Most audio enthusiasts are smart enough to let someone else do the design work. It is a lot of work to get to the point where you know what you are doing, and the chances are what you want has already been done and already posted online. So if your focus is getting the best results for the least money and effort, this list is for you.
First, the usual suspects
Zaph Audio >
John Krutke has measured many drivers for distortion and published many competent designs. Few will go to the effort of learning how to design a crossover like he can. You will also find the results of various driver tests and distortion measurements. Essential reading for any diy enthusiast.
Troels Gravesen >
You'll find a vast array of designs with considerable variety, including efficient, open baffle and wide baffle designs. Certainly different to what you will typically find at a hifi store.
Tony Gee >
Well designed and documented, catering to a number of different flavours of hifi. If you are looking for some high end speakers with exotic drivers, there are some projects that might appeal.
Curt's Speaker design works
Some of these designs will appeal for their budget conscious nature, others for their novelty. Definitely worth a look.
Other sources
It's important to keep in mind that some designs are very well sorted, while others could be the work of a first-time speaker builder. There may be some designs you find in these links that could be better. A little discernment is required.
Speakerbuilding.com >
Parts Express customer gallery >
Specific projects
Econowave >
This is one speaker to watch. The concept is an economical speaker based on a waveguide and efficient pro midbass. A waveguide with compression driver is used instead of a dome tweeter. The efficiency is very high and the sound less coloured than typical horns. Ideal for tube enthusiasts or those who like their speakers with effortless oomph. Also a very good choice for home theatre.
September 25, 2010
Aussie Hifi interviews
This coming series of interviews was inspired by the StereoNET series
StereoNET interviews >
Included are interviews with:
StereoNET interviews >
Included are interviews with:
- Greg Osborn, Osborn Loudspeakers
- Andrew Ward, Aslan Acoustics
- Mick Maloney, Supratek Amplifiers
- Colin Whatmough, Whatmough Monitors
- Dr. Rod Crawford, Legend Loudspeakers
- Mike Lenehan, Lenehan Audio.
September 21, 2010
I have the drivers, now what?
So, you've picked up some drivers that you like. This is your first diy speaker. Now to get the crossover sorted. This could be the beginning of a lifelong hobby, or it could be a mistake. There is something you should decide - what kind of diy speaker builder are you?
There are two kinds:
1. Those who like to do it the easy way
2. Those who enjoy designing the whole thing from scratch
Oops!
Let me guess - you've bought the drivers and you just want to get this done quick. You say: "Tell me what to do - monkey see, monkey do. It's something to do with a crossover right? How about I just buy one of those pre-made crossovers?" This is an "Oops" moment for you. You probably need to sell those drivers, then read about how to do this the easy way.
Ok, I admit I've had an oops moment, show me the easy way >
If you're really lucky, you might get to keep and use those drivers.
"Oh puh-lease, I'm smarter than that!"
You're a bit more serious - you're a process kinda guy. Ready for the learning curve, ready to give it a go like the guy tinkering away in his garage on a vintage car, or a yacht that might one day sail.
First choice - active, passive or hybrid
Passive is the choice if you want just one amp to drive them and you don't mind a bit more effort. Active can suit those who want to speed up the process a little, don't mind using multiple amps and are likely to try out a lot of different things. Hybrid is a good choice mixing the advantages of both. You might use a passive crossover between tweeter and mid, but bi-amp the bass.
With active, getting the desired filter is easier, but you still need to measure and get the filter and driver response to work together. You also have more choices with EQ and filter slopes. Don't get caught up in thinking active or passive is always better - it's more a matter of what suits you and the speaker you want to design.
If you think active is for you, then you might like to read about your options here >
Tools
You will need:
Elliot Sound products has some good articles on active and passive crossovers
Bi-amping >
Active vs passive >
Passive crossover design >
Audioholics have a good introduction to passive crossovers >
I'll be featuring some further articles covering more detail, but for now that should be enough to get you started.
There are two kinds:
1. Those who like to do it the easy way
2. Those who enjoy designing the whole thing from scratch
Oops!
Let me guess - you've bought the drivers and you just want to get this done quick. You say: "Tell me what to do - monkey see, monkey do. It's something to do with a crossover right? How about I just buy one of those pre-made crossovers?" This is an "Oops" moment for you. You probably need to sell those drivers, then read about how to do this the easy way.
Ok, I admit I've had an oops moment, show me the easy way >
If you're really lucky, you might get to keep and use those drivers.
"Oh puh-lease, I'm smarter than that!"
You're a bit more serious - you're a process kinda guy. Ready for the learning curve, ready to give it a go like the guy tinkering away in his garage on a vintage car, or a yacht that might one day sail.
First choice - active, passive or hybrid
Passive is the choice if you want just one amp to drive them and you don't mind a bit more effort. Active can suit those who want to speed up the process a little, don't mind using multiple amps and are likely to try out a lot of different things. Hybrid is a good choice mixing the advantages of both. You might use a passive crossover between tweeter and mid, but bi-amp the bass.
