Hello,
this is my first post in these forums. Im a hifi nerd that always belived building my own speakers was the way to go, I built a few but never really understood what I was doing. Somehow they turned out alright anyway but that was mostly luck I guess.
For my next project I need to get it done the right way, and for that I need some input. I know how to build & calculate a box, how to put together a crossover and make it all work, but Im lacking some practical basic knowledge.
The Project is this:
A pair of fullrange speakers mostly intended for outdoor use, playing disco style music. Power rating of atleast 800 w rms, capable of 125-130 dB max sound level. What Im looking at is either a dual 15" + a 2" horn, or single 18" + 2" horn, or single 18" + 10" + 1".
Some say that drivers of certain sizes either have or lack the right "punch". In dance music you have the drumbeat at one frequency rance and the bass at another. What Im hearing is that a 15" driver might be right for the drumbeat and bad at the bass, while its the opposite for an 18" driver. Is this true? If I look at frequenzy sheets for different 15" and 18" drivers you could acheive similar results, paper-wise.
Or is this this due to the Qts? At loudspeakerplus there is a table on wich Qts values are good for wich applications.
If anyone have any answers, or can tell me where to go look for information, please let me know.
regards
Daniel
this is my first post in these forums. Im a hifi nerd that always belived building my own speakers was the way to go, I built a few but never really understood what I was doing. Somehow they turned out alright anyway but that was mostly luck I guess.
For my next project I need to get it done the right way, and for that I need some input. I know how to build & calculate a box, how to put together a crossover and make it all work, but Im lacking some practical basic knowledge.
The Project is this:
A pair of fullrange speakers mostly intended for outdoor use, playing disco style music. Power rating of atleast 800 w rms, capable of 125-130 dB max sound level. What Im looking at is either a dual 15" + a 2" horn, or single 18" + 2" horn, or single 18" + 10" + 1".
Some say that drivers of certain sizes either have or lack the right "punch". In dance music you have the drumbeat at one frequency rance and the bass at another. What Im hearing is that a 15" driver might be right for the drumbeat and bad at the bass, while its the opposite for an 18" driver. Is this true? If I look at frequenzy sheets for different 15" and 18" drivers you could acheive similar results, paper-wise.
Or is this this due to the Qts? At loudspeakerplus there is a table on wich Qts values are good for wich applications.
If anyone have any answers, or can tell me where to go look for information, please let me know.
regards
Daniel
You're in luck I think. Another thread just started that is about this topic:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=86690&perpage=10&pagenumber=1
I t would be best if you posted there with the above info, and maybe we could delete this thread
http://www.diyaudio.com/forums/showthread.php?s=&threadid=86690&perpage=10&pagenumber=1
I t would be best if you posted there with the above info, and maybe we could delete this thread
You won't get that sort of dB level outside with that little power. Close up maybe.
Punch has more to do with good box design than speaker size. I don't use anything larger than a 15" driver (boxes get too big for my liking) and you can get nice low bass with punch that will kick your head in given enough power and a small enough room.
1x15" 1x10" 1x1" per side should do you quite well. Don't get hung up on inches But you WILL need to go active for the bass.
18+2 or 15+2 will sound pretty dire off axis or far away.
Punch has more to do with good box design than speaker size. I don't use anything larger than a 15" driver (boxes get too big for my liking) and you can get nice low bass with punch that will kick your head in given enough power and a small enough room.
1x15" 1x10" 1x1" per side should do you quite well. Don't get hung up on inches
But you WILL need to go active for the bass. 18+2 or 15+2 will sound pretty dire off axis or far away.
No offense Daniel, but you're asking what I consider to be basic newbie questions and trying to scratch design and build what will need to be a high performance system to meet your specs. Either buy stuff secondhand or build known designs. Otherwise you'll end up with a poorly performing system that cost you a lot in terms of money, time and sweat.SPL King said:
By all means learn, design and enjoy, but start a bit more reasonably and there is plenty of experience and advice here for that.
