screamersusa said:
There is no "pressures that help the box get louder" as sound itself is a periodical pressure change.
As i see it, the only force that is applied to the cone is due to its movement, which is the same in every possible alignment. A horn only couples a speaker better to the air, so the available power isnt lost due to the impedance mismatch between cone and air. I really cant see a relation between compression factor and cone stress here.
Look at the worst case, a speaker with a closed box on one side and another one with an infinitesimal small hole in it on the other side. This should instantly kill a cone if the high compression theory is correct, but i cant see this happen. Its just two spring forces opposing the cone movement, thus lowering the theoretical output.
I know how all you guys feel. It took quite a bit of time to figure out my double TH. Physics can be very cruel to us speaker designers. Sometimes I find it very difficult to make certain compromises. The thing I had to give in on was sensitivity for the double TH. With the chamber volume and the T/S parameters of the W8-740 woofers, the mouth had to be small to get a reasonably flat response. These woofers also like a small throat.
Just as MaVo mentioned, a woofer will only tolerate so much compression before the cone shreds. However, this is where the compression chamber becomes a very good friend. Due to the low frequencies of interest and air’s compressibility, the torture experienced by the cone is lessened to a good degree. The compression chamber lets you get away with a little higher compression ratio than usual.
Just as a side note I did some experimenting with my double TH in an effort to determine how successful the push-pull configuration canceled distortion. I reversed the polarity of the outside woofer to see what would happen. What I was expecting was near complete silence because the woofers were now out of phase with one another. What I ended up hearing was still a surprising amount of bass coming from the TH. Reason told me that any bass coming from the TH had to be the non-linear portion because anything in common should have been canceled. This revealed two very important things: 1.) the Tang Band W8-740 might have lots of excursion, but is not all that linear. 2.) For the highest purity and fidelity in bass reproduction, push-pull is a requirement. Of course this does not directly apply to this thread because I’m not talking about Live sound, but home audio. However, I thought I would still share this with you guys.
Rgs, JLH
Just as MaVo mentioned, a woofer will only tolerate so much compression before the cone shreds. However, this is where the compression chamber becomes a very good friend. Due to the low frequencies of interest and air’s compressibility, the torture experienced by the cone is lessened to a good degree. The compression chamber lets you get away with a little higher compression ratio than usual.
Just as a side note I did some experimenting with my double TH in an effort to determine how successful the push-pull configuration canceled distortion. I reversed the polarity of the outside woofer to see what would happen. What I was expecting was near complete silence because the woofers were now out of phase with one another. What I ended up hearing was still a surprising amount of bass coming from the TH. Reason told me that any bass coming from the TH had to be the non-linear portion because anything in common should have been canceled. This revealed two very important things: 1.) the Tang Band W8-740 might have lots of excursion, but is not all that linear. 2.) For the highest purity and fidelity in bass reproduction, push-pull is a requirement. Of course this does not directly apply to this thread because I’m not talking about Live sound, but home audio. However, I thought I would still share this with you guys.
Rgs, JLH
Why the nexo 18 (very expensive) scoopy design blows woofers without warning...... The woofer is sitting in the middle of the box and vents out in both directions. There is no compression, there is no air pressure resistance in the box at all.... The wofer can run out of xmax and smash the voice coil in a millisecond and you won't hear it coming. In the Meyer and EV subs, there is restriction in the ports due to size, strong spiders in the suspension of the drivers and a pressure "LAG" acting like a spring inside the cab. When you get a big inaudible peak the combination of spider and cabinet air pressure act like a shock absorber. It's not much but enough for a good engineer to realize there is a problem before he or she toasts all the subs.
Scoops don't give you much if any warning either.
Air pressure, compression and decompression , can be your friend as well as your enemy. Live sound is a BIG compromise to get volume at the cost of frequency response or power. Home and studio sound can be as perfect as you can get because it doesnt need to make 100 db 200 feet away for a thousand people.
