[stlblue]

Greetings:

Anyone with any experience w/ 604's in an OB? I read this site a while ago:http://members.myactv.net/~je2a3/open.htm, but then these pics from the Yamamoto site really got me thinking:




Is it "worth" the time and hassle to build a couple of these? Is there any sonic benefit to the wholes at the bottom of the legs? Any thoughts are sincerely appreciated...

[Dmason]

I dont see how you could  possibly go wrong... 100db Altec 604 + OB? Those are fantastic drivers, as are the new ones from www.greatplainsaudio.com  who are just about to release the 12 inch version, as a replacement to the old Altec 212 / Urei coaxials. THOSE, look even tastier. Beyond that is the implied stamp of approval, Yamamoto style. A bullseye if ever there were one...

[Bob in St. Louis]

In my opinion, I really can't see how those little holes would do much for sonics. That would be such a room dependant "finest of the fine" tweeks I've ever seen.
Also, I'd agree with Dan; Open Baffle is killer in many ways. It's hard to go wrong, especially with a proven driver / baffle combination like you've got here.

Bob

[launche]

The holes are designed for speaker cable routing.

[pbrstreetgang]

Those have always caught my eye  :drjavascript:void(0);
Droolool:

[stlblue]

Thanks for the quick replies, guys. A couple more questions, please. Do you think the depth of the legs could add more bass? The Yamamoto's seem to have almost no depth to their legs, versus the 5" & 10" depth from these plans:



Also, the top "plate" measures 8" wide, but do you think that is mostly for 8" drivers and 15" wide plate might be better for the 604's?


BTW Bob, I was born and raised in South STL.  Now living in NE Ohio.

I will give them a whirl in a couple weeks and report back...thanks!

[Bob in St. Louis]

Yes, bigger legs (wings / side baffles) provide more bass but the bigger you get the more 'mud' you get as well. Less clarity, soundstage etc... Small (or NO!) wings are "clearer" in sound quality.

St. Louis all my life.  I thought I smelled a BlueNote.  aa

Bob

[stlblue]

Yes, bigger legs (wings / side baffles) provide more bass but the bigger you get the more 'mud' you get as well. Less clarity, soundstage etc... Small (or NO!) wings are "clearer" in sound quality.

Maybe I'll try smaller wings one side and larger wings on the other side and see if I tell a difference w/ whichever one put to the inside/outside.

Any thoughts on the legnth of the top wing/baffle/"plate"? Do you think a longer one will have any added benefits? I saw on here a looooong time ago (I think it was on the Red Wine thread) someone who had a removable top to add different sizes, but I forget how it was done. Thanks...

[nullspace]

I dont see how you could  possibly go wrong... 100db Altec 604 + OB? Those are fantastic drivers, as are the new ones from www.greatplainsaudio.com  who are just about to release the 12 inch version, as a replacement to the old Altec 212 / Urei coaxials. THOSE, look even tastier.

I haven't spoken to Bill about it, but as far as I know GPA's 212-8A are available. The datasheet is here: http://www.greatplainsaudio.com/downloads/212_8A.pdf. Over on the Altec board, quoted at $540 per.

Regards,
John

[Bob in St. Louis]

stlblue - If this is your first dip in the OB pool, may I suggest something quick, cheap and easy for your first baffle?
A piece of 2' MDF with a hole poked in it. Then use cardboard wings held on with duct tape.
If you're interested, there's two ways you could do this.
#1 Make the baffles and wings too big. Listen to them for awhile. Trim a few inched off here or there until you've found what sounds best.
#2 Start off small and add pieces of cardboard (duct taped) until you achieve the sound you like.

I have no opinion as to how big a top plate should be. Personally, I don't like the sound of one. But if you'd like to experiment with different sizes, again pieces of duct tape and cardboard. Or, if you need something with a higher WAF, you can use Velcro to attach your different sized plates. It's been a long time since I read the Darkstar thread, sounds familiar but I don't remember the exact method used.

OB is a fun journey dude aa

Bob

[Graham Maynard]

Hi stlblue,

Wings cause a rear pressure wave reflection which is heard from the front.

It is possible to slightly improve LF with deeper wings by gapping them back from the baffle on spaced wood strips say 3/8" (1cm) thick.  This releases the (often symmetrical) pressure wavefront.

Cheers .......... Graham.

[stlblue]

Thanks, guys. I'll try it out w/ MDF and test it for a while and then go to some nice wood if I like it.

[amandarae]

Hello,

I saw your post and I thought I could contribute something.  Pictures worth a thousand words....

















