The delivered components
I took delivery of the ScanSpeak drivers on Mon 14/03/2005, however it was short of a mid-bass pair as the supplier had ran out of stock... will need to patiently wait another 2 months for new stocks to arrive. Initially thought of waiting till all are in before taking delivery. I later decided against it as I felt that I need some time to play around with the xover portion. Anyway, I could hardly bear the anticipation.... :)
The delivered components
The drivers used for this project is none other than the highly regarded ScanSpeak D2905/990000 tweeter or codename The Revelator and the 18W/8531G00 mid-bass. More technical information is available at the manufacturer website.
Being an ambitious project that this is, I'm using ALL Mundorf parts. This decision is partly reputation and convenience due to the fact that the local distributor of the ScanSpeak also carry this brand of part. Seen below (those in black) are the expensive but highly rately caps from their high-end Supreme range. It cost more than twice the already premium Mcaps series (white).
Mundorf are lesser known for their inductors and resistors. But from the quality of contruction of the parts, I am assured that they are of a high caliber.
This is the 1st item on the list. The ScanSpeaks are too expensive to take chances to connect them to the amp for functionality test without proper filtering. The mid-bass should be fine to direct connect, but the tweeter will burn-out if low frequency signals are pass through it.
A quickie is to get some thin MDF from Daiyo $2 Shop and viola!!!! You get the 1st xover mock-up shown below.
The very shiny, pretty Audio-Note silver speaker binding post.
The next step was to construct a test rig for mounting the drivers for the the functionality test. for simplicity, I decided on a open baffle construct (this being temporary anyway). This should suffice during the waiting period for the next pair of mid-bass as well as while the enclosure design proper is in progress.
After two days of hard work, with some minor scratches..... you get;
Not too shaby if I may say so myself. I purposely make a slight tilt to ensure time-alignment of the tweeter and woofer. I don't think the same will be done on the actual cabinet... will 'cheat' by performing the tilt via the spikes... you'll see what I mean once the final enclosure is done. And the naked rear view....
Close up of the mounted drivers:
And how does it sound literally 'out of the box',... wonderful highs, relatively - there were initial harshness. I expect it to improve further once broken in. At the moment the tweeter is at 4dB higher than the mid-bass as the current xover is for a dual parallel mid-bass design. I put on Eagle's live Hell Freezes Over concert - the acoustic guitar is SWEET! Of course with the open baffle design, there is little bass to speak of.
Update: I did not wanted to wait till the 2nd pair of mid-bass before i start appreciating this new 'monsters' of mine. So I got a cheapo 2ohm resistor to attentuate the tweeter. From Speaker Workshop simulation, I need to remove the notch filter to balance out the entire thing. There's little impact to the impedance curve, just a spike up to 10ohm.. a little hard on on the amp but I think the Krells should be able to handle it.
So after some rewiring and fixing up the 2nd xover unit, I have a working stereo pair.... the mid-high is pretty good. After careful listening, there are still area for improvements but I do seriously think it beats the DM603 in its current form. Technically this may not improve much with the enclosure as mid-high are rather independent of enclosure... then again I might be wrong - with a close box design, I will not get rear reflected signal from the mid-bass.
Further listening showed that the focusing and soundstaging is not very good... sounds ok for higher frequencies such as female vocals, however, it is worse off for lower octaves such as male vocals.... Again I suspect this is due to the open baffle design.... Hmmm... I wonder how the LR Orion design combat this issue.