Yup, but I take a personal interest in my subjects! 
Doesn't mean I'm an audio expert. I hope it means that I've learned a little something about people. That's more important in a mod. That, and a taste for unbridled power!!!
I mentioned the most basic info on calculation the boxes because you weren't responding and I thought that you might be overwhelmed on where to start. I knew that once you got started you could do it. Don't forget the 3/4" wall thickness!!
Actually the sizes I mentioned aren't bad. 30" high for the 18" boxes and 18" high for the mid/high section would add up to 6'-6"!
Oops, plus wall thicknesses: 4.5 " = very very close to 7'
Maybe better to make them a bit wider (more impressive) and a bit less deep..
Doesn't mean I'm an audio expert. I hope it means that I've learned a little something about people. That's more important in a mod. That, and a taste for unbridled power!!!
I mentioned the most basic info on calculation the boxes because you weren't responding and I thought that you might be overwhelmed on where to start. I knew that once you got started you could do it. Don't forget the 3/4" wall thickness!!
Actually the sizes I mentioned aren't bad. 30" high for the 18" boxes and 18" high for the mid/high section would add up to 6'-6"!
Oops, plus wall thicknesses: 4.5 " = very very close to 7'
Maybe better to make them a bit wider (more impressive) and a bit less deep..
Why are you gonna want a sub with 4 18s. You might change your mind after you get these running.
Anyhow, gotta agree with Joe again. A 10" is not going to keep up. But the Beta 12 or 2 Beta 8s will. If you like the 12, go for it.
I don't think there will be any issue with power on the Beta 12 if it's crossed above about 180Hz. Just not going to be a problem. WiIl it be loud enough for the 2 18s? Welllll.... Maybe. But lets remember, Mr. Punk does not want a balanced system. He wants BASS!! And bass he shall have. When he gets this cranking, it's the bass section that will take a pounding, not the mids.
Don't know what kind of music the Punkster listens to, but if it's Hip-Hop, Techno, House or any bass heavy stuff, the mids won't get much work. I've worked enough of those shows to know what the amp racks are doing. However, if he likes AC/DC, Metalica, Mega Death, or any other metal stuff, the mids WILL take a beating. All those screaming guitars and screaming singers. Same for Punk Rock.
A low cut filter is going to be usfull for high power levels. The 18s will need it. Their power handling drops fast under ~33Hz in our ported box. Most active crossover have this built in. Very useful in a PA rig.
FYI, Joe. the SD on the 18 is about 1140, PE is 500W, xmax is 6mm - if that helps your calculations any.
Punkrokr. $60 a sheet. Consider yourself lucky. Just cabinet grade birch costs that much where I Iive. The better plywood is the choice if you have to move the speakers much. Otherwise MDF will do. MDF breaks easily, that's one of the reasons that pro boxes don't use it. Your father can help you with making it sturdy. He probably knows a lot more than we do.
Anyhow, gotta agree with Joe again. A 10" is not going to keep up. But the Beta 12 or 2 Beta 8s will. If you like the 12, go for it.
I don't think there will be any issue with power on the Beta 12 if it's crossed above about 180Hz. Just not going to be a problem. WiIl it be loud enough for the 2 18s? Welllll.... Maybe. But lets remember, Mr. Punk does not want a balanced system. He wants BASS!! And bass he shall have. When he gets this cranking, it's the bass section that will take a pounding, not the mids.
Don't know what kind of music the Punkster listens to, but if it's Hip-Hop, Techno, House or any bass heavy stuff, the mids won't get much work. I've worked enough of those shows to know what the amp racks are doing. However, if he likes AC/DC, Metalica, Mega Death, or any other metal stuff, the mids WILL take a beating. All those screaming guitars and screaming singers. Same for Punk Rock.
A low cut filter is going to be usfull for high power levels. The 18s will need it. Their power handling drops fast under ~33Hz in our ported box. Most active crossover have this built in. Very useful in a PA rig.
FYI, Joe. the SD on the 18 is about 1140, PE is 500W, xmax is 6mm - if that helps your calculations any.
