My AVIDITY audio x-mas project: "The SHINING", Altec Lansing 920-8B open baffles

[L78Scout]

Hi all,
may I still wish a happy New Year and all the best for 2020?
I used my x-mas holidays at home to build my first open baffles following the plans of tube kingdom/ JElabs. I took a pair of quiet exotic speakers for this project that I never heard before live. The combination Altec 920-8B ( USA production) with oen baffles was a kind of experiment - to be honest:  I did not expect any good or Hifi like sound. The x-overs are the original Altec type that is integrated behind the speaker´s magnet.
I know... you are on the visual side & like to see what I am talking about...

The speakers:






A peek to the crossover:




The wood:   
construction plates ( inside spruce fir, laminated beam - outsides birchplywood) a little bit more than 1" thick










Wood staining for "The SHINING" effect:






Final coating with a clear wax and installed speaker chassis:






Last work was screwing a pair of terminals and connecting the chassis with Belden 9497 AWG 16, here we are, ready to rumble & excited for following audio testing:




I´m quiet sure not anyone can follow my colour concept  , maybe it is to be titled " extra-ordinary ". All in all I am quiet happy with the aesthetics... 


I´d like to give an impression what surprized me during the first vinyls that I played.  I really did not expect an amazing sound at all while building the baffles. The recording was made with Iphone 11 pro - so please consider that the live sound is better than the result via my YT videos... Maybe optimized individual crossover could these speakers to another higher level?

Enjoy,
Joerg

[ian]

Nice build Joerg.  The baffle material looks interesting and the staining, well, probably not to everybody's taste 
Maybe you should round off the edges of the baffle opening just to let those drivers breathe a little better although I have no knowledge of the drivers so maybe this is not necessary. 

[mred]

I like this project, very interesting 
I am going to look up those drivers and follow you for more impressions as you proceed.

[itskeith]

Hi Joerg, thanks for posting
Agree with:

I like this project, very interesting 
The baffle material looks interesting and the staining, well, probably not to everybody's taste 

Looking forward to hearing your thoughts / impressions on them.

[analogadikt]

How do they compare with the 604e ?

Regards,

[Bonzo]

I like this project, very interesting 
The baffle material looks interesting and the staining, well, probably not to everybody's taste 

I like it too!
The colour could be not very popular, but the finishing is top class!
I have something similar but with hinges (I want them to be foldable) for my Altec 755e and Saba Greencones (two holes per baffle to use Saba's tweeter). Never put them in use because of their uglyness and poor finishing, your post convinced me to have them rebuilt by a carpenter!

Really interested to hear some drums, can you make some more vids? 

[0TT0]

I like your project too, especialy the finnish.



 Jack Marshall & Shelly Manne ‎– Sounds!  [ Capitol Records ‎– T 2610 ]

Try to find this record.   

[L78Scout]

Hi Joerg, thanks for posting
Agree with:

I like this project, very interesting 
The baffle material looks interesting and the staining, well, probably not to everybody's taste 

Looking forward to hearing your thoughts / impressions on them.

Thanks Keith,
Sure, the coloring ist not everyone´s taste - sometimes my own taste is far away the mainstream... 
But to prevent any idea to call me crazy - I plan to build another pair of these baffles and they may get a wooden frontpanel veneer - perhaps rosewood anything like that.. .we´ll see.
Main problem for the next two or three months is a lack of free time for the audio hobby.
Regards,
Joerg

[L78Scout]

Nice build Joerg.  The baffle material looks interesting and the staining, well, probably not to everybody's taste 
Maybe you should round off the edges of the baffle opening just to let those drivers breathe a little better although I have no knowledge of the drivers so maybe this is not necessary. 

Thanks, Ian!
Indeed I thought myself about rounding the edges of the baffle´s opening while cutting the holes . Guys with OB´s building experience told me a horn like opening with rounded will perhaps bing a more negative sound.  They may be right - they may be wrong. I´m new to this - maybe I will do the edging with these baffles and if there positive experiences I will go on building a second pair including the edging.
It´s in laboratory status for the moment..

