After googling and reading around for a number of hours I keep finding a difference in opinion of what is appropriate in terms of matching power from the amp to power in the speaker. The norm seems to be that the amp should be about the same if not more or even in some cases double the RMS rating of the speaker to prevent clipping and burning the driver. However, Preston electronics claims
"Some even go so far as to say the amplifier power rating should be two times the speaker's IEC power rating(*2). The rationale is that speakers can normally handle brief pulses well in excess of their average power rating. While this is true, such applications are typically found in home theater and studio monitoring, where the average power level of the program material is normally well below the speaker rating"
Therefore, I suppose my question is what's the best answer? For reference, I plan to build a 2 way full range system, possibly running with a Drayton 6-1/2" woofer and 1/8" Drayton tweeter with an LM 3886 @ 35V. It would be actively crossed over and the woofer is rated at 50 W RMS which is the exact rating of the LM 3886 @ 35V supply. The tweeter is around the same if not lower. Would this work (assuming I pony up to buy a hammond CT 24-0-24 20A transfo)?
"Some even go so far as to say the amplifier power rating should be two times the speaker's IEC power rating(*2). The rationale is that speakers can normally handle brief pulses well in excess of their average power rating. While this is true, such applications are typically found in home theater and studio monitoring, where the average power level of the program material is normally well below the speaker rating"
Therefore, I suppose my question is what's the best answer? For reference, I plan to build a 2 way full range system, possibly running with a Drayton 6-1/2" woofer and 1/8" Drayton tweeter with an LM 3886 @ 35V. It would be actively crossed over and the woofer is rated at 50 W RMS which is the exact rating of the LM 3886 @ 35V supply. The tweeter is around the same if not lower. Would this work (assuming I pony up to buy a hammond CT 24-0-24 20A transfo)?
How loud do you want to listen and how big a room do you want to fill with sound?
If you want party speakers, a 6" 2 way will not cut it. If you listen at reasonable volumes (typically < 0.1 to 1 W) you can pretty much ignore speaker and amp power ratings. The only times I or anyone I ever knew has blown tweeters or woofers, it was due to stupidity, not over or under powering.
If you want party speakers, a 6" 2 way will not cut it. If you listen at reasonable volumes (typically < 0.1 to 1 W) you can pretty much ignore speaker and amp power ratings. The only times I or anyone I ever knew has blown tweeters or woofers, it was due to stupidity, not over or under powering.
Speakers are typically rated at continuous power, music or program power, and/or Maximum power.
But I speculate that none of those are absolute. Yes, many people both recommend and use amps that are rated in excess of their speakers, though in my experience, it is typically 1.5 times the speaker rated power. BUT, and this is a big BUT, they understand that they have to use the power wisely and safely. If they do not, then they risk damaging their speakers.
Also, keep in mind that even at moderately high volumes, the long term average power in unlikely to be above about 5 watts.
But that is true of any speaker and any amp of any power rating, large or small. There is this belief that low powered amps are more dangerous than high powered amps, which most would agree with only to the smallest degree. First, no one ever defines 'Low Powered Amp". Is that 5w, or do they mean 10w, or do they mean 50w? Personally I've found 50w/ch amps to be very functional and satisfying, and affordable.
The truth is, the absolute greatest danger to your speakers, is the guy running the volume control, and that applies to small, medium, large, and very large amps. If your speakers blow, it is not the amp that blew them, it was you!
To consistently and reasonably compare amps, in the USA, we use the FTC (Federal Trade Commission's) RMS test standard measured to 8 ohms. And before anyone jumps in, yes, the term RMS is misused in this case. But, we all understand what it means in this context, so let's not go there.
But the FTC/RMS is a very demanding rating that tends to drag down power supplies. Some say, though I wouldn't be one, that "Music Power" which is tested with a dynamic signal rather than a sinewave, is a more fair standard. I have no trouble with amp being rated at Music/Dynamic Power, as long as the FTC/RMS standard is also included.
