Hello there from Bavaria, this is my first post, I searched the forums for similar threads, but have a few questions not covered elsewhere. I want to create a soffit mount PA system in my event space (with a major focus on sound quality) and if anyone has any ideas please read on...The maximum number of people would be about 120 and as this PA system will never have to be moved around a lot of the normal considerations/ limitations for PA will not apply here. My family and friends use this space a great deal and as I record/ write music myself I would also enjoy the opportunity to have a separate listening space where I can play/ explore my own music.
Ideally I would love to be able to compose music on this system but the main limits to this are more about acoustically treating a 12x8 metre arched hall than the speaker design...
I renovated an old stone barn with my wife - we now run an event space/ function hall etc. My wife did not want any speakers in the room so I chiselled out holes in the wall so the speakers could be hidden away. Luckily the walls are approx 1,2 metre thick solid concrete/rock so they do not vibrate and there is no chance of the building collapsing! The building is a 400 year old farmhouse.
I have had a pair of B&O BEOVOX S75 speakers in the wall powered by a VFet Sony TA 5650 and have been content with the sound. Unfortunately during a party someone (the birthday boy) cranked the volume and fried the woofers with help from the fact that his itunes bass EQ WAS ON 12!!
Luckily the Sony VFET amp was ok. I have since replaced the SEAS 10 inch woofers with originals off ebay. The system sounds amazing to me and as a low/mid volume setup it is perfect, especially for jazz, lounge, classical etc.
However, I am worried that somebody will crank the volume again and obviously the current set up is no good for a party dancefloor.
Basically I need to get a PA system for the bigger functions and I want to replace the Beovox S 75's and build new more powerful speakers directly into the wall. Once again- my wife would prefer if the new system was also invisible.... I will post some photos of the current speaker soffits as well as my 'invisible' sound treatment panels.
As far as speaker cabinets go I assume I have an ideal starting point from the point of view that the walls are about 120 cm thick. The wall probably weighs over 50 tons. The dimensions of the SOFFITS are slightly larger than the Beovox S75s. SOFFITS= H=62cm W=35cm D=27cm.
The depth is rather shallow for a speaker of this size but I did not want to dig out too much of the wall as there is about 10 metres of wall above the speakers and these are load bearing areas. The soffits are 7 metres apart and unfortunately only 10 cm from each corner- ***I suppose the tweeters/mids could be angled slightly towards the centre of the room to lessen reflections off the side walls??***
This is my main question - for the best possible sound (within reason) what would be the best route to follow? COAXIAL? FULL RANGE? SEALED ENCLOSURE? PASSIVE RADIATOR? Any particular driver model/ company that would be ideal for this application? Ideally the system should be as good as possible for LISTENING to music ie , family, friends, myself. The fact that it will also be used as a party sound system should not be a reason to compromise the sound quality in any way. ie quality first, quantity second.
An ideal imaging sweet spot for 5 or 6 people sitting and listening to the music is of more concern in this design than coverage not being ideal on the dancefloor... There is still more acoustic treatment work to be done before the room can truly reveal whats in the music.
Another question is if the nature of such heavy cabinets would mean it is possible to create ultra efficient speakers and then be able to do what a lot of people advise strongly against and run a PA system with class A amps.
The 'heavy cabinets' increases the possibility of not needing any subwoofer? If possible I would love the system to produce sub 20hz bass frequencies accurately.
I hope that I have not rambled on too much and want to thank you if you are still reading this. I am really looking forward to completing this project and any advice/ ideas/ red flags comments will be appreciated. Also if anyone thinks that I will get better sound from passive speakers and a good amplifier and should forget the whole soffit mount idea please let me know your suggestions.
I will upload photographs of the current set up and document the project as it progresses.
Ideally I would love to be able to compose music on this system but the main limits to this are more about acoustically treating a 12x8 metre arched hall than the speaker design...
I renovated an old stone barn with my wife - we now run an event space/ function hall etc. My wife did not want any speakers in the room so I chiselled out holes in the wall so the speakers could be hidden away. Luckily the walls are approx 1,2 metre thick solid concrete/rock so they do not vibrate and there is no chance of the building collapsing! The building is a 400 year old farmhouse.