Punkrokr. $60 a sheet. Consider yourself lucky. Just cabinet grade birch costs that much where I Iive. The better plywood is the choice if you have to move the speakers much. Otherwise MDF will do. MDF breaks easily, that's one of the reasons that pro boxes don't use it. Your father can help you with making it sturdy. He probably knows a lot more than we do.
Hey, I just had a look at those tweeters. They look quite nice, and if the claimed levels of distortion are correct, they should be reasonably close to "hi-fi" at sane listening levels.
Unfortunately, I have to take back what I said about the 12" driver. Its response curve just doesn't look sensitive enough down low, and it looks kind of ragged at the top. I can appreciate that some people here have used it and like it, but I think you can do a little better.
I can personally vouch for the Eminence Beta 8, and I think the Hammer looks suspiciously similar. I wouldn't say they're the same driver, but they certianly have a family resemblance. You could get two Hammer 8's for the price of one Beta 12 LTA and (in my opinion) get a superior transition from midbass to tweeter.
I guess aesthetics are important too, but I just couldn't find a 12" driver for under $100 that would get you 98 db efficiency and 250 watts power handling with a smoother top end. Looking for a single 10" woofer able to hit 125 db at 400 hz is also probably going to be tough, since that's asking for a lot of power handling, xmax, and sensitivity. You could get it, but not for cheap.
Anyway, you're still on a pretty good track- the Beta 12LTA has plenty of fans. The dual 8's are just how I would do it, if it were my project.
Good night everybody!
Unfortunately, I have to take back what I said about the 12" driver. Its response curve just doesn't look sensitive enough down low, and it looks kind of ragged at the top. I can appreciate that some people here have used it and like it, but I think you can do a little better.
I can personally vouch for the Eminence Beta 8, and I think the Hammer looks suspiciously similar. I wouldn't say they're the same driver, but they certianly have a family resemblance. You could get two Hammer 8's for the price of one Beta 12 LTA and (in my opinion) get a superior transition from midbass to tweeter.
I guess aesthetics are important too, but I just couldn't find a 12" driver for under $100 that would get you 98 db efficiency and 250 watts power handling with a smoother top end. Looking for a single 10" woofer able to hit 125 db at 400 hz is also probably going to be tough, since that's asking for a lot of power handling, xmax, and sensitivity. You could get it, but not for cheap.
Anyway, you're still on a pretty good track- the Beta 12LTA has plenty of fans. The dual 8's are just how I would do it, if it were my project.
Good night everybody!
Pano- thanks for the numbers. It was to get ballpark figures anyway, so it'll be fine. Good call on the 12 LT's power handling... if he upgrades his amps enough to find out the 12's are running out of steam, a $150 driver to fit in the same hole will seem like a bargain.
Good call on the 30 hz highpass. I set up my old system like that, as well as a friend's, and it really does make a difference.
Good call on the 30 hz highpass. I set up my old system like that, as well as a friend's, and it really does make a difference.
Good night Joe!
We aren't going to go with the Beta 12LTA, but the Beta 12A-2 instead. It's going to be easier to mate with our tweeter. The LTA is good if you want the 12" driver to run up high, but we don't need it to. So let's use its brother, the 12A-2 instead.
I also vote for the Selenium D210 on the same waveguide, just because it's smoother up top then the Eminence and because I know what it sounds like. =) (Got 2 in the living room). Either one will be fine. Whatever Mr. P wants.
Variac. 1 cubic foot for the 12"driver. A little larger probably wouldn't hurt. Not too critical.
We aren't going to go with the Beta 12LTA, but the Beta 12A-2 instead. It's going to be easier to mate with our tweeter. The LTA is good if you want the 12" driver to run up high, but we don't need it to. So let's use its brother, the 12A-2 instead.
I also vote for the Selenium D210 on the same waveguide, just because it's smoother up top then the Eminence and because I know what it sounds like. =) (Got 2 in the living room). Either one will be fine. Whatever Mr. P wants.
Variac. 1 cubic foot for the 12"driver. A little larger probably wouldn't hurt. Not too critical.
