Hi,
http://img106.imagevenue.com/view.php?image=89614_4PACKEX_122_976lo.jpg
http://img173.imagevenue.com/img.php?image=89617_4PACKIMP_122_512lo.jpg
http://img45.imagevenue.com/view.php?image=89622_4-PACKLP_122_1073lo.jpg
For some one who`s interrested. I posted a comparison between a pack of 4 tapped horns clustered together. The red line is the one with the 3015LF driver in it. The black line is the one with the 15TBX100 driver in it. Both drivers using the same horn dimensions.
The one with the 15TBX100 has a lower frequency cutt-off, less excursion and does handle a lot more power (1000W).
The 3015LF has a greater xmax, but does not handle more power than 450W.
In this configuration you could see the 15TBX100 can handle about 85V RMS before hitting xmax, 9mm. This 4-pack result in a 110dB at 1W/1M from 45Hz up and is 107dB 1W/1M at 40Hz. I think it is a real powerful subwoofer.
So far it`s all an easy job with Akabak. The tough part is building a horn that is really presenting the input parameters of your simulationscript.
When placing a driver on the side of the horn, the driver is loaded with the acoustic impedance of the horn and a compliance trapped in the horn.
I think the best thing one can do, is building a straight horn (with your tapped horn dimensions).
Measuring your drivers impedance and Lp response, with one side in an enclosed volume and the other radiating in free air. Do your simulation with the right enclosed volume.
Placing the driver (with closed back) on the side of the horn and measuring it`s impedance and Lp respons. You should do this at the startpoint of your horn and where the Tap is. Again try to adjust your simulation with the right values, the measured respons must looks identical with your simulation.
Now you have a better feeling what a horn, with certain dimensions, should look like.
Cheers,
Marcel
http://img106.imagevenue.com/view.php?image=89614_4PACKEX_122_976lo.jpg
http://img173.imagevenue.com/img.php?image=89617_4PACKIMP_122_512lo.jpg
http://img45.imagevenue.com/view.php?image=89622_4-PACKLP_122_1073lo.jpg
For some one who`s interrested. I posted a comparison between a pack of 4 tapped horns clustered together. The red line is the one with the 3015LF driver in it. The black line is the one with the 15TBX100 driver in it. Both drivers using the same horn dimensions.
The one with the 15TBX100 has a lower frequency cutt-off, less excursion and does handle a lot more power (1000W).
The 3015LF has a greater xmax, but does not handle more power than 450W.
In this configuration you could see the 15TBX100 can handle about 85V RMS before hitting xmax, 9mm. This 4-pack result in a 110dB at 1W/1M from 45Hz up and is 107dB 1W/1M at 40Hz. I think it is a real powerful subwoofer.
So far it`s all an easy job with Akabak. The tough part is building a horn that is really presenting the input parameters of your simulationscript.
When placing a driver on the side of the horn, the driver is loaded with the acoustic impedance of the horn and a compliance trapped in the horn.
I think the best thing one can do, is building a straight horn (with your tapped horn dimensions).
Measuring your drivers impedance and Lp response, with one side in an enclosed volume and the other radiating in free air. Do your simulation with the right enclosed volume.
Placing the driver (with closed back) on the side of the horn and measuring it`s impedance and Lp respons. You should do this at the startpoint of your horn and where the Tap is. Again try to adjust your simulation with the right values, the measured respons must looks identical with your simulation.
Now you have a better feeling what a horn, with certain dimensions, should look like.
Cheers,
Marcel
I clarified on the xmax-Issue 
Modeled a simple closed box in Akabak and re-created the same conditions as used in other modeling-software. Then I did a comparison of the excursion. Cross referenced with WinISD, AjHorn and LSPCad, so results should be plausible.
Excursion in Akabak is not shown as peak-peak values . It´s "one way", just as mentioned in most data-sheets.
Has somebody taken a further look into the mutual-coupling issue?
