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In the Forum: Horn-Loaded Speakers
In the Thread: Coral x-viii
Post Subject: Sometimes measures are faster - sometimes slowerPosted by martinshorn on: 3/9/2018
Hi alex. Sure the 12 incher starts narrowing around 700. But the horn does too. And in that area you cross both at -6dB. which contributes to narrowing vertically. The magic is, to merge in a way that off axis its not getting too odd in a complex sum. What i mean, if you measure linear gated nearfield on axis crossing at 1k its all looking nice. But then you measure 0 and -10 and -20 -30 -60 degrees on some meter distance. Then you add those or make a magnitude averaging, everything without any gating but a simple smoothing (like 12th oct)... then your linear speaker will not be so linear after all. Thats coz all off-axis oddness changes the complex energy sum on the listening position - and thats why measures and listening can be very different. Depends on your personal approach if you want to find by ear whats better - or measure more complex. Then you see that listening can actually find the good setup faster. Good measuring can take weeks. But ok, not the topic 
With the tweeter crossover can be more difficult. You could cross at 5 or 6. Or go even to 10, or disregard it. The bullet is a very narrow dispersion, so it wont give more "air" to the top than the M104 would do himself. It rather gets stressed coz the diaphragm can absolutely handle no excursion at all, some say dont cross at 6 but rather 8-10 lowest. Well the M104 plays actually already nice in the highs, very colorfull dynamic and emotional but dull. The bullets are more clean fresh precise but colder. It could be a very nice combination to set a 10k first order lowpass to the M104 to roll off the very top gently, and then blend a little bullet-tweeter with a 10k 1st order hipass in to mix both. I think that might work best. But - important - to add an additional 5k 1st order for the bullet, so that he goes 2nd order below 5k, for excursion protection! (basically requires designated amps)cheers, JoshRerurn to Romy the Cat's Site