Joe,
the Hammer 8 has identical specs to the Beta 8 , so I think it is safe to say they are the same. Punkrockr had good intuition when he said that one of them didn't look big enough. Nice to know that two do seem to do the job well - -possibly better than the 12, but it seems the 12 will work too.
We are using the beta 12 but not the LTA's so we are avoiding some of the wiggly top end.
Punkr,
its true, there is almost NO sound low enough in rock music to require a sub. For movies, it could be good for explosions. Also some techno music goes quite low. Classical organ music for sure and some symphonic maybe..
Not only is ply lighter than MDF but a lot stronger, and we have already pointed out that you WILL move these around. I used an imported birch ply that was only $40 a sheet and it worked great IMHO so look around..
Pano- what was the cabinet volume you wanted for the 12?
the Hammer 8 has identical specs to the Beta 8 , so I think it is safe to say they are the same. Punkrockr had good intuition when he said that one of them didn't look big enough. Nice to know that two do seem to do the job well - -possibly better than the 12, but it seems the 12 will work too.
We are using the beta 12 but not the LTA's so we are avoiding some of the wiggly top end.
Punkr,
its true, there is almost NO sound low enough in rock music to require a sub. For movies, it could be good for explosions. Also some techno music goes quite low. Classical organ music for sure and some symphonic maybe..
Not only is ply lighter than MDF but a lot stronger, and we have already pointed out that you WILL move these around. I used an imported birch ply that was only $40 a sheet and it worked great IMHO so look around..
Pano- what was the cabinet volume you wanted for the 12?
Punkrokr,
we are using the Eminence Beta 12-A-2 instead of the Beta 12 LTA
Here is the link:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-408
It seems to be exactly the same driver without the tiny whizzer cone, which we don't need. Please update your list so you don't order the wrong thing!
Still using the Selenium tweeter and the same waveguide.
Still using the 18's you specced.
Joe,
Those 12's are supposed to sound good. We are using it mainly because of its reputation for sound and secondly for its low cost.
we are using the Eminence Beta 12-A-2 instead of the Beta 12 LTA
Here is the link:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-408
It seems to be exactly the same driver without the tiny whizzer cone, which we don't need. Please update your list so you don't order the wrong thing!
Still using the Selenium tweeter and the same waveguide.
Still using the 18's you specced.
Joe,
Those 12's are supposed to sound good. We are using it mainly because of its reputation for sound and secondly for its low cost.
Hi Pano,
re post425,
is the yellow curve a sealed box plot? or vented but with different tuning?
Why does the yellow plot fall at high frequencies but the other plot seems to have an extended flat reponse?
Surely the tuning and box types should not make this kind of high frequency difference.
Joe Carrow,
Design expertise like this is so invaluable. It sets a target to be aimed for and makes driver selection so much easier.
re post425,
is the yellow curve a sealed box plot? or vented but with different tuning?
Why does the yellow plot fall at high frequencies but the other plot seems to have an extended flat reponse?
Surely the tuning and box types should not make this kind of high frequency difference.
Joe Carrow,
I wish you had come in with that guidance way back at post50 and saved all this to-ing and fro-ing and the 350 posts in between.
Design expertise like this is so invaluable. It sets a target to be aimed for and makes driver selection so much easier.
Hey Andrew,
Yeah the yellow line is a sealed box. Don't know why it curves like that. Makes me think it might be a bug (or feature) in the new WinISD. Will have to check it with other box programs. Maybe I shouldn't have posted it, as it looked a little odd to me.
Still, ported is the way to go with this system.
We don't have an FR plot for this driver. I emailed Parts Express tech support a couple of days ago looking for further specs. So far, no response. I'd like to see the frequency and impedance charts just to have an idea of what we're dealing with. They shouldn't be too different from Eminence 18s, one would think.
Yeah the yellow line is a sealed box. Don't know why it curves like that. Makes me think it might be a bug (or feature) in the new WinISD. Will have to check it with other box programs. Maybe I shouldn't have posted it, as it looked a little odd to me.