604-8G in OB's with Time Aligned XO.  I am using a 2A3/45 amp.

regards,

Abe

[stlblue]

Hello,

I saw your post and I thought I could contribute something.  Pictures worth a thousand words....


604-8G in OB's with Time Aligned XO.  I am using a 2A3/45 amp.

regards,

Abe

Hi Abe:

I found your pics surfing the net a couple weeks ago and saved them "for future reference." 

Did you by chance hear your 604's in "boxes" before you put them in OB's? How was the bass compared to the OB's? I listen to as much SRV & The Who as I do Sinatra and jazz. Thanks for sharing your pics & thoughts.

[Dmason]

Amandarae,

I can't help noticing one thing that seems telling: the pair of unused Orions. Less is More

I can't help wondering if Yamamoto san would share his CNC cut plan for the Cherry baffles. Those are sooooo
sweet.

I can't help wondering if Altec 604 or 212 is about as good as it gets for Less is More OB. A+++

[amandarae]

Hello,

I saw your post and I thought I could contribute something.  Pictures worth a thousand words....


604-8G in OB's with Time Aligned XO.  I am using a 2A3/45 amp.

regards,

Abe

Hi Abe:

I found your pics surfing the net a couple weeks ago and saved them "for future reference." 

Did you by chance hear your 604's in "boxes" before you put them in OB's? How was the bass compared to the OB's? I listen to as much SRV & The Who as I do Sinatra and jazz. Thanks for sharing your pics & thoughts.

Hello,

Yes, I have the original 612C cabinets.





I also drove to a friend's set up with 604's and 620 cabs to listen and consider building a pair.  In the end, I prefer the OB's.  Bass IMHO, depends greatly with what amp to use and room positioning of the OB's with this set up.  My recommendation is if it is possible, find someone with the 604's on 620 cabs and bring your own favorite amp.  You will definitely hear the difference in the presentation of how the drivers perform in a close cab as oppose to OB's and make your decision from there.

Also, JE is a friend of mine.  Study the pics of OB's in his website and try to deduct why the owners keep on using them.  Surely, you would not think that most did not consider building and using Altec cabs along the way do you?

regards,

Abe

[amandarae]

Amandarae,

I can't help noticing one thing that seems telling: the pair of unused Orions. Less is More

I can't help wondering if Yamamoto san would share his CNC cut plan for the Cherry baffles. Those are sooooo
sweet.

I can't help wondering if Altec 604 or 212 is about as good as it gets for Less is More OB. A+++

Ahhh, yes......here( recent photo), make your own conclusion....



regards,

Abe

[Dmason]

And of course your new amp... tell us how that is evolving. I keep coming back to the idea of simple large "calibre" coaxial, and SET. Oh, and vinyl. Listen to Weather Report on vinyl + SET + OB. Stuff like that you would agree totally destroys you for anything else.

My first "stereo" system was using the 6550 amp in my Hammond organ into the 2X A7 we used as a PA system. Everything old is new again. Maybe it is time to close the circle. It has my attention, FWIW.

[amandarae]

And of course your new amp... tell us how that is evolving. I keep coming back to the idea of simple large "calibre" coaxial, and SET. Oh, and vinyl. Listen to Weather Report on vinyl + SET + OB. Stuff like that you would agree totally destroys you for anything else.

My first "stereo" system was using the 6550 amp in my Hammond organ into the 2X A7 we used as a PA system. Everything old is new again. Maybe it is time to close the circle. It has my attention, FWIW.

Hello,

Agree totally!  I spend a fortune chasing the sound I wanted and now I am in cruise control.  Yeah, its funny how the audio merry go round works.  I am now a believer that everything in audio was figured out during the 50's and 60's as my mentor(JE) onced told me.  New components comes around but not necesarily a better sounding design.

My amp (2A3/45) is performing really well, thank you.  I am in the process of gathering parts for a 300B amp driven by a 76 and 6SN7 combo and an octal full function preamp driven by 76 tubes also.  Well see what happens.   My current full function preamp (Supratek Chenin) sounds amazing to me.  I will know later if the one I will make can perform as well if not better.

regards,

Abe

[stlblue]

Hello,

Yes, I have the original 612C cabinets.


regards,

Abe

I have the same 612C cabinets (except my x-over hole is in the back) for my 604E's (COMPLETELY re-done by GPA). I bought the Iconic x-over protypes a few years back. I'll build a pair of OB's out of MDF in a couple weeks and if I like them as much as I suspect, I'll try to do something nicer, later on. Thanks for your insights!