I came here from another site after reading about Gainclone amps.
One thing I cannot find is their wattage output.
How "big" can they go, how big do they need to go?
I drive a set of Deftech 7002's with the 135watt amp built into my Yamaha receiver and wanted to go with a better cleaner sound.
Will these eclipse the internal amp or can it be built to do so?
Has anyone put these together in a group to make a true 5 channel amp?
I've been reading all day and already have 5 new projects
I did do some searching but could not find a concrete answer to what I was looking for.
One thing I cannot find is their wattage output.
How "big" can they go, how big do they need to go?
I drive a set of Deftech 7002's with the 135watt amp built into my Yamaha receiver and wanted to go with a better cleaner sound.
Will these eclipse the internal amp or can it be built to do so?
Has anyone put these together in a group to make a true 5 channel amp?
I've been reading all day and already have 5 new projects
I did do some searching but could not find a concrete answer to what I was looking for.
Hi Eric,
Welcome aboard.
The wattage depends on the chip used and supply voltage. Look at the LM1875, LM3875 etc datasheets for all the information.
http://www.datasheet4u.com/search.php
If you bridge and parallel them you can go up to a couple of hundred watts. Look for BPA-200 on Nationals site. The size you need depends on the efficiency of your speakers and their impedance. I find 30 to 50 watt amps are more than enough.
I have an old '90's Yamaha amp and a simple GC sounds a lot better to me. I guess newer Yamaha's *must* be better than my old thing though.
I remember a few 5 channel threads but they don't interest me so I can't add anything.
I suggest, as these things are so cheap, build a point to point wiring version and see if you like the sound of them. If you are happy with the results, build a bigger more complicated one (if necessary??).
Nuuk's site is a great place to learn all about these things:
http://myweb.tiscali.co.uk/nuukspot/decdun/index.html
regards
Welcome aboard.
The wattage depends on the chip used and supply voltage. Look at the LM1875, LM3875 etc datasheets for all the information.
http://www.datasheet4u.com/search.php
If you bridge and parallel them you can go up to a couple of hundred watts. Look for BPA-200 on Nationals site. The size you need depends on the efficiency of your speakers and their impedance. I find 30 to 50 watt amps are more than enough.
I have an old '90's Yamaha amp and a simple GC sounds a lot better to me. I guess newer Yamaha's *must* be better than my old thing though.
I remember a few 5 channel threads but they don't interest me so I can't add anything.
I suggest, as these things are so cheap, build a point to point wiring version and see if you like the sound of them. If you are happy with the results, build a bigger more complicated one (if necessary??).
Nuuk's site is a great place to learn all about these things:
http://myweb.tiscali.co.uk/nuukspot/decdun/index.html
regards
Greg Erskine said:
I think I might have to second this opinion
A basic GC (unregulated supply and the likes) is pretty easy to build (for me, finding, buying and cutting out things in the case was by far the hardest part!).
You might be suprised as to how loud ~30-40W, probably even 10W is (with moderately easy to drive / average sensitive speakers). I was.
Nuuk's site is definately a good place for GC related stuff
Greg,
Thanks for the reply.
I did find a site that I believe was 300 watt.
I've heard very good things about the amp built into the RX-V2600, I believe its a Class D.
Still I like the idea of doing things myself. I have been told by another 2600 owner running a 125 watt external amp that although the internal amp is good, running separate really does help the sound.
I have a set of PE BR-1's upstairs in the wife's workout room. I was planning on building a small unit and just plugging an iPod into it to see how it worked.
The biggest problem that I can see is the overwhelming amount of information. I've seen 15 different approaches to the same thing.
I've read that these amps are the best thing for the money but I guess I'm not sure how much you'd have to spend to get to the same quality.
5 channel would be something I am interested in since I do listen to a lot of surround stuff.
I'll check out the link you sent over.
Thanks
Thanks for the reply.
I did find a site that I believe was 300 watt.