Still, ported is the way to go with this system.
We don't have an FR plot for this driver. I emailed Parts Express tech support a couple of days ago looking for further specs. So far, no response. I'd like to see the frequency and impedance charts just to have an idea of what we're dealing with. They shouldn't be too different from Eminence 18s, one would think.
Variac said:
The filter consists in two sections:
A standard 4th-order state-variable filter that produces the "high" and "low" outputs, whose four 1/(2*pi*R*C) factors are (from input to output): 1560Hz, 1560Hz, 1846Hz, 1846Hz. Equalization in the crossover region is achieved thanks to dissimilar poles (attenuation for that particular case, since my Delta 10 tend to peak 6dB at 1800Hz).
5 all-pass filters applied to the tweeter for time and phase alignment, whose 1/(2*pi*R*C) factors are: 1941Hz, 1941Hz, 1941Hz, 1941Hz, 2340Hz. (Thus massive group delay is applied to the signal going to the tweeter in order to make its final radiation match the poles and physical delays associated with the radiation from the mid horn, and achieve proper on-axis summing).
The point that I was trying to make is that simple passive filters with a couple of coils and capacitors only produce satisfactory results with small Hi-Fi drivers.
Also, note that piles of massive direct-radiating drivers in DIY enclosures (made by people lacking crossover and acoustics skills) may look as if they could sound terrific, but in practice they usually doesn't. Unfortunately, I have seen too much of that stuff during the years that I worked touring small towns with some local band.
"Blue... you have talked about using that crossover....uses a 2.7uf....not much....but its with additional 4ohm series resistor....will look closer.....
If I calculate with 12 ohm....just to see.....it indicates 2500hz....seems ok and understandable.....could in reality be lower....depends on midrange driver
But inductor should be much bigger at this impedance.....the used 0.33mH....that would be more understandable with 4ohm instead of 12ohm.....it could be to protect tweeter better......makes me a bit uncertain....
If I calculate with 12 ohm....just to see.....it indicates 2500hz....seems ok and understandable.....could in reality be lower....depends on midrange driver
But inductor should be much bigger at this impedance.....the used 0.33mH....that would be more understandable with 4ohm instead of 12ohm.....it could be to protect tweeter better......makes me a bit uncertain....
Seriously... I think we could do a lot better than a pre-made passive crossover. We could do a LOT better.
If I had my choice, I'd go with the Behringer DCX2496 digital crossover. You said you have an amp that will take four inputs and give four 50 watt outputs? If it will do that into 4 ohms, you're ready to rock and roll at 110 db. The tweeter is going to have efficiency of over 100 db, maybe pushing 105 db. Anything over 10 watts (like a Sonic Impact T-Amp) will push the tweeters loud enough to keep up.
The crossover is $250 (but includes some great tools that will be really useful if you gig with this), and the T-amp is about $35. I'd also recommend an inexpensive mixer, like the Behringer EB802, if you can find it. This will act as a microphone input and a volume control for the input to the crossover. Expect that to cost $50, again- if you can find it.
Fifty watts on the dual 18"s and 12"mid plus 10 watts on the tweeter, with an active crossover, will already get you far louder than most people listen. It will be loud enough to impress people while you save up for the next year for a high quality 100 watt amp for the tweeter, 250 watt amp for the mids, and 1000 watt amp for the bass.
If you want this to sound good, you can do trial and error with this digital crossover. The other alternative is to build it, perform measurements, and then design a passive crossover based on your measurements. Unless someone out there is really comfortable with simulating the drivers in their cabinet and designing a crossover based on published response curves... I'd see a much better chance of success with the flexibility the DCX2496 gives.
If I had my choice, I'd go with the Behringer DCX2496 digital crossover. You said you have an amp that will take four inputs and give four 50 watt outputs? If it will do that into 4 ohms, you're ready to rock and roll at 110 db. The tweeter is going to have efficiency of over 100 db, maybe pushing 105 db. Anything over 10 watts (like a Sonic Impact T-Amp) will push the tweeters loud enough to keep up.
