Hello all,
I'm aiming to build a custom front loaded horn for an outdoor sound system.
The cabinet will be similar to altec m-17 (but smaller).
it should go between 150Hz and 1500Hz approximately.
I've been reading about horn theory and design. This paper (http://www.quarter-wave.com/Horns/Front_Horn.pdf, page 16) says that good driver for horn should have Qts between 0.15 and 0.25.
These are however difficult to find in 10" and rather expensive
my choice came to this driver RCF L10 750 YK
with this indicated frequency response
and those T/S Parameters
But i Would like to know : WHAT PARAMETERS SHOULD I CHECK FOR DRIVER IN ORDER TO BUILD A FRONT LOADED HORN LOUDSPEAKER ?
Thanks in advance for your answers !
Alix
I'm aiming to build a custom front loaded horn for an outdoor sound system.
The cabinet will be similar to altec m-17 (but smaller).
it should go between 150Hz and 1500Hz approximately.
I've been reading about horn theory and design. This paper (http://www.quarter-wave.com/Horns/Front_Horn.pdf, page 16) says that good driver for horn should have Qts between 0.15 and 0.25.
These are however difficult to find in 10" and rather expensive
my choice came to this driver RCF L10 750 YK
with this indicated frequency response
An externally hosted image should be here but it was not working when we last tested it.
and those T/S Parameters
- Resonance frequency (Fs): 68 Hz
- DC resistance (Re) (ohm): 5.10 ohm
- Mechanical factor: 4.20 Qms
- Electrical factor: 0.25 Qes
- Total factor: 0.24 Qts
- Bl factor (Bl) (T x m): 17.50 T x m
- Effective moving mass (Mms): 36.0 g
- Equivalent Cas air loaded (Vas): 26.0 liters
- Effettive piston area (Sd): 0.040 m2
- Max. linear excursion (Xmax): 3.0 mm
- Voice coil inductance @ 1kHz (Le1k): 0.50 mH
- Half-space efficency (Eff): 3.15%
But i Would like to know : WHAT PARAMETERS SHOULD I CHECK FOR DRIVER IN ORDER TO BUILD A FRONT LOADED HORN LOUDSPEAKER ?
Thanks in advance for your answers !
Alix
you might not gonna get this wide.
135 hz Mid Bass Horn - The Paper Horn by Inlow Sound
Even this mighty inlow 135 horn start to fall from 600hz from floor.
[Alix, here is your image. Imgur doesn't like other sites linking.]
Consider the efficiency bandwidth product. EBP=Fs/Qes. Larger values indicate a stronger motor suited to creating pressure against a restriction. EPB should probably be larger than 100. I like to confirm with hornresp.
Consider the efficiency bandwidth product. EBP=Fs/Qes. Larger values indicate a stronger motor suited to creating pressure against a restriction. EPB should probably be larger than 100. I like to confirm with hornresp.
Attachments
After using Bruce Edgar papers for building a midbass horn I kept using 2xFs/Qes as the upper limit for which a driver is suitable for. When searching for a proper driver to load a horn look after a not so low Fs (for example, over 60-70Hz) and high Bl value (big magnet for the motor). Your driver si optimal to 2x68/0.25=544 Hz .It's working over that limit but would need some kind of EQ.
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Great ! thank you all for your answers, many usefull information here, thanks manninen, Allen B, Dorin D and 4real !!!