I've heard very good things about the amp built into the RX-V2600, I believe its a Class D.
Still I like the idea of doing things myself. I have been told by another 2600 owner running a 125 watt external amp that although the internal amp is good, running separate really does help the sound.
I have a set of PE BR-1's upstairs in the wife's workout room. I was planning on building a small unit and just plugging an iPod into it to see how it worked.
The biggest problem that I can see is the overwhelming amount of information. I've seen 15 different approaches to the same thing.
I've read that these amps are the best thing for the money but I guess I'm not sure how much you'd have to spend to get to the same quality.
5 channel would be something I am interested in since I do listen to a lot of surround stuff.
I'll check out the link you sent over.
Thanks
Hi,
for a first amp project keep it simple.
You can use it for sound reinforcement somewhere. If it turns out to better than the multichannel versions that come later you can always build a second to make a pair of monoblocks.
Build a single channel chipamp and get it working properly. With this experience you can then make informed decisions on what you need for power, channels, etc.
Down load the datasheets (from national.com) for your proposed chips. If you can't understand them, then come back with some/lots of questions.
for a first amp project keep it simple.
You can use it for sound reinforcement somewhere. If it turns out to better than the multichannel versions that come later you can always build a second to make a pair of monoblocks.
Build a single channel chipamp and get it working properly. With this experience you can then make informed decisions on what you need for power, channels, etc.
Down load the datasheets (from national.com) for your proposed chips. If you can't understand them, then come back with some/lots of questions.
I've spent most of the time since I posted this yesterday and now reading every single page I can find on it.
My biggest problem is a lack of reference in regards to some of the terminology and schematic layout.
I've built a crossover from a schematic, although it did come with a pre-printed PCB.
Most of the designs I've seen do not talk about power output. I guess I should start with the simple stuff.
1. What is speaker efficiency and how does it relate to power output. All the pages I read say build the amp and choose the power supply to relate to the speakers efficiency but I did not find any explanation as to what that means. My current speakers dont' give much info. Just compatible with 8ohms and recommended power rating is 20-400 watts. They are Definitive Technology 7002's and that is the only information I could find on Definitives web page.
2. If I do want 150-200 watts per channel, how many of these things can I bridge together? Do you reach a point of diminishing return or do you start to create problems when you get to a certain number in series?
3. What kits out there relate to what power ratings?
Maybe I'm too stuck on the whole power output thing and if I am I don't understand why I should not be
My goal isn't so much to build one to build one and tinker around. I want to build one if it is going to be superior to what I have now, and or superior to what I could get for 1K USD in a 5.1 200 watt Outlaw amp.
Thats for our main setup. Now for my office, the wife's office, etc I would be interested in building a smaller model.
I guess my best place to start is I have a set of Parts Express BR-1's that I built to test out my soldering skills. They current are in my wife's workout room and what I would like to do is build a amp to drive them and use something simple like an iPod for music.
The speaker I built has the following specs from their site:
System Specification: Frequency response: 43-18,000 Hz, SPL: 85 dB 2.83V/1m
Power handling: 100 watts max.
What can I go do this week to build something for that? We have a large electronics store which carries pretty much everything you can imagine so I should be able to get the parts. I don't care if its in a box I can rough wire it together, try it out, then worry about doing it ina box or something similar.
I tend to understand more when I see cause and effect. I have some more reading to do on electronic theory from some of those pages. I'm sure once I have more of an understanding of why it works it will help out quite a bit.
Yesterday this started out trying to find out where to install some accoustic panels and EQ'ing my room, I read one thread and now here I am
Thanks for everyones help
My biggest problem is a lack of reference in regards to some of the terminology and schematic layout.
I've built a crossover from a schematic, although it did come with a pre-printed PCB.
Most of the designs I've seen do not talk about power output. I guess I should start with the simple stuff.