I gotta disagree, while several others share your idea of start simple I think if one is prepared to learn, nothing is lost by buying good components. If they dont turn out great you can tweak the crossover, if that doesnt help then you replace the driver that is causing the imbalance. And you get to keep that driver for a future project.
It is your money, so the less you know at the time of purchase the higher the odds that you will have to purchase additional equipment to correct the mistake.
Then again I enjoy taking the time to learn how and why everything works, its almost an obsession.
Agreed with Brett
I built 10 prototype boxes - have a shelf full of drivers left over and zipped up multi-yards of MDF - before I settled on an established design (which I modified later to my GREAT delight).
People who design loudspeakers for a living know what they are doing. Luck is a tiny part of the equation.
You have nothing to lose by starting at a known point - in fact - you'll be knocked sideways by what you'll learn.
The trick is to find an established DIY design that gets close to what you want. Spend less cash, get really spectacular results...
Then... once you get the drift of it - buy the equipment and go wild and start building what you want
Regards,
Tom
I built 10 prototype boxes - have a shelf full of drivers left over and zipped up multi-yards of MDF - before I settled on an established design (which I modified later to my GREAT delight).
People who design loudspeakers for a living know what they are doing. Luck is a tiny part of the equation.
You have nothing to lose by starting at a known point - in fact - you'll be knocked sideways by what you'll learn.
The trick is to find an established DIY design that gets close to what you want. Spend less cash, get really spectacular results...
Then... once you get the drift of it - buy the equipment and go wild and start building what you want
Regards,
Tom
Hi Daniel,
If you are looking for that kind of SPL and haven't done a lot of this, you can often find manufacturers that have done the work for you.
You should consider going active XO as you want a steep slope to your drivers for protection.
The question then becomes how much do you want to spend? Even a modest two piece modular will cost upwards of a few grand USD. This would be a 2 X 18 in a folded horn and a 2 X 10" or 2 x 12" plus a 2" horn
Or you can start small and go for a 2 X 15" and a 1" horn in a 2.5 way. Maybe throw in a midbass for good measure but you are talikng some serious dB, not sure the smaller unit would do that.
If you are looking for that kind of SPL and haven't done a lot of this, you can often find manufacturers that have done the work for you.
You should consider going active XO as you want a steep slope to your drivers for protection.
The question then becomes how much do you want to spend? Even a modest two piece modular will cost upwards of a few grand USD. This would be a 2 X 18 in a folded horn and a 2 X 10" or 2 x 12" plus a 2" horn
Or you can start small and go for a 2 X 15" and a 1" horn in a 2.5 way. Maybe throw in a midbass for good measure but you are talikng some serious dB, not sure the smaller unit would do that.
Yes Im reiterating part of your point, excuse me if I wasnt clear. Im not saying you save money by jumping in wallet first. The learning curve applies to any speaker regardless of application, design is design and building is building.
One of his plans is a loud 2-way, Im sorry guys but what are you telling him to build... a "simple" and not so loud 2-way! The difference between loud and not is efficiency and power handling, so purchasing big pro audio components will achieve this goal. He still has to design the system the same way, xover and enclosure, etc.
You learn from doing, if you can afford to buy parts for experimentation then go for it they wont be wasted, my other point.
Hello,
thanx for intresting answers! Ill definatley check out that other thread.
Maybe the SPL I stated is too much outdoors - I dont need to reach a certain number - but I know these speakers would be enough for a small party for say 50-100 people.
Buying a pair of finished speakers is out of the question, Im not looking for a perfect result but rather a fun project during the winter. I already built a 3-way speaker with drivers that I choosed myself and a bunch of resistors, so I know I can get right given enough time. But ofcourse, building a ready-made kit would make things easier.