I have had a pair of B&O BEOVOX S75 speakers in the wall powered by a VFet Sony TA 5650 and have been content with the sound. Unfortunately during a party someone (the birthday boy) cranked the volume and fried the woofers with help from the fact that his itunes bass EQ WAS ON 12!!
Luckily the Sony VFET amp was ok. I have since replaced the SEAS 10 inch woofers with originals off ebay. The system sounds amazing to me and as a low/mid volume setup it is perfect, especially for jazz, lounge, classical etc.
However, I am worried that somebody will crank the volume again and obviously the current set up is no good for a party dancefloor.
Basically I need to get a PA system for the bigger functions and I want to replace the Beovox S 75's and build new more powerful speakers directly into the wall. Once again- my wife would prefer if the new system was also invisible.... I will post some photos of the current speaker soffits as well as my 'invisible' sound treatment panels.
As far as speaker cabinets go I assume I have an ideal starting point from the point of view that the walls are about 120 cm thick. The wall probably weighs over 50 tons. The dimensions of the SOFFITS are slightly larger than the Beovox S75s. SOFFITS= H=62cm W=35cm D=27cm.
The depth is rather shallow for a speaker of this size but I did not want to dig out too much of the wall as there is about 10 metres of wall above the speakers and these are load bearing areas. The soffits are 7 metres apart and unfortunately only 10 cm from each corner- ***I suppose the tweeters/mids could be angled slightly towards the centre of the room to lessen reflections off the side walls??***
This is my main question - for the best possible sound (within reason) what would be the best route to follow? COAXIAL? FULL RANGE? SEALED ENCLOSURE? PASSIVE RADIATOR? Any particular driver model/ company that would be ideal for this application? Ideally the system should be as good as possible for LISTENING to music ie , family, friends, myself. The fact that it will also be used as a party sound system should not be a reason to compromise the sound quality in any way. ie quality first, quantity second.
An ideal imaging sweet spot for 5 or 6 people sitting and listening to the music is of more concern in this design than coverage not being ideal on the dancefloor... There is still more acoustic treatment work to be done before the room can truly reveal whats in the music.
Another question is if the nature of such heavy cabinets would mean it is possible to create ultra efficient speakers and then be able to do what a lot of people advise strongly against and run a PA system with class A amps.
The 'heavy cabinets' increases the possibility of not needing any subwoofer? If possible I would love the system to produce sub 20hz bass frequencies accurately.
I hope that I have not rambled on too much and want to thank you if you are still reading this. I am really looking forward to completing this project and any advice/ ideas/ red flags comments will be appreciated. Also if anyone thinks that I will get better sound from passive speakers and a good amplifier and should forget the whole soffit mount idea please let me know your suggestions.
I will upload photographs of the current set up and document the project as it progresses.
Honestly, please load some photos. I am interested to help. As I am from Vienna, we could even speak german, but not here coz other guys would not be able to follow the discussion.
It seams you are mixing several ideas here...sub 20Hz sounds interesting, but the thing is to specify what SPL levels at what distance to reach. For 140+dB at 20 Hz, you'd have to replace the whole wall by concrete-based subwoofers (google "wall of bass", "club sub - wr. neustadt".). Don't think that is what you want, .. ;-) Also, "ultra efficient" speakers sounds like 2meter big horns to me. Class A is generally no good since you cannot get big power from class A. Class A is a room heater - real pro stuff is mostly class H, TD or class D (or "I").
To really protect your speakers, you'd need a limiter as close to the amp in the signal chain as possible - and well configured - best case to have a limiter within the amp's DSP section. This case you could play around with the iPod bass / mixer volume control / attenuators or whatever - the limiter would not allow to exceed a certain amount of voltage. Also - what is the budget?
It seams you are mixing several ideas here...sub 20Hz sounds interesting, but the thing is to specify what SPL levels at what distance to reach. For 140+dB at 20 Hz, you'd have to replace the whole wall by concrete-based subwoofers (google "wall of bass", "club sub - wr. neustadt".). Don't think that is what you want, .. ;-) Also, "ultra efficient" speakers sounds like 2meter big horns to me. Class A is generally no good since you cannot get big power from class A. Class A is a room heater - real pro stuff is mostly class H, TD or class D (or "I").
