For home use, I like response to 20 Hz, for PA use, 35 Hz is the compromise I'm willing to accept between LF extension, output, and size.
That said, for home use I don't require nearly the level needed for outdoor live shows, so a pair of sealed 12" is adequate for me.
Does the B&C 15NA100 also work with the Tham15 design
I have tried this speaker in a small vented box and was not very satisfied.
Amplification will be a class d module with 900W peak , highpass is fixed 25Hz 12db
The peak power is equal to rms power, the limiter in it works very well.
(Fs)47 Hz (Re)5.1 ohms (Le)1.2 mH (Qms)6.1 (Qes)0.29 (Qts)0.28 (Vas)3.1 ft.³
(BL)26.3 Tm (Mms)136g
Maximum Linear Excursion (Xmax)10 mm
Surface Area of Cone (Sd)855 cm²
Sensitivity98 dB 1W/1m
Voice Coil Diameter4"
I have tried this speaker in a small vented box and was not very satisfied.
Amplification will be a class d module with 900W peak , highpass is fixed 25Hz 12db
The peak power is equal to rms power, the limiter in it works very well.
(Fs)47 Hz (Re)5.1 ohms (Le)1.2 mH (Qms)6.1 (Qes)0.29 (Qts)0.28 (Vas)3.1 ft.³
(BL)26.3 Tm (Mms)136g
Maximum Linear Excursion (Xmax)10 mm
Surface Area of Cone (Sd)855 cm²
Sensitivity98 dB 1W/1m
Voice Coil Diameter4"
It's different because it's showing different things. Check the Hornresp help file. The max spl graph shows the spl limits, not the frequency response. Xmax limited spl is shown in one color, power limited spl is shown in a different color.
Are you using the wrong tool? Depends what you want to see. If you want to see the spl limits then it's the right tool. If you want to see frequency response it's the wrong tool. Personally I choose to view frequency response and diaphragm displacement graphs, shown at reasonable power levels. I don't ever use the max spl graph.
If I enter 1W power and 10mm X-max, there should be no difference in the graph, because there should be no limting factor, but the curve looks different.
One thought is that the calculation in HR ads the calculated impedance and shows the simulation with 2,83V fixed input. Than it will give a different graph.
I´m trying to understand the principle of the TH and the work of the driver in it.
I do not want to wreck a 300€ driver during listening to normal music because the driver rans out of excursion.
Thermal the driver seems to be bullet proof.
Its actually doing the oppossite of what you think. instead of giving it 2.83v, (like we would when hooking it up to an amp and running a sweep to get freq resp), its giving it 1 watt, which is variable voltage. Thus, it will show output peaks anywhere there is an impedance peak, because its getting far more than 2.83 v at those freqs.
If you want to find max spl, just play with the Eg field and the filter wizard until you find a combination of input power and hipass filter that results in acceptable excursion. Its not hard.
If you want to find max spl, just play with the Eg field and the filter wizard until you find a combination of input power and hipass filter that results in acceptable excursion. Its not hard.
Ok now I managed to see the excursion for 90V, it seems to be safe until I´m not going under 30Hz.
When using the filter wizard , you can´t see any direct results in the excursion diagram.
But with a 25Hz 12db high pass, nearly 3db will be cut at 30Hz, so the speaker works in safe area. -3db = half the power. With 70V at 30Hz it still will be safe.
Better would be a 35hz high pass with 24db, but this is not integrated in the plate amp I want to use. With the plate amp I could drive to subs.
In the basement I have a spare amplifier from a Linn Sizmik Subwoofer, this one has an adjustable high pass, and it is smaller than the plate amp I wanted to use. Output voltage is nearly 80V, so it will drive the speaker very well. This amp can only drive one sub.
I´m only concerned about heat, as the amp was designed for a hifi-sub.
I ran it a few nights in the year on a Klipsch horn (built it about 20years ago) with a Beyma 15G450 inside and had no issues whith heat, but I think it was not driven to the limits, as the bar has only place for 100-150 people.
When using the filter wizard , you can´t see any direct results in the excursion diagram.
But with a 25Hz 12db high pass, nearly 3db will be cut at 30Hz, so the speaker works in safe area. -3db = half the power. With 70V at 30Hz it still will be safe.
Better would be a 35hz high pass with 24db, but this is not integrated in the plate amp I want to use. With the plate amp I could drive to subs.
In the basement I have a spare amplifier from a Linn Sizmik Subwoofer, this one has an adjustable high pass, and it is smaller than the plate amp I wanted to use. Output voltage is nearly 80V, so it will drive the speaker very well. This amp can only drive one sub.
I´m only concerned about heat, as the amp was designed for a hifi-sub.
I ran it a few nights in the year on a Klipsch horn (built it about 20years ago) with a Beyma 15G450 inside and had no issues whith heat, but I think it was not driven to the limits, as the bar has only place for 100-150 people.
Hi Dominik,
You will need a 24dB/oct @ 36Hz or 12dB/oct @ 43Hz, for the original Tham15. Max excursion will be reached @ 68,61V in theory for your driver.