1. What is speaker efficiency and how does it relate to power output. All the pages I read say build the amp and choose the power supply to relate to the speakers efficiency but I did not find any explanation as to what that means. My current speakers dont' give much info. Just compatible with 8ohms and recommended power rating is 20-400 watts. They are Definitive Technology 7002's and that is the only information I could find on Definitives web page.
2. If I do want 150-200 watts per channel, how many of these things can I bridge together? Do you reach a point of diminishing return or do you start to create problems when you get to a certain number in series?
3. What kits out there relate to what power ratings?
Maybe I'm too stuck on the whole power output thing and if I am I don't understand why I should not be
My goal isn't so much to build one to build one and tinker around. I want to build one if it is going to be superior to what I have now, and or superior to what I could get for 1K USD in a 5.1 200 watt Outlaw amp.
Thats for our main setup. Now for my office, the wife's office, etc I would be interested in building a smaller model.
I guess my best place to start is I have a set of Parts Express BR-1's that I built to test out my soldering skills. They current are in my wife's workout room and what I would like to do is build a amp to drive them and use something simple like an iPod for music.
The speaker I built has the following specs from their site:
System Specification: Frequency response: 43-18,000 Hz, SPL: 85 dB 2.83V/1m
Power handling: 100 watts max.
What can I go do this week to build something for that? We have a large electronics store which carries pretty much everything you can imagine so I should be able to get the parts. I don't care if its in a box I can rough wire it together, try it out, then worry about doing it ina box or something similar.
I tend to understand more when I see cause and effect. I have some more reading to do on electronic theory from some of those pages. I'm sure once I have more of an understanding of why it works it will help out quite a bit.
Yesterday this started out trying to find out where to install some accoustic panels and EQ'ing my room, I read one thread and now here I am
Thanks for everyones help
Eric_B_C said:1. What is speaker efficiency and how does it relate to power output. All the pages I read say build the amp and choose the power supply to relate to the speakers efficiency but I did not find any explanation as to what that means. My current speakers dont' give much info. Just compatible with 8ohms and recommended power rating is 20-400 watts. They are Definitive Technology 7002's and that is the only information I could find on Definitives web page.
2. If I do want 150-200 watts per channel, how many of these things can I bridge together? Do you reach a point of diminishing return or do you start to create problems when you get to a certain number in series?
3. What kits out there relate to what power ratings?
Maybe I'm too stuck on the whole power output thing and if I am I don't understand why I should not be
My goal isn't so much to build one to build one and tinker around. I want to build one if it is going to be superior to what I have now, and or superior to what I could get for 1K USD in a 5.1 200 watt Outlaw amp.
Thats for our main setup. Now for my office, the wife's office, etc I would be interested in building a smaller model.
I guess my best place to start is I have a set of Parts Express BR-1's that I built to test out my soldering skills. They current are in my wife's workout room and what I would like to do is build a amp to drive them and use something simple like an iPod for music.
The speaker I built has the following specs from their site:
System Specification: Frequency response: 43-18,000 Hz, SPL: 85 dB 2.83V/1m
Power handling: 100 watts max.
I said keep the first one simple. I really mean that. Get more ambitious later.
Sensitivity is measured in 85db/2.83V.
This means that an amplifier that can push 100W into 8r and 200W into 4r and 400W into 2r will try to maintain 2.83V into the speaker at any frequency. The 100W will produce an output +20dbW above the 85db reference equating to a maximum output of 105db. This is loud, loud enough to damage your ears in the short term and deafening , in the literal sense, in the long term.
But, average music levels are 10db to 20db below maximum, so the 100W amp & 85db speakers when the volume control is set to loud BUT WITHOUT CLIPPING will produce between 85db and 95db. This range is still quite loud but not deafening. Turn the volume down another 10 to 20db and that is a loud conversation.
So, using power and sensitivty you can predict the range of SPL the system will produce and decide if this is suitable to your needs/wants.