Some compression and HPF work on the tapped horn will probably help keep woofers from dying. My TH gets that soft compressed sound some of us are familiar with so you know where to stop. The Bulldog without compression has already taken one 3015 out of comission with LESS POWER!!!!!.
Lovely smell. 3015 will smell before it blows.
Scoops don't give you much if any warning either.
Air pressure, compression and decompression , can be your friend as well as your enemy. Live sound is a BIG compromise to get volume at the cost of frequency response or power. Home and studio sound can be as perfect as you can get because it doesnt need to make 100 db 200 feet away for a thousand people.
Some compression and HPF work on the tapped horn will probably help keep woofers from dying. My TH gets that soft compressed sound some of us are familiar with so you know where to stop. The Bulldog without compression has already taken one 3015 out of comission with LESS POWER!!!!!.
Lovely smell. 3015 will smell before it blows.
Here is the HTH15 to play with
The HTH15 is a reverse mounted hybrid tapped horn.
I'm sure someone will find this interesting. It uses a ported chamber. The woofer faces out into the mouth, the port feeds the horn side. This version fit in a 31x39x21 casing. It had very good mid bass response well above the hornresp prediction.
100 db at 100 hz, from 102db at 95, 106db at 70, 104db at 60, 99db at 50, 98db at 45hz and drops like a rock past that.
Since the woofer is flush with the horn mouth top, you can use a standard 15 dollar grille to protect the driver. The upper bass sounds clearer than the reverse tappeds so I think it might be a good choice for non drum heavy bands who only need two.
|DATA EXPORTED FROM HORNRESP - RESONANCES NOT MASKED
|COMMENT: corrected final HTH15 chambered reverse internalmount mouth adj
|========================================================================================================
|REQUIRED AKABAK SETTINGS:
|File > Preferences > Physical system constants:
|Sound velocity c = 344m/s
|Medium density rho = 1.205kg/m3
|Sum > Acoustic power:
|Frequency range = 10Hz to 20kHz
|Points = 533
|Input voltage = 2.80V rms
|Integration = 2Pi-sr
|Integration steps = 1 degree ... 1 degree
|Integration method = Cross
|========================================================================================================
Def_Const |Hornresp Input Parameter Values
{
|Length, area and volume values converted to metres, square metres and cubic metres:
S1 = 40.00e-4; |Horn segment 1 throat area (sq cm)
S2 = 649.67e-4; |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)
S3 = 840.00e-4; |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)
S4 = 2150.00e-4; |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5 = 2575.00e-4; |Horn segment 4 mouth area (sq cm)
L12 = 17.20e-2; |Horn segment 1 axial length (cm)
L23 = 4.00e-2; |Horn segment 2 axial length (cm)
L34 = 169.60e-2; |Horn segment 3 axial length (cm)
L45 = 22.00e-2; |Horn segment 4 axial length (cm)
Ap = 344.40e-4; |Chamber port cross-sectional area (sq cm)
Lpt = 2.00e-2; |Chamber port tube length (cm)
Vtc = 30420.00e-6; |Throat chamber volume (cc)
Atc = 1521.00e-4; |Throat chamber cross-sectional area (sq cm)
|Parameter Conversions:
Sd = 881.00e-4; |Diaphragm area (sq cm)
Ltc = Vtc / Atc;
I'll post build pics in a few days. For now someone can try to tweak it to go lower without making the box bigger, but maybe wider. Cheers
The HTH15 is a reverse mounted hybrid tapped horn.
I'm sure someone will find this interesting. It uses a ported chamber. The woofer faces out into the mouth, the port feeds the horn side. This version fit in a 31x39x21 casing. It had very good mid bass response well above the hornresp prediction.
100 db at 100 hz, from 102db at 95, 106db at 70, 104db at 60, 99db at 50, 98db at 45hz and drops like a rock past that.
