Reality Check Here
The JBL speakers you have are quoted as 98db for 1 watt
The JBL spec sheet says that they can peak at 128dB - That 30db increase is 1000W. Add in a 3db power increase to compensate for thermal compression and were up to 2000W to reach that volume
The 1850 horn is 105db for 1 watt add in 30db for 1000W subtract 3db for compression and we are already at 132db. The 1850 horn is a good cabinet but really works best groups of 4 or more
There is no way your current speakers can keep up!
If you choose a less ambitious design for the bass bins you can still achieve enough SPL to match your mid tops, but with a lot smaller cabinet, or one that trades some efficiency for more bass extension
Thanks.
WRT the first link, I don't think you mentioned a problem with tapped horn measurements vs simulations, so I don't think I need to read that whole thing right now. (I've read quite a bit of it in the past, and I'll revisit it again as time allows, but I don't think it's got much to do with this conversation.)
WRT the second link, I took a quick look but didn't see a hornresp sim anywhere so there's nothing to compare.
Sure, but I don't have anything to show that's going to convince you of anything. I lost most of my measurements and sims when my old computer died unexpectedly, so all I have left is really old stuff that I posted online in various places when I was still learning.
In addition, most of my sims were done in hornresp and refined in akabak and I don't have any of my old akabak records. Also, most of my measurements are not documented. (Some were done outside at 10m, some were done in my driveway right beside the house, some were done in the middle of a room at 1ft, some were done in room with the mic inside the horn mouth and most of them are not marked.)
So I can show you a bunch of sims and measurements that may or may not show anything useful or you can take my word (or not) that I noticed a strong correlation between response curves in sims and measurements. Especially down near tuning.
Here's an example. This is a hornresp sim.
I imported that into Akabak and continued the design, trading a higher tuning for more peak spl but ultimately keeping the same response shape. Unfortunately I don't have the final Akabak sim.
Here's a measurement. The top (green) line is the one to look at. But I think this was done in room (in the middle of a room) about a foot from the mouth. I don't have any of the measurements that I took outside anymore, but the curve shape was the same. (I could prove that by showing the measurement of the other horn in the pic as measured outside but there's no point in trying to qualify these measurements.) The dip at 90 hz was unexpected and likely due to a problem with the fold.
Here's another one, I think the mic was right in the horn mouth this time.
Anyway, all the resonances are right where they are supposed to be, the measurement matches the Akabak sim (that I don't have anymore). Unfortunately I can't resimulate this with Hornresp since I made changes that Hornresp can't simulate due to lack of segments and I can't remeasure it since I don't have the horn anymore.
So as I said, I've seen a strong correlation between the sims and measurements but I don't have anything to show that will convince you of anything. I lost all my more accurate sims and most of the outside measurements.
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Agree, Without a Phase response(Not minimum phase as it's pointless) or an impulse response any shown TH FR + a minimum phase plot is IMO a 'clever' 'floobydust' thrown at those who just want to be impressed with eye-candy.
b
Lots of OT stuff in previous posts.
Can´t we just cooperate and help Steve? Answer his questions that is and give advice on request?
This is what we know
1) He will be playing dubstep outdoors for 500 people. Lower frequency is 20-25 Hz.
2) Top section is JBL JRX 115. These will go down to 100 Hz. Probably not adequate in terms of output for outdoors 500 people, but Steve did not ask advice on these. If the subs outmatch the tops maybe he will trust us with advice for new top section next season
3) Steve wants to go for front loaded horn. Probably because I stated that they sound better because of better impuls response. Anyone challenging this?
This is what we don´t know
a) Budget
b) Transportation capability and people helping setting up the equipment.
c) Carpenting skills
This is what I assume
I) Budget is limited, otherwise Steve would just have bought the stuff and not asked here
II) Size of the system is not of big importance since it is outdoors.
Can´t we just cooperate and help Steve? Answer his questions that is and give advice on request?
This is what we know
1) He will be playing dubstep outdoors for 500 people. Lower frequency is 20-25 Hz.
2) Top section is JBL JRX 115. These will go down to 100 Hz. Probably not adequate in terms of output for outdoors 500 people, but Steve did not ask advice on these. If the subs outmatch the tops maybe he will trust us with advice for new top section next season
3) Steve wants to go for front loaded horn. Probably because I stated that they sound better because of better impuls response. Anyone challenging this?