As to matching an amp to the speakers, it depends on how you intend to use them. If you intend to moderately abuse the speakers, then 50W amp on 100w speakers is probably wiser. If you can exercise some restraint, but still enjoy a good party, then amp and speakers of equal power ratings. If you are sane, educated, restrained, and capable of understanding and staying within the mechanical and electrical limits of your speaker, then certainly you can use and amp of 1.5x to 2x the rated power of the speakers.
In your case, while you have an amp capable of 50w, nothing says you have to fully run it at that power. You could step back to 40w.
Also, is a single amp going to run both woofer and tweeter, or are they both going to have their own separate amp?
The real advantage to an active speaker, is that it can also have a much easier to control active crossover. A few op-amps, a few resistor, a few small capacitors, and you are set.
If you are using a passive crossover with an internal active amp, that's fine, but it is not much better than a passive speaker with an external amp.
Again, we are back to how do you intend to use these speakers? If you are planning to throw a RAVE with a couple of 6.5" speaker, not likely. If you and some friend are planning to sit around a normal smoke filled drink filled room, then a couple of 6.5" will be fine.
Keep in mind, on each side of my amp, I have one 12" 3-way, and another 2x 8" 3.5-way. I just uses the 2x 8" for music, and bring the 12" 3-way in for movies. And this is in a modest common sided room. I have no problem with party volume levels, though I confess, my party days are long gone.
But to actually give a short answer, the amp should be fine with the speakers. But I temper that by saying again, it is not the amp that is going to damage the speakers, it is the guy running the volume control.
But then ... that's just my opinion.
Steve/bluewizard
But I speculate that none of those are absolute. Yes, many people both recommend and use amps that are rated in excess of their speakers, though in my experience, it is typically 1.5 times the speaker rated power. BUT, and this is a big BUT, they understand that they have to use the power wisely and safely. If they do not, then they risk damaging their speakers.
Also, keep in mind that even at moderately high volumes, the long term average power in unlikely to be above about 5 watts.
But that is true of any speaker and any amp of any power rating, large or small. There is this belief that low powered amps are more dangerous than high powered amps, which most would agree with only to the smallest degree. First, no one ever defines 'Low Powered Amp". Is that 5w, or do they mean 10w, or do they mean 50w? Personally I've found 50w/ch amps to be very functional and satisfying, and affordable.
The truth is, the absolute greatest danger to your speakers, is the guy running the volume control, and that applies to small, medium, large, and very large amps. If your speakers blow, it is not the amp that blew them, it was you!
To consistently and reasonably compare amps, in the USA, we use the FTC (Federal Trade Commission's) RMS test standard measured to 8 ohms. And before anyone jumps in, yes, the term RMS is misused in this case. But, we all understand what it means in this context, so let's not go there.
But the FTC/RMS is a very demanding rating that tends to drag down power supplies. Some say, though I wouldn't be one, that "Music Power" which is tested with a dynamic signal rather than a sinewave, is a more fair standard. I have no trouble with amp being rated at Music/Dynamic Power, as long as the FTC/RMS standard is also included.
As to matching an amp to the speakers, it depends on how you intend to use them. If you intend to moderately abuse the speakers, then 50W amp on 100w speakers is probably wiser. If you can exercise some restraint, but still enjoy a good party, then amp and speakers of equal power ratings. If you are sane, educated, restrained, and capable of understanding and staying within the mechanical and electrical limits of your speaker, then certainly you can use and amp of 1.5x to 2x the rated power of the speakers.
In your case, while you have an amp capable of 50w, nothing says you have to fully run it at that power. You could step back to 40w.
Also, is a single amp going to run both woofer and tweeter, or are they both going to have their own separate amp?
The real advantage to an active speaker, is that it can also have a much easier to control active crossover. A few op-amps, a few resistor, a few small capacitors, and you are set.
If you are using a passive crossover with an internal active amp, that's fine, but it is not much better than a passive speaker with an external amp.
