Yes for 450Wrms into 4ohms you'll want a supply voltage of about +/-75V... Of course, i would use seperate rails for the front end and the output stage.... +/-85V for the front end and +/-67V for the output stage. I also have access to switching power supplies that can supply these power levels 🙂
Sweet! Where can I get switching supplies like that? Also, why ever would you use two voltages? I would much rather use one, as it would make it much simpler, and that's what everyone does.
Kilowatt,
I think that EV speakers absolutely rule for PA work, but that, as I said before, is a whole different animal than hifi.
It sounds like you are well on the way to success, and I think you will have a lot of help from a lot of different people from here on out.
As far as the Eminence speakers go, where are you looking? Parts express titanics are nice subwoofers, as are the NHT1259 (I believe that's the model number- they're sold at madisound)but it is better in closed boxes (probably not ideal for you). Peerless also sells some kick butt high excursion woofers, available at parts express. I've heard some good things about the 10" Vifas. I really like the specs on the titanics. In my opinion, you want something that will handle max wattage, and have long excursion for low distortion and great bass extension, which the titanics fit nicely. Remember- those two woofers being driven by that 450 watt amp will share the power, so you don't necessarily need a 1000 watt driver. With a woofer like the titanic, which is meant for home theater and music, you will get outstanding bass quality, as compared to PA speakers, which are compromised for the sake of durability (excursion limited) and extending the high end. Bass extension and quantity could be amazing with a setup like this! Have you ever felt the 16hz fundamental of a pipe organ? I haven't yet, but I may have to travel to MT if you pull this off, ha ha.
As far as mids go, you have SO many options, and using an array (and quite a monster, according to your post) will let you share the power among many drivers, which will let you concentrate on audio quality- again, the pa speakers being a compromise. I like the vifas P17WJ's because they have a very natural rolloff with no bad upper resonances, and they should work well with an active xover. Plus, they are a great value, which matters to me, since I'm not made of $$$$ haha. You may also look into 5" drivers, as that will slightly extend your high end ability before lobing (close center-center spacing). If I remember right, it is not very much better, and you will probably be better off going with the 6.5's to get the midbass quantity you need. Remember that driver phase will play a part in the crossing over, and it may be necessary to get the mids out in front of the horn a little ways to get them to sum right, which is ok since you are using seperate cabinets, right?
If you look at the linus array design, and the paper published along with it (I can't remember who wrote it) there is a formula that uses the center to center spacing of the drivers and the speed of sound to calculate the frequency where the drivers stop looking like an array and start creating interference patterns (lobing). The upper limit will be around 2Khz with 6.5's if I remember right- at double this frequency you will start to see severe lobing (hot and dead spots in the frequency response). Keep the drivers spaced as closely together as possible, and keep this info in mind when choosing your crossover frequency to the horn. I will try to find the pdf of that paper, which has a lot of great info. Be very cautious about running the mids too high. Choose a very good horn that will allow you to cross over fairly low. I wouldn't skimp on that area. I think you may be amazed how little power it will take to get that horn to ear-shattering levels.
Man, would I like to be there when you turn this thing on! I think you will even be impressed. If you want me to help in any way, just let me know what I can do for you.
Steve
I think that EV speakers absolutely rule for PA work, but that, as I said before, is a whole different animal than hifi.
It sounds like you are well on the way to success, and I think you will have a lot of help from a lot of different people from here on out.
As far as the Eminence speakers go, where are you looking? Parts express titanics are nice subwoofers, as are the NHT1259 (I believe that's the model number- they're sold at madisound)but it is better in closed boxes (probably not ideal for you). Peerless also sells some kick butt high excursion woofers, available at parts express. I've heard some good things about the 10" Vifas. I really like the specs on the titanics. In my opinion, you want something that will handle max wattage, and have long excursion for low distortion and great bass extension, which the titanics fit nicely. Remember- those two woofers being driven by that 450 watt amp will share the power, so you don't necessarily need a 1000 watt driver. With a woofer like the titanic, which is meant for home theater and music, you will get outstanding bass quality, as compared to PA speakers, which are compromised for the sake of durability (excursion limited) and extending the high end. Bass extension and quantity could be amazing with a setup like this! Have you ever felt the 16hz fundamental of a pipe organ? I haven't yet, but I may have to travel to MT if you pull this off, ha ha.
As far as mids go, you have SO many options, and using an array (and quite a monster, according to your post) will let you share the power among many drivers, which will let you concentrate on audio quality- again, the pa speakers being a compromise. I like the vifas P17WJ's because they have a very natural rolloff with no bad upper resonances, and they should work well with an active xover. Plus, they are a great value, which matters to me, since I'm not made of $$$$ haha. You may also look into 5" drivers, as that will slightly extend your high end ability before lobing (close center-center spacing). If I remember right, it is not very much better, and you will probably be better off going with the 6.5's to get the midbass quantity you need. Remember that driver phase will play a part in the crossing over, and it may be necessary to get the mids out in front of the horn a little ways to get them to sum right, which is ok since you are using seperate cabinets, right?