Build your first amp and try it out, remember I said "informed decision" making.
The attraction of chipamps is simplicity. Start bridging and that advantage disappears. I believe that higher powers are better achieved with discrete. However there is a chipamp that I only recently became aware of, it is the whole chipamp but without an output stage and with care can be scaled from 20W to 200W into any conventional load impedance. It will not drive 2ohm speakers to high power. It is the next level of complexity above the true chipamp and fills the gap between simple discrete and chipamp, but includes a number of nice add-ons that would normally make discrete quite complex.
Don't get bogged down in the power game like the car audio folk have.
BTW 90db speakers and 50W (achievable with a chipamp) will give about 107db maximum, just a little bit louder than that previous example.
Thanks, that makes more sense, I'll have to do some more diggiing around about my speakers efficiency.
I assume this is at a A weighting?
I do listen around 85 a A weighting, disregarding the readings I get when bass is playing. I'll see 105db out of my sub but have been lead to believe that is not dangerous, its the midrange stuff at those levels.
One of the things I thought having more wattage did was drive up the low end. Its tough to explain. At low volumes my system is, well low Some of the smaller details are lost at those volume levels. I thought with an amp where you had a higher wattage starting point at the low end you would get more definition and clarity even at the low volume levels.
There are so many designs out there. Can you point me in the direction of a simple small 2 channel unit. I want to build a 2 channel because it will give me a direct reference to other 2 channel stuff I have in the house. I don't care if it fits in a box, I just want to solder something together and try it out.
Thanks
I assume this is at a A weighting?
I do listen around 85 a A weighting, disregarding the readings I get when bass is playing. I'll see 105db out of my sub but have been lead to believe that is not dangerous, its the midrange stuff at those levels.
One of the things I thought having more wattage did was drive up the low end. Its tough to explain. At low volumes my system is, well low
Some of the smaller details are lost at those volume levels. I thought with an amp where you had a higher wattage starting point at the low end you would get more definition and clarity even at the low volume levels.There are so many designs out there. Can you point me in the direction of a simple small 2 channel unit. I want to build a 2 channel because it will give me a direct reference to other 2 channel stuff I have in the house. I don't care if it fits in a box, I just want to solder something together and try it out.
Thanks
Eric_B_C said:
No. The drivers are arranged in series and parallel and the resultant impedance is 6 ohm. Even a 10 watt amp would probably be enough for "normal" listening levels. It's not till you start building these things you realise how far a few watts go. I'm not suggesting 10 watts is a long term solution though, 50 or 60 watts will probably work very well.
regards
This may help. Or it may sound stupid.
Realize what you are trying to do when you listen to music. Are you trying to put the band in your room or are you trying to take your room to the concert.
If you are trying to put a rock band in your room, then all you need is PA quality speakers and a lot of power. But rent the equipment because you will be deaf soon.
On the other hand, if you take your room to the concert, then faithful reproduction (quality) is prime. Power becomes only a number. Any gainclone kit will make you very happy. The quality of the sound will astound you.
What impresses me more than power is how good a sound a system can make even at very low levels. A gainclone will impress you both ways. From a sweet high note on a violin or the thwack of a kick drum and wall shaking bass guitar. This with no signal processing. Just straight from the CD player to the amp. Tone controls are for cheap systems!
May I suggest : here or: here
I have built kits from both sites and point to point LM3886 chips. And am very happy with the results.
Realize what you are trying to do when you listen to music. Are you trying to put the band in your room or are you trying to take your room to the concert.
If you are trying to put a rock band in your room, then all you need is PA quality speakers and a lot of power. But rent the equipment because you will be deaf soon.
On the other hand, if you take your room to the concert, then faithful reproduction (quality) is prime. Power becomes only a number. Any gainclone kit will make you very happy. The quality of the sound will astound you.