Again, we are back to how do you intend to use these speakers? If you are planning to throw a RAVE with a couple of 6.5" speaker, not likely. If you and some friend are planning to sit around a normal smoke filled drink filled room, then a couple of 6.5" will be fine.
Keep in mind, on each side of my amp, I have one 12" 3-way, and another 2x 8" 3.5-way. I just uses the 2x 8" for music, and bring the 12" 3-way in for movies. And this is in a modest common sided room. I have no problem with party volume levels, though I confess, my party days are long gone.
But to actually give a short answer, the amp should be fine with the speakers. But I temper that by saying again, it is not the amp that is going to damage the speakers, it is the guy running the volume control.
But then ... that's just my opinion.
Steve/bluewizard
Last edited:
What you want to avoid is a situation where the amplifier is close to clipping and the corresponding listening level is not as loud as you would like it to be. Whether or not that situation occurs depends on what Ron E and BlueWizard have referred to. Another important factor is the sensitivity of the speakers.
If the amplifier is driven into clipping, that is, it is putting out square waves, then high frequency harmonics are generated that can destroy the tweeter.
So it would seem that there is no simple answer to a proper ratio of power ratings of the amplifier and speaker. Probably there are commercial clipping indicators, but maybe an interesting DIY project would be a clipping warning device connected to the output terminals of the amp.
Regards,
Pete
If the amplifier is driven into clipping, that is, it is putting out square waves, then high frequency harmonics are generated that can destroy the tweeter.
So it would seem that there is no simple answer to a proper ratio of power ratings of the amplifier and speaker. Probably there are commercial clipping indicators, but maybe an interesting DIY project would be a clipping warning device connected to the output terminals of the amp.
Regards,
Pete
I am aware of the discrepancies between "Music Power" and Peak power and RMS power and understand what each of these ratings refers to. My plan for this setup is to have each driver individually amped in a 2 channel, bi amp situation. After a little reviewing, I am thinking that based on power supply constraints and other practical reasons, I would like to have a seperate PSU for each channel. There would be an active crossover followed by individual amp per driver. Like you said, I would be running the crossover on a 741C with a few resistors and caps. The speakers would not be 2 way but the system would be so I misspoke. However, this setup would be as you said for a "smoke filled room" situation, so IMHO a 6" woofer and 1/8" tweet 2 channel/4 driver system would be fine. Could you possibly help me pick drivers based on each driver being powered by an LM 3886 GC situation after active crossover? It would most likely be a 2nd order Sallan-Key topology. Thanks for all the help already.
As said before, it's about who controls the volume.
If you want to go all out you'll have to listen when distortion starts. Try a more powerful amp and distortion will usually start at higher SPL levels.
I'm not sure if mine's the most extreme, but I've got 2000 watts coupled directly to tweeters and midrange, no problem here.
If you want to go all out you'll have to listen when distortion starts. Try a more powerful amp and distortion will usually start at higher SPL levels.
I'm not sure if mine's the most extreme, but I've got 2000 watts coupled directly to tweeters and midrange, no problem here.
When I was a uni student I hauled my 100W amp and Speakers from party to party. I blew MANY tweeters, and even some mid ranges. I had a big blue line on the chasis next to the volume control, the DO NOT turn it up past this point line. Invariably someone would decide it wasn't loud enough (even though it could be heard two blocks away) and a speaker would blow.
The blue line was there from experience, any further than that and it started to sound distorted, that was how it was determined. It's still there and is at around 2 oclock on the volume scale.
Many years later I got some dummy loads and some scope software for my pc and discovered that just past the blue line was indeed the point that the amp started clipping. The amp would play for hours at or below that line, but the speakers would last only a few seconds when pushed past that point. I eventually put polyswitches in (All party speakers should have them IMO) I could still play up to the blue line, but go over it and the speakers would just stop playing, difference was that if I turned the volume down they would come back to life
So for me and my experience, clipping (and the drunk people who cause it in the first place) does kill speakers!
Tony.
The blue line was there from experience, any further than that and it started to sound distorted, that was how it was determined. It's still there and is at around 2 oclock on the volume scale.
