Right, as of previous threads I have started I am interested in building my own SMALL PA system. I mean small drivers, power, everything. This is a project for myself and if it can be of actual use all the better, but its not for anything other than the fun of building it. I have looked into all aspects of
Speaker building but most is aimed at high quality hifi speakers. Obviously I want to be able to hear the music but
I also understand that pa speakers aren't designed to sound brilliant musically. This may seem pointless but I want to do this for myself.
I looked into speaker plans everywhere And all that and into crossovers etc but then I have also looked into pa speakers specifically and found very little in anywhere near as much detail. And have found things like this for sale
PA Knock-Down Trapezoid Birch Cabinet for 12" Driver 245-325
So I got to thinking, how much design goes into it or is it a case of standard cab volume for speaker size and dot give it any further thought?
And pa crossovers don't seem to come into anything much.
Please someone explain all this to me.
Thanks
Speaker building but most is aimed at high quality hifi speakers. Obviously I want to be able to hear the music but
I also understand that pa speakers aren't designed to sound brilliant musically. This may seem pointless but I want to do this for myself.
I looked into speaker plans everywhere And all that and into crossovers etc but then I have also looked into pa speakers specifically and found very little in anywhere near as much detail. And have found things like this for sale
PA Knock-Down Trapezoid Birch Cabinet for 12" Driver 245-325
So I got to thinking, how much design goes into it or is it a case of standard cab volume for speaker size and dot give it any further thought?
And pa crossovers don't seem to come into anything much.
Please someone explain all this to me.
Thanks
PA=public address
Yes, not much information about what's inside the 'black box'.
One thing that comes to my mind is that a trapezoidal box can be positioned aside to another, in order to have more coverage angle.
But the industrial manifactures know how to make a good sounding loudspeaker; around here you'll find some designs such as the Econowave.
I prefer at least 3 way, plus a subwoofer: high efficiency brings also more fragmentation of the audiio spectrum or, it needs much more specialized drivers
to output power in narrow audio bands. Things differ from home hifi; the massive use of processing through the audio chain is also common : DSP, electronic crossovers, equalizers, those can help in making the sound right to your ears.😱
Yes, not much information about what's inside the 'black box'.
One thing that comes to my mind is that a trapezoidal box can be positioned aside to another, in order to have more coverage angle.
But the industrial manifactures know how to make a good sounding loudspeaker; around here you'll find some designs such as the Econowave.
I prefer at least 3 way, plus a subwoofer: high efficiency brings also more fragmentation of the audiio spectrum or, it needs much more specialized drivers
to output power in narrow audio bands. Things differ from home hifi; the massive use of processing through the audio chain is also common : DSP, electronic crossovers, equalizers, those can help in making the sound right to your ears.😱
I know what pa stands for but in the interest of ease
And the assumption that people would get what I meant I couldn't be bothered to say sound reinforcement system! I know there is a lot of processing involved I just want the 'inside' scoop on the actual speakers.
And the assumption that people would get what I meant I couldn't be bothered to say sound reinforcement system! I know there is a lot of processing involved I just want the 'inside' scoop on the actual speakers.
Read the manual linked on this page:
Alpha System - Technology - Nexo
I routinely work with...
3x S2, 6x B1-15, 6x M3, per side, with around 35kW of Crown amplification.
There's rather a lot to it.
For a small PA system, I'd clone something like a PA System Kustom Profile 1 One - 100w | eBay
Sounds rather good, surprising amount of bass given the speaker size, and projects well due to the MTM arrangement.
Chris
Alpha System - Technology - Nexo
I routinely work with...
3x S2, 6x B1-15, 6x M3, per side, with around 35kW of Crown amplification.
There's rather a lot to it.
For a small PA system, I'd clone something like a PA System Kustom Profile 1 One - 100w | eBay
Sounds rather good, surprising amount of bass given the speaker size, and projects well due to the MTM arrangement.
Chris
Basically, not a lot of thought, they are generic ballpark designs. The box could sound Ok with some drivers, not too good with others. The crossovers are designed with theoretical 4 ohm loads in mind, and little to no account of the drivers natural roll-off or resonance.