What impresses me more than power is how good a sound a system can make even at very low levels. A gainclone will impress you both ways. From a sweet high note on a violin or the thwack of a kick drum and wall shaking bass guitar. This with no signal processing. Just straight from the CD player to the amp. Tone controls are for cheap systems!
May I suggest : here or: here
I have built kits from both sites and point to point LM3886 chips. And am very happy with the results.
Thanks!
Low volume high definition is what I am looking for and I am looking also for high volume clarity.
I've seen the evilness that signal processing does I've learned a lot about bass management on multichannel music and now play all my stuff straight through a analog bass manager with zero no other dodads besides the DAC in the player in the way.
For my sub I was looking at a Carver1800 or a EP2500, both very high wattage amps for subs which I still believe you need a lot of power for. I assume I am still better off with one of these because of their cost, roughly $250 USD for approx 600 watt per channel. This is only pertaining to the sub itself.
Well I went and ordered the Chipamp Stereo kit w/ PS, the one on sale for $55.
What else am I going to need? I think the perfect box for the unit, at least on the cheap, is one of the old external USB HD boxes I have laying around.
1. I need something to get power to the unit correct?
2. Input/outputs?
3. Potential meters for the knobs?
4, Best type of solder?
Any other misc stuff I need to pick up?
I'd like to know what else I'll need so I can pick the stuff up this week.
Thanks for all the help...I'm hoping this is going to turn into something pretty interesting.
I'll admit I'm still having a hard time believing the quality of these amps simply because outside of this site, even on the other DIY speaker sites there is very little if any talk of these units.
I'm pretty excited to try this out. Now if I can find out how to turn the iPod into a Line Out instead of a amped output.
Low volume high definition is what I am looking for and I am looking also for high volume clarity.
I've seen the evilness that signal processing does
I've learned a lot about bass management on multichannel music and now play all my stuff straight through a analog bass manager with zero no other dodads besides the DAC in the player in the way.For my sub I was looking at a Carver1800 or a EP2500, both very high wattage amps for subs which I still believe you need a lot of power for. I assume I am still better off with one of these because of their cost, roughly $250 USD for approx 600 watt per channel. This is only pertaining to the sub itself.
Well I went and ordered the Chipamp Stereo kit w/ PS, the one on sale for $55.
What else am I going to need? I think the perfect box for the unit, at least on the cheap, is one of the old external USB HD boxes I have laying around.
1. I need something to get power to the unit correct?
2. Input/outputs?
3. Potential meters for the knobs?
4, Best type of solder?
Any other misc stuff I need to pick up?
I'd like to know what else I'll need so I can pick the stuff up this week.
Thanks for all the help...I'm hoping this is going to turn into something pretty interesting.
I'll admit I'm still having a hard time believing the quality of these amps simply because outside of this site, even on the other DIY speaker sites there is very little if any talk of these units.
I'm pretty excited to try this out. Now if I can find out how to turn the iPod into a Line Out instead of a amped output.
Hi,
be quick, buy in some stock of tin/lead (63/37) cored solder in various thicknesses. If you think you may become addicted to this DIY lark then buy in 500gms of each and maybe 1kg of 16g.
If all your speakers are the same sensitivity, let's take an example at 90db/W (/W implies similar impedance), then each speaker needs the same drive voltage to reproduce the recorded signal.
So your 50W into 8r amp can push out about 28Vpk and each speaker is capable of 107db maximum output.
You DO NOT NEED more power into the bass speakers.
If the sensitivities are not matched, which is much more common, then the drive voltage (and power) need to be adjusted to allow each driver to produce the same volume from the same recorded signal (at the appropriate frequency).
A PA bass driver can easily manage 96db/W (and more) and would need one quarter of the power that a 91db mid driver requires.
However a HiFi bass driver that has swapped efficiency for extended bass response could just as easily have a sensitivity of 84db/W and require four times as much power as the 90db mid driver and 16 times the power of the PA driver. Thats's where the misconception comes from. Understand the numbers and don't be misled by the uneducated.
