Horns have an effect of emphasizing some frequencies, and reducing others.
Putting this flat response 10" driver into the Syntrip, we see the response is no longer flat. It becomes less sensitive down at 200hz and more sensitive at 500, with a big kick (in mine) at 70hz.
To get it back to flat, some pretty hefty EQ is required.
I noticed before EQing the group delay was very flat.
After EQ, the response was flat, but the group delay was shifting around the eq'd frequencies.
If we can find a driver that has the opposite response to the horn, say a boost at 200hz which then rolls off, we may find that putting it in this horn will give a natural flat response.
This is something that Function One do with their designs, the end result is they need very little eq and so have no induced group delay induced.
Something seems wrong here
in that the normal is a drivers response is minimum phase domain (IRR), and that IRR domain have a predicted behavior in amplitude verse phase that is frq dependant and what makes the lag in group delay when we only have a certain amplitude bandpass with stopbands at hand verse a IRR domain without stopbands that goes from DC to lightspeed this will have flat amplitude plus flat phase = flat groupdelay, so at normal EQ is not evil for inducing group delay when targeting a flat amplitude it actually repairs the frq dependant amplitude verse phase predictions. Use of a driver that have the opposite acoustic response to the horn verse use of a driver that is EQed to same opposite response should give exactly same result for group delay (IRR domain frq dependant amplitude verse phase).
Observations that non flat response had flat group delay seems not to follow predictions in IRR domain so think of some other errors must been there example can maybe be diffraction, other reflections sneaking into measurement window or drivers acoustic offset not aligned.
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Something seems wrong here
Use of a driver that have the opposite acoustic response to the horn verse use of a driver that is EQed to same opposite response should give exactly same result for group delay (IRR domain frq dependant amplitude verse phase).
Observations that non flat response had flat group delay seems not to follow predictions in IRR domain so think of some other errors must been there example can maybe be diffraction, other reflections sneaking into measurement window or drivers acoustic offset not aligned.
Wow great info. Thanks for pointing that out. Looks like i still have quite a bit to learn!
Fin,
I have not received any current drawings, and when/if they arrive, it will be a while before I have a chance to review them, as several other new projects are presently occupying my time, as well as dealing with a landlord who has wasted over 70 hours of my time since end of June.
Art
Johnnyjo,
If you find an Eminence 10" with similar TS parameters to the B&C 10CL51, results should be similar. That said, I don't recall any 10" from Eminence that is very similar, or the equal to the 10CL51, at any price.
Art
Although I have a long history of using Eminence woofers and HF drivers, you should not mistake my suggestion that the Eminence N314T-8 may be a good alternative to the Celestion CDX14-3050 suggests in any way that using an Eminence woofer would be preferable to the B&C I chose to use.
As I have explained in various posts through this thread, my dealings with Celestion were not pleasant, while my dealings with Eminence and B&C have been great. That said, B&C continues to innovate, and produces many readily available drivers that Eminence can not presently match.
I recently obtained a pair of B&C DE90TN, and will be A/B testing them in my SynTripP cabinets. Based on previous tests of the B&C DE82, which is not as smooth as the newer B&C DE90TN, but smoother than the CDX14-3050s, I have no doubt the new B&C will remain in the SynTripP enclosures after testing.
At that time I will be selling the pair of CDX14-3050, (with a spare diaphragm) below my cost, I received one demo unit at no cost, so figure buy one, get one free, plus shipping from 32720. They are small & light enough for the pair to go in USPS flat rate box.
Anyone interested in them can PM me to make arrangements, and I could move up the testing if you are in a hurry to purchase.
Art
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Yes, Johnny, it would be, which is why I'll soon be building six of them.
http://www.diyaudio.com/forums/subwoofers/185588-keystone-sub-using-18-15-12-inch-speakers-3.html
The new 50" tall "B-Low" Keystones will go a bit lower than the 45" tall ones I originally built, easily reproducing 30 Hz.
Art
So i had my first synergy horn experience today. One sh50 and one sh60 in mono configuration tried out separately, together with a danley th118 in a rather well sounding studio room of maybe 25 kvm.
I had a very odd feeling from the synergys, I simply got psyched out from the feeling i got from the small area generating sound compared to conventional BR and horn designed tops. They felt manipulated in a way for me difficult to stand and for the approx one hour of listening time I could not get used to it. What's up here? Why was I not blown away, but quite the opposite.
Will a regular stereo set-up make up for this feeling and turn it into the synergy horns favor? I'm thinking there must be some way to set them up for them to exceed the performance of conventional BR and horn top designs.
I had a very odd feeling from the synergys, I simply got psyched out from the feeling i got from the small area generating sound compared to conventional BR and horn designed tops. They felt manipulated in a way for me difficult to stand and for the approx one hour of listening time I could not get used to it. What's up here? Why was I not blown away, but quite the opposite.
Will a regular stereo set-up make up for this feeling and turn it into the synergy horns favor? I'm thinking there must be some way to set them up for them to exceed the performance of conventional BR and horn top designs.
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Setup is important. Were they setup by an experienced person ? They have less reflected sound from walls so sometimes people say they sound like large headphones in that there is very little ambient reflection. That's what makes the sound very clean and high definition. Having messed up XO points, improper phase/polarity etc can cause problems. When done right you will be stunned by the great sound.