Is going with active XO really neceseary? Would I loose alot if I didnt? I would ofcourse do that, and buy a dbx drive rack pa for XO, but I dont have that kind of money to play with. Also I have a limited amout of power at my hands - the generator delivers 2500 watts and I need some left for lighting.
thanx for intresting answers!
Ill definatley check out that other thread. Maybe the SPL I stated is too much outdoors - I dont need to reach a certain number - but I know these speakers would be enough for a small party for say 50-100 people.
Buying a pair of finished speakers is out of the question, Im not looking for a perfect result but rather a fun project during the winter. I already built a 3-way speaker with drivers that I choosed myself and a bunch of resistors, so I know I can get right given enough time. But ofcourse, building a ready-made kit would make things easier.
Is going with active XO really neceseary? Would I loose alot if I didnt? I would ofcourse do that, and buy a dbx drive rack pa for XO, but I dont have that kind of money to play with. Also I have a limited amout of power at my hands - the generator delivers 2500 watts and I need some left for lighting.
Hi there
There are plenty of simple designs possible for a quality P.A style of speaker.
first quality components
JBL make some some stunning sounding P.A drivers and if you can afford them so do EV, if cost is an issue P. Audio and Sollenium have good price/ results. what you ideally want is 2 x 15" mid/woofer with a high spl of around 98db @ 1 meter.
Neomidium magnets keep the weight right down so if you want to carry/ lug them it may be worth the premium price.
Strong Box is vital
A typical twin 15 with a 2" horn box would be around a 250 litres box and a ported design, 18mm MDF heavly cross braced for structual strength is a good compromise for weight / performance.
Buy the biggest flare that you can afford/ fit for the best results from the 2"driver (500hz cut off is someting to look for)
cross over low around 500hz - 800hz and you will get the smoothest sound including off axis/ crossing over high 1 200hz to 1 800hz /best power handling less smooth crossover as our hearing
is more sensitive in that region.
most commercial systems are a balance of these parameters
Personally I feel that this may match or excede your expectation, its totally a case of budget and need. If you would like more advice and far more detail, just let me know, I have the plans somewhere around and can be modified for most of the drivers mentioned above.
Yes good results can be achieved with passive crossovers / electric can sound better though.
There are plenty of simple designs possible for a quality P.A style of speaker.
first quality components
JBL make some some stunning sounding P.A drivers and if you can afford them
so do EV, if cost is an issue P. Audio and Sollenium have good price/ results. what you ideally want is 2 x 15" mid/woofer with a high spl of around 98db @ 1 meter.Neomidium magnets keep the weight right down so if you want to carry/ lug them it may be worth the premium price.
Strong Box is vital
A typical twin 15 with a 2" horn box would be around a 250 litres box and a ported design, 18mm MDF heavly cross braced for structual strength is a good compromise for weight / performance.
Buy the biggest flare that you can afford/ fit for the best results from the 2"driver (500hz cut off is someting to look for)
cross over low around 500hz - 800hz and you will get the smoothest sound including off axis/ crossing over high 1 200hz to 1 800hz /best power handling less smooth crossover as our hearing
is more sensitive in that region.
most commercial systems are a balance of these parameters
Personally I feel that this may match or excede your expectation, its totally a case of budget and need. If you would like more advice and far more detail, just let me know, I have the plans somewhere around and can be modified for most of the drivers mentioned above.
Yes good results can be achieved with passive crossovers / electric can sound better though.
Bollocks. An EL84SE can sound decent, but a well thought out and implemented design by someone with experience and understanding will be far better even on first iteration than a newbie. A PA of the OP's spec is more akin to an 805 A2 amp. Which do you think has the most chance of being successful in a smallish number of iterations from the POV of a relatively inexperienced designer? Do you think you'd come up with a better design than the LABhorn quickly? Or is it better to build Tom's design. After all, he does know a little bit about the subject, and the design has been proven in the field and refinements made by pro sound guys who have the experience knowledge and test gear to know what actually works.nunayafb said:
Where exactly did I say that?
