[rockdrummer]

I have been on a quest to improve my definitive technology set up for years now.  I have wanted electrostats for a long time, but after stumbling across GR Research, my enjoyment of DIY projects paired with audio has driven me in another direction.  I eventually would like to build a pair of OB 7 and then an open baffle sub. 

Not sure how quickly this project will begin, but for starters, I have really newby questions about external vs internal crossovers. Which is better and why. Thinking going with Skiing Ninja assembling an external crossover.  Did I read somewhere that the OB 7 is a four ohm speaker?  I wouldn't know just by looking at the drivers and such. See, a NOOB! Also, I have so many little questions about cabinet built, size of box for the crossover, etc., that I don't want to bore you all.  I have searched builds and had a couple answered for me.
How does a Sunfire (8 inch high watt sub) compare to 2 12" open baffle with 370 watts?
Thanks so much for your time, and time flies casually researching all the great info here. 
Ben

[Danny Richie]

Not sure how quickly this project will begin, but for starters, I have really newby questions about external vs internal crossovers. Which is better and why.

There is some benefit to isolation of the caps. It's not a huge deal, but noticeable. Potting the crossover does basically the same thing.

Thinking going with Skiing Ninja assembling an external crossover.  Did I read somewhere that the OB 7 is a four ohm speaker?

It is mostly an 8 ohm load with a minimum at the woofer end that dips to 6 ohms and a minimum at the tweeter end right at 4.5 ohms. So it is a fairly easy load to drive.
 

How does a Sunfire (8 inch high watt sub) compare to 2 12" open baffle with 370 watts?

That is a bit like asking me how my Corvette compares to a Ugo. Honestly, right now there is no better sounding bass on the market than our servo controlled 12's in an open baffle.

[rockdrummer]

I understand about the sub question.  I like the sunfire, I am happy with it.  But I am trying to learn about how my system "sounds" compared to others, and compared to what I plan to buy.  From what is reported open baffle subs sound like, I'm going to like the fast, accurate sound. 

Do all internal bracing on speakers and subs need to have rounded edges?  I see that on some builds I have looked at. 

I have seen stuffing material inside some cabinets.  Searched for info but haven't seen if there is a time to use one or the other.  I assume no rez takes the place of that? Not sure.  Thanks for the info.  I see the tyler acoustics review.  I was looking at Tyler before I learned about GR.  I really like the look of their towers and had to admit the prices eliminated those as a possibility.  Then I saw the OB 7 Plus.  Being a novice woodworker, I toned it down to something more doable. 

Ben

[Danny Richie]

I understand about the sub question.  I like the sunfire, I am happy with it.  But I am trying to learn about how my system "sounds" compared to others, and compared to what I plan to buy.  From what is reported open baffle subs sound like, I'm going to like the fast, accurate sound.

 

Those little subs are often referred to as one note wonders. They tend to hard pretty hard in one frequency range. They also have very limited output in the fist octave (20Hz to 40Hz).

The servo subs have a linear output down into the teens. So smooth and balances. Open baffle takes it a step further as it does not load the room in the same way as a boxed woofer. It tends to give you a more even room response.

Do all internal bracing on speakers and subs need to have rounded edges?  I see that on some builds I have looked at. 

In a ported speaker the braces are rounded over to minimize any surface reflections that could be reflected back through the cone and to keep down any air flow turbulence that might be heard from the ports.

Subs are a little different. The wavelengths are too long to do any real reflecting in the box. So you are really only concerned with port noise, unless it is a sealed box.

I have seen stuffing material inside some cabinets.  Searched for info but haven't seen if there is a time to use one or the other.  I assume no rez takes the place of that?

No Rez does take on the roll of absorbing standing waves. It can also be supplimented with some additional material for some cases.

One other thing: Welcome to AC. 

[rockdrummer]

Thanks for the welcome!  I feel like another door has opened and the info is flooding in. 

i don't have to worry about any rounding inside the sealed OB 7 cabinet then. 

I'm giddy.  Now to convince the wife!

ben

[Danny Richie]

i don't have to worry about any rounding inside the sealed OB 7 cabinet then.

 

I'd still round those braces to minimize surface reflections. They are not sub woofers. They do play all the way up to the mids.

[rockdrummer]

Okay, thanks. 

[newportcycle]

  I see the tyler acoustics review.  I was looking at Tyler before I learned about GR.  I really like the look of their towers and had to admit the prices eliminated those as a possibility.  Then I saw the OB 7 Plus.  Being a novice woodworker, I toned it down to something more doable. 

Ben

I hearya on price brother, limited budget here as well. Compared to some of the systems I heard this year at Capitol Audio Fest, it was money and time well spent. The OB-7 is quite doable even for the novice. If you can read a tape, use a skill saw and router, your in. I built a pair in my driveway with a $59 skill saw and $49 router. Inexpensive, qualitity tools can be sourced from Craigslist at quite a discount. I as well as others here would recomend a Jasper Jig for cutting holes in the baffles and lost of cheap clamps available at Harbor Freight or other like source. As you look around this forum you will find lots of talented builders full of friendly advice to assist you if you get hung up.

[freerider]

Ditto, I just picked up 6 metal clamps from Harbor Freight for the same price as two clamps from the local HW store.