Want to try OB-need suggestion for plans

keager

Member
2012-07-14 7:26 pm
Here's what I have- A receiver, four channel 1000w amp, mini dsp, and an underfloor IB subwoofer system. I want to try OB for music listening. I would have some room challenges, but want to give it a shot. I have REW and a mic to test frequency response. Can somebody suggest pairing of a woofer and mid/tweeter and a baffle plan? Don't want to get too expensive till i experiment to make sure I want to go all the way down the rabbit hole.. thanks gents! Max price for drivers btw, 500 USD for now.
 

mortron

Member
2011-08-20 6:02 am
Town
Just built four 18" HFrames with a pair of used Visaton B200, and under $1000 with a big pro amp for bass, a chip amp and passive line level crossover.

Martin J King has some interesting projects and served as partial inspiration, but many other members have great projects that don't break the bank and are tops on fun.
 

keager

Member
2012-07-14 7:26 pm
Have you seen my thread?
httop://www.diyaudio.com/forums/multi-way/110583-fast-fun-inexpensive-ob-project.html

Lot's of good info there and several versions. I highly recommend these as a place to start.
Thanks Pano!
Yes, those are at the top of my lust due to the low cost and ease of construction. Pardon the nube question, as I am still learning. Could the tops of the baffles have any amount of curve to change the appearance, or would that drastically affect the sound?
 

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
They could certainly be curved or slanted. In some ways that can improve the sound.

You have to be a little careful with a curve, as you don't want an edge that is equal distance to the driver - as you can imagine, that would reinforce any ripple in the response.

I've used the smallest of John's designs (the first one) in a bedroom and a hotel room. Worked just fine. John left some notes in the thread about wall distance. Remember that there is a null at each side of the baffle, so side wall distance is less important than the wall behind the baffle.
 
Brilliant idea! The woofer, due to its high power handling, could be left unfiltered ( no high pass ). But problems may arise when chosing the
mid & treble drivers, which has to be mid-hi sensitivity.

The problems with vibrations, and sound mutation induced by them, may find
the solution by suspending the drivers ( not simply hang them )
http://www.diyaudio.com/forums/planars-exotics/233909-string-mounted-dipole.html
 

keager

Member
2012-07-14 7:26 pm
So after some research it sounds like the eminence 15 and the fe103en full range driver are a good beginners combo. Is there any drivers the are close in price that offer better performance? Interested in very detailed mids and highs Without any need for bass under 50 hz. How about baffle thickness. Did I miss info on that bin my reading?
 
You talked about 1000 W...so that would lead to some more complex solution.
You nominated something like a 10-50 W set-up, being controvertial in many ways : but it's ok :p
I suggest to tweak some existing designs, like some 2 or 3 way boxes
that you ( hopefully) already have .
If you have already a subwoofer, you just need to put the speakers you have
in a OB-dipole-open frame configuration .
For mid-wf applications the Eminence seems to me a little outdated...
Something in the 8" range ( with enough excursion ) would be better ...Well, this goes a little OT...as I'm still considering Pro woofers, while you can pick
any driver and build a whole project around it. You can start from the tweeter, just make clear what your target is : definition, high power, long throw...coverage, positioning in the room; when filtered with the passive crossover, which frequency and slope would better fit to match with a, say, 4 " midrange ...!?!
Making practice with existing drivers and crossovers would get you accostumed to dipole listening very quick :eek:
 
I suspect that the OS might not be the right project to start from.
Is it the one with the Hivi metal woofer ?
I was thinking more of a 3 way. Or something more light...meaning: fast and dynamic .
Of course you can put any fullrange in open baffle,open-frame-suspendend-in your hands!! whatever...and listen to dipole. At least the sound won't be affected by box resonance or sound coming thru the cone after bouncing in the box . But then you'll need to attenuate the back wave, which I remind you, is in acustical anti-phase, which means that what the woofer ( or mid ) emits from its back is the negation ( absolute !!) of what happens on the front wave.
:scratch1:
 

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
So after some research it sounds like the eminence 15 and the fe103en full range driver are a good beginners combo.
Good, but I think you can do better. Try the GRS 15" and the Vifa fullrange.

The advantage of the fullrange is that it will easily reach down to 15" and play loud enough. Hard to do at any volume with most tweeters. The disadvantage is not all fullrange speakers sound good. :)