Just ordered an OB7 kit and posted some pictures in a gallery

jdbrian · « **Reply #40 on:** 1 Apr 2010, 10:29 pm »

Neil

A plunge router is best for doing circles. If you use a fixed base you might get away with it by drilling a pilot hole on the edge of each circle or by very carefully lowering it into the work, but it is not nearly as easy, accurate or safe as using a plunge router. You may want to experiment on some scrap and see how it goes. I was pretty nervous when doing the baffles as a lot of work went into them to get to that point.

Brian

NeilT · « **Reply #41 on:** 2 Apr 2010, 12:39 am »

Your baffles came out great, and it looks like I will be buying a plunge base.
Neil

jdbrian · « **Reply #42 on:** 5 Apr 2010, 09:15 pm »

Hi Folks

I now have everything painted and finished and have assembled the box to the base. The crossovers are under construction with the components tye wrapped and siliconed in place. The no rez is installed as well as the 2 sets of vampire posts on each cabinet. Cut the norez on the table saw. It only took a few minutes.
The bass management networks are installed in the enclosure on the back wall above the H brace and I added a switch on the back panel so the bass management can be turned on and off. The crossover layout took quite a while as the space available is not that large. It was easier to mount the bass networks seperately.
Next will be to drill the mounting holes for the drivers and run the wiring inside the cabinet before gluing the baffles on.
The boxes are semigloss black latex which was hard to work with. I applied it with a flocked roller to get a smooth surface but there is still more texture than I wanted. I topped the paint with a coat of satin water based varathane. The varathane maked the boxes look really black and contrasts well with the light baffle. It is also very hard and protects the paint from damage and fading.The pictures don't do it justice. The camera dosen't seem to like the flourescent light in the workshop and pictures don't seem to look that great.

Binding posts and bass man. switch. Thats a piece of tape on top of the right posts.

Bass network on back wall. Posts and switch below.

Baffle clamped to cabinet

Close up of baffle/box

Danny Richie · « **Reply #43 on:** 5 Apr 2010, 09:35 pm »

Looks good!

Did you radius the back side of the woofers holes? That is very important.

You won't need that switch to turn the bass management on an off. It's more likely that you'll want a switch or two that will allow you to vary the resistor values used across that part of the circuit.

jdbrian · « **Reply #44 on:** 6 Apr 2010, 10:15 am »

Hi Danny

Yes, the woofer holes and mids on the OB section are radiused 3/8" on the back side. I am using a Behringer DEQ2496 and can use that for bass managemnt but I wanted to include the network and be able to switch it in or out. I assume you mean that the series resistance in the network can be changed.
For those using tube amps with a high Zout the network would be a big benefit as it will reduce the sealed box tuning peak in the speaker impedance. The network looks like it is tuned to about the same frequency as the box tuning.
I hope to have these done later this week. Can't wait!

Brian

jdbrian · « **Reply #45 on:** 8 Apr 2010, 03:01 pm »

A quick update. I installed the wiring in the box and glued the baffles on last night, so they are finally starting to look like OB 7's. I got 1 crossover wired up and have started working on the other.
I pre drilled the driver mounting holes before I glued on the baffles. I used a transfer punch to center punch the holes and this made it easy to get well centered holes.
It won't be long now!

Brian

jdbrian · « **Reply #46 on:** 11 Apr 2010, 11:39 pm »

Hi Folks

Got them finished Saturday morning at about 9:00. They were playing all day yesterday and today as well. They sound pretty nice. It is early days yet but a few things are obvoius now. These speakers really do have great resolution and low level detail. There is a clarity in the mids that is very natural and revealing. They are very dynamic even when playing at low levels.
I was just listening to Mark O"Connors Hot Swing Trio the title track of the CD In Full Swing. And the title describes this piece well. Violin, bass and guitar going full out in the style of Grappelli and Reinhardt's hot club quintette. The listening room was very quiet and the volume was quite loud. When the music stopped I just had to say "Wow". The 7's sorted out this high energy music like I have never heard it before. I was able to follow each instrument in the mix.
I am still playing with positioning and toe in and would like to hear any advice on positioning from Danny or other owners. I have them about 5ft from the back wall and a bit less than 6ft apart. I am about 7.5ft from them and the room is about 13x20ft. I got the subs hooked up this afternoon and they integrated well.

Got to go now! Here are a few pictures

Brian

Finished - sitting on some foam so I can move them easily

Closer View

Rear View

OB wiring

Nick77 · « **Reply #47 on:** 11 Apr 2010, 11:50 pm »

Those look great! And yes they are very revealing and love good recordings and electronics. I have settled in at about 4' rear and approx 6 1/2ft apart and a little more toe in than what you are showing. Awesome job!