Many years later I got some dummy loads and some scope software for my pc and discovered that just past the blue line was indeed the point that the amp started clipping. The amp would play for hours at or below that line, but the speakers would last only a few seconds when pushed past that point. I eventually put polyswitches in (All party speakers should have them IMO) I could still play up to the blue line, but go over it and the speakers would just stop playing, difference was that if I turned the volume down they would come back to life
So for me and my experience, clipping (and the drunk people who cause it in the first place) does kill speakers!
Tony.
This is the reason pro sound guys recommend double the power. It's much easier to hear tweeter distortion than amp clipping, so they simply guarantee the amp won't clip.
i.e. DC.
DC fries tweeters and drivers alike, the tweeters just normally die first due to the smaller thermal mass.
The only way to prevent an amp from clipping is to limit the input voltage, and even that is not set in stone as you just have to increase the load to upset the applecart again.
I will add one additional point, though most here are certainly aware of this.
The relationship between Power and Voltage is not linear.
What this mean in practice is that the farther you turn the volume control up, the faster the wattage increases. Is it generally accepted that a just barely perceptible increase in volume of 3db DOUBLES the POWER. And that is a very small change in volume. If you turn you volume dial just the smallest amount, just enough to hear a slight change in volume, you have doubled the average power output of the amp.
I ran some tests on my amp/speakers, at about 10 o'clock on the volume dial, I was averaging about 3 watts, at about 12 o'clock I was averaging about 6 watts. Though keep in mind this was long term average as measured by an analog voltmeter. And, this was near unbearably loud in my small living room.
If we start tweaking the volume upward in the smallest increments, the power ramps up like this - 6w becomes 12w, becomes 24w, becomes 48w, becomes 96w, which in turn, since it is unlikely your amp goes that high, then tries to become 192 watts.
That is only 5 steps of the Volume Control upward, or roughly 15dB. One of my amps has the volume control calibrated in dB. The above change in power is the difference between 12 o'clock on the dial and just short of 2 o'clock on the dial.
Notice how very very quickly the power ramps up on the high end for the dial. That one last tiny tweak upward of the volume control cause a massive cascade in the average power level.
So, indeed from experience, and in my personal opinion, there is nothing above 2 o'clock on the dial but misery and destruction. Misery to my ears on several fronts, and destruction of the speaker and my ears.
Again, most of you already know this, but I think in the context of this conversation, it bares repeating.
Steve/bluewizard
The relationship between Power and Voltage is not linear.
What this mean in practice is that the farther you turn the volume control up, the faster the wattage increases. Is it generally accepted that a just barely perceptible increase in volume of 3db DOUBLES the POWER. And that is a very small change in volume. If you turn you volume dial just the smallest amount, just enough to hear a slight change in volume, you have doubled the average power output of the amp.
I ran some tests on my amp/speakers, at about 10 o'clock on the volume dial, I was averaging about 3 watts, at about 12 o'clock I was averaging about 6 watts. Though keep in mind this was long term average as measured by an analog voltmeter. And, this was near unbearably loud in my small living room.
If we start tweaking the volume upward in the smallest increments, the power ramps up like this - 6w becomes 12w, becomes 24w, becomes 48w, becomes 96w, which in turn, since it is unlikely your amp goes that high, then tries to become 192 watts.
That is only 5 steps of the Volume Control upward, or roughly 15dB. One of my amps has the volume control calibrated in dB. The above change in power is the difference between 12 o'clock on the dial and just short of 2 o'clock on the dial.
Notice how very very quickly the power ramps up on the high end for the dial. That one last tiny tweak upward of the volume control cause a massive cascade in the average power level.
So, indeed from experience, and in my personal opinion, there is nothing above 2 o'clock on the dial but misery and destruction. Misery to my ears on several fronts, and destruction of the speaker and my ears.
Again, most of you already know this, but I think in the context of this conversation, it bares repeating.
