm on my own sometimes I don't notice how loud it is until things fall of the shelves or I try and sing along without hearing myself.
The amps are MC2 Audio MC750, MC450, T500 and Omniphonics Footprint 150.
Xovers are modified BSS FDS360 currently directly fed from an EchoAudio AudioFire12 ADDA convertor. Usually I use a Audio Developments Pico mixer as pre-amp but that is being modified at the mo'.
The danger is when I'm on my own sometimes I don't notice how loud it is until things fall of the shelves or I try and sing along without hearing myself.
My speakers are made of 2 Alcone AC8HE and Alcone AC1 HAT in MTM formation.
Hard Trance is generally faster than Trance. Generally very heavily compressed. Beat is stronger and it's less melodic. Bass lines are faster and more "chunky". Seems more in your face than normal trance. This probably won't help but it's between Trance and Hard Dance in the genres. All I Know is when I download stuff for mixing, the stuff I like is always from the Trance and Hard Trance sections.
Had to look up oxymoron by the way😕
Hard Trance is generally faster than Trance. Generally very heavily compressed. Beat is stronger and it's less melodic. Bass lines are faster and more "chunky". Seems more in your face than normal trance. This probably won't help but it's between Trance and Hard Dance in the genres. All I Know is when I download stuff for mixing, the stuff I like is always from the Trance and Hard Trance sections.
Had to look up oxymoron by the way😕
I have 2 amps. One DIY class a tube amp (3 watt total power) another semiconductor 200 watt one.
THe semiconductor one does not come "alive" till you crank it up to something like 5-10 watts.
The tube class A amp is crisp and detailed at small volumes so i don't feel a need to crank it up to more than 0.25-1 watt, 3 watt max volume on it sounds loud and unnecessary.
Maybe this is because my powerful amp does not play well on small volumes and with tube amp i hit the spot in my ear which is not often being hit with powerful amp - go figure.
It is also possible that you really feel need to crank up volume when you don't hear details well (i e some problem with the sound quality present). Also most of "casual" amps have crappy distorsion numbers on low volumes (the measurements are usually done at max volumes).
That's an interesting comment.
I've never owned a tube amp but have found the effect you describe when comparing SS amps of different topologies.
Designs such as the JLH original 10 watt class A would be one that would perform well at low volume and there are others (not just class A) that can pull this trick off.
I think a lot has to do with the distortion spectrum produced by the amp.
I've never owned a tube amp but have found the effect you describe when comparing SS amps of different topologies.
Designs such as the JLH original 10 watt class A would be one that would perform well at low volume and there are others (not just class A) that can pull this trick off.
I think a lot has to do with the distortion spectrum produced by the amp.
I have been doing years of research on this. It depends a lot on your mood and the activities you perform while in said mood. This mood is mostly influenced by the type and loudness of your music score. I've found that the required watts of your amp is in direct relation to the watts of your vacuum cleaner. Imagine cleaning your house. You want to get it over with quick, so you turn up the volume to overcome the noise produced by your vaccuum cleaner, allowing you to feel good while doing such a boring job. The more power your amplifier, the easier you can swamp out the sound of your vacuum cleaner. I've discovered that the more watts the vacuum, the more noise it makes, although its cleaning performance is better. An amp capable of driving about vacuum cleaner amps divided by the "Box constant" which is 4, should be sufficient: As an example, a 2KW cleaner requires 500W amp to overcome its noise and still retain a good mood, allowing you to absorb all the details of your favourite track. Empirically proved 😉
Disclaimer: No harm meant to anything
Disclaimer: No harm meant to anything
Mooly...
Try ECL82 SE. It is cheap and simple to build. It is my favorite amp when I work late...hehe. Maybe 2W of output and it is enough even in combination with lazy AR17.....But of course it is not good combination for some serious listening session.
Best regards, Taj
Try ECL82 SE. It is cheap and simple to build. It is my favorite amp when I work late...hehe. Maybe 2W of output and it is enough even in combination with lazy AR17.....But of course it is not good combination for some serious listening session.
Best regards, Taj
Yeh the "efficient" B class amp has "switching" distortions at zero signal levels. The transistor amp in additional to that has harsh bend in characteristic at low level. SS amp is also usually more complicated and negative feedback is a must to have which opens another can of worms.
THe tube amp is possible to make without negative feedback (if you do have one it is not much better than SS amp). But the real beauty is that there are less components in it. THat has 2 side effects.
1. Less components meaning more simple schematics and more simple distorsions to deal with. Basically tube type, bias and type of decoupling capacitors define your sound. You can do all work on your kitchen table, only multimeter and soldering iron needed.
2. Less components means it is very easy to DIY, you understand schematics better and the results are achieved easily and you can experience them right away while still having previous sound in memory. So it can be lots of fun. SS amp i'd rather buy but tube amp i would always build myself (or buy old chassis and change schematics to my liking).
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