Re: New Project with JBL's 4647 and 2445
Quote:
Originally Posted by Zilch
That's a VERY important question, actually.
The more drivers there are in a system, the more difficult it is to get them to integrate with one another. The ideal system would have but one driver, and it would cover the entire audio spectrum. It doesn't exist in practice, of course, largely because of the laws of physics in sound reproduction.
Recognizing this, I believe everyone would agree that two-way is the next reasonable choice, and a worthy pursuit. Because of the same limitations of technology, however, it's not easily achieved. There are compromises that must be made in putting together a good sounding system with just two drivers.
Getting full high-frequency extension is one of the problems. The simple answer is to add a tweeter on top of a competent two-way, and some would argue, since the tweeter is "supplemental," it's still a two-way system. That's a stretch, I'd say. On the other hand, using a sub at the other end IS, in my mind, merely an enhancement of a two-way system.
To most accurately reproduce the entire audio spectrum, more drivers, four or even five, often, are required. There are many advocates of such multi-way systems here, and they dedicate themselves to overcoming the difficulties of having the multiple drivers play together accurately and cohesively. Many threads in this forum document that endeavor.
Your system is a competent two-way. I am encouraging you to acquire the proper crossover for it and to see if you like the way it sounds. You may have to do some reconditioning of the drivers, as well.
I have no experience with your horn and mid/high driver, but considering what the system was designed for, I assume it's worth keeping together. I suspect there are other members here who know the 2445 and 2380/A well. They can better advise you on achieving optimum performance with that particular combination.
I DO know the 2225/6H in that box, and you'll likely find you'll want to add a subwoofer to your system for best performance, or replace the woofer and retune the box as I'll be describing in the Q&D thread. 2226H will not provide extended bass, but that which it DOES provide is highly accurate and articulate. Read punchy and dynamic here.
Bottom line, know what you have first before proceeding. Get the proper crossover, and play it for a couple of months. Who CARES what it looks like for now? That is easily remedied, once you determine it is worthy of the effort. As you say, the MUSIC is the prime consideration here, and THAT is yet to be experienced....
Zilch's point are well explained and noted. (If he ever wishes to teach, please make a go at it. Myself I relish the thought of spending a few weeks in your comapny) Zilch's answer however, in my young mind on this issue, raise some questions I hope the abled forum member might answer for the benefit of us all.
Does it not suffice that a crossover would deal with the eminent problems the presence of a lot of drivers would have on a system? All the drivers, from my understanding, reproduce particular output in the spectral length, and in areas where this reproduction overlaps, a crossover is brought in to redress that problem.
I accept that one driver would not and cannot reproduce the entire audio spectrum. However, may I point forum members to this fellow. Those who spend time designing cabs would find it of particular interest.
http://www.danleysoundlabs.com/DTS20.html
I struggle with the logic that because for scientific reasons we cannot have one driver that would produce the entire audio spectrum, therefore, we must subsequently settle for the next figure to one, which is two. The problem it seems to me is accurate representation and since a lot of drivers cannot do that, why could it be held then that two would or should?
The need to add a subwoofer to this system, which I would, for I take much of what Zilch says with much respect and read with close attention, shows that except if the drivers of any system is designed to reproduce most, since all can't be the case, of the audio spectrum, then there would always be the need for "supplemental" cabs on the system. The point here is one, is not possible, two is often found to be inadequate. Thus, where does that lead us? Does anyone here has a two ways system that reproduces at least 90% of the audio spectrum? Would they care to share?
Zilch pointed out, rightlyfully, that two-ways systems could be found to be lacking, ususally he says around the HF areas. This I assume is generally, because most drivers are made to produce mid to sub woofer frequencies, thus when you use them to create two-ways, it's almost only natural that you would need a tweeter or horn to compensate for the HF spectrum. Such is not the case on this particular system, as is well noted by Zilch. Thus, I would be looking for a sub-woofer. Please forward suggestions.
On from theory to more practical issues about this system. If I may ask some more questions.
Would anyone with particular knoweldge of the horns discussed here PLEASE pitch in with what they know. In particular, advise on achieving optimum performance with this particular combination. Please.
Zilch mentioned that I may need to "reconditioned" my drivers. This is my first time going pro on a home system. That naturally means I have never heard of "reconditioning" drivers. Any and all help would be GREATLY appreciated. Or how to recondition the cab.
Truly, the music is yet to be enjoyed. And that raises yet another question. I know there are equipements used to measure sound production from speakers. Would someone please say how this is done, and say why one must do such measurements? Are they really accurate, given that they measure one thing and the music, the song itself, is made to sound in another way-not sure if that makes sense written down.
Zilch is right, I will keep my eyes on that Q&D thread and proceed to set this system up and listen to it. I am still stuck on finding proper equipments that would compliment these drivers.
(P.S Please forgive all erros in spellings. Currently baby-sitting twins. Distractions abound!)
I always used a different forumula
wavelength(inches) = frequency / 13,500
I use this for aligning voice coils in a multiple driver system when vertical alignment of the voice coils is not possible.
I come up with 1.1" for 15khz
Not saying mine is right, just what I have used and it works fairly close for me.
Ron