Steve/bluewizard
Last edited:
Assuming that you will be using the LM3886 for both bass/ midrange and treble channels in a bi-amping arrangement, that should be about foolproof in protecting the tweeter from clipping distortion. That is, with the active crossover you are reducing the voltage level at input to the treble channel relative to that of the bass/ midrange channel. In fact, you could reduce the cost by making the power supply for the treble channel less robust than the PSU for the bass channel.
The spec sheet for LM3886 states 50W cont. avg. power into an 8 Ohm load where Vcc equals +/- 35V. Given the type of listening that you would do in combination with the output power rating of the chip, most of the commonly available drivers would be satisfactory. That is, you could use drivers of average sensitivity and power handling.
Regards,
Pete
The spec sheet for LM3886 states 50W cont. avg. power into an 8 Ohm load where Vcc equals +/- 35V. Given the type of listening that you would do in combination with the output power rating of the chip, most of the commonly available drivers would be satisfactory. That is, you could use drivers of average sensitivity and power handling.
Regards,
Pete
Thanks Pete. However, I plan to rail at +/- 30 V but your statement remains quite the same. Could you possibly help me pick out a couple of your best suggestions for drivers for this idea based on the LM 3886 GC? I plan to run each channel with its own PSU but not each driver as I stated before. This is going to be my first serious build and as such I need lots of help. Also, what would you suggest if I wanted to run the tweeter but it was say a 4 Ohm impedance and only drew about 30 W RMS? As in what is the best way to chop the supply voltage from the PSU to that amp? Thanks for everything.
For Orchestral music, according to a book* I have, the distribution of power accross the frequency spectrum peak at around 350hz, or roughly in the 250hz to 500hz range. Keep in mind, this is power distribution.
If we assume 10w in that range, then in the 500hz to 100hz range, the relative power is 2 watts, 1000hz to 2000hz = 1.75w, 2khz to 4khz =1w, 4khz to 20khz 0.5w. Going down from the 250hs to 500hz range, 125hz to 250hz = 4w, 63hz to 125hz = 2w, 0hz to 63hz = 1.75w.
Now a lot of things can affect this, I suspect House/Techo/etc... are very bass heavy and the the power distributions would not be the same. None the less, this illustrates an important point. The tweeter don't have to be and rarely are equal to the power of the amp feeding them.
I would be perfectly possible to build a 3-way speaker with driver powers as follows - Woofer = 100w, Midrange = 50w, Tweeter = 25w. One could very reasonably call that a 100 watt speaker system.
There are two ways you can damage a Tweeter, though both are related, and to some extent it applies to all drivers.
One is overheating them. Simply driving them to long and too loud until the voice coil melts. And to put that in perspective, the standard rated melting point of copper is 1984°F.
The other way to physically damage them from over driving them. This can occur because of several thing. One is simply demanding too much volume from them. The physical excursion also increases if they are crossed over too low. If a tweeter is rated at, say, 1500hz to 20,000hz, it would be unwise to actually cross them over at 1.5khz. Better would be 2khz or 3khz.
The problem with that high crossover is that not many bass driver really perform that well at the high a frequency; 2khz maybe, but 3khz is pushing it.
This is precisely the dilemma of choosing matching bass and high frequency drivers. If you want bass drivers that go DEEP, they you give up midrange to get it. Which means deep drivers won't go high enough to crossover to the tweeter. If on the other hand you choose speaker that reach up nice and high into the midrange, then you give up that low bass.
This can be somewhat solved buy creating a 2.5-way system or a 3-way system. Most popular now is the 2.5-way, This is simply a 2-way speaker with a mid-bass rather than a deep woofer. Then a second specifically low-bass driver is added to fill out the bottom end. This is call a half-way because the low-bass driver does not have a unique frequency range to itself. Both the mid-bass and the low-bass share the ultra low frequencies.
A 3-way speaker splits the spectrum into three parts, bass, midrange, and treble. Exactly where the boundaries of a 3-way are, depends on the specific drivers and the design concept. But each speaker has its own unique frequency range to cover.