This is what we don´t know
a) Budget
b) Transportation capability and people helping setting up the equipment.
c) Carpenting skills
This is what I assume
I) Budget is limited, otherwise Steve would just have bought the stuff and not asked here
II) Size of the system is not of big importance since it is outdoors.
When you state something as fact and people disagree, that's not OT. The conversation that results is also not OT but I agree it doesn't help the OP. In conversations like these, a lot of generalizations and sometimes misinformation is passed off as fact, like the tapped horn 1.5 octave bandwidth statement. Even the statement about the required horn length to achieve a given tuning is a generalization since it depends so heavily on the flare geometry.
Sure.
There's not many horns of any type that can hit 20 hz with the required high pass filter in place. There's Gjallerhorn and F20 cinema horn and maybe a couple others at avsforum. Then there's Danley products like DTS 10 and similar. All of these will need multiple cabs to be loud enough. And none of them will be flat down to 20 without eq when used outside without boundary support.
Or he can design his own, or request a design, but that's a lot of work.
I've heard tapped horns that sound better than front loaded horns and vice versa. It depends on a lot more than just impulse response. Different materials (and thickness of materials) will sound different, different response shapes will sound different, every choice you make has the potential to introduce audible differences. There'a also personal preference - some people prefer the high distortion of ported boxes, some prefer the lower distortion of horns for example. Sweeping generalizations may or may not turn out to be true and "better" is a judgement call. The only way to decide which design will sound best is to listen to them. (Unless one of them has a clear and blatant defect in design.)
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Im not going to lie there is a lot of information there i am struggling to understand...
Thank you for all your help so far though!
Yes i will be upgrading my mid/tops this summer, but i'd like to get some bass bins first! i will probably build mid/tops at some point.
So its a switch between tapped and front loaded folded horn.
Can someone please in less technical terms (though i am not a complete n00b) explain to me the benefits and disadvantages of both. PLEASE!
Im building for the future! I would like the bass to be filling! but at the same time accurate.
to put it in my terms, i would choose a ported sub over an enclosed sub!
Thank you people
Thank you for all your help so far though!
Yes i will be upgrading my mid/tops this summer, but i'd like to get some bass bins first! i will probably build mid/tops at some point.
So its a switch between tapped and front loaded folded horn.
Can someone please in less technical terms (though i am not a complete n00b) explain to me the benefits and disadvantages of both. PLEASE!
Im building for the future! I would like the bass to be filling! but at the same time accurate.
to put it in my terms, i would choose a ported sub over an enclosed sub!
Thank you people
You are asking the wrong questions. You need to define your goals before you start picking designs. You still have not defined how loud the system needs to be (spl at furthest distance of interest), how low it needs to play, and probably most important, a budget. You also need to decide how large you want the entire system to be, and how large each cab can be.
You haven't defined any goals and yet you've already disqualified simple ported boxes.
Ported boxes are the best bang for the buck as far as size vs spl. If portability is important and you don't want to move a stack of subs the size of a garden shed (or potentially much larger), ported might be the best way to go. If you are not so worried about size and instead want to use less power then horns might be the way to go.
So the first thing I would do is figure out how loud you want it to be at the BACK of the audience. Are there any solid boundaries you can use to reinforce the output or is it a wide open field?
Next, use a program like Audessey to figure out how low your music actually goes. If it actually does go down to 20 hz you need to determine if it's important for you to actually reproduce that.
Are you expecting to be able to move this system in a car? Or do you have a bunch of vans or a moving truck?
How much power do you have? What kind of amps? Is there somewhere to plug this in or are you using generators?
The pros and cons of front loaded vs tapped horns is a question you should be asking near the end of this process, not at the beginning.
The system needs to be designed as a whole, you can't just pick a random design that looks good and keep adding more and more cabs until it's loud enough, especially if you need it to be tuned very very low. At some point the stack is going to get large enough to cause big problems with dispersion patterns unless you split it up into separate stacks, but that will not take full advantage of mutual coupling.
If you want to do it right the first time you need to start by clearing stating your goals.
You haven't defined any goals and yet you've already disqualified simple ported boxes.