To really protect your speakers, you'd need a limiter as close to the amp in the signal chain as possible - and well configured - best case to have a limiter within the amp's DSP section. This case you could play around with the iPod bass / mixer volume control / attenuators or whatever - the limiter would not allow to exceed a certain amount of voltage. Also - what is the budget?
Hey Tom
thank you for the reply. English is my first language- I do live in Munich though.
The Neustadt wall of bass looks perfect -32000 watts! - if only.
The sub bass accuracy is mostly for me to listen to my own compositions, but it would be great if the characteristics of the wall/soffits could be exploited to offer superior sound and decent sub bass without the need for separate subwoofers/ amps.
I think I should simplify my intitial comment to point out that I already have two holes in the wall. Dimensions - H=62cm W=35cm D=27cm.
This wall is 1, 2metres thick. I would like to use these holes as the cabinets for speakers.
I only want to pusue this direction of putting the PA speakers into the wall soffits if the sound quality will be as good or better than a comparably priced PA system. The budget for the system is €3000. SPL is not too extreme- loud enough for 100 people dancing. Sound quality more of an issue. Me and family and friends will be listening to music on the system mainly.
Good soffit mounting increases bass spl by 6db- on average- . This is the starting point for my idea to try to make the speakers as efficient as possible and running the speakers with class A amps. Would 100 watt class A to each speaker be a waste of time for a decent volume on the dancefloor +- 100 people?
Another question is what would happen if I put these JBL STX 812 M speakers in the soffits?The main reason I am interested in these speakers is that they are one of the few 12 inch systems that are compact enough to fit into the soffits...JBL STX 812 M - Thomann UK
I am also really interested in any opinions about the benefits/drawbacks of COAXIAL? FULL RANGE? SEALED ENCLOSURE? PASSIVE RADIATOR? options.
file:///Users/desmondmeintjes/Desktop/P1070307.jpg[/IMG]
thank you for the reply. English is my first language- I do live in Munich though.
The Neustadt wall of bass looks perfect -32000 watts! - if only.
The sub bass accuracy is mostly for me to listen to my own compositions, but it would be great if the characteristics of the wall/soffits could be exploited to offer superior sound and decent sub bass without the need for separate subwoofers/ amps.
I think I should simplify my intitial comment to point out that I already have two holes in the wall. Dimensions - H=62cm W=35cm D=27cm.
This wall is 1, 2metres thick. I would like to use these holes as the cabinets for speakers.
I only want to pusue this direction of putting the PA speakers into the wall soffits if the sound quality will be as good or better than a comparably priced PA system. The budget for the system is €3000. SPL is not too extreme- loud enough for 100 people dancing. Sound quality more of an issue. Me and family and friends will be listening to music on the system mainly.
Good soffit mounting increases bass spl by 6db- on average- . This is the starting point for my idea to try to make the speakers as efficient as possible and running the speakers with class A amps. Would 100 watt class A to each speaker be a waste of time for a decent volume on the dancefloor +- 100 people?
Another question is what would happen if I put these JBL STX 812 M speakers in the soffits?The main reason I am interested in these speakers is that they are one of the few 12 inch systems that are compact enough to fit into the soffits...JBL STX 812 M - Thomann UK
I am also really interested in any opinions about the benefits/drawbacks of COAXIAL? FULL RANGE? SEALED ENCLOSURE? PASSIVE RADIATOR? options.
file:///Users/desmondmeintjes/Desktop/P1070307.jpg[/IMG]
It sounds to me like you need 2 systems.
One that will go loud for the dancefloor, and another that will go low for your own listening.
I don't think you can have both just in the soffits.
If it were mine, I'd use a pair of 12" two-way speakers in the soffits, with 500w/ch. 100w/ch simply isn't enough, even at 98dB@1w. Make sure the cabinets are ported, tuned around 60Hz, and add a steep filter to stop low bass.
To get the 20Hz stuff, you're going to need dedicated subwoofers. There is no way you can have a high efficiency 20Hz system in the soffits.
Chris
One that will go loud for the dancefloor, and another that will go low for your own listening.
I don't think you can have both just in the soffits.