The crossover is $250 (but includes some great tools that will be really useful if you gig with this), and the T-amp is about $35. I'd also recommend an inexpensive mixer, like the Behringer EB802, if you can find it. This will act as a microphone input and a volume control for the input to the crossover. Expect that to cost $50, again- if you can find it.
Fifty watts on the dual 18"s and 12"mid plus 10 watts on the tweeter, with an active crossover, will already get you far louder than most people listen. It will be loud enough to impress people while you save up for the next year for a high quality 100 watt amp for the tweeter, 250 watt amp for the mids, and 1000 watt amp for the bass.
If you want this to sound good, you can do trial and error with this digital crossover. The other alternative is to build it, perform measurements, and then design a passive crossover based on your measurements. Unless someone out there is really comfortable with simulating the drivers in their cabinet and designing a crossover based on published response curves... I'd see a much better chance of success with the flexibility the DCX2496 gives.
"Seriously"....I misplaced my words....I meant that a homemade passive would be better than premade, anyway
Your suggestion with all active would be preferable....thats why I suggested a very powerfull all active 2-way....as only 2-way active seems economical possible
But Punk may do that bit by bit.....but it would be a good idea to start with the suggested 3-way active crossover....even if only will be 2-way for a start
Your suggestion with all active would be preferable....thats why I suggested a very powerfull all active 2-way....as only 2-way active seems economical possible
But Punk may do that bit by bit.....but it would be a good idea to start with the suggested 3-way active crossover....even if only will be 2-way for a start
Ok, I think I know a lot what Punkrockr wants after so many posts, and the first thing is to use two 18" bass drivers per side, so calculating whether they were needed or not is irrelevent. I also am pretty sure he wants to look at the drivers with a sense of satisfaction and to impress his friends, so a scoop or other type of horn that hides the drivers won't go over well I think.
Theose drivers are pretty much fixed in stone.
Joe,
the Behringer 2496 is clearly the best crossover choice, but I thought that the cheaper Behringer might do the job and is also much simpler to use. But it might not be versitle enough. Maybe you can look its manual over. I posted it again a page back It looks like all its slopes might be 24dB, which might be limiting but maybe not bad, and at $130 it would probably be cheaper than a bunch of crossovers
I suspect that Punkr's dad's amp has 6 channels at least, which is perfect.
Panomaniac - you looked it up can you answer this?
I think the Sonic impact is more like 5 watts/channel with low distortion.
I will only speak for myself, but I have to agree with Eva, BUT that won't keep us from doing this anyway, right? Actually, my 2 way with 15" 1505 woofer and Selenium tweeter sounded shockingly good after trying about 3 different crossover values. Just lucky is my analysis. A 2 way is easier of course!
Theose drivers are pretty much fixed in stone.
Joe,
the Behringer 2496 is clearly the best crossover choice, but I thought that the cheaper Behringer might do the job and is also much simpler to use. But it might not be versitle enough. Maybe you can look its manual over. I posted it again a page back It looks like all its slopes might be 24dB, which might be limiting but maybe not bad, and at $130 it would probably be cheaper than a bunch of crossovers
I suspect that Punkr's dad's amp has 6 channels at least, which is perfect.
Panomaniac - you looked it up can you answer this?
I think the Sonic impact is more like 5 watts/channel with low distortion.
I will only speak for myself, but I have to agree with Eva, BUT that won't keep us from doing this anyway, right? Actually, my 2 way with 15" 1505 woofer and Selenium tweeter sounded shockingly good after trying about 3 different crossover values. Just lucky is my analysis. A 2 way is easier of course!
Here is the cheaper crossover again. Anyone think it will do the job?
Could handle a stereo 3-way setup, has delay, 25 hz filter, mostly straightforward knob controls.....
http://www.partsexpress.com/pdf/248-668s.pdf
Pano, maybe you could link to the receiver information?
Could handle a stereo 3-way setup, has delay, 25 hz filter, mostly straightforward knob controls.....
http://www.partsexpress.com/pdf/248-668s.pdf
Pano, maybe you could link to the receiver information?
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