Ported boxes are the best bang for the buck as far as size vs spl. If portability is important and you don't want to move a stack of subs the size of a garden shed (or potentially much larger), ported might be the best way to go. If you are not so worried about size and instead want to use less power then horns might be the way to go.
So the first thing I would do is figure out how loud you want it to be at the BACK of the audience. Are there any solid boundaries you can use to reinforce the output or is it a wide open field?
Next, use a program like Audessey to figure out how low your music actually goes. If it actually does go down to 20 hz you need to determine if it's important for you to actually reproduce that.
Are you expecting to be able to move this system in a car? Or do you have a bunch of vans or a moving truck?
How much power do you have? What kind of amps? Is there somewhere to plug this in or are you using generators?
The pros and cons of front loaded vs tapped horns is a question you should be asking near the end of this process, not at the beginning.
The system needs to be designed as a whole, you can't just pick a random design that looks good and keep adding more and more cabs until it's loud enough, especially if you need it to be tuned very very low. At some point the stack is going to get large enough to cause big problems with dispersion patterns unless you split it up into separate stacks, but that will not take full advantage of mutual coupling.
If you want to do it right the first time you need to start by clearing stating your goals.
@ just a guy
Sorry to hear about older PC ! The good news is, that if you still have it, you can disconnect the Hard Drive from it & connect inside to your new PC. Make sure BOTH PC's are unpowered when you do this.
Once installed & powered up, you can go into "My Computer" & you should see the old HD. Double click on it & open it up. From there you can Copy/Paste whatever you want from your old Files/Folders to your new HD. If you like you could also leave it in place, & dig into it etc whenever you like.
Regards
Sorry to hear about older PC ! The good news is, that if you still have it, you can disconnect the Hard Drive from it & connect inside to your new PC. Make sure BOTH PC's are unpowered when you do this.
Once installed & powered up, you can go into "My Computer" & you should see the old HD. Double click on it & open it up. From there you can Copy/Paste whatever you want from your old Files/Folders to your new HD. If you like you could also leave it in place, & dig into it etc whenever you like.
Regards
Im sorry to hear about that but i have no idea how thats helping me
Please just look at my innitial question
The difference between a scoop and a folded horn subwoofer? A scoop is a back loaded horn and a folded horn is any type of horn (front loaded, back loaded or tapped) that is folded to fit into a rectangular box.
Please read post 28 and at least try to answer some of those questions. Are we supposed to just guess what you need?
What you are doing now is very much like showing up at a car dealership that sells everything from little tiny hybrids to transport trucks and asking which vehicle is best for you without giving any information on what you are using it for. Some of your comments narrow it down a bit but really not much.
Or if by "initial question" you mean the difference between front loaded horns and tapped horns, a front loaded horn is a horn (or a 1/4 wave resonator if it's designed too small to be a true horn) that loads the flare with only the output of one side of the cone while a tapped horn is a rear loaded 1/4 wave resonator that uses clever driver placement to fill in the first harmonic null created by the line by using output from both sides of the cone (one side produces the bulk of the bass while the other side fills in a harmonic null).
There are dozens of similarities and differences between the two and it would take many pages to describe them in full.
What I suspect you are asking for is someone to tell you which sounds "better" and there's really no way to do that in simple fashion to someone that has no background in acoustic theory. "Better" is simply a matter of which type best fits your goals, and is described by things like frequency response, group delay, impulse response, and a host of other terms that you are probably not familiar with. If you know what your goals are in those areas it's a relatively simple matter to choose which is better for you. If you don't know what those things are then it's impossible to try to answer which is "better". Everything is a compromise and we pick the compromises that fit our goals.
There are dozens of similarities and differences between the two and it would take many pages to describe them in full.
What I suspect you are asking for is someone to tell you which sounds "better" and there's really no way to do that in simple fashion to someone that has no background in acoustic theory. "Better" is simply a matter of which type best fits your goals, and is described by things like frequency response, group delay, impulse response, and a host of other terms that you are probably not familiar with. If you know what your goals are in those areas it's a relatively simple matter to choose which is better for you. If you don't know what those things are then it's impossible to try to answer which is "better". Everything is a compromise and we pick the compromises that fit our goals.
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@ just a guy
OK now i understand !
Just for the record, if you or anyone else, should ever have HD issues/errors etc again, fortunately there is solution. Depending on the issues/errors, it can either fix them permanently, or enough to be able to transfer the data to another drive.