If it were mine, I'd use a pair of 12" two-way speakers in the soffits, with 500w/ch. 100w/ch simply isn't enough, even at 98dB@1w. Make sure the cabinets are ported, tuned around 60Hz, and add a steep filter to stop low bass.
To get the 20Hz stuff, you're going to need dedicated subwoofers. There is no way you can have a high efficiency 20Hz system in the soffits.
Chris
JBL STX is a great series. These two top speakers can only give you 75Hz, although I would not crossover them below 100Hz or so... they alone eat up your budget - but you also need amping, and decent subwoofers and then amping for the subs, crossover etc etc....
Actually, for 100 people dancefloor I d recommend something like that 2 x 12" or 10" 2-way tops plus at least one good subwoofer.
Even if you do this well you end up spending like two times your budget - or more. And then - you still won't have anything at 20Hz, since bass cabinets for the dancefloor usually cannot really go below 35Hz - at least not in the budget category.
Actually, for 100 people dancefloor I d recommend something like that 2 x 12" or 10" 2-way tops plus at least one good subwoofer.
Even if you do this well you end up spending like two times your budget - or more. And then - you still won't have anything at 20Hz, since bass cabinets for the dancefloor usually cannot really go below 35Hz - at least not in the budget category.
thanks for the input. Yes i think those stx have a lot of utility/tech/ cost in the design that exceeds my requirements for soffit mount. Chris the 2x 12 inch woofer sounds about right and I also think 2 systems will be the way to go.
Having decided this now my question is simply how to get the best sound out of these 60 litre holes that are already in the wall...Does this mean I should now move this thread to speaker design? Perhaps there should be a separate section for soffit mount??
I am more than happy to get a decent freestanding PA for the function dancefloor if limiting the power in the soffits will produce a better 'listening' sound. Another point to question is the compatibility of the two systems and the possibility of using both the external PA and the soffit system at the same time...
I saw another soffit post on using tang band full range woofers in soffits. I have also been looking at Audio Nirvana Full-Range Speakers and Amplifiers For Sale. The magic of full-range, high efficiency, DIY speaker kits with no crossover. . Their 'super 12 inch cast frame' is $298 per pair. Granted they are only 30 watt. 99 DB efficiency though. 36 hz to almost 20,000 hz... These would then be possible to easily drive with a class a amp.
I have been looking at vintage class A amps from Yamaha. At least- amps that can run in class A up to a certain point. I have a 1985 Yamaha A 1020 which runs in class A only to 5 watts.
An idea for a direction for this project. Yamaha M80 or M85 running in class A to 30 watts through Audio Nirvana super 12 inch 99 DB efficiency, 36 hz to almost 20,000 hz.
Are there any problems with this design bearing in mind the 12 inch drivers will be mounted in max. 60 litre solid wall enclosures?
Having decided this now my question is simply how to get the best sound out of these 60 litre holes that are already in the wall...Does this mean I should now move this thread to speaker design? Perhaps there should be a separate section for soffit mount??
I am more than happy to get a decent freestanding PA for the function dancefloor if limiting the power in the soffits will produce a better 'listening' sound. Another point to question is the compatibility of the two systems and the possibility of using both the external PA and the soffit system at the same time...
I saw another soffit post on using tang band full range woofers in soffits. I have also been looking at Audio Nirvana Full-Range Speakers and Amplifiers For Sale. The magic of full-range, high efficiency, DIY speaker kits with no crossover. . Their 'super 12 inch cast frame' is $298 per pair. Granted they are only 30 watt. 99 DB efficiency though. 36 hz to almost 20,000 hz... These would then be possible to easily drive with a class a amp.
I have been looking at vintage class A amps from Yamaha. At least- amps that can run in class A up to a certain point. I have a 1985 Yamaha A 1020 which runs in class A only to 5 watts.
An idea for a direction for this project. Yamaha M80 or M85 running in class A to 30 watts through Audio Nirvana super 12 inch 99 DB efficiency, 36 hz to almost 20,000 hz.
Are there any problems with this design bearing in mind the 12 inch drivers will be mounted in max. 60 litre solid wall enclosures?
You can't get 99dB@1w from 36Hz from a 12" speaker in that cabinet size (Hoffman's Iron Law at play). Try WinISD Pro or Hornresp.