In an Active speaker, that's not quite that easy. These are invariably 2-way speaker.
What I would do if I were you, is search out passive 2-way speaker designs, and simply duplicate them as active speakers. Someone will have researched and determined which drivers are a good match, and what crossover frequencies work best.
I'm sure you will find countless proven 2-way bookshelf passive speaker design out there.
If you are not dead set on small bookshelf/studio monitor sized speakers, you could make an MTM design (midbass, tweeter, midbass), There are plenty of these around. Or, I'm sure if you look, you could find a design that is a 2.5way, sort of a BMT (low-bass, mid-bass, tweeter).
Still for a basic bookshelf 2-way, I think it would be best to search out proven 2-way passive design, and duplicate them as active.
It can be very frustrating searching through various drivers, trying to determine what will work with what. Also, for bass drivers, you can not use the rated high end frequency response number.
For example, if the spec say a bass driver is good from 40hz to 4000hz, very very likely, it is really good up to 1khz, tolerable up to 2khz, and it starts to get shaky after that. You really need a spec sheet that shows a frequency response graph.
A good place to start would be Zaph Audio -
Zaph|Audio
These designs are proven, and pretty meticulously detailed and tested.
Though I speak only in general, there are MANY here much more experienced that myself, I would suggest the Dayton Classic, or the Dayton Aluminum cone bass drivers -
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-300
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-305
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-330
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-335
If you look over in the column on the right side of these pages, you will see a link to the Spec Sheet for each speaker.
Here is an example of the Dayton Classic 5-1/4" DC130AS-8 Woofer -
http://www.parts-express.com/pdf/295-300s.pdf
It does pretty well out to about 2khz, then has a peak that would have to be suppressed. Adding a notch filter to suppress that peak should be relatively easy with active filters. Also note that the rated high end is 4khz.
You can't choose the tweeter until you have the woofer, and know the realistic working range of that woofer.
My advise - get ready for a bumpy ride.
Steve/bluewizard
If we assume 10w in that range, then in the 500hz to 100hz range, the relative power is 2 watts, 1000hz to 2000hz = 1.75w, 2khz to 4khz =1w, 4khz to 20khz 0.5w. Going down from the 250hs to 500hz range, 125hz to 250hz = 4w, 63hz to 125hz = 2w, 0hz to 63hz = 1.75w.
Now a lot of things can affect this, I suspect House/Techo/etc... are very bass heavy and the the power distributions would not be the same. None the less, this illustrates an important point. The tweeter don't have to be and rarely are equal to the power of the amp feeding them.
I would be perfectly possible to build a 3-way speaker with driver powers as follows - Woofer = 100w, Midrange = 50w, Tweeter = 25w. One could very reasonably call that a 100 watt speaker system.
There are two ways you can damage a Tweeter, though both are related, and to some extent it applies to all drivers.
One is overheating them. Simply driving them to long and too loud until the voice coil melts. And to put that in perspective, the standard rated melting point of copper is 1984°F.
The other way to physically damage them from over driving them. This can occur because of several thing. One is simply demanding too much volume from them. The physical excursion also increases if they are crossed over too low. If a tweeter is rated at, say, 1500hz to 20,000hz, it would be unwise to actually cross them over at 1.5khz. Better would be 2khz or 3khz.
The problem with that high crossover is that not many bass driver really perform that well at the high a frequency; 2khz maybe, but 3khz is pushing it.
This is precisely the dilemma of choosing matching bass and high frequency drivers. If you want bass drivers that go DEEP, they you give up midrange to get it. Which means deep drivers won't go high enough to crossover to the tweeter. If on the other hand you choose speaker that reach up nice and high into the midrange, then you give up that low bass.
This can be somewhat solved buy creating a 2.5-way system or a 3-way system. Most popular now is the 2.5-way, This is simply a 2-way speaker with a mid-bass rather than a deep woofer. Then a second specifically low-bass driver is added to fill out the bottom end. This is call a half-way because the low-bass driver does not have a unique frequency range to itself. Both the mid-bass and the low-bass share the ultra low frequencies.