Modeled a simple closed box in Akabak and re-created the same conditions as used in other modeling-software. Then I did a comparison of the excursion. Cross referenced with WinISD, AjHorn and LSPCad, so results should be plausible.Excursion in Akabak is not shown as peak-peak values . It´s "one way", just as mentioned in most data-sheets.
Has somebody taken a further look into the mutual-coupling issue?
Hornresp (version 15) now models tapped horns - but I've not done it
whats are good ways to tweak William's simple 30Hz horn model besides higher fs driver?. - - looking at 4012HO in 2.9M version - but graph is not pretty enough
http://img243.imageshack.us/img243/4563/29mexcou2.gif
whats are good ways to tweak William's simple 30Hz horn model besides higher fs driver?. - - looking at 4012HO in 2.9M version - but graph is not pretty enough
http://img243.imageshack.us/img243/4563/29mexcou2.gif
freddi said:
Hi ,
Easy , just play with the numbers . I have notes on 4012HO that xmax is only 4.4mm which is not enough really . What you need is a driver with moderate Vas and good xmax , tune the line length to around 2/3 of the driver Fs . Here's a model based on the fairly inexpensive and available Eminence Kappa Pro 15LF (Fs 35Hz xmax 6.7mm)
hi 316a - that looks pretty strong - so it could be built simple like William Cowan's 30Hz horn? do you think the prediction's slight roughness around 80Hz will occur or smooth out in real life?
http://img207.imageshack.us/img207/3825/316aklfpl9.gif
http://img207.imageshack.us/img207/3825/316aklfpl9.gif
IF you want results in halfspace, you have to look at "acoustic power" (F7) and select 2pi-sr. Best ist to also include the floor as reflecting wall with this line under the driver definition:
Def_Reflector Wall=0.01cm VAngle=-90°
This includes a Wall with almost no (0,01cm) distance to the speaker (stanindg on the floor) and the speaker turned 90degrees (so it´s the floor, not a back wall).
TH in Hornresp:
Take the default settings.
enter the driver specs
enter zero volume for back and front chamber
deisgn three horn-segmenst. (conical or exp).
length of the first segment ist the distance from hornthroat to middle of the cone (look at williams schematics oder the ones postet here)
kength of second segment is path length from front-side of driver to back-side (middle of the cone in both cases)
segment three is the length from backside of cone to the hornmouth
hit "calculate"
HORNRESP asks, if you want a Tapped-Horn to be modelled.
Hit "Yes"
Voilá - finished.
Results compare nicely to ABakak Models. Slight differences are noticable, specialy for upper resonances introduced by large first segments.
max-SPL Feature seems to have some bug. If Input Voltage is set to 2.83V, hornresp disregards xmax. Enter some higher level and you´re good to go.
Mutual Coupling seems not implemented, since excursion are the same than in Abakak Models where mutual coupmling is not used.
I am just cross-referenicing my abakak Models with hornresp, most seem pretty much the same...
Def_Reflector Wall=0.01cm VAngle=-90°
This includes a Wall with almost no (0,01cm) distance to the speaker (stanindg on the floor) and the speaker turned 90degrees (so it´s the floor, not a back wall).
TH in Hornresp:
Take the default settings.
enter the driver specs
enter zero volume for back and front chamber
deisgn three horn-segmenst. (conical or exp).
length of the first segment ist the distance from hornthroat to middle of the cone (look at williams schematics oder the ones postet here)
kength of second segment is path length from front-side of driver to back-side (middle of the cone in both cases)
segment three is the length from backside of cone to the hornmouth
hit "calculate"
HORNRESP asks, if you want a Tapped-Horn to be modelled.
Hit "Yes"
Voilá - finished.
Results compare nicely to ABakak Models. Slight differences are noticable, specialy for upper resonances introduced by large first segments.
max-SPL Feature seems to have some bug. If Input Voltage is set to 2.83V, hornresp disregards xmax. Enter some higher level and you´re good to go.
Mutual Coupling seems not implemented, since excursion are the same than in Abakak Models where mutual coupmling is not used.