Spinrite - https://www.grc.com/default.htm
I havn't used it myself, but have seen countless reports over the years of people being saved with it. So i wouldn't recommend it unless i thought it was useful.
Whilst you're on the www, check out the excellent Free Tools, which i've made use of several times. Also have a look at the other pages filled with Excellent security advice etc. Including SheildsUp, which tests your Firewall/Router/Modem for holes !
Regards
OK now i understand !
Just for the record, if you or anyone else, should ever have HD issues/errors etc again, fortunately there is solution. Depending on the issues/errors, it can either fix them permanently, or enough to be able to transfer the data to another drive.
Spinrite - https://www.grc.com/default.htm
I havn't used it myself, but have seen countless reports over the years of people being saved with it. So i wouldn't recommend it unless i thought it was useful.
Whilst you're on the www, check out the excellent Free Tools, which i've made use of several times. Also have a look at the other pages filled with Excellent security advice etc. Including SheildsUp, which tests your Firewall/Router/Modem for holes !
Regards
Code:
System 'stk12th4'
Def_Driver 'stroker12d4
Re=8.65ohm
Qms=9.909
Qes=0.240
Le=8mH
Mms=196.50g
Cms=0.11mm/N
Sd=538cm2
Def_const
{
S1=70e-4;
S2=75e-4;
S3=480e-4;
S4=3250e-4;
S5=3800e-4;
L12=10e-2;
L23=220e-2;
L34=150e-2;
L45=80e-2
}
Filter 'highpass'
fo=25Hz vo=1
{b4=1;
a4=1; a3=2.828427; a2=4; a1=2.828427; a0=1; }
Filter 'lowpass'
fo=150Hz vo=1
{b0=1;
a4=1; a3=2.828427; a2=4; a1=2.828427; a0=1; }
Driver 'D1' Def='stroker12d4' Node=1=0=4=11
Duct 'Throat chamber'
Node=4=9
SD=600cm2
Len=1.8cm
Visc=0
off Duct 'Port'
Node=4=9
SD=100cm2
Len=2cm
Visc=0
Waveguide 'W1'
Node=8=9
Sth={s1} Smo={s2} Len={l12} Conical
Waveguide 'W2'
node=9=10
Sth={s2} Smo={s3} Len={l23} conical
Waveguide 'W3'
node=10=11
Sth={s3} Smo={s4} Len={l34} Conical
Waveguide 'W4'
node=11=12
Sth={s4} Smo={s5} Len={l45} conical
Radiator node=12
Sd={s5}
and the other one...
System 'Stroker15D2 TH'
| template for 4 section tapped horn including throat chamber & port elements
Def_Driver 'stroker15d2'
fs=35Hz
Re=3.629ohm
Qms=4.678
Qes=0.2659
Vas=26.020L
Le=4.495mH
Mms=218.5g
Cms=0.09mm/N
BL=25.6Tm
Sd=890cm2
Def_const
{
S1=1e-4;
S2=330e-4;
S3=1175e-4;
S4=4660e-4;
S5=8000e-4;
L12=5e-2;
L23=240e-2;
L34=85e-2;
L45=133e-2
}
Driver 'D1' Def='stroker15d2' Node=1=0=4=11
|CHANGE NODES IF ADDING THROAT CHAMB. OR PORT!!!!
Duct 'Throat chamber'
Node=4=9
SD=900cm2
Len=1.8cm
Visc=0
off Duct 'Port'
Node=4=9
SD=100cm2
Len=2cm
Visc=0
Waveguide 'W1'
Node=8=9
Sth={s1} Smo={s2} Len={l12} Conical
Waveguide 'W2'
node=9=10
Sth={s2} Smo={s3} Len={l23} conical
Waveguide 'W3'
node=10=11
Sth={s3} Smo={s4} Len={l34} Conical
Waveguide 'W4'
node=11=12
Sth={s4} Smo={s5} Len={l45} conical
Radiator node=12
Sd={s5}
Filter 'highpass'
fo=20Hz vo=1
{b4=1;
a4=1; a3=2.828427; a2=4; a1=2.828427; a0=1; }
Filter 'lowpass'
fo=120Hz vo=1
{b0=1;
a4=1; a3=2.828427; a2=4; a1=2.828427; a0=1; }- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.