I am putting together a PA system for piano-organ-voice and harmonica playing usually in a relatively small practice space. I don't need huge volume potential but want to get a full and natural sound.
I have done lots of projects and built electric and acoustic guitars, but the only experience I have building audio speakers is years ago when I put a pair of vintage Western Electric 755a speakers in and open baffle. I loved the simplicity of that form and want to create something similar at a larger scale for practice and performance.
I am using some new parts and some items I have been using with my current setup... re-used will be a Mackie 8 channel mixer for input. New is a B-52 Matrix-1500 BBE 3-Ch Plate Amplifier (1200W w/sub crossover), two Eminence Beta-12CX 12" Coaxial Driver with PRV Audio D280Ti-S 1" Titanium Horn Drivers and LaVoce SAF184.01 18" Subwoofer.
I'm thinking of putting the 12's in an open baffle and the sub in an open "H" cab.
is that a stupid idea? and how much math do I need to learn to figure out the dimensions of the baffle and sub cab?
I have done lots of projects and built electric and acoustic guitars, but the only experience I have building audio speakers is years ago when I put a pair of vintage Western Electric 755a speakers in and open baffle. I loved the simplicity of that form and want to create something similar at a larger scale for practice and performance.
I am using some new parts and some items I have been using with my current setup... re-used will be a Mackie 8 channel mixer for input. New is a B-52 Matrix-1500 BBE 3-Ch Plate Amplifier (1200W w/sub crossover), two Eminence Beta-12CX 12" Coaxial Driver with PRV Audio D280Ti-S 1" Titanium Horn Drivers and LaVoce SAF184.01 18" Subwoofer.
I'm thinking of putting the 12's in an open baffle and the sub in an open "H" cab.
is that a stupid idea? and how much math do I need to learn to figure out the dimensions of the baffle and sub cab?
I'd say yes, using a dipole system for any kind of PA duties probably counts as stupid. Sorry.
Dipole systems throw away a huge amount of output potential, particularly below a few hundred Hz.
To give you an idea, an OB needs 1x15" a side, minimum, for acceptable bass. I used a pair of Beyma 15P1200Nd to try this, and found I could get pretty decent domestic levels out of them, if I pushed to around 30mm p/p travel - requiring a lot of EQ and power.
With those drivers loaded into ported boxes, they do just fine at reproducing the kick and bass for a rock band for a couple of hundred people.
I'd suggest going for ported boxes all-round. For PA duties, they'll wipe the floor with open baffles in terms of both output and feedback problems. Remember - OBs throw as much sound forwards as backwards. The backwards sound will get right into your mics.
Chris
Dipole systems throw away a huge amount of output potential, particularly below a few hundred Hz.
To give you an idea, an OB needs 1x15" a side, minimum, for acceptable bass. I used a pair of Beyma 15P1200Nd to try this, and found I could get pretty decent domestic levels out of them, if I pushed to around 30mm p/p travel - requiring a lot of EQ and power.
With those drivers loaded into ported boxes, they do just fine at reproducing the kick and bass for a rock band for a couple of hundred people.
I'd suggest going for ported boxes all-round. For PA duties, they'll wipe the floor with open baffles in terms of both output and feedback problems. Remember - OBs throw as much sound forwards as backwards. The backwards sound will get right into your mics.
Chris
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What exactly are you going for with this? As an interesting personal studio system that generates ambience as part of the design this is an interesting concept, but this effectively makes the speaker system another instrument instead of the blank canvas isolated sound source that a PA system is intended to be. As such your listening room will be integral to the results generated so this will not make a portable PA that can be transported around to different venues, a room with less reflective properties won't generate as much ambience and one with more reverb or a significant reverb time will result in very poor intelligibility.
I'm trying to imagine "music practice" "in a relatively small practice space" using a PA system. Back when I was hosting a band practice at my home, one of the best innovations I came up with was the use of independently volume controlled, over the ear headphones for everyone involved. The reduction of stress from having to - repeatedly - listen to the band's output at live or near live levels was significant, moving from wholly intolerable to actually pleasant much of the time. Key to that pleasantness was the independent volume adjustments, along with significant compression of the board mix, done using a DBX unit at the time.
For a performance situation, the use of OBs I suppose depends on where you'll be playing and what material your band covers. A typical PA speaker is very efficient and wants to cover all possible on-stage performances, and an absolute requirement is that it can handle the loud ones - without detracting from the performer's sound. If your gigs arent teenager-loud by necessity (I've no idea the kind of music you play) I see nothing wrong with trying other than "PA speakers" for your sound system.
Way back when, I used to live in Massachusetts. The BSO put on an annual concert at the Hatch and with the multitudes gathered, we used to joke that most heard the orchestra not from the acoustic output of the Shell, but through "somebody's sound system". That sound system - of course - being comprised of typical PA system components, units purposefully designed for efficient, practical and general sound reinforcement.
Doing something different could be a step in the right direction, depending of course on how well you pull it off. I'd say all sound systems require at least some setup attention as you move from venue to venue. Perhaps with a combination of not needing to go so loud, DSP and some care toward the physical design of your OBs regarding microphone feedback, you might have something that could enhance the sound of your band.
Somebody's sound system, indeed!
For a performance situation, the use of OBs I suppose depends on where you'll be playing and what material your band covers. A typical PA speaker is very efficient and wants to cover all possible on-stage performances, and an absolute requirement is that it can handle the loud ones - without detracting from the performer's sound. If your gigs arent teenager-loud by necessity (I've no idea the kind of music you play) I see nothing wrong with trying other than "PA speakers" for your sound system.
Way back when, I used to live in Massachusetts. The BSO put on an annual concert at the Hatch and with the multitudes gathered, we used to joke that most heard the orchestra not from the acoustic output of the Shell, but through "somebody's sound system". That sound system - of course - being comprised of typical PA system components, units purposefully designed for efficient, practical and general sound reinforcement.
Doing something different could be a step in the right direction, depending of course on how well you pull it off. I'd say all sound systems require at least some setup attention as you move from venue to venue. Perhaps with a combination of not needing to go so loud, DSP and some care toward the physical design of your OBs regarding microphone feedback, you might have something that could enhance the sound of your band.
Somebody's sound system, indeed!
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wow.. food for thought...
My friends and I used to play out as a band but no more. This is pretty much going to stay in my"practice" space that is basically a 16' x 20' basement room where i keep all my gear setup. What am I going for is a big sound at relatively low volume. When you mentioned "ambience" that pretty much hit the nail on the head. My speaker choices were more to do with getting a full range of frequency than it was to create reach to the back of a hall. I do have a Behringer 3102 Ultragraph FBQ wich could be helpful shape the sound to the room as well.
I may have been posting in the wrong place because I suppose this isn't a public address system- more like a multipurpose amplification system
I so appreciate all your input- thanks !
My friends and I used to play out as a band but no more. This is pretty much going to stay in my"practice" space that is basically a 16' x 20' basement room where i keep all my gear setup. What am I going for is a big sound at relatively low volume. When you mentioned "ambience" that pretty much hit the nail on the head. My speaker choices were more to do with getting a full range of frequency than it was to create reach to the back of a hall. I do have a Behringer 3102 Ultragraph FBQ wich could be helpful shape the sound to the room as well.
I may have been posting in the wrong place because I suppose this isn't a public address system- more like a multipurpose amplification system
I so appreciate all your input- thanks !