It's knocked together stuff like these that give cheap PA a bad name really.
So expensive PA systems use same techniques as hifi in design and production? And cheap ones guess
Same with home systems.
PA means lots of volume for the buck, rugged, and little concern for looks - think 4X4 truck.
HiFi is about reproducing as accurately as possible, not as concerned about durability or volume, but should look nice - think sports car.
PA means lots of volume for the buck, rugged, and little concern for looks - think 4X4 truck.
HiFi is about reproducing as accurately as possible, not as concerned about durability or volume, but should look nice - think sports car.
It's the appropriate box volume for a 96dB/W 12" that's expected to get down to about 70-80 Hz. Drivers that are appropriate are common. Port tuning would depend on what was chosen. You can make the resulting system as bad or as good as you like, depending on budget and resources.
Well yes that is one aspect of it. There is also the quality of parts side as well. For example there is some more budget end hifi and PA out there that is actually designed, but uses cheaper parts.
Don't forget that PA is also typically designed to array, which hifi almost never is.
In an old school point source hang you can have many boxes hung next to each other and it is important that the off axis behaviour be very well controlled (Otherwise you get moster comb filtering).
Crossovers are usually electronic these days with multiple channels of power amp, amps being cheap in terms of system cost, and often extensive DSP for time alignment, crossiver and driver protection.
Small systems are maybe a 10 inch plus compression driver in a 60 degree trapezoidal box (So that they can be easily arrayed), maybe passive, maybe not, depends on how the manufacturer is. For good stuff take a look at the D&B E9 (My favorite small box), or maybe product from K&F, Nexo (The PS10 makes a decent hifi speaker actually), L'acoustics and the like.
LOTS of research goes into making these small boxes well behaved off axis (In a PA, an off axis lobe can cause severe feedback problems, not something hifi has to deal with).
Generally at this size, 10 inch is felt to be better then 12 unless you lack a sub (And often even then) because it gets the crossover region up out of the vocal band, with a 12 inch driver you will be into cone breakup by the time you get out of the vocal band.
These small box rigs use boxes that apart from being more robust and having flyware fitted are not that different to a decent hifi box, and they usually cost similar sort of money (Maybe £500 - 1200/box).
Regards, Dan.
In an old school point source hang you can have many boxes hung next to each other and it is important that the off axis behaviour be very well controlled (Otherwise you get moster comb filtering).
Crossovers are usually electronic these days with multiple channels of power amp, amps being cheap in terms of system cost, and often extensive DSP for time alignment, crossiver and driver protection.
Small systems are maybe a 10 inch plus compression driver in a 60 degree trapezoidal box (So that they can be easily arrayed), maybe passive, maybe not, depends on how the manufacturer is. For good stuff take a look at the D&B E9 (My favorite small box), or maybe product from K&F, Nexo (The PS10 makes a decent hifi speaker actually), L'acoustics and the like.
LOTS of research goes into making these small boxes well behaved off axis (In a PA, an off axis lobe can cause severe feedback problems, not something hifi has to deal with).
Generally at this size, 10 inch is felt to be better then 12 unless you lack a sub (And often even then) because it gets the crossover region up out of the vocal band, with a 12 inch driver you will be into cone breakup by the time you get out of the vocal band.
These small box rigs use boxes that apart from being more robust and having flyware fitted are not that different to a decent hifi box, and they usually cost similar sort of money (Maybe £500 - 1200/box).
Regards, Dan.
"PA" is such a generic term. It starts at something small like a battery powered speaker for crowd control, to maybe one powered two-way speaker for a folksinger with a guitar, to a small group with a pair of cabs, and progresses through larger club systems with multiple cabs and subwoofers, and on up to, well, the Rolling Stones.
Your basic basement/garage band may have an 8-channel powered mixer and a pair of cabinets with a 15" woofer and a compression driver with horn. It works for them playing the small clubs. They don't think about biamp and triamp arrangements, and the little graphic equalizer on the mixer works well enough. I always thought Yorkville made a nice enough product at reasonable price for that market, or of course Peavey. For serious touring bands or smaller PA companies, then we are talking racks of power amps with triamp speakers, and we might find upscale cabs like EAW or whatever is hot right now. Those can be darn nice sounding systems.