Since the woofer is flush with the horn mouth top, you can use a standard 15 dollar grille to protect the driver. The upper bass sounds clearer than the reverse tappeds so I think it might be a good choice for non drum heavy bands who only need two.
|DATA EXPORTED FROM HORNRESP - RESONANCES NOT MASKED
|COMMENT: corrected final HTH15 chambered reverse internalmount mouth adj
|========================================================================================================
|REQUIRED AKABAK SETTINGS:
|File > Preferences > Physical system constants:
|Sound velocity c = 344m/s
|Medium density rho = 1.205kg/m3
|Sum > Acoustic power:
|Frequency range = 10Hz to 20kHz
|Points = 533
|Input voltage = 2.80V rms
|Integration = 2Pi-sr
|Integration steps = 1 degree ... 1 degree
|Integration method = Cross
|========================================================================================================
Def_Const |Hornresp Input Parameter Values
{
|Length, area and volume values converted to metres, square metres and cubic metres:
S1 = 40.00e-4; |Horn segment 1 throat area (sq cm)
S2 = 649.67e-4; |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)
S3 = 840.00e-4; |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)
S4 = 2150.00e-4; |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5 = 2575.00e-4; |Horn segment 4 mouth area (sq cm)
L12 = 17.20e-2; |Horn segment 1 axial length (cm)
L23 = 4.00e-2; |Horn segment 2 axial length (cm)
L34 = 169.60e-2; |Horn segment 3 axial length (cm)
L45 = 22.00e-2; |Horn segment 4 axial length (cm)
Ap = 344.40e-4; |Chamber port cross-sectional area (sq cm)
Lpt = 2.00e-2; |Chamber port tube length (cm)
Vtc = 30420.00e-6; |Throat chamber volume (cc)
Atc = 1521.00e-4; |Throat chamber cross-sectional area (sq cm)
|Parameter Conversions:
Sd = 881.00e-4; |Diaphragm area (sq cm)
Ltc = Vtc / Atc;
I'll post build pics in a few days. For now someone can try to tweak it to go lower without making the box bigger, but maybe wider. Cheers
Here is the PATH15
This is the cabinet I am probably going to use. I like the sound of the HTH15 better but it's not low enough.
It fits in a 40x31x25.5 casing. Wheels and handles on the back like the Danley Box. Rumbles pretty good, especially in pairs.
|DATA EXPORTED FROM HORNRESP - RESONANCES NOT MASKED
|COMMENT: Smallest possible actual build translate 1 fix to try version 2 pathagain
|========================================================================================================
|REQUIRED AKABAK SETTINGS:
|File > Preferences > Physical system constants:
|Sound velocity c = 344m/s
|Medium density rho = 1.205kg/m3
|Sum > Acoustic power:
|Frequency range = 10Hz to 20kHz
|Points = 533
|Input voltage = 2.80V rms
|Integration = 2Pi-sr
|Integration steps = 1 degree ... 1 degree
|Integration method = Cross
|========================================================================================================
Def_Const |Hornresp Input Parameter Values
{
|Length, area and volume values converted to metres, square metres and cubic metres:
S1 = 367.00e-4; |Horn segment 1 throat area (sq cm)
S2 = 708.82e-4; |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)
S3 = 710.00e-4; |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)
S4 = 2247.44e-4; |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5 = 2456.00e-4; |Horn segment 4 mouth area (sq cm)
L12 = 33.80e-2; |Horn segment 1 axial length (cm)
L23 = 0.10e-2; |Horn segment 2 axial length (cm)
L34 = 202.70e-2; |Horn segment 3 axial length (cm)
L45 = 21.00e-2; |Horn segment 4 axial length (cm)
Ap = 424.10e-4; |Chamber port cross-sectional area (sq cm)
Lpt = 9.80e-2; |Chamber port tube length (cm)
Vtc = 1843.00e-6; |Throat chamber volume (cc)
Atc = 900.00e-4; |Throat chamber cross-sectional area (sq cm)
|Parameter Conversions:
Sd = 881.00e-4; |Diaphragm area (sq cm)
Ltc = Vtc / Atc;
}
|========================================================================================================
