The other old rig is x 8 PD1851 hogs and x6 PD186 ES18 ES18*Electrikal all PD186.2 loaded all made by Stable Audio.

We also now have x4 reflex faital pro loaded tops with another two being made by Stable Audio at the moment. 


Powered by 4 racks of Matrix amplification and x2 VOID INF8's but currently looking at powersoft for bass.


Photos of everything together for the first time below:

When the horn profile is kept constant but the length and thus frontal area is kept the same whilst the expansion rate is thus unchanged, only the cutoff freuquency will change. That is assuming the roundover at the edge of the horn etc are equivalent having an equal mouth impedance termination for the desired frequency band above the cutoff frequency of both horns. 

Therefor, if the crossover frequency is sufficiently high enough for the size of the horn, there will be no difference when the horn size is (unnecesarily) increased.

There are several benefits and also downsides to using small horns.

Generally though you see two(or 3) common setups for the frequncy area above 800Hz. That is either 

A: A 6''-10'' midrange cone loaded on a low compression midhorn with a small 1'' driver above it.

C: A coaxial 2'' compression driver like the BMS series that have already a smaller HF diafragm in them.

A: The midrange cone loaded on a horn will generally offer lower distortion figures for low SPL values, however is generally larger and less common as the flares are not widely available. Since the distance from the midrange horn to the HF horn is generally much larger than a single wavelength at the crossover frequency, this setup will have severe comb filtering around the crossover region. Such setups benefit greatly from very steep crossover slopes or even FIR filtering which almost completely removes comb filtering and thus also lobing. Audio quality, with proper horns that have proper mouth termination reducing reflections and giving efficient coupling but also keeping proper dispersion can be increased due to having two seperate horns for each frequency band that can be tuned to that specific band. A downside is however that generally the midrange horns will start beaming pretty soon in the passband and thus needs to be crossed pretty early to the smaller HF horn, thus increasing the power demand on the HF driver. Upside is that the midrange horns can be crossed lower to the section below it due to high mechanical capacbilities of the midrange cone compared to a 2'' compression driver with a 4'' diafragm.

B: Using a 2'' compression driver will generally allow for a higher lowpass crossover point if the 2'' is complemented by a 1'' relieving the power requirement on the 1''. This way you can get silky smooth top end with very low distortion figures. The availability of 2'' compression drivers and horns aids in its popularity. They suffer from the same problems as the midrange horn>HF setup in that the distance between drivers is again large compared to the wavelength around the crossover. Again steep slopes or FIR filtering reduces this. Again the MF and HF horns can be tuned to their specific passband optimizing audio quality and dispersion characteristics.

C: Using a coaxial 2'' compression driver completely removes the lobing issues as the driver is now a point source. Power distribution is also good as the entire spectrum is handled by two seperate diafragms. The larger diafragm can be made such that it will never need to produce high frequencies which in turn makes it possible to increase mechanical limits of the diafragm, which is why the BMS for example can be crossed from about 500Hz upwards if the horn is sufficiently large. Downside of this setup is that one horn has to cover the entire passband and in this aspect there will always be sacrifices made which most times results in poor HF dispersion. This solution is popular for the point source behavior and the availability of the drivers and horns as well as the possibility of crossing the driver to the low frequencies section at a realatively low frequency. Also the reduced size of the total setup is very intersting, because obviously no additional HF horn is needed.

The solution electrikal uses is obviously option A, which in my eyes is a perfectly good one. This will give very good audio quality and also dispersion characteristics. Proper measuring and DSP filtering is however required, but i think they have taken care of that. Concluding, we can say that that horn is probably large enough, if the midrange horn do not start to beam early on. Why the HF driver was placed higher above the midrange horn than possible though is probably only aesthetic/construction practicality since it would be much better to place it directly above the midrange horn to reduce comb filtering and also lobing, since i highly doubt that FIR filtering is used. (i do not know, but generally only very few people use it, so....). Even a centimeter can make a large difference.

Tannoy IQ10 solves this problem as the HF driver and horn are place inside the phaseplug of the midrange horn, although this does again reduce the dispersion control and impedance matching of both midrange and HF horn.

Indeed you are correct we are using option A and the HF is so high due to Aesthetic/adding the electrikal logo to the box. 

I was going to get smaart out on the Saturday during the day but slept in and didn't make it back down to the festival until 5 minutes before the first DJ was on sadly. 

Although the bonus was my house was literally 15 minutes away from the Festival so no camping and plenty of showers for me this weekend which made a nice change.

 

they do when the system is hitting the limiters