NeilT · « **Reply #48 on:** 13 May 2010, 01:39 am »

Hey Brian, how you liking those OB's?
Still waiting for pictures of em with grills.
Neil

jdbrian · « **Reply #49 on:** 13 May 2010, 03:05 pm »

Hi Neil

I have been busy and have just started working on the grills this week. The 3/4" round over makes it difficult to make a grill that covers the whole front panel so there will be a strip of maple visible down each side. I should have them done in the next week.
After breaking them in for 100 hrs or more I still found them a bit tipped up in overall balance. I contacted Danny and ordered some 4ohm resistors for the tweeter xover to lower the level a bit. I also ordered the platinum bypass cap's and I installed all this stuff last weekend.
The balance is now much better suited to my room, equipment and taste.
The 7's have very high resolution and have a clarity in the mids and highs that I have not heard from any other speaker anywhere near it's cost. They continue to impress me and have caused me to look at upgrading the rest of my system.
The bass response is fast and detailed. There is less room interaction than I am used to, with 1 peak at about 100hz. They integrate well with my 2 15" subs and I am getting mid bass impact that I could never get with my Newform 645's no matter where I set them up in the room. It is easy to follow bass lines and I find myself tapping my foot and getting into the rhythm of the music much more.
Imaging is not the same as the newforms which were a line source from 1200hz up. The image width and depth seemed to improve immediately when I lowered the tweeter level and installed the bypass caps. I am still experimenting a bit with toe in and placement.
In summary I am impressed and looking forward to enjoying them for years to come.

Brian

NeilT · « **Reply #50 on:** 13 May 2010, 03:32 pm »

Sounds good, no pun intended, and thanks for the update.
Glad that you are enjoying them.

Neil

jdbrian · « **Reply #51 on:** 22 May 2010, 02:46 pm »

Hi Folks

Have the front grills finished now and they look quite nice. I didn't want to get into a lot of circle cutting with the router again so I decided to use 1/4 round moulding for the sides of the grill frame and mdf for the horizontal pieces. This was a bit fussy because of the lack of clearance on the baffle due to the 3/4" roundover. I had to cut some notches in the grill frame to clear the drivers but overall it didn't take too long to make them and I think they look nice, showing off the tall thin profile of the 7's by leaving a narrow strip of the light colored baffle visible. Here are some pictures below.
The 7's continue to impress me with their detail and ability to portray percussion in particular with a realism that I have seldom heard.

Brian

ebag4 · « **Reply #52 on:** 22 May 2010, 03:26 pm »

Great look! I really like those grills. It's a shame to cover up those beautiful baffles but those grills look great as well

.

Best,
Ed

Danny Richie · « **Reply #53 on:** 22 May 2010, 03:31 pm »

Man, those look good!

Nick77 · « **Reply #54 on:** 22 May 2010, 04:40 pm »

Wow those look really great, I might think about grills myself now.

NeilT · « **Reply #55 on:** 22 May 2010, 06:24 pm »

Wow those look really, really great, I might think about building some OB7's now.

I love the exposed baffle edge.
Thanks for the pics.
Are you going to build grills for the backs?
Neil

persisting1 · « **Reply #56 on:** 22 May 2010, 07:38 pm »

This is one impressive build. Nice work on the grills

jdbrian · « **Reply #57 on:** 22 May 2010, 09:15 pm »

Thanks guys

Yes, Neil I am going to make rear grills. Stay tuned.
Danny, I must thank you for making these kits available. These are so much better than the stuff I auditioned locally up to 4k$. They seem to be settling in after I installed the platinum bypass caps and continue to impress me. I got my tube amp out the other day and biased it up and I am going to try it on them sometime soon. The 7's are transparent enough to let me know what the differences in sound are between my tube design and the Rotel SS amp I am using.
I am now considering new amplification and front end so I have been watching the DAC shootout thread with interest.

Cheers
Brian

Nick77 · « **Reply #58 on:** 22 May 2010, 10:10 pm »

Brian if your open to more diy you might consider the classD Audio amps, long thread in cheap and cheerful. I have one of the Super series at 125 wpc hooked up to my 7's and they are singing like never before. Hope to throw one of the diy Dodd buffers in front of it soon.

drphoto · « **Reply #59 on:** 22 May 2010, 11:11 pm »

Man, those don't look good....they look freaking awesome! I think you've got a retirement career as a speaker builder if you wanted.

Personally, I like 'em without the grill. That baffle is just too pretty to cover IMHO.