Just to exercise your brain. Tell us what power each driver would need to produce 110dbA from this hypothetical driver array:- bass 84dbW, mid 90db/W, treble 100db/W. Clue you are exceeding half a kW in total (and the "problem" is the 84db bass driver).
be quick, buy in some stock of tin/lead (63/37) cored solder in various thicknesses. If you think you may become addicted to this DIY lark then buy in 500gms of each and maybe 1kg of 16g.
If all your speakers are the same sensitivity, let's take an example at 90db/W (/W implies similar impedance), then each speaker needs the same drive voltage to reproduce the recorded signal.
So your 50W into 8r amp can push out about 28Vpk and each speaker is capable of 107db maximum output.
You DO NOT NEED more power into the bass speakers.
If the sensitivities are not matched, which is much more common, then the drive voltage (and power) need to be adjusted to allow each driver to produce the same volume from the same recorded signal (at the appropriate frequency).
A PA bass driver can easily manage 96db/W (and more) and would need one quarter of the power that a 91db mid driver requires.
However a HiFi bass driver that has swapped efficiency for extended bass response could just as easily have a sensitivity of 84db/W and require four times as much power as the 90db mid driver and 16 times the power of the PA driver. Thats's where the misconception comes from. Understand the numbers and don't be misled by the uneducated.
Just to exercise your brain. Tell us what power each driver would need to produce 110dbA from this hypothetical driver array:- bass 84dbW, mid 90db/W, treble 100db/W. Clue you are exceeding half a kW in total (and the "problem" is the 84db bass driver).
Sounds like you are well on your way! And yes you will need a transformer. You can get a good toroid at Parts Express. But of course you may want to shop around.
The enclosure is a whole different world. Wide open to the limits of your imagination and budget.
You'll find that the hardware part is more difficult than the actual electronics.
PS My thoughts only: Better to go overboard on the heat sinks!
ENJOY!!! I've yet to hear of anyone regretting building a gainclone.
The enclosure is a whole different world. Wide open to the limits of your imagination and budget.
You'll find that the hardware part is more difficult than the actual electronics.
PS My thoughts only: Better to go overboard on the heat sinks!
ENJOY!!! I've yet to hear of anyone regretting building a gainclone.
Andrew,
Thanks for the excellent explanation...of not much I understand
I understand the concept but none of the nomenclature means anything to me. I have pretty much zero electrical background and my biggest challenge is finding out how different terms. Like Vpk, and when you say 8r, is r impedence?
Also by PA Driver, your talking sub woofer correct?
I understand your question and know the idea that the values will increase exponentially as efficiency goes down. Is the watt per db linear?
Meaning if 50watt at 8ohms produces 107 db does that mean that it takes 2.14 watts per db?
So the hypothetical speaker at 90db/W efficiency you talk about would take 51.4 watts to run at 110db?
If that is correct, or close at least I'm trying to figure out how I do the math backwards for the subwoofer at 84db/W.
Now the sub/PA in my setup would be a seperate, but the mid and tweeter would be one and they have different power requirements. Is the splitting of the wattage handled in the crossover?
I always thought the crossover handled splitting up the frequencies but I guess now the way its being explained it also handles managing how much wattage goes where.
That leads me to another question if that is true. My towers include 4 mids, 2 tweeters, 1 active sub with its own 300 watt amp, and 2 passive woofers.
If the network manages wattage and frequency is mine a two stage? I have wattage going into the speaker. It has its own internal cross over at 80hz that it feeds to the sub. It also has its own LFE. Since the woofers are passive(they react against the sub) then where does that wattage go? Assuming that the wattage/frequency split in one single function.
I think I know the answer but it will help me understand hearing it from someone else and comparing it to what I think.
Am I getting close?
Thanks for the excellent explanation...of not much I understand
I understand the concept but none of the nomenclature means anything to me. I have pretty much zero electrical background and my biggest challenge is finding out how different terms. Like Vpk, and when you say 8r, is r impedence?