I am just cross-referenicing my abakak Models with hornresp, most seem pretty much the same...
Does anyone know how to model the influence of BL-Product?
I have a 10" 8 Ohm Speaker with a BL of 12 which I plan to use in a tapped horn. AFAIK, BL must be high for a speaker to work properly in a horn. But since people building Bill Fitzmaurice´s T24 use Deltalite for these which only have a BL of about 10, I was wondering how much of a difference it would make.
Any clues on how to predict this?
I have a 10" 8 Ohm Speaker with a BL of 12 which I plan to use in a tapped horn. AFAIK, BL must be high for a speaker to work properly in a horn. But since people building Bill Fitzmaurice´s T24 use Deltalite for these which only have a BL of about 10, I was wondering how much of a difference it would make.
Any clues on how to predict this?
Can't say I know the answer to that one but I believe that what is often said about ideal drivers for horns will not always apply to sub bass horns.
Does anyone know how to model a sealed/vented box in akabak? I have been trying to work it out and haven't gotten very far! I've found dialogue boxes to define vented box parameters, but can't get it into a script form that it will accept. I'd like to compare ...
Does anyone know how to model a sealed/vented box in akabak? I have been trying to work it out and haven't gotten very far! I've found dialogue boxes to define vented box parameters, but can't get it into a script form that it will accept. I'd like to compare ...
Take a look at the sample script "bassunit", it´s a simplified reflex-enclosure.
This is a sample for a sealed enclosure
Def_Driver 'D1'
|Tesla ARN 5614
fs=42Hz Vas=30L
Qms=4 Qes=0.5
Re=3.5ohm fre=10kHz Le=0.3mH ExpoLe=0.5
Sd=135cm2
System 'Bass'
| Sealed Enclosure 19 liters
Resistor 'Rg' Node=1=2 R=0.5ohm
Driver Def='D1' Node=2=0=3=4
Radiator Def='D1' Node=3=0 x=0cm
Enclosure 'E1' Node=4 Vb=19.0L
This is a sample for a sealed enclosure
Def_Driver 'D1'
|Tesla ARN 5614
fs=42Hz Vas=30L
Qms=4 Qes=0.5
Re=3.5ohm fre=10kHz Le=0.3mH ExpoLe=0.5
Sd=135cm2
System 'Bass'
| Sealed Enclosure 19 liters
Resistor 'Rg' Node=1=2 R=0.5ohm
Driver Def='D1' Node=2=0=3=4
Radiator Def='D1' Node=3=0 x=0cm
Enclosure 'E1' Node=4 Vb=19.0L
djk said:
Yes, it´s effect on high frequencies is higher wehn looking at horn-usable drivers. Could you clarify, why it´s not a larger concern in the tapped Horn?
I agree. It´s not the most recommended driver, but so far I´ve seen Bill only talk about limitations due to xmax, not due to BL. This got me wondering, because the recommended driver (HL-10C) has a very high BL, the deltalite doesn´t. Since the T24 is a front-loaded horn, I´d have assumed this would be a "no-go", but people seem to be quite happy with the deltalite.
Hello David,
many thanks for this very finde peace of software!! And welcome to this board, it´s very nice to have you here
I did some x-checking with my akabak-models and first found excursion to be the same in akabak and hornresp. After doing some more comparison, they differ. Is mutual coupling implemented in hornresp?
Oh and BTW, can I just copy the new 15 version over the old 15 without loosing my saved projects?
Edit: Just tried it, I was so curious, I couldn´t resist It works perfect, everything is still there
Many thanx
Sabbelbacke
many thanks for this very finde peace of software!! And welcome to this board, it´s very nice to have you here
I did some x-checking with my akabak-models and first found excursion to be the same in akabak and hornresp. After doing some more comparison, they differ. Is mutual coupling implemented in hornresp?
Oh and BTW, can I just copy the new 15 version over the old 15 without loosing my saved projects?
Edit: Just tried it, I was so curious, I couldn´t resist
It works perfect, everything is still there Many thanx
Sabbelbacke