Here's what I'd do...
Get a nice pair of 12" two-way PA speakers, and have a (bypassable) EQ. For serious listening, switch in the EQ - it doesn't matter if you use 12dB of boost in places to get a nice frequency response - you've got loads of headroom to do so. For louder stuff, switch the EQ off.
Have one or two subwoofers in the room corners (maybe long sonotube for a full-height cylinder?) that are set up for good LF reproduction, and only switch those on when you're doing the serious listening.
Chris
Here's what I'd do...
Get a nice pair of 12" two-way PA speakers, and have a (bypassable) EQ. For serious listening, switch in the EQ - it doesn't matter if you use 12dB of boost in places to get a nice frequency response - you've got loads of headroom to do so. For louder stuff, switch the EQ off.
Have one or two subwoofers in the room corners (maybe long sonotube for a full-height cylinder?) that are set up for good LF reproduction, and only switch those on when you're doing the serious listening.
Chris
Your audio Nirvana speakers are drivers only with no enclosure. The final product frequency response if up to the user and his testing program, which involves test equipment I prefer not to buy and keep in calibration. Reference level microphones, a calibrated level meter, a calibrated distortion meter. Then there is the endless testing of baffling and porting to provide flat distortion free response in either an anechoic chamber, the open air in silence, or in the actual room installation. Time alignment is a separate dimension to testing, and is required for drum hits not to audibly produce frequency sweeps.
I prefer to buy an enclosed sealed speaker system with a +-3 db frequency specification as many pro PA products are specified. 52 hz to 14 khz seems adequate to me to reproduce piano, although the top end of my hearing is damaged, as are most people's over age 20.
The last pair of speakers I bought, Peavey SP2 even have a distortion limit specification, with low distortion at 1 W individual listening, and higher distortion at the 50W level. They are rated at 500 W continuous, which is enough for noisy crowds of up to 300 IMHO. Unfortunately, the 54 hz -3 db spec bottom of the SP2 requires a 78 cm x 52cm x 58 cm recess for the 15" driver. Perhaps you could make do with a SP5 12" or PR10 speaker pair plus some sort of 3rd channel sub speaker mounted outside the wall. Perhaps you could hide the sub under a table or bar or some other furniture. Sub location is not critical due to the long wavelengths.
A live room such as a stone room, can require considerable sound absorbant material to flatten out the resonances. Pros use pink noise and a sound meter, but prefering not to own expensive instruments that might break between uses (like all the scopes and meters I have owned have done) I use grand piano source material and my ears to make setups. I have enough experience to know what a grand piano is supposed to sound like. I have a parallelapiped 14'x11'x33' living/dining/music room with plaster walls (reflective) and considerable carpet, stuffed furniture, and filled bookcases to damp out the reflections.
I find separate amplification to be convenient for repairing the amp, which will fit on a table for analysis and can be tested with a log resistor load. Powered speakers from reputable PA companies like Peavey and JBL don't sound any worse than passive speakers IMHO, but the heat would have to be dissipated in the niche (soffit is your word). Repair would also most likely have to be done by a professional shop, or at least smp removal which could damage the sound baffling of the speaker, and this is diyaudio.com. I buy my amps blown up, and repair them myself.
Class A amplification is not necessary IMHO for decent sound. I've got 4 generations of amp with the tube ST70 just okay, the transistor ST120 needed considerable modification to sound good, and the CS800s sounding the best of all. The speaker and room setup have much more effect than a properly designed class AB amp with adequate idle current through the output transistors. You want enough amp power to avoid clipping at maximum volume, which sounds really vile. Tube (valve) amps do not suffer from hard clipping but the source of new tubes is iffy at best, and at worst involves a country that invades or subverts their neighbors.
Digital class transistor amps now are all the rage in PA, and they are cheap, but I have suspicions about the internal RF frequencies leaking out into some of my sound sources, like AM/FM radio and magnetic phono cartridge. I'm quite happy about the sound of the Peavey CS800s class AB I own, which I use mostly at the 1.5 Vpp level into my 8 ohm SP2-XT speakers. I find the built in three level speaker protection circuits of the CS800s quite professionally done (according to East Electronics and Enzo). I am not as impressed by the protection circuits built into the PV-1.3k I own, and am in the middle of a diy protection redesign on that one. Many speakers are blown by too much power, followed by wiring faults that blow the amp, which then puts DC voltage into the speaker and blows it up. If your wiring is not unstalled in conduit with professional quality splices, you want amp with serious protection like a high end Crown, QSC, or Peavey.
