Still no answer :( horn<->direct radiating freq.

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   Hi yall,

I have some FLH kickbins that i'm trying to time and phase align with my scoops.
Xover point will be 80-90Hz.

I'm basically treating the scoops as front loaded horns (as in inverting polarity of the scoops and delaying the rest of the system to their hornlength).

What i'm interested in is knowing at which frequency the front radiating part of the scoop actually becomes dominant over the horn, does anybody know this?

If 80-90Hz is actually dominated by the front radiating part, then it's no use in treating them as front loaded horns at that Xover freq.

I know the phase/timing with scoops is vague anyway, but it seems to me that if you know which band is dominated by the horn and which by direct radiation, it's best to adjust your system accordingly. I have read through many posts asking basically the same question, but haven't heard any concrete answers, I'm hoping that anyone has some true knowledge about it.

Also, to get the time alignment completely correct I would like to know the group delay of (the horn part of) scoops.

Ps. With scoops i mean the Mogale Super Scooper (loaded with PD186/2)
Pps. In the link below Rog Mogale states that scoops have a frequency where the front radiating part becomes dominant, but not at which frequency for his design.
http://www.performing-musician.com/pm/may09/articles/diypacabs.htm

Thanks for reading!

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patchoreep Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 13 May 2013 Status: Offline Points: 23	Post Options Post Reply Quote patchoreep Report Post Thanks(0) Quote Reply Topic: Still no answer :( horn<->direct radiating freq. Posted: 26 May 2015 at 9:55pm
	Hi yall, I have some FLH kickbins that i'm trying to time and phase align with my scoops. Xover point will be 80-90Hz. I'm basically treating the scoops as front loaded horns (as in inverting polarity of the scoops and delaying the rest of the system to their hornlength). What i'm interested in is knowing at which frequency the front radiating part of the scoop actually becomes dominant over the horn, does anybody know this? If 80-90Hz is actually dominated by the front radiating part, then it's no use in treating them as front loaded horns at that Xover freq. I know the phase/timing with scoops is vague anyway, but it seems to me that if you know which band is dominated by the horn and which by direct radiation, it's best to adjust your system accordingly. I have read through many posts asking basically the same question, but haven't heard any concrete answers, I'm hoping that anyone has some true knowledge about it. Also, to get the time alignment completely correct I would like to know the group delay of (the horn part of) scoops. Ps. With scoops i mean the Mogale Super Scooper (loaded with PD186/2) Pps. In the link below Rog Mogale states that scoops have a frequency where the front radiating part becomes dominant, but not at which frequency for his design. http://www.performing-musician.com/pm/may09/articles/diypacabs.htm Thanks for reading!

Teunos Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2008 Location: The Netherlands Status: Offline Points: 1799	Post Options Post Reply Quote Teunos Report Post Thanks(0) Quote Reply Posted: 26 May 2015 at 10:03pm
	You can actually simmulate this in hornresp. Really dont want to start quoting its help functie so i suggest you take a look at that. Gut feeling says its probably above at least 90hz
	Best regards, Teun.

patchoreep Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 13 May 2013 Status: Offline Points: 23	Post Options Post Reply Quote patchoreep Report Post Thanks(0) Quote Reply Posted: 27 May 2015 at 12:24am
	Yeah i did that just now. Should have done that a long time ago. Seems like the horn dominates up untill 100Hz, after that, the overall response drops (cancellation from front and horn), after 120Hz the front radiating part is dominant. group delay from the horn part is low at 80Hz (about 8ms which is roughly the delay of the horn path), and quickly rises to about 20ms at 90Hz. So a good starting point in trying to combine super scoops (PD186/2 loaded) with FLH kicks in a time/phase aligned manner would be: - cross at 80Hz for minimum group delay - invert polarity of scoops - Delay kicks for 8ms - kick horn path (in my case 4,1ms) = 3,9ms After this it's only a matter of playing a 80Hz sine wave, inverting the kicks, fiddling with a litte extra/less delay to get the biggest cancellation, and then switching polarity of the kicks again (for biggest 'summification'). Just putting this here, for other people with the same question in mind :) I'll be testing this setup soon and i'll post the results. We used to have a reflex 18" kick section + treat our scoops as direct radiators. That sound was heavy, but slow, only good for dub... Now we've switched to FLH kicks for faster upper bass, which is a big improvement. I hope that with these settings I can actually achieve reasonably dynamic and defined bass... With scoops! :p

b grade Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 05 October 2012 Location: Portland OR USA Status: Offline Points: 1337	Post Options Post Reply Quote b grade Report Post Thanks(0) Quote Reply Posted: 27 May 2015 at 1:17am
	For timing, I usually just make a test tone at the crossover point and feed it independently through both speakers and record the output to a daw. The mic should be at a spot level with the average human ear and directly in front of the stack. I then record the output to a muted audio track for both speakers. Check the difference in arrival time and adjust to correct it for that specific crossover point. They will likely wander out of time alignment as you get farther from the crossover point, but if the slope is set correctly, both speakers should dominate in their relative band so the problem will be minimal unless you are really overlapping a lot.

toastyghost Members Profile Send Private Message Find Members Posts Add to Buddy List The 10,000 Points Club Joined: 09 January 2007 Location: Manchester Status: Offline Points: 10920	Post Options Post Reply Quote toastyghost Report Post Thanks(0) Quote Reply Posted: 28 May 2015 at 12:55am
	Why at human ear level? Are you happy working to a ground plane reflection?