New Member from somewhere on the east coast! :)

Greetings!

First serious listening as teenager: my brother's Phase Linear/Klipsch Cornwall system in our basement
Years later: Luxman R1070/Magnepan SMGa
Then Scott 222D (Mapleshade modded)/Dynaudio 42

Current amps:
Kenwood Model 500 (refreshed by Echowars)
Heathkit AA-151 (modified by Sam's Audio Lab)
Sony TC-500a (refreshed)

Current Speakers:
Kef 104/2
Bozak 302 Century (Tobin crossover)
Altec Bolero 890C

Current goal: Build best speaker possible using Altec 601C & MR931-12 (for use with subwoofers handling low frequencies)

Very open to feedback/suggestions :-)

Cheers!
Jeff
 
Thanks a lot for all the welcomes! I appreciate it. When I lie down on the pillow at night, oftentimes, I fall asleep visualizing how to get all my Altec/Bozak/EV/Janszen drivers into various configurations and test to see how they'd sound. I keep trying to think of some way to create an easily adjustable loudspeaker test cabinet - one in which cu/ft, driver size openings, port size, crossover, etc. could be changed quickly to enable effiecient experimentation. I've looked around on various sites for discussion around this idea but have not really found anything. To me, this would be worth a million bucks! Guess I just need to keep thinking.

My most recent thought was to incorporate the Altec 601C in the Bolero 890C... maintaing the robust bass (via 406Y & passive radiator) with addition of the 414 midrange and 3000 tweeter. Man oh man. I think I'm ill. :)
 
Thanks a lot for all the welcomes! I appreciate it. When I lie down on the pillow at night, oftentimes, I fall asleep visualizing how to get all my Altec/Bozak/EV/Janszen drivers into various configurations and test to see how they'd sound. I keep trying to think of some way to create an easily adjustable loudspeaker test cabinet - one in which cu/ft, driver size openings, port size, crossover, etc. could be changed quickly to enable effiecient experimentation. I've looked around on various sites for discussion around this idea but have not really found anything. To me, this would be worth a million bucks! Guess I just need to keep thinking.

My most recent thought was to incorporate the Altec 601C in the Bolero 890C... maintaing the robust bass (via 406Y & passive radiator) with addition of the 414 midrange and 3000 tweeter. Man oh man. I think I'm ill. :)

Here's the best I've got for you on the "Transformer test cab": you build a nice big refrigerator cabinet that in regular mode is as big as you can imagine you'd want to go, lets say it's 9 cu ft. in it's regular mode. Front baffle is removable of course, set up for a maximum diameter of 12" or 15" or whatever if you think your going to go that big. Then you've got inserts to adapt smaller woofers into. That parts easy!

Similar for the port, cut out a nice big one then I'm imagining a sliding bit that's you can use to cover the port at variable distances to adjust for different tuning.

To adjust the volume of the cabinet you've got an interior false top. The interior top has a dovetail on either side and there are cleats spaced on the sides of the interior of the cabinet that it can slot into, to drop the cu ft. to say 7,6,5, or whatever. That keeps it pretty rigid while giving you customization. I have an antique bookshelf that lets you adjust the shelf spacing this way. I guess you just stuff some insulation into the cavity above the false top to take it out of the equation. If your false top gets lower than your woofer opening on your baffle you flip the baffle and speaker upside down and the top becomes the bottom.

Crossover customization just requires a good stockpile of components in different values and some alligator clips to link it all together 😁

Let me know how it all works out 😜
 
That's a lot of food for thought. Thank you! I've read your post attentively, twice. I'm sure I'll refer back to it again and again as I continue to think through this.

What is your plan for the 414?

Kind regards!
 
That's a lot of food for thought. Thank you! I've read your post attentively, twice. I'm sure I'll refer back to it again and again as I continue to think through this.

What is your plan for the 414?

Kind regards!

No problem! For the record I've never tried any of that stuff but I think it would work 😁

414s are getting bass reflex cabinets (in fact, I received the plywood for them today and will be building tomorrow!) and paired with 802g compression drivers mounted on 3D printed horns. I've got a rough draft of the crossover network already since I've been running the horns with my Boleros, will just need to fine tune to match the relative efficiency & crossover point!
 
No problem! For the record I've never tried any of that stuff but I think it would work 😁

414s are getting bass reflex cabinets (in fact, I received the plywood for them today and will be building tomorrow!) and paired with 802g compression drivers mounted on 3D printed horns. I've got a rough draft of the crossover network already since I've been running the horns with my Boleros, will just need to fine tune to match the relative efficiency & crossover point!
Hi. Did you finish your build? Impressions? :)
 
Hi. Did you finish your build? Impressions? :)
Howdy again! It is more or less finished - still need to make some fancy mounting sleds for the horns but have them blocked up on top of the cabinets in a way that is not aesthetically finished but sonically complete. I've got longer term plans to do one more iteration of the printed horns with either a glass-filled polymer, or a metal polymer mixture... Either copper or brass. That will likely color the sound from the horns too but I'm still really happy with where they are right now.

I ended up with an interior cabinet volume of 6 cu/ft., used NOS Russian military PIO caps and Mills wirewound resistors in the crossover. Pretty simple crossover, as people tend to do around here. Nothing on the 414, horn gets caps for the XO point then resistors to pad down the efficiency but with a small value cap to take out the resistor at the higher frequencies where it starts to fall off.

I've been loving the sound. Honestly the best thing I could do for my listening situation at this point is get a bigger listening space because my apartment is tiny and I can't put them very far apart. I think the printed horns are crisp and detailed without any of the harshness or ringing that people describe from the vintage metal cast 32s, though I haven't personally heard those to compare. Everything feels balanced and distinct through the frequency range. I'm not great at describing these things and don't have a lot of experience with hifi but I'm very enthusiastic about what I'm hearing with this setup! I've got some other details from the build process in a thread in the high efficiency sub forum but heres a picture of how they look right now! IMG_20210510_203427.jpg
 
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