I assume you are not planning to do sound for the Rolling Stones, so we'll not go there.
Hifi speakers are intended to sit politely in your living room and sound good. PA speakers are intended to be movable. SOME PA cabs are made to be flown, meaning suspended from cables. But that requires special construction. A lot of basic cabs are NOT ready for flying. CLoser to earth, a lot of smaller PA cabs have a cup in the bottom so they can be perched atop a tripod and pole.They are made to be transported without falling apart, and the connections are such that reliable hookups can be made and unmade day in and day out. Flexibility is also important. Some mid level gear might have both full range and biamp inputs, so you can use the speaker cab in more than one setting.
PA gear is more likely to have protection. Fuses, light bulbs, polyswitches, thermistors, etc are sometimes used to prevent overpowering from damaging the parts.
PA speakers are often concerned with projecting sound. Hifi speakers are more likely to be concerned with general coverage of the immediate area. When I first started touring, I had to learn the difference between the short throw horns and the long throw horns.
The parts all do the same jobs in each, a crossover splits the highs and lows for their respective drivers. A woofer for lows a tweeter for highs. And connections on the rear.
Your basic basement/garage band may have an 8-channel powered mixer and a pair of cabinets with a 15" woofer and a compression driver with horn. It works for them playing the small clubs. They don't think about biamp and triamp arrangements, and the little graphic equalizer on the mixer works well enough. I always thought Yorkville made a nice enough product at reasonable price for that market, or of course Peavey. For serious touring bands or smaller PA companies, then we are talking racks of power amps with triamp speakers, and we might find upscale cabs like EAW or whatever is hot right now. Those can be darn nice sounding systems.
I assume you are not planning to do sound for the Rolling Stones, so we'll not go there.
Hifi speakers are intended to sit politely in your living room and sound good. PA speakers are intended to be movable. SOME PA cabs are made to be flown, meaning suspended from cables. But that requires special construction. A lot of basic cabs are NOT ready for flying. CLoser to earth, a lot of smaller PA cabs have a cup in the bottom so they can be perched atop a tripod and pole.They are made to be transported without falling apart, and the connections are such that reliable hookups can be made and unmade day in and day out. Flexibility is also important. Some mid level gear might have both full range and biamp inputs, so you can use the speaker cab in more than one setting.
PA gear is more likely to have protection. Fuses, light bulbs, polyswitches, thermistors, etc are sometimes used to prevent overpowering from damaging the parts.
PA speakers are often concerned with projecting sound. Hifi speakers are more likely to be concerned with general coverage of the immediate area. When I first started touring, I had to learn the difference between the short throw horns and the long throw horns.
The parts all do the same jobs in each, a crossover splits the highs and lows for their respective drivers. A woofer for lows a tweeter for highs. And connections on the rear.
Yes, as long as you are prepared to invest an amount of time to study and learn the principles of design, and invest in some equipment to do testing. If you don't have that luxury maybe you can find a published design to work to.
Do bear in mind that ecomonies of scale are very much against the DIYer. If you just want an end result for low cost then buying decent gear second hand will be a much better route. DIY audio is more about the knowledge, satisfaction and customisation than saving money in my opinion.
Do bear in mind that ecomonies of scale are very much against the DIYer. If you just want an end result for low cost then buying decent gear second hand will be a much better route. DIY audio is more about the knowledge, satisfaction and customisation than saving money in my opinion.
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So, you want to build some speakers that aren't particularly loud and doesn't sound all that good? Should be easy!!!
Seriously though, the answer to this is - it depends. In most cases a passive subwoofer can be built cheaper than it can be bought new. However, most low end to mid level PA mains can be bought used in good condition for cheaper than it would cost in parts/material to build them.
I picked up a pair of NOS peavey impulse 100's for ~$300. After mods to improve the cabinet, I would put them up against any home hi-fi bookshelf speaker under $2000, they sound that good.