There is a key statement here, and it came from Djim, and it is "in theory".
The music signal is far more complex and diverse to be determined with any grater certainty in simulations, the simulation shows the correct state in theory, hence the term simulation, and i have no reason to doubt them.
It is an old disussion, and it keeps coming back to the fact that real world results do not correspond to that shown in simulations with regards to excursion in real world usage.
Or what about the person firmly beliving that the xmax was reached at 500W, that was what the sims said, and math is never wrong (correct, it is not, but our interpretation of it might be) or the person feeding 1300W (93 V) into a B&C 15PS100 with great results during a whole season, all in the same design, THAM15, and with simillar drivers.
Take the excusrion simulation results for what they are, a mathematical theoretical representation, and by all means, if you use your speakers in theory then that's what you will get, otherwise I would not worry to much about it, alternativly choose a more suitable driver.
The music signal is far more complex and diverse to be determined with any grater certainty in simulations, the simulation shows the correct state in theory, hence the term simulation, and i have no reason to doubt them.
It is an old disussion, and it keeps coming back to the fact that real world results do not correspond to that shown in simulations with regards to excursion in real world usage.
Or what about the person firmly beliving that the xmax was reached at 500W, that was what the sims said, and math is never wrong (correct, it is not, but our interpretation of it might be) or the person feeding 1300W (93 V) into a B&C 15PS100 with great results during a whole season, all in the same design, THAM15, and with simillar drivers.
Take the excusrion simulation results for what they are, a mathematical theoretical representation, and by all means, if you use your speakers in theory then that's what you will get, otherwise I would not worry to much about it, alternativly choose a more suitable driver.
Yes, I should use a filter like mentioned above.
But the plate amp has a fixed filter, and all I want to be sure is that the coil doesn´t hit metal. Excursion one way is over all 19mm. I do not bother if this is Xmax or Xlim.
I know that the excursion calculation ist only in theory.
With power compression an other losses there should not be any problem with the driver (BC 15NA100) I want to use. That´s all the math tells me.
After I build the cabinet I will test it to the limits of the amp, and if there is any excursion problem at any frequency I will change the amplification. But I want to try at first the plate amp I already have, because it can drive two Subs. I´m using the same plate amp already for two 3015LF in Reflex loaded cabinet and have no excursion issus.
The single Tham15 should replace two nearly 10 year old D.A.S. Audio SUB18A.
Less space, less weigth, (I bougth the version made of MDF, 45kg), and nearly the same output.
Consider 40hz and 80hz tones mixed 1:1 with a drive level of 80V.
The low tone will require 40V of the drive, the upper tone the other 40V.
The woofer will travel X at the low tone, and 1/4X on the high tone.
If we call X 8mm, the total excursion would be 10mm.
If all 80V went in on the low tone the excursion would be 2X.
Unless playing sine tones, excursion shouldn't be a problem. Even the 'music' that sounds like swept sine tones has strong harmonic content. A low E played on a Fender P bass has a second harmonic that is over 6dB higher than the fundamental (have seen 9dB).
This is just a 'theory', but it does seen to fit the facts.
The low tone will require 40V of the drive, the upper tone the other 40V.
The woofer will travel X at the low tone, and 1/4X on the high tone.
If we call X 8mm, the total excursion would be 10mm.
If all 80V went in on the low tone the excursion would be 2X.
Unless playing sine tones, excursion shouldn't be a problem. Even the 'music' that sounds like swept sine tones has strong harmonic content. A low E played on a Fender P bass has a second harmonic that is over 6dB higher than the fundamental (have seen 9dB).
This is just a 'theory', but it does seen to fit the facts.
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This sub will be used only 8 days a year.
Therefore the driver can be driven near to it´s mechanical limits. Knowing that spl will not increase much and the sound will not get better with more excursion.
The only thing that I really care is that the driver can handle full power without the coil hitting the plate, that is what I will with swept sine wave test after building the cabinet.
If the sexcursion will be near simulation than everything is ok. If I mesure more excursion I have to change the amp and highpass filter.
I managed only to wreck one driver a few years ago when I changed amping from a Mackie M1400 to a Behringer EP2500 and trustet the 30Hz highpass written in the manual.
After I took out the destroyed driver , I measured the filter and found out that the highpass settings produced a 5 db peak at 32Hz, which made the coil hit the plate.
Since there I always double check everything.
Therefore the driver can be driven near to it´s mechanical limits. Knowing that spl will not increase much and the sound will not get better with more excursion.
The only thing that I really care is that the driver can handle full power without the coil hitting the plate, that is what I will with swept sine wave test after building the cabinet.
If the sexcursion will be near simulation than everything is ok. If I mesure more excursion I have to change the amp and highpass filter.
I managed only to wreck one driver a few years ago when I changed amping from a Mackie M1400 to a Behringer EP2500 and trustet the 30Hz highpass written in the manual.
After I took out the destroyed driver , I measured the filter and found out that the highpass settings produced a 5 db peak at 32Hz, which made the coil hit the plate.
Since there I always double check everything.
It will be in the range of 40-50 kg (90-110lbs), depending of driver and wood used.