Delays on a pair of scoops |
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Audio Hallucinations
Registered User Joined: 23 December 2009 Location: Brighton Status: Offline Points: 52 |
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Posted: 24 September 2010 at 5:18pm |
how much is the delay on a pair of 18" an on a pair of 15" scoops?
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tweeter box
Old Croc Joined: 21 October 2007 Location: United Kingdom Status: Offline Points: 6784 |
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dude u must be hallucinating!
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Audio Hallucinations
Registered User Joined: 23 December 2009 Location: Brighton Status: Offline Points: 52 |
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lol, why am i hallucinating now?
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Speaker Sol
Young Croc Joined: 15 September 2009 Location: Ireland Status: Offline Points: 1320 |
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Yes.
Interesting, As a scoop is front loaded, it is common to run with no delay and except that the sound from the horn will be somewhat behind the sound from the front of the driver. Or you could run the driver 180 degrees out of phase and time the system up to the horn and except that the sound coming from the cone is going to be well depending on frequency and the length of the horn out of time with the horn. Knowing this, I think that running a rig with more than one type of scoop is probably a bad idea and should be avoided altogether. As even if you time the two horns together the direct sound from the cone will be out, or you can time the direct sound and the horn sound will be out. But then my knowledge of scoops is limited...
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king david
Young Croc Joined: 17 January 2007 Location: italy Status: Offline Points: 1324 |
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what about the sound from 2 stacks of same boxes but different drivers?
i also see many scoops linkups pictures, never heard one, but like to know some feedback
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http://www.warriorcharge.noblogs.org
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Audio Hallucinations
Registered User Joined: 23 December 2009 Location: Brighton Status: Offline Points: 52 |
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,y understanding of it (correct me if im wrong) is that the higher bass frequencies come out of the front loaded an the amplified lower sub freq come out of the horn......i think......so if you cross it over so that kickss are doin the higher bass then u dont have the delayed bassline effect....? so im after the delay time for the horn itself
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TONY.A.S.S.
Old Croc Joined: 21 February 2007 Location: United Kingdom Status: Offline Points: 6878 |
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I would say that the correct way to explain what come from where is that all the bass frequencies come from the front radiating speaker. You must remember that what comes from the front of the speaker is exactly the same as what radiates from the rear. It's the rear radiation that takes advantage of the horn and gets amplified. The result is that the lower end gets a boost while upper bass frequencies take a dive through virtue of the horn. Only part of the rear radiation is out of phase with the front. Depending on length of horn, this will cause a dip just after 100hz. Having a dip at this frequency is no bad thing, as all bass speakers are pretty efficient at this frequency. When 100hz is prominent, it will mask your lower bass.
Regarding time alignment, you can't assume it's a sub that has to be delayed. It depends on the positioning. When I'm testing, until it's done I don't know whether the sub, bass or mid will be the zero cab.
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Speaker Sol
Young Croc Joined: 15 September 2009 Location: Ireland Status: Offline Points: 1320 |
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I don't really see how this would be true unless there is something very special going on in the horn. The horn will be more efficient so the sound coming from this part of the speaker will sound louder, it would be possible to tune the horn so that it is operating in a narrow bandwidth, say 40hz to 90hz and then the cone takes the rest. But I am not sure if this is the case in most scoop designs. The sound emitted from the cone would include all frequency at some level, but would probably be most efficient from 70hz and above. While what you are saying is could be true I don't know if it is the case. Also this would not help if you had two types of scoop cab in the same stack.
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Speaker Sol
Young Croc Joined: 15 September 2009 Location: Ireland Status: Offline Points: 1320 |
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Yes this man knows what he's talking about, I will bow out of the conversation.
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TONY.A.S.S.
Old Croc Joined: 21 February 2007 Location: United Kingdom Status: Offline Points: 6878 |
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SS, I'm sure someone else will have a way to explain it, What I write are only my observations.
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JR.junior
Old Croc Joined: 14 December 2009 Location: Slovenija Status: Offline Points: 1789 |
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2m long horn is cca. 5ms behind, compare to direct radiation.
Edited by JR.junior - 25 September 2010 at 2:03am |
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Support the scoop technology, larger mouth plays louder!
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TONY.A.S.S.
Old Croc Joined: 21 February 2007 Location: United Kingdom Status: Offline Points: 6878 |
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JR you have mentioned an interesting point, regarding length of horn versus delay. When we consider delay we must assume if there is any, we must be talking about 2 different starting points, (as in delay towers).
With a rear loaded horn cab the starting points are the same, albeit 180 degrees out of phase. I've never been able to make up my mind how much delay the horn adds. I think the horn may only add delay for the parts that are not coming forward. I say this because if you unfold the horn to make it straight, and say for instance it was 20 metres long, if you then put another direct radiating speaker directly over the speaker in the horn and put the same signal in both, they would be perfectly in time. In all of this I only try to take notice of what is relevant, so in spite of any delay from front to back, perhaps we can consider that it may not matter so much as the wavelength of bottom E on a bass guitar is around 42 hz which equates to about 26 ms. I have an Iasys machine for measuring all of this, and it is noticeable that the lower the frequency, the longer it takes to measure, I have always assumed that it must be taking a mean average, because, I have always wondered when it comes to time, considering a wavelength of 28" long, which bit is in time, front, middle, back? Answers on a postcard please.
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