|Network node numbers for this tapped horn system:
| 0-Voltage-1
| |
| -Port-4-Chamber-5-Driver-
| | |
|8-Segment-9-Segment-10-Segment------11-Segment-12-Radiator
|========================================================================================================
Def_Driver 'Driver'
Sd=881.00cm2
Bl=18.60Tm
Cms=1.40E-04m/N
Rms=3.90Ns/m
fs=42.4464Hz |Mmd = 85.40g not recognised by AkAbak, fs calculated and used instead
Le=4.90mH
Re=5.30ohm
ExpoLe=1
System 'System'
Driver Def='Driver''Driver'
Node=1=0=5=11
Duct 'Throat chamber'
Node=4=5
SD={Atc}
Len={Ltc}
Visc=0
Duct 'Port'
Node=4=9
SD={Ap}
Len={Lpt}
Visc=0
Waveguide 'Horn segment 1'
Node=8=9
STh={S1}
SMo={S2}
Len={L12}
Conical
Waveguide 'Horn segment 2'
Node=9=10
STh={S2}
SMo={S3}
Len={L23}
Conical
Waveguide 'Horn segment 3'
Node=10=11
STh={S3}
SMo={S4}
Len={L34}
Conical
Waveguide 'Horn segment 4'
Node=11=12
STh={S4}
SMo={S5}
Len={L45}
Conical
Radiator 'Horn mouth'
Node=12
SD={S5}
...........................
Tweak away
This is the cabinet I am probably going to use. I like the sound of the HTH15 better but it's not low enough.
It fits in a 40x31x25.5 casing. Wheels and handles on the back like the Danley Box. Rumbles pretty good, especially in pairs.
|DATA EXPORTED FROM HORNRESP - RESONANCES NOT MASKED
|COMMENT: Smallest possible actual build translate 1 fix to try version 2 pathagain
|========================================================================================================
|REQUIRED AKABAK SETTINGS:
|File > Preferences > Physical system constants:
|Sound velocity c = 344m/s
|Medium density rho = 1.205kg/m3
|Sum > Acoustic power:
|Frequency range = 10Hz to 20kHz
|Points = 533
|Input voltage = 2.80V rms
|Integration = 2Pi-sr
|Integration steps = 1 degree ... 1 degree
|Integration method = Cross
|========================================================================================================
Def_Const |Hornresp Input Parameter Values
{
|Length, area and volume values converted to metres, square metres and cubic metres:
S1 = 367.00e-4; |Horn segment 1 throat area (sq cm)
S2 = 708.82e-4; |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)
S3 = 710.00e-4; |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)
S4 = 2247.44e-4; |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5 = 2456.00e-4; |Horn segment 4 mouth area (sq cm)
L12 = 33.80e-2; |Horn segment 1 axial length (cm)
L23 = 0.10e-2; |Horn segment 2 axial length (cm)
L34 = 202.70e-2; |Horn segment 3 axial length (cm)
L45 = 21.00e-2; |Horn segment 4 axial length (cm)
Ap = 424.10e-4; |Chamber port cross-sectional area (sq cm)
Lpt = 9.80e-2; |Chamber port tube length (cm)
Vtc = 1843.00e-6; |Throat chamber volume (cc)
Atc = 900.00e-4; |Throat chamber cross-sectional area (sq cm)
|Parameter Conversions:
Sd = 881.00e-4; |Diaphragm area (sq cm)
Ltc = Vtc / Atc;
}
|========================================================================================================
|Network node numbers for this tapped horn system:
| 0-Voltage-1
| |
| -Port-4-Chamber-5-Driver-
| | |
|8-Segment-9-Segment-10-Segment------11-Segment-12-Radiator
|========================================================================================================
Def_Driver 'Driver'
Sd=881.00cm2
Bl=18.60Tm
Cms=1.40E-04m/N
Rms=3.90Ns/m
fs=42.4464Hz |Mmd = 85.40g not recognised by AkAbak, fs calculated and used instead
Le=4.90mH
Re=5.30ohm
ExpoLe=1
System 'System'
Driver Def='Driver''Driver'
Node=1=0=5=11
Duct 'Throat chamber'
Node=4=5
SD={Atc}
Len={Ltc}
Visc=0
Duct 'Port'
Node=4=9
SD={Ap}
Len={Lpt}
Visc=0
Waveguide 'Horn segment 1'
Node=8=9
STh={S1}
SMo={S2}
Len={L12}
Conical
Waveguide 'Horn segment 2'
Node=9=10
STh={S2}
SMo={S3}
Len={L23}
Conical
Waveguide 'Horn segment 3'
Node=10=11
STh={S3}
SMo={S4}
Len={L34}
Conical
Waveguide 'Horn segment 4'
Node=11=12
STh={S4}
SMo={S5}
Len={L45}
Conical
Radiator 'Horn mouth'
Node=12
SD={S5}
...........................