If you look at the linus array design, and the paper published along with it (I can't remember who wrote it) there is a formula that uses the center to center spacing of the drivers and the speed of sound to calculate the frequency where the drivers stop looking like an array and start creating interference patterns (lobing). The upper limit will be around 2Khz with 6.5's if I remember right- at double this frequency you will start to see severe lobing (hot and dead spots in the frequency response). Keep the drivers spaced as closely together as possible, and keep this info in mind when choosing your crossover frequency to the horn. I will try to find the pdf of that paper, which has a lot of great info. Be very cautious about running the mids too high. Choose a very good horn that will allow you to cross over fairly low. I wouldn't skimp on that area. I think you may be amazed how little power it will take to get that horn to ear-shattering levels.
Man, would I like to be there when you turn this thing on! I think you will even be impressed. If you want me to help in any way, just let me know what I can do for you.
Steve
You need a higher front end rail to compensate for the gate-source bias voltage of the output Mosfets. It will need to swing about 5 volts per rail more than you will need at the output. See the pass A75 for details on that one.
Also, you want the power stage to clip before the front end- you should have about 3db headroom in the front end over the output stage.
I wish I could help you with the switchers... That's getting WAY high tech. If you're going that far, why not use class D output stage for the woofers- 90% efficiency looks really good!
Steve
Also, you want the power stage to clip before the front end- you should have about 3db headroom in the front end over the output stage.
I wish I could help you with the switchers... That's getting WAY high tech. If you're going that far, why not use class D output stage for the woofers- 90% efficiency looks really good!
Steve
Yes as SteveG stated, you need the higher front end voltage or the entire amp would need to run off this higher in order to get the required output swing. You dissipate far less power with separate rails.
Not only does class D have bad distortion characteristics- even for woofers, but I'm not that high-tech. AudioFreak said he knew about some ready-made switchers that will suit my needs. I want all my channels to have full range capability even though they won't all be doing full range, just in case the need arises for them to do so.
Since I won't be dissapating as much heat with this dual voltage thing, can I get away with 10 output devices instead of 12 for each 450W channel?
I like the specs of those Dayton Titanics, but I don't get enough bass that way because I can only use 8 per side (unless I put some in series or drive 450W into 1ohm). I'll only reach 132dB. The Peerlesses, being 8 ohm drivers, would be a little better, I could reach about 134dB per side, they're each not quite as sensitive. That might be enough with a low xover freq. All these woofers are reasonable in price. I'm impressed, for a home hifi sub. Car subs, however, are far superior in Xmax and power handling, like the Audiobahn ALUM12X, with 31mm Xmax, they claim 1kW RMS power capability and 96.4dB sensitivity. They only cost $169. The JL 13W7 comes to mind also, with it's 1.25" Xmax and 1kW/2kW RMS/Peak power capability, but it's more like 87dB@1W@1m and costs about $750. I have heard that these would suck outside though. What do you guys think?
P.S. You meant 450W into 2 ohms right AudioFreak? That's what I'm doing here. 45V would do it in numbers, but it would clip off all the peaks, so I'd need 85/75V.
Since I won't be dissapating as much heat with this dual voltage thing, can I get away with 10 output devices instead of 12 for each 450W channel?
I like the specs of those Dayton Titanics, but I don't get enough bass that way because I can only use 8 per side (unless I put some in series or drive 450W into 1ohm). I'll only reach 132dB. The Peerlesses, being 8 ohm drivers, would be a little better, I could reach about 134dB per side, they're each not quite as sensitive. That might be enough with a low xover freq. All these woofers are reasonable in price. I'm impressed, for a home hifi sub. Car subs, however, are far superior in Xmax and power handling, like the Audiobahn ALUM12X, with 31mm Xmax, they claim 1kW RMS power capability and 96.4dB sensitivity. They only cost $169. The JL 13W7 comes to mind also, with it's 1.25" Xmax and 1kW/2kW RMS/Peak power capability, but it's more like 87dB@1W@1m and costs about $750. I have heard that these would suck outside though. What do you guys think?
P.S. You meant 450W into 2 ohms right AudioFreak? That's what I'm doing here. 45V would do it in numbers, but it would clip off all the peaks, so I'd need 85/75V.
Kilowatt said:
1. NO!
2. Yeah badly!
3. My bad sorry. My calculations were indeed for 4 ohms ... for 2 ohms 50V/65V rails would be fine for 450Wrms continuous but its all a matter of a matter of how much headroom you want... just remember that higher voltage equals more dissipation.