Also by PA Driver, your talking sub woofer correct?
I understand your question and know the idea that the values will increase exponentially as efficiency goes down. Is the watt per db linear?
Meaning if 50watt at 8ohms produces 107 db does that mean that it takes 2.14 watts per db?
So the hypothetical speaker at 90db/W efficiency you talk about would take 51.4 watts to run at 110db?
If that is correct, or close at least I'm trying to figure out how I do the math backwards for the subwoofer at 84db/W.
Now the sub/PA in my setup would be a seperate, but the mid and tweeter would be one and they have different power requirements. Is the splitting of the wattage handled in the crossover?
I always thought the crossover handled splitting up the frequencies but I guess now the way its being explained it also handles managing how much wattage goes where.
That leads me to another question if that is true. My towers include 4 mids, 2 tweeters, 1 active sub with its own 300 watt amp, and 2 passive woofers.
If the network manages wattage and frequency is mine a two stage? I have wattage going into the speaker. It has its own internal cross over at 80hz that it feeds to the sub. It also has its own LFE. Since the woofers are passive(they react against the sub) then where does that wattage go? Assuming that the wattage/frequency split in one single function.
I think I know the answer but it will help me understand hearing it from someone else and comparing it to what I think.
Am I getting close?
Hi,
getting closer
db/W is logarithmic not linear. It very roughly follows what our ears/brain do.
db is a RATIO. 1=0db, 10=10db, 100=20db,1000=30db etc.
notice the number of zeros = the first digit of the db ratio.
db ratio =10log[p1/p2], you need a calculator for this.
The power ratio P1/P2 = inv log[db/10], "inv log" is the 10^x key.
If you want 110dbA in the room from a 100db/W driver you need an extra 10db of power. 10db=10times (from above).
So, if 1watt produces 100db then 10watts produces 110db. That's what the sensitive treble driver needs after the crossover.
Now consider the mid driver's power requirement. It manages 90db/W so it needs an extra 20db. that is 100times. So, 100Watts after the crossover will take the mid driver to the same 110db as the treble unit.
The bass driver is just 84db/W. This needs an extra 26db of power. P1/P2 (the power ratio) = inv log [26/10]=inv log (2.6)=398.1 so the bass needs 398W to match the volume level coming from the mid and treble speakers.
You can put about 400W into an actively driven bass and 100W into an actively driven mid and 10W into an actively driven treble and with an appropriate active crossover preceeding the amplifiers, the sound will be balanced . That's a total power from the amps of 508Watts. If the drivers had a passive crossover and the crossover was sending the correct frequencies to each of the speakers AND adjusting the POWER sent to the drivers to match their sensitivities then about a 1kW amp would be required to match the active system for loudness.
Now the revelation.
If all the drivers were the SAME sensitivity and you chose carefully to ensure each was 100db/W (some would be very expensive) then all the drivers would reach the same 110db with just 10W amplifiers on each, a total of just 30Watts, (cf. 598Watts). Passively a 20W amplifier would drive the combined set to about the same volume as the 1kW amp and the cheap drivers.
Just to put that into perspective. Some listeners only choose horn loaded drivers and often these can have sensitivities exceeding 105db/W. that's why they need just 8W of ClassA power to play LOUD.
The BIG message in all this Bass does not need extra power. Less sensitive drivers need extra power.
PA is public address and is often used to identify Disco and similar sound reinforcement duty. It is usually designed to reproduce music and optimised for (low quality) music duty, enabling very sensitive drivers to produce deafening volume in people filled auditoria from just a few tens of kW.
getting closer
db/W is logarithmic not linear. It very roughly follows what our ears/brain do.
db is a RATIO. 1=0db, 10=10db, 100=20db,1000=30db etc.
notice the number of zeros = the first digit of the db ratio.
db ratio =10log[p1/p2], you need a calculator for this.