Second turbodawg. subwoofers are pricy used, but 54 hz -14000 hz PA cabinets show up on craigslist cheap a lot. And in this flyover town, the only decent sounding (+- 3 db frequency chart, distortion specified by manufacturer) speakers are in fact PA. Hifi out here means lots of glitzy looking drivers (5 usually in the high end demonstrators) and a sound like buzz buzz buzz buzz like a low rider car with a bazooka in the back. I'm thinking the demonstrators at RentalAccessCenter or AAron's. It is not just here, look at JBL's website, the consumer side. Their high end model has 5 drivers, a +- 10 db frequency range, no chart, no distortion figures, nothing but glitz.
The most accurate speakers I've ever heard are Peavey SP2, using grand piano as a test track. They are built sturdily enough to throw around, mount on poles to throw the highs all the way into the kitchen 40' away, and make my living room look like a disco. But the sound is pure Steinway when I play the piano records, and ZZ Top & E Power Biggs are impressive, too. Paid $600 the pair for my SP2-XT's, and since have seen SP2 for $500 the pair and PR15 for the same. Maybe some maintenance required at the lower prices, but original drivers and cones are still in production. It is up to the buyer to keep the crossover caps current, many bar bands aren't savvy to this trick. I've gone through 2 sets of hifi speakers (LWE III, KLH23) where the tweeter blew out and no matching driver was available. Just roll the dice, buy some speaker that fits, and take whatever sound comes out after the repair. Or buy a lot of test equipment, build some sort of test chamber, and replace the tweeter or crossover or damping 6 or a dozen times until results are suitable.
The most accurate speakers I've ever heard are Peavey SP2, using grand piano as a test track. They are built sturdily enough to throw around, mount on poles to throw the highs all the way into the kitchen 40' away, and make my living room look like a disco. But the sound is pure Steinway when I play the piano records, and ZZ Top & E Power Biggs are impressive, too. Paid $600 the pair for my SP2-XT's, and since have seen SP2 for $500 the pair and PR15 for the same. Maybe some maintenance required at the lower prices, but original drivers and cones are still in production. It is up to the buyer to keep the crossover caps current, many bar bands aren't savvy to this trick. I've gone through 2 sets of hifi speakers (LWE III, KLH23) where the tweeter blew out and no matching driver was available. Just roll the dice, buy some speaker that fits, and take whatever sound comes out after the repair. Or buy a lot of test equipment, build some sort of test chamber, and replace the tweeter or crossover or damping 6 or a dozen times until results are suitable.
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One thing that I don't see, and maybe I'm just in the wrong places, is much discussion about what sound reinforcement drivers are actually made to sound good -- "good" meaning reasonable accuracy, relatively flat response across frequency, good transient response, no compression, and NO RESONANCES.
When people say that a speaker sounds good, it might mean anything. A restaurant in town has a system that sounds like there's a graphic eq in it with all the sliders all the way down and the 250 Hz slider all the way up. That's what "good" is to them. For guitar players, "good" means whatever distortion their favorite metal band or blues schmuck uses. And some people who are interested in fancy sound equipment aren't much better.
Fifty years ago you could build competitive boxes yourself. Now it's really just something you do for fun; the stuff that you can buy can be very good. If you can find the stuff that is very good. The vast majority of it is horrible. The best (cleanest, highest-fi) inexpensive cabs I ever heard were made by a company that went out of business, so there you are.
When people say that a speaker sounds good, it might mean anything. A restaurant in town has a system that sounds like there's a graphic eq in it with all the sliders all the way down and the 250 Hz slider all the way up. That's what "good" is to them. For guitar players, "good" means whatever distortion their favorite metal band or blues schmuck uses. And some people who are interested in fancy sound equipment aren't much better.
Fifty years ago you could build competitive boxes yourself. Now it's really just something you do for fun; the stuff that you can buy can be very good. If you can find the stuff that is very good. The vast majority of it is horrible. The best (cleanest, highest-fi) inexpensive cabs I ever heard were made by a company that went out of business, so there you are.