You might have to look at PA subs, if you are primarily running this thing outside. Keep in mind though that the bass will not be extremely deep- those woofers usually only work best down to 40 or 50 hz. Not the best way to go for quality, I would think.
As far as car audio goes, I have a feeling that a lot of the specs are a little on the optimistic side.
Maybe the eminence woofers are right for your ap... Where are you drawing the line between PA and home stereo? If you want a PA system, you will be better off with the really efficient PA drivers. You'll have to find the balance between quality and quantity.
As far as car audio goes, I have a feeling that a lot of the specs are a little on the optimistic side.
Maybe the eminence woofers are right for your ap... Where are you drawing the line between PA and home stereo? If you want a PA system, you will be better off with the really efficient PA drivers. You'll have to find the balance between quality and quantity.
If you have the room...
This looks like it would do really well for a large outdoor setup:
Parts Express
Technical Information
#295-085
Parameter
Specification
Sens. 1W/1m
97 dB
Impedance (nom.)
8 ohms
Power Handling (RMS/Max)
500/700
Fs
25
Qts
.34
Qms
6.74
Qes
.36
Vas (ft3)
16.12
Cms (mm/N)
.25
DCR (W )
6.01
Levc (mH) @ 1 KHz
2
BL (Tesla m)
20.62
Sd (cm2)
1140
Xmax; one way (linear mm)
6
P-Vd (cm3)
687.8
Mms (grams)
161.3
Magnet Weight (oz)
109
Coil diameter (in)
4
Net weight
29 lbs.
Dimensions
A: 18", B: 16-1/2", C: 8-1/4", D: 8-3/4"
This looks like it would do really well for a large outdoor setup:
Parts Express
Technical Information
#295-085
Parameter
Specification
Sens. 1W/1m
97 dB
Impedance (nom.)
8 ohms
Power Handling (RMS/Max)
500/700
Fs
25
Qts
.34
Qms
6.74
Qes
.36
Vas (ft3)
16.12
Cms (mm/N)
.25
DCR (W )
6.01
Levc (mH) @ 1 KHz
2
BL (Tesla m)
20.62
Sd (cm2)
1140
Xmax; one way (linear mm)
6
P-Vd (cm3)
687.8
Mms (grams)
161.3
Magnet Weight (oz)
109
Coil diameter (in)
4
Net weight
29 lbs.
Dimensions
A: 18", B: 16-1/2", C: 8-1/4", D: 8-3/4"
I take it those drivers you mentioned yesterday are not meant for outdoor use. Still, I wonder how they, or even car subs would work outside if they were in a sealed bandpass enclosure. (I admit I don't know a thing about bandpass enclosures, but it looked like a possibility.) One must also be curious about horn loaded car or home hifi subs, but I don't think car subs could ever achieve the sound quality I want anyway.
As for pro subs, another one with good specs at Parts Express is a $75 Eminence 200W 18", it has a 7mm Xmax, goes to 25Hz. It's #299-716. The Dayton one has more power handling, but the Eminence has an extra mm of Xmax. Lower Vas than the Dayton though. It looks like I'll have to choose between those 2. Nothing else pro comes close. What gives lower distortion, rubber surround or accordion surround? The Eminence has a rubber surround, the Dayton doesn't. Does it make a difference?
Here's something else, 292-774, it has a way longer Xmax (12mm), but it's not as efficient and has a dual 2 ohm voice coil. Maybe I could make some separate powered subs with these for like 40Hz and below.
As for pro subs, another one with good specs at Parts Express is a $75 Eminence 200W 18", it has a 7mm Xmax, goes to 25Hz. It's #299-716. The Dayton one has more power handling, but the Eminence has an extra mm of Xmax. Lower Vas than the Dayton though. It looks like I'll have to choose between those 2. Nothing else pro comes close. What gives lower distortion, rubber surround or accordion surround? The Eminence has a rubber surround, the Dayton doesn't. Does it make a difference?
Here's something else, 292-774, it has a way longer Xmax (12mm), but it's not as efficient and has a dual 2 ohm voice coil. Maybe I could make some separate powered subs with these for like 40Hz and below.
Member
Joined 2002
alpine
i like alpine or rockford there nice but also ive seen a alpine type 15" HALL ASSS if you want basss.. why dont use make a server sub and feed it 1k sounds more senceable to me..
J'
you should email me so i can talk to you directly
jleaman@kaien.net or jleaman@citytel.net
i like alpine or rockford there nice but also ive seen a alpine type 15" HALL ASSS if you want basss.. why dont use make a server sub and feed it 1k sounds more senceable to me..
J'
you should email me so i can talk to you directly
jleaman@kaien.net or jleaman@citytel.net
Those are car subs aren't they? This is like an outdoor hifi system I'm building. Like a hifi PA. What I might do though is make powered bass reflex of bandpass subs for really looooww bass because PA subs can't do it. These might use some really high excursion car or home stereo subs or something. I'd have to use PA subs for like 30 or 40Hz-200Hz, they're the only thing that will work. Below that, distortion doesn't matter so much anyway. The frequency response of those powered subs might extend down to like 10Hz or something.