I find serious listening to involve no conversation in the room, and concentration on the music without distractions. This is what I do in many of my leisure hours, distracted only by a good book perhaps. My PA based system provides the best fidelity I can buy and audition in this flyover town where the "audio audition room" is Best Buy's concrete warehouse with the 10 m high corrugated metal ceiling.
Good luck and good listening.
I prefer to buy an enclosed sealed speaker system with a +-3 db frequency specification as many pro PA products are specified. 52 hz to 14 khz seems adequate to me to reproduce piano, although the top end of my hearing is damaged, as are most people's over age 20.
The last pair of speakers I bought, Peavey SP2 even have a distortion limit specification, with low distortion at 1 W individual listening, and higher distortion at the 50W level. They are rated at 500 W continuous, which is enough for noisy crowds of up to 300 IMHO. Unfortunately, the 54 hz -3 db spec bottom of the SP2 requires a 78 cm x 52cm x 58 cm recess for the 15" driver. Perhaps you could make do with a SP5 12" or PR10 speaker pair plus some sort of 3rd channel sub speaker mounted outside the wall. Perhaps you could hide the sub under a table or bar or some other furniture. Sub location is not critical due to the long wavelengths.
A live room such as a stone room, can require considerable sound absorbant material to flatten out the resonances. Pros use pink noise and a sound meter, but prefering not to own expensive instruments that might break between uses (like all the scopes and meters I have owned have done) I use grand piano source material and my ears to make setups. I have enough experience to know what a grand piano is supposed to sound like. I have a parallelapiped 14'x11'x33' living/dining/music room with plaster walls (reflective) and considerable carpet, stuffed furniture, and filled bookcases to damp out the reflections.
I find separate amplification to be convenient for repairing the amp, which will fit on a table for analysis and can be tested with a log resistor load. Powered speakers from reputable PA companies like Peavey and JBL don't sound any worse than passive speakers IMHO, but the heat would have to be dissipated in the niche (soffit is your word). Repair would also most likely have to be done by a professional shop, or at least smp removal which could damage the sound baffling of the speaker, and this is diyaudio.com. I buy my amps blown up, and repair them myself.
Class A amplification is not necessary IMHO for decent sound. I've got 4 generations of amp with the tube ST70 just okay, the transistor ST120 needed considerable modification to sound good, and the CS800s sounding the best of all. The speaker and room setup have much more effect than a properly designed class AB amp with adequate idle current through the output transistors. You want enough amp power to avoid clipping at maximum volume, which sounds really vile. Tube (valve) amps do not suffer from hard clipping but the source of new tubes is iffy at best, and at worst involves a country that invades or subverts their neighbors.
Digital class transistor amps now are all the rage in PA, and they are cheap, but I have suspicions about the internal RF frequencies leaking out into some of my sound sources, like AM/FM radio and magnetic phono cartridge. I'm quite happy about the sound of the Peavey CS800s class AB I own, which I use mostly at the 1.5 Vpp level into my 8 ohm SP2-XT speakers. I find the built in three level speaker protection circuits of the CS800s quite professionally done (according to East Electronics and Enzo). I am not as impressed by the protection circuits built into the PV-1.3k I own, and am in the middle of a diy protection redesign on that one. Many speakers are blown by too much power, followed by wiring faults that blow the amp, which then puts DC voltage into the speaker and blows it up. If your wiring is not unstalled in conduit with professional quality splices, you want amp with serious protection like a high end Crown, QSC, or Peavey.
I find serious listening to involve no conversation in the room, and concentration on the music without distractions. This is what I do in many of my leisure hours, distracted only by a good book perhaps. My PA based system provides the best fidelity I can buy and audition in this flyover town where the "audio audition room" is Best Buy's concrete warehouse with the 10 m high corrugated metal ceiling.
Good luck and good listening.
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