Just a suggestion -- If you do a search for "Econowave" you'll find a whole mess of DIY projects using pro sound drivers in an economical 2-way system that's accurate enough for most for hifi use. The basic version uses a pro sound 12" or 15" woofer with a reasonably priced Selenium compression tweeter driver in an inexpensive waveguide/horn. There are suggested crossover designs published that you can build from. The horizontal dispersion from the waveguide/horn will be fairly wide by PA system standards, but is controlled from the mids on up ("controlled dispersion"). You'll probably want to add pro touring style connectors (Speakon maybe), rugged cabinet covering and protective grilles for the woofer cones.
As a hi fidelity fan, my idea of good is "reproduces the original recording accurately". Because pianos are so often reproduced badly, I test speakers and amps with a recording of a Steinway grand. I know what they are supposed to sound like, and the closer the speaker and amp are to that, the better I like it.
On the other hand, in pop/rock/country/techno/new wave/disco/international music, fads of "sounding good" are linked to what the most popular songs are now as they sound on the most popular media. This is generational like hair and clothing styles. I suppose the standard now would be earbuds and an MP3 player, but that is viewing the phenomenon from the outside. Perhaps some people actually heard the song in a famous venue, and prefer the sound as it was presented there. Thus, that sound is "good". this sound is quite likely to be modified from the high fidelity standard. I viewed they whole car audio in mini cars and low riders phenomenon with great suspicion, but it sold hundreds of thousands of units of systems that were by hifi standards, pretty vile.
Between this and your other thread about subs, I've been meaning to make a detailed response. First, there is nothing except budget stopping a PA system from sounding as good as a great hifi system. Pro electronics are balanced signal and can have very good D/A and processing. Good analog and digital amps are available. High efficiency/sensitivity horn and ported speaker systems are widely used by the tube amp crowd. It is all very doable.
It is fairly simple to quantify your goals by frequency response and volume requirements. Bass response will need to extend down to about 40-45hz for rock, or 30 hz for EDM, etc. Volume depends on the size of the venue. 100-105db at 10m outdoors (roughly 110-115db in the middle of a 100 m^2 closed and reflective room, or 120-125db@1m) is plenty loud for most people at a party. Normal home listening will be 90db to 100db. Here is a page that will let you calculate volume based on distance, sensitivity and power:
Efficiency and sensitivity conversion - loudspeaker percent and dB per watt and meter loudspeaker efficiency versus sensitivity vs speaker sensitivity 1 watt = 2,83 volt box - sengpielaudio Sengpiel Berlin
(3/4 down the page)
There are four basic formats for a small pa system, each with their pros and cons:
1. DIY boombox. The leading design is the boominator:
http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine.html
This will give maximum portability at the expense of output, but can sound very good.
2. Large pair of speakers. This can be either a pair of 15" PA mains or high sensitivity hifi floor standing speakers such as klipsch's or econowaves. Very simple and can provide decent bass and handle lots of power. Can be tough to get them up high enough to fire over a crowd and still maintain good bass response. Typically will use an external amp. Pretty much the easiest solution.
3. Small mains plus subwoofer(s). Either 10" or 12" PA mains and 15" or 18" subs(s). This is probably the the most popular mobile DJ or small scale sound re-enforcement solution. Speakers/subs can be internally powered or use amps. Can use very basic cheap components all the way up to very high end or custom designs. My own personal PA is a mix of custom and modified, with many details and tweaks to max out sound quality and portability. This thread talks about my sub build and the system:
http://www.diyaudio.com/forums/subwoofers/219923-ultra-compact-ported-15-dayton-ref-ho.html
4. Multi way active sound system. This would basically be a small version of the typical "sound system" that seems to be popular in the UK, europe and large clubs. Usually a four way system - subs, kick bins/midbass, mids, and highs. External amps and crossovers/processing. Definitely the most complicated to pull off properly, but may have the most potential. Here is a thread for a recent build of a compact sound system that looks very good:
http://www.diyaudio.com/forums/multi-way/234954-4-way-active-pa-techno-system-build-thread.html
All are valid choices and all can sound very good rocking a house party sized crowd. You need to research the options and consider how capable you are, what you want to deal with, and how big your budget is.
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