With active, getting the desired filter is easier, but you still need to measure and get the filter and driver response to work together. You also have more choices with EQ and filter slopes. Don't get caught up in thinking active or passive is always better - it's more a matter of what suits you and the speaker you want to design.
If you think active is for you, then you might like to read about your options here >
Tools
You will need:
- mic preamp and calibrated mic - see example >
- software for measuring & crossover design (eg Speaker workshop, HolmImpulse, Arta)
- software for box design (WinISD) - more >
- active crossover - see active options >
- soldering iron
- multimeter to measure resistance, capacitance and inductance
Elliot Sound products has some good articles on active and passive crossovers
Bi-amping >
Active vs passive >
Passive crossover design >
Audioholics have a good introduction to passive crossovers >
I'll be featuring some further articles covering more detail, but for now that should be enough to get you started.
September 15, 2010
What is the difference between an active and passive speaker?
An active speaker has an active crossover. A passive speaker has a passive crossover. A powered speaker has built-in amps, but an active speaker may have the amps built in or external. The crossover is the critical distinction.
August 24, 2010
JV60 upgrades
One of the most popular speaker kits in Australia was the Jaycar JV60. I upgraded one of these in the past with very good results.
If you are looking for an upgrade, I now recommend LSK TL6.
If you are looking for an upgrade, I now recommend LSK TL6.
August 23, 2010
Are sealed subs faster than vented?
A common opinion expressed is that sealed subs are "faster" than vented, and it's often argued that this is related to their transient response. I'm going to argue a case for vented subs when used in a particular way and it won't suit everyone. There are some important facts that are typically overlooked in the often overly simplified arguments that are frequently made on internet audio forums.
Sealed vs vented subs outdoors
When measured outdoors or in an anechoic chamber, sealed subs tend to have better time domain performance. A vented sub will have some ringing, as seen here:
You can see the port causes a much slower decay when compared to the same driver in a sealed box as shown below:
To put these into perspective, a 20db drop in level means only 1% of the output remains. So in this context we can compare the time taken for a 20 db drop, denoted T20
What happens in a real room?
When placed in a room, the room itself will start to interact as well. Room modes will cause their own ringing, and this will generally be much worse than either sealed or vented subs.
In a typical room it will take around 250ms to achieve T20. Both of the charts above only show down to 200 ms and in both cases, it's off the chart. So even the vented version which has some ringing is actually not the bottleneck - the room is. It should also be noted that this ringing occurs down low where sounds reproduced are most likely to be artificial LFE content and not critical. In the range that deals with instruments, there is no real difference.
So why do they sound different?
Usually there are numerous differences going on simultaneuously and that makes it difficult to pin anything down. A common mistake is to pick just one thing and pin it down as the cause - often something like transient response or group delay which are real and measurable but often more than likely not the audible cause of difference.
The first suspect is frequency response and room transfer function. A sealed sub will have more roll off and this will tend to sound a bit tighter, and when combined with room modes can often yield a better raw response. But if both are equalised flat in room the main differences are likely to quickly disappear.
There are other issues involved here, but I think we can rule out transient response in most rooms.
A dynamic solution
My reason for making this point is that I often see sealed subs chosen for their perceived improvement where a vented design could be made to work better. To do the same job with a sealed driver requires more power and excursion due to the loss of efficiency. More power means more power compression which can be a backward step for dynamics. More excursion also has it's downsides and will also tend to further reduce efficiency. So there is a performance and financial cost involved.
Efficiency and dynamics go hand in hand. A solution I suggest for music applications is a vented active woofer. Aim for a driver with a fs around 40 Hz, decent excursion and high efficiency. Tune around 40 Hz then use EQ to get the in-room response right. Many pro woofers with about 9mm xmax are ideal choices, with about 95 db efficiency. With about 200w you will see about 118 db before compression. Try to get the same result with a sealed woofer and you will lose 12db of efficiency. The typical solution is a HT sub driver, but you will need a lot more power, a very expensive high excursion driver at many times the cost. An equivalent result is possible only with a major cost blowout. A better choice would be a higher quality driver.
Don't dismiss vented alignments
Avoid this mistake. A sealed woofer can be more of a plug and play solution, but also consider the cost in terms of efficiency.
Sealed vs vented subs outdoors
When measured outdoors or in an anechoic chamber, sealed subs tend to have better time domain performance. A vented sub will have some ringing, as seen here:
You can see the port causes a much slower decay when compared to the same driver in a sealed box as shown below:
To put these into perspective, a 20db drop in level means only 1% of the output remains. So in this context we can compare the time taken for a 20 db drop, denoted T20
What happens in a real room?
When placed in a room, the room itself will start to interact as well. Room modes will cause their own ringing, and this will generally be much worse than either sealed or vented subs.
In a typical room it will take around 250ms to achieve T20. Both of the charts above only show down to 200 ms and in both cases, it's off the chart. So even the vented version which has some ringing is actually not the bottleneck - the room is. It should also be noted that this ringing occurs down low where sounds reproduced are most likely to be artificial LFE content and not critical. In the range that deals with instruments, there is no real difference.
So why do they sound different?
