[Mmaxed]

...I'm hooked on OB.

Been reading here for a while and liking what everyone said about the OB sound.  Since I had Maggies in the past I knew the potential.

First step a few months ago was to put some automotive subs I have in a H frame.  Someone here, can"t remember who, said that dual voice coil auto subs could work in OB if you just drive one coil.  It is said to double the Qts.  I have been running these subs with my Altecs.  worked pretty well using a DBX 223 crossover.  MP301 MkIII on top with a ClassD Audio SDS254 on the subs.

Yesterday the UPS man delivered a pair of Beta 12LTA's.  I built some particle board test baffles, with nearly zero planning, similar to PG's Beta over Alpha  build.  Brought them home from the shop and hooked them up while the glue was still drying.

OK, gotta be honest here, without bass support the Beta sounds like a big transistor radio from the '60s.  For a few minutes I thought I had bought the suit that king in the story had bought.  Finished hooking everything up and, BAM, I get it.  This OB stuff has big potential.

Spent the next few hours tweaking.  Have some polyfill wrapped between the whizzer and the main cone.  Put the 12 band EQ back to work.  A 2 db cut at 4k and 1 db at 2k and things really started falling into place.  These things sound gooood!

Since my ringing old ears only hear up to 10k or so I figured I might get away without a tweeter.  While the Beta's do better than they seem like they should I think a tweeter will be necessary.  While a hi hat sounds very natural, cymbals are not as clear as I would like.  Even though I got the Beta's second hand they show no signs of being used except they had the dust caps removed and came with the egg phase plugs.  After about 3 hours of play some of it loud I can tell that they are breaking in.  Getting smoother. 

Are they better than the Altec's?  In many ways yes.  While the Val's filled the front third of my room with a very satisfying sound stage these do better.  Bigger, more open.  Still playing with positioning and removal/repositioning of sound panels, but WOW, things are really coming together.  One thing the Val's are better at is drums, but I have never had any speaker that did drums better.

All in all these Beta over auto subs are amazing for no more than I have done so far.  Thanks to everyone here, I am going head first down the OB rabbit hole, and loving every minute of it so far. 

   
         

[jk@home]

So how does the sound compare to the Maggies you had? I'm running MMGs with subs, the room is already setup for OBs. Pros and cons?

[mcgsxr]

Glad to hear that your explorations to date have been satisfying!

I might have chimed in with that idea about running a single voice coil on a DVC woofer and the QTS impact.  I ran a similar setup for years, and enjoyed it with a simple analog EQ.

Have fun!

[Mmaxed]

It's been a long time since I had the Maggies in a room that did them justice so going off memory.  The 2 biggest differences are smoothness and dynamics.  The Beta's are very efficient and dynamic.  I'm driving them with 6 tube watts and they can get very loud.  They are not smooth to my ears, not as smooth as the Val's even.  They are like the Maggies in that they image very well and have a large deep sound stage. 

Mcgsxr, I do believe that it might have been your input on the auto subs.  As I have played with these some more today, the bass is blending very well.  Positioning is more critical than I would have thought to get the tonal balance right.  Have them closer to the side walls now and it is working well.