The power ratio P1/P2 = inv log[db/10], "inv log" is the 10^x key.
If you want 110dbA in the room from a 100db/W driver you need an extra 10db of power. 10db=10times (from above).
So, if 1watt produces 100db then 10watts produces 110db. That's what the sensitive treble driver needs after the crossover.
Now consider the mid driver's power requirement. It manages 90db/W so it needs an extra 20db. that is 100times. So, 100Watts after the crossover will take the mid driver to the same 110db as the treble unit.
The bass driver is just 84db/W. This needs an extra 26db of power. P1/P2 (the power ratio) = inv log [26/10]=inv log (2.6)=398.1 so the bass needs 398W to match the volume level coming from the mid and treble speakers.
You can put about 400W into an actively driven bass and 100W into an actively driven mid and 10W into an actively driven treble and with an appropriate active crossover preceeding the amplifiers, the sound will be balanced . That's a total power from the amps of 508Watts. If the drivers had a passive crossover and the crossover was sending the correct frequencies to each of the speakers AND adjusting the POWER sent to the drivers to match their sensitivities then about a 1kW amp would be required to match the active system for loudness.
Now the revelation.
If all the drivers were the SAME sensitivity and you chose carefully to ensure each was 100db/W (some would be very expensive) then all the drivers would reach the same 110db with just 10W amplifiers on each, a total of just 30Watts, (cf. 598Watts). Passively a 20W amplifier would drive the combined set to about the same volume as the 1kW amp and the cheap drivers.
Just to put that into perspective. Some listeners only choose horn loaded drivers and often these can have sensitivities exceeding 105db/W. that's why they need just 8W of ClassA power to play LOUD.
The BIG message in all this Bass does not need extra power. Less sensitive drivers need extra power.
PA is public address and is often used to identify Disco and similar sound reinforcement duty. It is usually designed to reproduce music and optimised for (low quality) music duty, enabling very sensitive drivers to produce deafening volume in people filled auditoria from just a few tens of kW.
Andrew,
Thanks again. It is making more sense now. The array I am looking at is efficient at 90db so 50watt should be way more then enough at your example.
In fact when I was reading some more on the array most people run them with around 50-100 watt. The designer did say they sounded better with 100watt but I don't know why that would be if they are efficient at 50watt, is there an advantage?
We're off to the electronics store in a bit to pick up the rest of the needed pieces and then its just a matter of waiting for the kit to show up.
I plan on testing them on my DIY speakers I have first then my main drivers.
So last question...what is the advantage of doing monoblock at 50 watt and stero at 50 watt per channel. I ordered the stereo unit but if there is an advantage will upgrade it to dual monoblocks.
Thanks again. It is making more sense now. The array I am looking at is efficient at 90db so 50watt should be way more then enough at your example.
In fact when I was reading some more on the array most people run them with around 50-100 watt. The designer did say they sounded better with 100watt but I don't know why that would be if they are efficient at 50watt, is there an advantage?
We're off to the electronics store in a bit to pick up the rest of the needed pieces and then its just a matter of waiting for the kit to show up.
I plan on testing them on my DIY speakers I have first then my main drivers.
So last question...what is the advantage of doing monoblock at 50 watt and stero at 50 watt per channel. I ordered the stereo unit but if there is an advantage will upgrade it to dual monoblocks.
I also found out that my current speakers have an efficiency rating of 92db!
So the unit I'm building from Chipamp, along with a 330va transformer should give me more than enough to drive them at max volume, correct?
I'm really wondering how thats going to compare to the 135watt my Yamaha puts out which was measured in real world at around 117watts actual output.
So the unit I'm building from Chipamp, along with a 330va transformer should give me more than enough to drive them at max volume, correct?
I'm really wondering how thats going to compare to the 135watt my Yamaha puts out which was measured in real world at around 117watts actual output.
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