Following recent prolific musings over E2 inspired ideas in the E2 clone thread I have elected to open a new thread on my own project.
I welcome on lookers and feedback but please refrain from splashing Monet's palette or Rolf Harris's 6 inch brush with subject matter that is just not relevant. It just makes it hard for those with a genuine interest to follow the real proceedings.
(Dont expect posts here every day or hundreds of SPL graphs. Do expect and system that sounds good and measures well. Sound Easy and various other tools will assist with optomising the system. In my experience most real problems are audible and the tools just help pin down where they are)
The notion behind my project is from the opening pages of the Everest and K2 product brochures. The idea being to bring to the table a 2 way based system that will deliver a very smooth, coherent and detailed sound not found in the earlier 43XX systems with hi sensitivity, low power compression and very low distortion. Will it be an MTM ? No. Will this be a rediculously expensive project. No. But dont expect it to be wife friendly.
Using a 2435 Be driver with acqualas treatment is preferred over titanium based/aquaplas treated drivers because of the superior resolution that beryllium brings to compression drivers. Careful selection of the woofer will it is hoped ensure that a higher crossover point deemed acceptable for the 2435 Be does not compromise performance.
My logic here is that superior accuracy can be obtained over titamium based compression drivers with good quality direct radiator 2 and 3 way systems so much so that a compromise in overall sensitivity is acceptable. But Beryllium in a properly execute horn/wave guide can offer resolution and sensitivity not found any other way.
It is not envisaged that a multiway horn system using 4 inch large format drivers will be explored.
The high frequency horn will be sourced from elsewhere because to the best of my knowledge the better quality JBL consumer horns are unobtainable now. It is intended that several types of full size horns will be trialed in the course of developing the project to explore and compare how they effect the sound.
Some links here to various horn offerings
http://www.artec-france.com/etudes.php?system=compact&item=pavillon&lang=en
http://audioheritage.org/vbulletin/showthread.php?p=123500/lpost123500
http://www.users.uswest.net/~ddshorns/cfd2-90x.htm
http://www.users.uswest.net/~ddshorns/cfd2-110.htm
http://www.azurahorn.com/azurahorn_links.html
Links to various woofers:
http://www.akoustik.fr/tad.php?RubID=5&r=Woofer
http://www.audioheritage.org/vbulletin/showthread.php?t=21713
http://www.precision-devices.com/showdetails.asp?id=79
http://www.phlaudio.com/datasheets/38_pdf/5010.pdf
In the earlier E2 clone thread I hinted at a idea of a JBL Suma (after Geddes).
While I admire much of Earls' work I think a lot of common sense applies to controlling the effect of the room by adequately treating early and near field reflections with appropriate room treatments. It is quite easy for example control stereo image width and depth with some basic room treatments just like they do in major recording studios. Even so horn with constant power response and those with flat only on axis response will be explored.
The notion of controlled and constant directivity will form a key aspect of the project where ideal and less then ideal power response will be examined and subjectively evaluated.. The effect and audibility of early and near field reflections will also be documented..
As far as selecting horns is concerned the intent here being that the system will where possible offer a controlled polar response and low horn related distortions.
From my own perspective this is as much about using a horn of the correct physical proportions rather than compromise performance for marketing or size considerations. I am not stacking horns for an array so there no point getting too excited about the cheapest, smallest horn to squeeze into the front baffle.
A fundermental study of horn theory and this is abundantly obvious. Even Earl agrees a 12 inch (1 khertz crossover point) waveguide is better then a 10 inch and a 15 inch works best.
Why use a pissy/sissy little ear lobe guide with a response like a wee dogs broken hind leg is beyond me . They are perfectly acceptable for SR applications but less than ideal for high quality audio playback where mininal reflections and diffraction distortions are preferred.
There are pretty horns out there too like the Tad 1400 clones seen on Ebay.
The thread has been place here to allow flexibility in using other than purely JBL drivers and parts to fine tune and optimise the system by selecting customised hand built woofers if required. In the case of the 1500AL it would be ideal but the cost and shipping are I imagine outside the scope of this project. Of course if I am convinced that a particular JBL woofer meets the requirements then it will be used. I have not determined what size woofer or how many per channel yet or what type of tuning .
I dedicate this thread to our good friend Rich who it would seem is MIA by all accounts. I doubt if my woodwork will ever be up to Rich's standards but there will be little to moan about otherwise...LOL
For those interested I will be selling off some 4345 related drivers at some stage....all going well.
These link's represent the type of system I am considering. Nothing too outlandish but quality. As they say the devil is in the details but as you can see in all these images the horn is not small.....nor the woofer.
http://www.audioheritage.org/vbullet...ad.php?t=20088
http://www.audioheritage.org/vbullet...5&postcount=52
http://www.audioheritage.org/vbullet...5&postcount=52
http://www.audioheritage.org/vbullet...5&postcount=52
http://www.audioheritage.org/vbullet...5&postcount=52
http://www.audioheritage.org/vbullet...5&postcount=52
Ian
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Originally Posted by richluvsound