Usually there are numerous differences going on simultaneuously and that makes it difficult to pin anything down. A common mistake is to pick just one thing and pin it down as the cause - often something like transient response or group delay which are real and measurable but often more than likely not the audible cause of difference.
The first suspect is frequency response and room transfer function. A sealed sub will have more roll off and this will tend to sound a bit tighter, and when combined with room modes can often yield a better raw response. But if both are equalised flat in room the main differences are likely to quickly disappear.
There are other issues involved here, but I think we can rule out transient response in most rooms.
A dynamic solution
My reason for making this point is that I often see sealed subs chosen for their perceived improvement where a vented design could be made to work better. To do the same job with a sealed driver requires more power and excursion due to the loss of efficiency. More power means more power compression which can be a backward step for dynamics. More excursion also has it's downsides and will also tend to further reduce efficiency. So there is a performance and financial cost involved.
Efficiency and dynamics go hand in hand. A solution I suggest for music applications is a vented active woofer. Aim for a driver with a fs around 40 Hz, decent excursion and high efficiency. Tune around 40 Hz then use EQ to get the in-room response right. Many pro woofers with about 9mm xmax are ideal choices, with about 95 db efficiency. With about 200w you will see about 118 db before compression. Try to get the same result with a sealed woofer and you will lose 12db of efficiency. The typical solution is a HT sub driver, but you will need a lot more power, a very expensive high excursion driver at many times the cost. An equivalent result is possible only with a major cost blowout. A better choice would be a higher quality driver.
Don't dismiss vented alignments
Avoid this mistake. A sealed woofer can be more of a plug and play solution, but also consider the cost in terms of efficiency.
August 19, 2010
Sub amp options
Budget
In general, I suggest if you can't afford the options discussed here right now, wait and save. You give up a lot by saving a little, and you gain very little in spending any more.
Amp location
Do you want your amp built in? Choose a plate amp.
Do you mind another amp in your rack? In some cases, an amp can be installed out of sight.
Power requirement
This depends on your driver and the design as well as your listening habits, although keep in mind a sub will often change things for many. You might get excited and turn it up more than you expect. Simulations are a good tool for making this choice.
Typical plate amps range from 240 - 500w and they are economical in this range. Higher powered versions increase the cost a great deal and if you need more power, it's often better to use a pro amp.
Plate amp vs stand alone amp
This is the main choice. If you want a simple out of the way solution with decent power, no rack space taken up and decent power, a plate amp is the attractive option. Where more power is desired, a pro power amp is the way to go as they are the most economical option. The downside is this usually means replacing the fan with a quieter version, but instructions online are available for this. Warranty is an issue here but the procedure is quite simple. With a pro amp, an external sub pre/crossover is required. These can be purchased at a kit from places like Jaycar or Altronics in Australia, or you could also consider a MiniDSP active board.
Two recommendations
For a well rounded good value plate amp, I recommend O Audio >
The filtering options are better than most and they are generally cheaper than comparable options. Cheaper options tend to fall short.
For a good bang for buck pro amp with very high power, I recommend Behringer EP4000 >
Instructions online are available for the fan mod. This is a popular choice. You can spend more without any real benefit.
One more suggestions ...
You might also consider Rythmik audio. If you are DIY inclined, then you can buy driver and plate amp designed to go together. All of their products feature servo control, and if you aren't DIY inclined then you can buy them ready made. I have two Rythmik subs > I recommend them highly, they are very accurate subs.
In general, I suggest if you can't afford the options discussed here right now, wait and save. You give up a lot by saving a little, and you gain very little in spending any more.
Amp location
Do you want your amp built in? Choose a plate amp.
Do you mind another amp in your rack? In some cases, an amp can be installed out of sight.
Power requirement
This depends on your driver and the design as well as your listening habits, although keep in mind a sub will often change things for many. You might get excited and turn it up more than you expect. Simulations are a good tool for making this choice.
Typical plate amps range from 240 - 500w and they are economical in this range. Higher powered versions increase the cost a great deal and if you need more power, it's often better to use a pro amp.
Plate amp vs stand alone amp
This is the main choice. If you want a simple out of the way solution with decent power, no rack space taken up and decent power, a plate amp is the attractive option. Where more power is desired, a pro power amp is the way to go as they are the most economical option. The downside is this usually means replacing the fan with a quieter version, but instructions online are available for this. Warranty is an issue here but the procedure is quite simple. With a pro amp, an external sub pre/crossover is required. These can be purchased at a kit from places like Jaycar or Altronics in Australia, or you could also consider a MiniDSP active board.
Two recommendations
For a well rounded good value plate amp, I recommend O Audio >
The filtering options are better than most and they are generally cheaper than comparable options. Cheaper options tend to fall short.
For a good bang for buck pro amp with very high power, I recommend Behringer EP4000 >
Instructions online are available for the fan mod. This is a popular choice. You can spend more without any real benefit.
One more suggestions ...
You might also consider Rythmik audio. If you are DIY inclined, then you can buy driver and plate amp designed to go together. All of their products feature servo control, and if you aren't DIY inclined then you can buy them ready made. I have two Rythmik subs > I recommend them highly, they are very accurate subs.
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