Correct in a philosophical sense, but pragmatically, you have no idea of the task involved. Designing pro gear that need to survive all sorts of movement, handling (incl ergonomics, balance and packing densities), abuse, accidents etc on top of the basic design parameters.
Again, philosophically true, but one of my original points was to build known designs. There are two very good reasons for this
1: I'd like SPL King to be successful in this project, and not just build something that he loves (Beranek's Law) but makes everyone else cringe or suffer ear bleed; and
2: Once he has something that he's built and works well (known design), other designs can be tested against a known reference, which can be especially valuable and illuminating if the new designs use some of the same components, eg drivers.
SPL King said:
That does change things a bit. Over what sort of area would you need coverage?
Yes and yes.
A Driverack is a godsend when designing, as you have a squillion possible configurations at the touch of a button but simpler active xovers are still a lot quicker and effectively cheaper than a lot of passives required for experimenting.
http://www.speakerplans.com/index.php?id=plans
http://www.audioheritage.org/html/perspectives/drews-clues/system.htm
More info/links when I find my old bookmarks.
Let's back up a bit here gentlemen. Rather than debate the merits of designing your own systems, perhaps SPL King just wants some decent party speakers. As mentioned in post 8, some manufacturers will do the ground work for you. If you go to the Selenium site via Parts Express, you will find the designs they recommend, with the links to the drivers.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=220
If you have heard the Selenium stuff, you will know that they offer bang for the buck. It really boils down to how much you can squeeze from your wallet for this. It's not cheap but the results are more likely to satisfy than attempting a design of which SPL King might not be ready for.
The reason you want to go active XO is that using a 24dB passive hogs it's share of power and costs a lot as well.
Amps are very different in the use of power also. Consider using something like a class D for the low end at least. That is what I am using in my big stuff now. Easier to carry.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=220
If you have heard the Selenium stuff, you will know that they offer bang for the buck. It really boils down to how much you can squeeze from your wallet for this. It's not cheap but the results are more likely to satisfy than attempting a design of which SPL King might not be ready for.
The reason you want to go active XO is that using a 24dB passive hogs it's share of power and costs a lot as well.
Amps are very different in the use of power also. Consider using something like a class D for the low end at least. That is what I am using in my big stuff now. Easier to carry.
I agree.
My thought for SPL King was that for his first fast car he might want to drive a Ford Mustang before ordering his McLaren F1.
I was thinking he might even get an old set of Altec 828 (A7) or 825 (A5) cabinets and horns from ebay and stuff them himself. He did say 50 - 100 people. That all I use when the party is small.
My thought for SPL King was that for his first fast car he might want to drive a Ford Mustang before ordering his McLaren F1.
I was thinking he might even get an old set of Altec 828 (A7) or 825 (A5) cabinets and horns from ebay and stuff them himself. He did say 50 - 100 people. That all I use when the party is small.
Im sorry that you misunderstood me, Im not seeking anything for large outdoor events. These boxes are for a certain purpose - smaller private parties. 200 ppl max. High soundquality and sound pressure is a must, as well as simplicity. I also have a very small budget: about $1500, wich buys me the following:
4 x P.Audio C15-400B 15"
2 x 2" driver OEM brand with large 15"x15" horns
1 x Power Amp oem brand 2 x 750 rms 4 ohm
All required hardware & components
or anything similar
For a bigger event, I could add a couple of dual 18" subs to those.
Would I need such a steep slope as 24 dB for the XO? Ive looked at designs with just 12 dB, they have a lot less components in them...
4 x P.Audio C15-400B 15"
2 x 2" driver OEM brand with large 15"x15" horns
1 x Power Amp oem brand 2 x 750 rms 4 ohm
All required hardware & components
or anything similar
For a bigger event, I could add a couple of dual 18" subs to those.
Would I need such a steep slope as 24 dB for the XO? Ive looked at designs with just 12 dB, they have a lot less components in them...
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