A 3-way speaker splits the spectrum into three parts, bass, midrange, and treble. Exactly where the boundaries of a 3-way are, depends on the specific drivers and the design concept. But each speaker has its own unique frequency range to cover.
In an Active speaker, that's not quite that easy. These are invariably 2-way speaker.
What I would do if I were you, is search out passive 2-way speaker designs, and simply duplicate them as active speakers. Someone will have researched and determined which drivers are a good match, and what crossover frequencies work best.
I'm sure you will find countless proven 2-way bookshelf passive speaker design out there.
If you are not dead set on small bookshelf/studio monitor sized speakers, you could make an MTM design (midbass, tweeter, midbass), There are plenty of these around. Or, I'm sure if you look, you could find a design that is a 2.5way, sort of a BMT (low-bass, mid-bass, tweeter).
Still for a basic bookshelf 2-way, I think it would be best to search out proven 2-way passive design, and duplicate them as active.
It can be very frustrating searching through various drivers, trying to determine what will work with what. Also, for bass drivers, you can not use the rated high end frequency response number.
For example, if the spec say a bass driver is good from 40hz to 4000hz, very very likely, it is really good up to 1khz, tolerable up to 2khz, and it starts to get shaky after that. You really need a spec sheet that shows a frequency response graph.
A good place to start would be Zaph Audio -
Zaph|Audio
These designs are proven, and pretty meticulously detailed and tested.
Though I speak only in general, there are MANY here much more experienced that myself, I would suggest the Dayton Classic, or the Dayton Aluminum cone bass drivers -
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-300
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-305
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-330
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-335
If you look over in the column on the right side of these pages, you will see a link to the Spec Sheet for each speaker.
Here is an example of the Dayton Classic 5-1/4" DC130AS-8 Woofer -
http://www.parts-express.com/pdf/295-300s.pdf
It does pretty well out to about 2khz, then has a peak that would have to be suppressed. Adding a notch filter to suppress that peak should be relatively easy with active filters. Also note that the rated high end is 4khz.
You can't choose the tweeter until you have the woofer, and know the realistic working range of that woofer.
My advise - get ready for a bumpy ride.
Steve/bluewizard
Last edited:
How would the DC get past the series capacitor of a passive hi pass filter?
The reason square waves fry tweeters is that they contain all possible harmonics at full level ie they are bursts of white noise.
This can easily be shown to be correct with the help of a analogue subtractive synthesizer.
milsman,
If you plan to make your speakers fully active, then LM3886 GCs will be fine (I use them in an active three way). Using a +- 30V supply will give plenty of power to the speakers and, in normal listening, (NOT parties) will give plenty of volume.
The provisos are:
They aren't big drivers so don't expect huge volume,
Use speaker protectors on all drivers and a cap on the tweeters won't hurt (despite what a lot of people say, you won't tell the difference)
Use an active crossover that has individual level control
My advice is to go for it; you will learn a lot and enjoy it. I love my active three ways which I converted from active two ways. They were originally passives. Each step improved things greatly. Going active means you can change part of the speaker without changing everything else; something passive doesn't allow.
It isn't rocket science and it isn't as hard as a lot of people make out. The over-riding consideration is to treat mains voltages with total respect and follow good earthing and wiring principles.
Frank
If you plan to make your speakers fully active, then LM3886 GCs will be fine (I use them in an active three way). Using a +- 30V supply will give plenty of power to the speakers and, in normal listening, (NOT parties) will give plenty of volume.
The provisos are:
They aren't big drivers so don't expect huge volume,
Use speaker protectors on all drivers and a cap on the tweeters won't hurt (despite what a lot of people say, you won't tell the difference)
Use an active crossover that has individual level control
My advice is to go for it; you will learn a lot and enjoy it. I love my active three ways which I converted from active two ways. They were originally passives. Each step improved things greatly. Going active means you can change part of the speaker without changing everything else; something passive doesn't allow.