Cheers,
Joerg

[L78Scout]

I like this project, very interesting 
I am going to look up those drivers and follow you for more impressions as you proceed.

Hi,
actually the Altec 920-8B are cheap, really cheap - only a few people know them at all. And most audio enthusiast from the higher end of Hifi will lift their noses, saying - these speakers are NOTHING FOR HIFI USE. Sure, they werde made for PA, mainly for churches, exhibition centers, hotel ballrooms with priority to voice not to music. But they were also used in different Altec Lansing monitor cabinets as stage monitors, complex cinema installations.
I wasn´t sure myself if the 920 will do a good audio job  -but I have to say: I got positively surprised.

Anyone who is interterested in an own test and likes to buy these chassis will be in the lucky position to be able to catch them for a reasonable low price. I saw the pair in really fine condition as cheap as 150,- USD on Ebay.com. A price level that you will not find with any other Altec Lansing speaker, I guess.

If you like to hear Rock, Metal or bass music - they might be the wrong chassis. For Jazz, Vocal music they are near perfect in my experiences till now.
Stay tuned!

Regards,
Joerg

[L78Scout]

I like your project too, especialy the finnish.



 Jack Marshall & Shelly Manne ‎– Sounds!  [ Capitol Records ‎– T 2610 ]

Try to find this record.   

Thanks, OTTO!
Another guy with a taste on the extravangant side.. haha 
I will have look for this vinyl -

Cheers,
Joerg

- always on the run -

[L78Scout]

How do they compare with the 604e ?

Regards,

Your question is difficult to answer.
This are my first OB´s - I haven´t heard another pair with different speakers.
And I haven´t heard them since building with different music styles, drums, bass, rock, electronic. There is a lot to test before I could give a kind of final statement. It´really a test laboratory for the moment.
I hear with my Altec 604 in the closed cabinets for around a year. They are clearly different with their big closed enclosures. They are cost a few thousand Euros more than the Altec 920 in OB´s. They have well fine crossovers made by a guy with decades of experiences with the Altec suff. I experimented for two months with the 604 crossovers outside the enclosures until I got my final settings. You may know, the 604E are in no way "bass wonders" - but they are 15" and thats a noticeable difference in stage, presence, detail of the music reproduction. The 604 seem to have stronger and more detailed heights. On the other side the 604E are the speakers I am used to over a longer period. I will have some guys here within the next weeks and will see what they judge in comparison...
By the way, I will get a pair of wooden stands from the carpenter mid february to lift the tweeter in the height of my ears. That was the last thing to fix with the 612/ 604E´s. 

[0TT0]

Some pic`s at the attic of the Beauvechain LencoHeaven Meet 2016.

[0TT0]

Thanks, OTTO!
Another guy with a taste on the extravangant side.. haha 
I will have look for this vinyl -

Cheers,
Joerg

- always on the run -

This is not a Jazz album, even Malcolm can dig it. 

[L78Scout]

I like it too!
The colour could be not very popular, but the finishing is top class!
I have something similar but with hinges (I want them to be foldable) for my Altec 755e and Saba Greencones (two holes per baffle to use Saba's tweeter). Never put them in use because of their uglyness and poor finishing, your post convinced me to have them rebuilt by a carpenter!

Really interested to hear some drums, can you make some more vids? 

Thank you!
As far as I know there have been historical open baffles with hinges for transportability. In certain cases the hinges will make sense. I thougt it would be better to couple the rear panels fixed by glueing them to the front panel - I may be wrong but in my thinking that could better the performance by an optimized, larger wall of sound. If you think of historical  commercial walls of sound/ baffles the German company Klangfilm e.g. builded enoumous large baffles on the cinema stage to support their speakers. I haven´t studied the physical theory deep enough to place a final statement but I guess a larger baffle and no hinges could be the better way. Maybe anyone with open baffle experiences could comment?