A couple of years or so later, Bastanis released his Mandala, which retained the Altlas wideband/tweeter baffle, but added dipole bass in the form of an 18” S-frame. Back to the drawing board and the CNC shop and these were born!
You will notice the Bastanis used active bass, and I went from using built in plate amps to separate units, in this case XTZ
Bass from the Dipole was more open & detailed, but there was a few things I didnt like. It was very fussy regarding room placement. I decided to ditch the S-frame and mount the 18” woofer on the baffle. I was also after a new 18” driver, eventually settling on the AE Dipole 18. My ‘Monster’ series of speakers was born:
These retained the Atlas baffle. Construction was also beefed up using 38mm MDF and painted white.
Before you ask, I have a loving understanding wife..........
I quite enjoyed these speakers, but looking at them I wondered if I could compact them & achieve the same..I fiddled with the format (I was getting good with Microsoft Draw) and came up with the Mini Monster......back to the Prometheus single wideband arrangement.......
These actually worked very well and I didnt miss the extra wideband of the Atlas.
During this period of time, I expanded the permutation of this design with Selenium NEO 15" drivers. These suited the Open Baffle format and gave deep, clean detailed bass (Note: unfortunately no longer made). They were also lighter than dramatically heavy AE 18's!
My main issue now concentrated on the Gemini tweeter. I was noticing a lot of sibilance on some recordings, and originally I put it down to the recording. It was about this time I was helping my buddy build a set of Duet baffles for his Hawthornes. When they were completed I was stunned by how smooth they sounded!
....so back to Draw. I wanted something bigger & better!
....and the Trios were born.
These were huge. The 15” at the top is a dual concentric unit with the tweeter positioned behind the magnet firing through the dustcap. Twin Augie woofers below....these things rocked & were smooth. Also, no need for sub-amp as the Hawthornes came with a Crossover.
I spent 6 months with these but I found myself playing my hifi less and less. Whereas my buddy loved his Duets, I was getting bored with my Trios. They were too smooth and laid back.
It was at this stage I sat down and pondered what direction to head in. I didnt like the Bastani tweeter, but really didnt have the electronic knowledge on how to fix it. I wanted to design my own speaker.....but something simple I could cope with.
Enter Full Range, but not in a box.....in an open baffle. After a lot of research, I settled on the Mark Audio Alpair 12P. I had no idea how this would turn out....but what the hell......…
My experience from listening to FR speakers in the past was not good. Lack of treble was most noticeable, and the units with whizzer cones sounded brittle to me.
So, the Alpairs have a 500 hour run-in time, and they changed noticeably in the coming weeks. I became more and more impressed as they opened up. I thought to myself ......who needs a tweeter?
Also, before I designed this baffle I took note of what the experts were saying. I could increase my bass efficiency by adding a U baffle at the back.....which I did, and the bass increased. More on that later!
I spent a long time living with this format and exhausted all the permutations:
I did notice the narrower the baffle, the better the imaging, but something still not right.
I happen to listen to a lot of different music, and sometimes the music needs volume......lots of it. These just didnt deliver. Adding volume would cause the FR’s to flap like crazy with their compliant surrounds meant for a box. Actually, I didnt need this compliance as I wasn’t relying on them for bass....I had my woofers. I asked John at Temple Audio if there was a way to restrict the bass frequencies reaching the FR’s. He suggested an 80nF capacitor after the volume control but before the amps would work.
I duly installed this in my amp and the FR’s responded. No more flapping cones and the sound became cleaner with more detail. This was a revelation.
In case any of you are wondering, I am not into crossover design and had always driven the woofers actively Behringer Ultracurve. Coincidentally around this time, they came out with the iNuke series, a powerful amp that had the Ultracurve built in. Not only that, but it was so simple to program even I could do it. They provided software that ran on my laptop and the amp connected via USB. I could dial in the crossover in real time and achieve perfect integration. After a while, I became quite adept.
