Well they feel like they have been eons coming, since I placed the initial order back in July
They have been stuck in the garage since November, only just found time to get them wired up, learning how to solder in the process.
But here they are 4 OT12s looking rather ridiculous stacked up all together in my lounge but hey!
First of all, yes I know they are inside, this was just an initial listening session to check my wiring, check stuff is sealed and check that everything is as it should be. Also a chance to listen to lots of different source material and try and get a feel for a general EQ curve.
After running the AEQ on the DEQ2496 I kept the pink noise running and backed off some of the more extreme EQ settings to give what sounded to me like a balanced sound, bearing in mind I was just listening to noise.
Then I had to test it so I played several source tracks and listened.
I decided with my piezos to run 3 banks rather than 2, and I think it was the right decision, with 900W of power available I didn't want to run too much power by mistake and fry the tweeters. I have added a small boost in the region of between 1-3dB across the board on the tweeter frequencies - forgot to take a picture of my EQ settings.
By contrast the P.Audio SN12MB woofers I am using have needed on average 1-3dB of cut to get a good sound. As to their suitability, I can confirm that there is no audible hole in the mid range and the RTA shows nothing either. Others have used SN12Bs in the past with a compression driver and also reported good sound. So it just goes to show that other woofers can and do work in these designs. I am using the old style LP filter on the cab, Bill changed the parameters of this because some parts were obviously tough to find in the US, I don't know if the old one was more effective than the new one but anyway it works!
Initially I was running some CD tracks through them full range at comfortable listening volume with about 8dB of 60Hz boost to try and loosen up the suspension, because of this two of them sound distinctly better than the other two, because they had already had a day running in. It probably didnt help that I have had the drivers hanging around for about 2 years. Still.....
After that I decided to hook them up to the crossover, and played around with various crossover points, 100Hz seems best for both the 1x12 and 2x12. 120Hz also seemed ok for the 1x12, without losing too much low end off the vocal sounds.
That also cleaned up a couple of boomy room notches I was getting, so I could get a much better idea of what they were sounding like over their intended frequency range
Initial comments
1) Very very loud, my amp has a dB scale and with a CD track hitting -3dB on the DEQ input, I still had the amp down at -18dB, so at the most I was hitting about 9W into a pair. I did not want to turn it up any more at that point without donning some ear protection, which wasn't what this test was about.
2) Take a fair bit of EQ to get them to sound to my fairly critical standards, well the EQ isnt extreme, its just the time it took to get there was quite a while. The drivers aren't even broken in yet either, so I expect I will revise these settings later, hopefully outdoors.
3) With 100Hz crossover point they can really pound in the low end, surprisingly so, I had experienced this before with the O10KBW I built, but this is a different slightly less controlled bigger grunt, rather than a tight phutt sound.
4) Having the 10.5 that I recently got up and running was useful to compare, in the same room with the same amp, I think I preferred the sound of the 10.5, its just somehow cleaner and more accurate, no crossover, I suppose less going on to colour the sound really. However SPL is often the deciding factor in PA, and these have it by the bucketload. A lot more low end than the O10.5 - by low end I mean 100Hz area but this is expected.
So the big debate OT12 vs O10.5 - Each has its merits, I prefer the slightly tighter more controlled sound of the 10s but if you need to let rip some SPL, the OT12 wins hands down, now that Vlad has replaced his straight arrays with melded I am beginning to wonder if I should do the same.
I think I need more time with them before I decide that I am that unhappy that I need to make such a time consuming modification.
A few gigs down the road I should know. Due to their high efficiency nature they wont get used on most small gigs so I am not sure if it will be weeks or months before I have the answer.
Stu