Tweak away
What I found....
To contribute a few things I seem to have discovered with and without help:
Compression in a tapped does help a great deal.
Getting upper bass to sound good is a pain in a th.
So I wouldn't consider a DIY TH if you have top boxes that are weak at 100hz. If you have 15" tops you should be ok. Otherwise
stick with a double 18 or 15. Especially if you only want two subs.
If you are one of those rare quiet acts (especially midi) you might like the path15.
You have a very limited bandwidth to work with.
While not as loud as a typical folded horn, TH boxes sound better for live use. (I gave away my one folded DIY...empty).
A couple of cm makes a BIG difference in a PA type cabinet.
Folding certainly causes issues that I'd love someone to point me at information on how to solve them.
Considering I've spent almost a month, almost every day building and unbuilding boxes, I've cleaned out my horn resp database 3 times, I gone through countless styrofoam and plywood boards, done close to a hundred tests, I'll say this.....
If you have the money....Dont cheap out, go buy the Danley.
My goal was to get to 103db from 45 to 120, couldn't do it.
Although for a DIY the HTH might be interesting as it pushed
up to 106db at 70hz due to compression and the chamber.
For the rest of us who probably won't be able to afford new subs... we'll keep plugging away at it.
Cheers
Scott MacAuley
To contribute a few things I seem to have discovered with and without help:
Compression in a tapped does help a great deal.
Getting upper bass to sound good is a pain in a th.
So I wouldn't consider a DIY TH if you have top boxes that are weak at 100hz. If you have 15" tops you should be ok. Otherwise
stick with a double 18 or 15. Especially if you only want two subs.
If you are one of those rare quiet acts (especially midi) you might like the path15.
You have a very limited bandwidth to work with.
While not as loud as a typical folded horn, TH boxes sound better for live use. (I gave away my one folded DIY...empty).
A couple of cm makes a BIG difference in a PA type cabinet.
Folding certainly causes issues that I'd love someone to point me at information on how to solve them.
Considering I've spent almost a month, almost every day building and unbuilding boxes, I've cleaned out my horn resp database 3 times, I gone through countless styrofoam and plywood boards, done close to a hundred tests, I'll say this.....
If you have the money....Dont cheap out, go buy the Danley.
My goal was to get to 103db from 45 to 120, couldn't do it.
Although for a DIY the HTH might be interesting as it pushed
up to 106db at 70hz due to compression and the chamber.
For the rest of us who probably won't be able to afford new subs... we'll keep plugging away at it.
Cheers
Scott MacAuley
FlipC said:
Not exactly, and they're not that cheap.
I tried the 4015 and teh 15btx in the sims. Similar issues with all 3. The 4015 would be better, the 15btx is the most expensive.
I try Jbl 2225H drivers as well just to see what they'll do at lower volumes. I like the sound of the JBL much much better. I'm guessing the BTX would probably be best, 4015 second then maybe the 3015lf. The other eminence offerings don't have the xmax. The HTH15 looks like it may be able to take other drivers since the horn is actually just a giant port.
In max spl, yes the waveform goes to hell..as it should. Speakers are not linear.