P.S. do you mean servo sub? I've never heard of a server sub.🙂 I'd rather just stick to ordinary drivers, but I haven't looked into anyhting else.
P.S. do you mean servo sub? I've never heard of a server sub.🙂 I'd rather just stick to ordinary drivers, but I haven't looked into anyhting else.
Member
Joined 2002
email me
email me and yes i ment servo not server hehe
i was writing my report of the day and that word was tuck in my head haha
email me and yes i ment servo not server hehe
i was writing my report of the day and that word was tuck in my head haha
Hi Kilowatt,
For the sub end:
I once ran a PA rig with a Renkus main system with Turbosound subs in a bass reflex enclosure that we crossed over at 80Hz that had all the sub bass you would ever need. I think they used 21" jbl drivers in the boxes, and if you are interested I will find out more...
We had one per side, driven from a 1600w into 4ohm stereo amp, and they filled a 2000 peson capacity venue with no problems at all
Good Luck
Al
For the sub end:
I once ran a PA rig with a Renkus main system with Turbosound subs in a bass reflex enclosure that we crossed over at 80Hz that had all the sub bass you would ever need. I think they used 21" jbl drivers in the boxes, and if you are interested I will find out more...
We had one per side, driven from a 1600w into 4ohm stereo amp, and they filled a 2000 peson capacity venue with no problems at all
Good Luck
Al
I'm stumped, to be honest.
This system of yours seems to be a fine balance between quality and quantity, and I don't really know what drivers will work well for you. If the system is being used exclusively outside, I would lean toward PA woofers. I remember hearing some eminence in a small club, and they were really kicking- seemed fairly clean. The sound guy had a lot of good to say about them too, but he wasn't exactly Einstein- Kept telling me his hearing was so good that he could hear to 40Khz! Wow, he probably has every dog in the neighborhood beat.🙄
Of course EV's will sound good, but the price!
I am wondering also if an array of home hi-fi subs wouldn't sound good outside. Why not? And, why wouldn't car subs sound good? No one has provided any real reason that they wouldn't. Question is, do you stick to a sure thing, or try something different. I'm glad it's not my money. BTW, where is this money tree planted that you're picking from? I want one.
Steve
This system of yours seems to be a fine balance between quality and quantity, and I don't really know what drivers will work well for you. If the system is being used exclusively outside, I would lean toward PA woofers. I remember hearing some eminence in a small club, and they were really kicking- seemed fairly clean. The sound guy had a lot of good to say about them too, but he wasn't exactly Einstein- Kept telling me his hearing was so good that he could hear to 40Khz! Wow, he probably has every dog in the neighborhood beat.🙄
Of course EV's will sound good, but the price!
I am wondering also if an array of home hi-fi subs wouldn't sound good outside. Why not? And, why wouldn't car subs sound good? No one has provided any real reason that they wouldn't. Question is, do you stick to a sure thing, or try something different. I'm glad it's not my money. BTW, where is this money tree planted that you're picking from? I want one.
Steve
Alot if not most car subs are designed to make use of cabin gain, take them out of the cabin and often they dont fair very well at all.
I don't think that guy ever used a signal generator. Or maybe he meant his hearing was so bad he could only hear to 4kHz.🙂 I can hear to about 17kHz, and I'm only 16, which always helps in the hearing department.
What I'll probably do is get some Eminence 18s, they're only $75.88 each, and I'll be buying lots of them, so maybe there will be a bulk discount, and they have a 7mm Xmax. These will be horn loaded, if I can find plans for a horn. I'll then get maybe 4 Audiobahn ALUM12Xs for sub bass, and build bass reflex enclosures for them and cross them over at about 50Hz.
P.S. I was recently trying out my Xplods in a friend's vehicle, and from this, and from listening to other car systems in the past, I have noticed that they don't sound any worse with the door open than closed.
What I'll probably do is get some Eminence 18s, they're only $75.88 each, and I'll be buying lots of them, so maybe there will be a bulk discount, and they have a 7mm Xmax. These will be horn loaded, if I can find plans for a horn. I'll then get maybe 4 Audiobahn ALUM12Xs for sub bass, and build bass reflex enclosures for them and cross them over at about 50Hz.
P.S. I was recently trying out my Xplods in a friend's vehicle, and from this, and from listening to other car systems in the past, I have noticed that they don't sound any worse with the door open than closed.
Eminence 18"
The Eminences from Parts Express are a buyout product which were originally used in the Definitive Technology flagship speaker - the BP3000TL.
The Eminences from Parts Express are a buyout product which were originally used in the Definitive Technology flagship speaker - the BP3000TL.
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