It isn't rocket science and it isn't as hard as a lot of people make out. The over-riding consideration is to treat mains voltages with total respect and follow good earthing and wiring principles.
Frank
Frank,
I have learned a ton in the past few weeks in terms of redoing my design and rethinking my approach but I am pretty settled on what I have so far which is my 2 way fully active speakers. These plan to be my "hey guys lets kick it in the apartment and listen to some crisp home made speakers" speakers.
However, being that I am at this point, here is my current foundation upon which I humbly ask you and everyone else on this thread and diyaudio.com to help me build.
I will most likely use this driver as my woofer :
http://www.parts-express.com/pdf/295-300s.pdf
I need help picking a good tweeter to match. The rail voltage will probably be around +/- 30V as stated before and I hope to put in a 2nd order Sallen-Kay crossover at about 2 Khz with a notch filter there as well and a zobel network and baffle step correction applied appropriately.
Any thoughts on tweeters or other things I havent thought of?
I have learned a ton in the past few weeks in terms of redoing my design and rethinking my approach but I am pretty settled on what I have so far which is my 2 way fully active speakers. These plan to be my "hey guys lets kick it in the apartment and listen to some crisp home made speakers" speakers.
However, being that I am at this point, here is my current foundation upon which I humbly ask you and everyone else on this thread and diyaudio.com to help me build.
I will most likely use this driver as my woofer :
http://www.parts-express.com/pdf/295-300s.pdf
I need help picking a good tweeter to match. The rail voltage will probably be around +/- 30V as stated before and I hope to put in a 2nd order Sallen-Kay crossover at about 2 Khz with a notch filter there as well and a zobel network and baffle step correction applied appropriately.
Any thoughts on tweeters or other things I havent thought of?
milsman2,
In regards to the PSUs, my suggestion would be to have a first PSU for the two (left and right channel ) bass/ midrange amps and a second less robust PSU for the two treble amps.
A tweeter that I recently discovered offered by Parts Express is 270-182, Goldwood #GT-525, a 1" soft dome tweeter with quite high power handling. It is one of the least expensive tweeters offered by PE. Fs of this tweeter = 1 kHz, which is what you would need if your crossover frequency is 2 kHz. I haven't given the GT-525 extensive listening yet, but I think that it is at least a tweeter of good quality. Another tweeter that I have used in the past is the Morel MDT-12 (PE # 277-060) which IMHO has a superb sound (purely subjective). However the MDT-12 is fairly expensive.
Regards,
Pete
In regards to the PSUs, my suggestion would be to have a first PSU for the two (left and right channel ) bass/ midrange amps and a second less robust PSU for the two treble amps.
A tweeter that I recently discovered offered by Parts Express is 270-182, Goldwood #GT-525, a 1" soft dome tweeter with quite high power handling. It is one of the least expensive tweeters offered by PE. Fs of this tweeter = 1 kHz, which is what you would need if your crossover frequency is 2 kHz. I haven't given the GT-525 extensive listening yet, but I think that it is at least a tweeter of good quality. Another tweeter that I have used in the past is the Morel MDT-12 (PE # 277-060) which IMHO has a superb sound (purely subjective). However the MDT-12 is fairly expensive.
Regards,
Pete
Last edited:
Hi,
Not to put too fine a point on it your overcomplicating
what will be a fairly mundane loudspeaker, going active
with budget drivers is really not the way to do things.
rgds, sreten.
undefinition (see FAQs)
Zaph|Audio
FRD Consortium tools guide
Designing Crossovers with Software Only
RJB Audio Projects
Jay's DIY Loudspeaker Projects
Speaker Design Works
HTGuide Forum - A Guide to HTguide.com Completed Speaker Designs.
DIY Loudspeaker Projects Troels Gravesen
Humble Homemade Hifi
Quarter Wavelength Loudspeaker Design
The Frugal-Horns Site -- High Performance, Low Cost DIY Horn Designs
Linkwitz Lab - Loudspeaker Design
Music and Design
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.