If you are using the new max spl option in the wizard here's how I use it. (nice addition there David!).
Set your xmax, adjust your power level until something starts CLIPPING. Go to your chamber or horn and tweak away in the chamber section or s1 and 2 to try to minimize the clipping.
Then raise the level a little and try again.
Also look at the displacement as well, the 3015 runs out of xmax
very quickly below 40. I have not figured out how to set a hpf in hornresp. It's a big balancing act.
I basically try to get it so the tops of the waveforms peak at max spl at about the same time. For example if I have a peak at 45hz and 65hz, I try to get them to max out at the same level.
At 400w and 9.0 xmax on the 3015 those two peaks look about the same at 126-130 db if I get it right.
The end result is a cabinet that sounds fairly loud and full versus a loud sounding box with no...balls
.I can tell you that if you want 94 db at 100 feet full blast...you need at least two diy TH horns coupled together, and you'll be pushing the hell out of em.. Personally I believe one should consider all subs in pairs where ever possible. Saves a ton of amp dollars and prevents blow ups. That 20,000 watt amp isn't much good if the speaker can only take 1200 watts
.I have played with the "Input Power"
and Xmax setting but dont understand the Xmax one. Does this disregard the Input Power? Cause it still says 100 watts 15 mm Xmax... (on a my particular driver)
Shouldn't it be so you set max Xmax and it figures amount of power it would take to reach that and the given SPL graph to boot...
And what do you mean clipping?
Not like I see a clip indicator ?Something else I am missing...?
I assume HR
can not model multiple TH speakers like it can other horns?
and Xmax setting but dont understand the Xmax one. Does this disregard the Input Power? Cause it still says 100 watts 15 mm Xmax... (on a my particular driver)
Shouldn't it be so you set max Xmax and it figures amount of power it would take to reach that and the given SPL graph to boot...
And what do you mean clipping?
Not like I see a clip indicator ?Something else I am missing...?
I assume HR
can not model multiple TH speakers like it can other horns?
FlipC said:
Xmax is the xmax rating of the speaker not the maximum excursion before damage rating. The 3015 xmax is 9.0 and If I remember correctly the maximum excursion before damage is 15.
The speaker runs out of gas at 9, it disentegrates at 15....I'e.
physically damaged beyond repair in less than the time it takes for one kick drum beat. You can hit xmax of 9 with a 3015lf at 40 hz with only 45 watts. Even less at 30hz!!!!!
Clipping.
Look at the top of the waveforms (peaks) as you raise the level.
You will see probably the lowest frequency one start to flatten out or become distorted and deformed. That's clipping.
You can not eliminate it completly but you can balance it.
Horn resp has been damn good. While the levels may be different depending on your test procedure, the cabinets built tend to respond as expected. Using the max spl otpion along with displacement, the cabs I build have all behaved as predicted.
Don't go by the manufacturers max power rating only. The compression factor of the speaker blasting away will throw off your horn adjustments. I only use that rating to see if my maximum pushed to hell level is fairly balanced.
The last box peaked at 128db at 45hz and I think 80hz at the same time in hornresp. The actual box peaked at 126db at 45 and 80 as expected at about the same time.
Look at your displacement as well, you may be running out of xmax at lower frequencies and will not be able to get any more out of it down there. So you work with the next higher freq peak.
The box will roll off as it gets louder and the driver runs out of gas.
Hope that helps
FlipC said:
Yes Xmax ignores power input but it tells the program where the woofer will reach xmax based on the other driver parameters.
You can put 2 hundred watts into a driver at 120hz and barely reach xmax, but the same driver may hit xmax at 40 with only 65 watts. One example is the jbl2225. It's so stiff that 40 hz wont really hurt it too easily. It won't make much 40hz, but you'll have a harder time blowing it than a 3015lf or a very loose home woofer. The point where the JBL will clip at 40hz will be at a higher input level than the 3015 but with a lower output level.
Once again...it's all a balancing act, give a little here get a little there till you reach the best compromise for what you have.
Spikes as clips
Not the spikes themselves, the point where the tips of the spikes flatten out is clipping. When a nice curve turns into a flat line at its peak or upper limit, that's clipping.
A picture is worth a thousand words but I cant get to my server from here.
GM thanks for the tip.
Rademakers said:
FlipC said:
You may find that adjusting something doesn't seem to make much difference..... after you tweak a few things that do, suddenly the first adjustment you were making seems to actually
do something. That's because somewhere down the line something else is effecting what you were adjusting such that
any changes would seem to have no effect.
The easiest way to explain it (I think sometimes.....)
It's like water in a pipe, you can turn the knob all you want but only so much will come out of the faucet. You can install a bigger pipe but you may still only get the same amount of water because the main valve isn't open all the way..... or you are still using the same faucet which will only allow a certain amount of water to flow regardless of how big a pipe feeds it. The same theory applies here. Luckilly we don't have to deal with gravity too much as well
So I have built 3 TH's so far.
The first was a test box for proof of concept.Even being built out of OSB it still sounded good. So I built 2 more to spec out of MDF.
They run 50-200 Hz with a 24db crossover. I lap over the upper bass with 15" mids at 150 Hz to even out some dips. I also bump 50 Hz just a tad to get it flatter. I have used these 2 subs at an event and ran them full bore for almost 5 hours. I checked them before break down and the drivers were luke warm to touch. Yet another reason why I like the TH design. Long as no drunk throws a beer into it!
Anyway. I have been wanting to build some "sub sonic" tapped horns to fill the lower end.
These really only have to fill below 60 Hz. I have been playing around and have come up with some possibilities but was having issues with excursion in the upper low end.
So I just fiddled with using 4 cabinets
(as long as I understood GM correctly and just multiplied ALL my speakers' specs by 4) and it looks promising. Also using MAX spl which is what I am going for so used 80volts for 400 watts at 4 ohm. (ish) Just over 580 Lt per cab. Not small but doable. Specially rectangular shape for center fill with mouths together. (alla DTS style)
So lets see:
So how far am I off things?
(I know it would take some EQing to get it this flat at this level but I can do that.)
Also - how does stuffing effect
TH's? Will it effectively make a segment length "longer" to the wave ? Is there a way to model this in HR?
The first was a test box for proof of concept.Even being built out of OSB it still sounded good. So I built 2 more to spec out of MDF.
They run 50-200 Hz with a 24db crossover. I lap over the upper bass with 15" mids at 150 Hz to even out some dips. I also bump 50 Hz just a tad to get it flatter. I have used these 2 subs at an event and ran them full bore for almost 5 hours. I checked them before break down and the drivers were luke warm to touch. Yet another reason why I like the TH design. Long as no drunk throws a beer into it!
Anyway. I have been wanting to build some "sub sonic" tapped horns to fill the lower end.
These really only have to fill below 60 Hz. I have been playing around and have come up with some possibilities but was having issues with excursion in the upper low end.
So I just fiddled with using 4 cabinets
(as long as I understood GM correctly and just multiplied ALL my speakers' specs by 4) and it looks promising. Also using MAX spl which is what I am going for so used 80volts for 400 watts at 4 ohm. (ish) Just over 580 Lt per cab. Not small but doable. Specially rectangular shape for center fill with mouths together. (alla DTS style)
So lets see:
An externally hosted image should be here but it was not working when we last tested it.
So how far am I off things?
(I know it would take some EQing to get it this flat at this level but I can do that.)
Also - how does stuffing effect
TH's? Will it effectively make a segment length "longer" to the wave ? Is there a way to model this in HR?
O.K. I'm done. Out of time, money and my lady's patience..
I'll have two offerings to post in a few days as soon as I have time to remeasure and draw them out, and post them on the server. I'm hoping someone more masterfull with compression and path smothing can tweak them before I actually build the real 6.
They are the PATH15 and the HTH15. Perfect, NO, usable, YES, practical, DEFINITELY, Portable, most certainly. Loud?......... every musician in the neighborhood wants to hire me after rattling thier houses with only one and then finding out I'm building 6.
The scripts I posted earlier are basically correct.
Both boxes have a 39x31 side profile. Wheels on the back bottom ramp, and the top back ramp will house built in handles.
The Path15 needed some tweaking on s1-s2 and a ramp added to get the box geometry to work. The box is 24" internal width.
The HTH15 is actually the more interesting of the two as the woofer cone fires down into the mouth. That puts the woofer in a protective and voicable chamber. The articulation is really sweet. It's a 21 inch internal width. To make it wider you would have to make it shorter and deeper which would allow a little more horn for better gut wrenching bass. The secret to it is in the woofer's chamber. I discovered that you need to make it as small as possible to get the cabinet tight. Difficult to do without molding a custom filler out of expanding high density foam.
This box should be played with!! If we can chamber it right and get the chambers port compression optimized for the horn it may become the best diy utility pa box. The absence of a 80-100 dollar grille ordered from LA to protect the driver makes it VERY attractive. The prototype also seems to behave pretty well to driver swaps. My Jbls sounded pretty nice in it too.
The HTH can be crossed over much higher than the PATH and will work well with weaker tops. Try 20400 as the chamber volume to start instead of the 30400? You'll see what I mean.
Smaller the chamber the better it gets. A squatter version doesn't bother me as I'd be stacking them sideways anyway.
I ran my "finals" with tops. The Path is a SUB and it will make you sick. The mid bass articulation is not good enough to meet weak tops. Probably because of the inverted cone and the physical frame of the woofer in the direct path.
The HTH in 21" sounds pretty damn good but lacks the "Brown Note" cabable 40hz or so low end. At least for now. Once again very articulate and clear. It runs about the same level as the PATH. I think they each have a specific use.
I'll have two offerings to post in a few days as soon as I have time to remeasure and draw them out, and post them on the server. I'm hoping someone more masterfull with compression and path smothing can tweak them before I actually build the real 6.
They are the PATH15 and the HTH15. Perfect, NO, usable, YES, practical, DEFINITELY, Portable, most certainly. Loud?......... every musician in the neighborhood wants to hire me after rattling thier houses with only one and then finding out I'm building 6.
The scripts I posted earlier are basically correct.
Both boxes have a 39x31 side profile. Wheels on the back bottom ramp, and the top back ramp will house built in handles.
The Path15 needed some tweaking on s1-s2 and a ramp added to get the box geometry to work. The box is 24" internal width.
The HTH15 is actually the more interesting of the two as the woofer cone fires down into the mouth. That puts the woofer in a protective and voicable chamber. The articulation is really sweet. It's a 21 inch internal width. To make it wider you would have to make it shorter and deeper which would allow a little more horn for better gut wrenching bass. The secret to it is in the woofer's chamber. I discovered that you need to make it as small as possible to get the cabinet tight. Difficult to do without molding a custom filler out of expanding high density foam.
This box should be played with!! If we can chamber it right and get the chambers port compression optimized for the horn it may become the best diy utility pa box. The absence of a 80-100 dollar grille ordered from LA to protect the driver makes it VERY attractive. The prototype also seems to behave pretty well to driver swaps. My Jbls sounded pretty nice in it too.
The HTH can be crossed over much higher than the PATH and will work well with weaker tops. Try 20400 as the chamber volume to start instead of the 30400? You'll see what I mean.
Smaller the chamber the better it gets. A squatter version doesn't bother me as I'd be stacking them sideways anyway.
I ran my "finals" with tops. The Path is a SUB and it will make you sick. The mid bass articulation is not good enough to meet weak tops. Probably because of the inverted cone and the physical frame of the woofer in the direct path.
The HTH in 21" sounds pretty damn good but lacks the "Brown Note" cabable 40hz or so low end. At least for now. Once again very articulate and clear. It runs about the same level as the PATH. I think they each have a specific use.