Stereo

Discussion in 'Members' Systems' started by holepunch, Jun 17, 2017.

  1. holepunch

    holepunch New Member

    Messages:
    26
    Although registered with this forum for some years I have not been recently active. I saw the AudioKarma forum rules which I hope will insulate this forum from the attention seekers who have degraded other forums with their presence and disrespect of those with credible but different views. So I will be an occasional current participant.

    My interest in loudspeakers is in the high sensitivity area and I settled on Altec Lansing components as my way to go. I spent a lot of time(years) acquiring technical information and opinions from credible sources in this subject and understanding of the benefits, shortcomings and compromises that should be considered in the design of a loudspeaker system.
    My aim was, within the costraints of domestic environment, to achieve accuracy in reproduction. If you get to listen to a trumpet, saxophone or drums in a club at a distance similar to home listening ,they can be very much in-your-face. I didn't want my system to add 'warmth' to soften the sound, I wanted it to be 'accurate - at least as good as it could be when dependant on source material. Of course there was a budget to consider.

    I had in the early stages of the project decided upon the Altec A7 500 the suitable project. Upon reflection I realised that this 'small' theatre loudspeaker had serious shortcomings for domestic(smaller) spaces.

    I had already cut the panels for the A7 enclosure(called 828) when I decided a Bass Reflex design would better meet my requirements. I designed a BR enclosure using the outer panels of the 828 enclosure and luckily I could effectively utilise the remaining panels with no cutting required. The panels are heavily braced and have automotive constrained- layer damping judiciously applied internally and absorbent acoustic material internally applied lightly to the back, bottom and one side panel. The two 4inch/100mm ports are located low on the front port panel. I have sets of ports in lengths from 1.75 inches to 5.5inches to try.

    The net. internal volume is 13.75 cu.ft. and tuning is presently about 30Hz. I love the detail they present, even tt low volume. They are clean at all volumes, limited only by room reflections at the higher(too loud) levels.
    I have found that a clean loudspeaker can have you believing it is not operating loudly until you try to talk to someone next to you and realise you can't be heard.

    The LF driver is Altec 416-8B -16inch.

    HF is Altec 802 compression driver coupled to Altec 511B horn - constrained layer damping treated(zero mechanical ringing).

    Crossover is active, as is room compensation.

    After problems with an old Sony classic amp and a Sony V-Fet amp I purchased a couple of new amps .

    A NAD C326 BEE (50W + 50W plus extra for transients)for system pre amp and HF power amp
    A Yamaha XP 1000 PRO power amp(100W + 100W, designed with clarity of vocals as a goal).
    These amps are quiet at idle and I am very pleased with their performance.

    Sources:
    Luxman R-1050 receiver now used for AM/FM on main system and with power section on some Yamaha NS-10 monitors.
    CD player; Yamaha - respectable but not esoteric
    Multi format player, OPPO: DVD, SACD, HDCD, CD, DVD-A, etc.
    Panasonic 4K video recorder, Blu Ray, DVD,CD player.

    Turntables( linear trackers):
    Pioneer PL-L1000 with Shure v15 IV MM cartridge.
    Technics SL-10 with EPS-310MC MC cartridge.

    I have no interest in using tube amps for various reasons. I have no issues with the use of tube amps if they suit others.
     
    Last edited: Jun 18, 2017
  2. ronscat

    ronscat Active Member

    Messages:
    339
    Location:
    South Georgia
    Sounds like a plan and wonderful writeup - I would love to hear your system. I bet it sounds great!!
     
  3. botrytis

    botrytis Trying not to be a Small Speaker Hoarder Subscriber

    :needpics:or it isn't true :D
     
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  4. w1jim

    w1jim I can fix it but good... Subscriber

    Messages:
    7,432
    Location:
    Boston western 'burbs
    No attitude here - that seems like a really cool system.
    Take pride!
     
  5. BillWojo

    BillWojo AK Subscriber Subscriber

    Messages:
    2,031
    Location:
    Burlington, NJ
    Welcome to the forum, you will fit right in. I'm an Altec fan myself. There are a small number of us on here that are Altec fanatics. The Speaker forum and occasionally the Dollars and Sense forum seem to get most of the Altec action.
    Looking forward to having another Altec fan aboard.

    BillWojo
     
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  6. tcdriver

    tcdriver AK Subscriber Subscriber

    Messages:
    4,843
    Location:
    Valley of Heart's Delight
    Welcome to AudioKarma. I would love to see some pictures.
     
  7. holepunch

    holepunch New Member

    Messages:
    26
    Thank you for the warm welcome. The system definitely suits my needs and more. About the only things that might tempt me in the future are adding some JBL 2404H baby butt cheek tweeters that I have, using an on-hand pair of Altec 15095 transformers to make a passive MC step-up transformer and replacing a NAD 3020 amp used as a phono preamp with a discrete one.

    I am happy to post some pics. if I can work out how to do it here. I will see what I have on file as my 'equipment room' is presently set up for taking photos of all the DIY audio parts I am going to sell. After some years, I am basically getting out of making tube guitar amps and new audio projects.
     
    Last edited: Jun 18, 2017
  8. mark warren

    mark warren Always Learning! Subscriber

    Messages:
    1,091
    Location:
    southern USA
    Welcome to AK.....:beatnik:
     
  9. kjello

    kjello AK Subscriber Subscriber

    Messages:
    234
    Location:
    Trondheim, Norway
    WORD
    A live trumpet at full tilt is harsh and loud!
    And should be IMO. Thanks. And welcome :)
     
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  10. holepunch

    holepunch New Member

    Messages:
    26
    I tried to upload some pics and got an error message. What is an acceptable size for pics?.

    Size of files was not a problem. I've got it, now.
     
    Last edited: Jun 19, 2017
  11. danomar

    danomar AK Subscriber Subscriber

    Messages:
    70
    Location:
    Atlanta, GA USA
    Welcome!
     
  12. holepunch

    holepunch New Member

    Messages:
    26
    IMG_0526.JPG IMG_0531.JPG IMG_0539.JPG IMG_0540.JPG

    Heavy duty steel and hard rubber casters. Roller bearings - -no slack, no rattle. Necessary on large heavy speakers.

    IMG_0543.JPG



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    Basic assembly stage. Assembly done in kitchen. Glued all fixed components - no nails or screws. Bracing and cleats - used what was at-hand. IMG_0540.JPG IMG_0543.JPG IMG_0540.JPG

    Messed up posting some pics. I couldn't manage to delete the repeats in edit mode.
     
    Last edited: Jun 19, 2017
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  13. holepunch

    holepunch New Member

    Messages:
    26
    Carcase painted and trial fitting baffles.

    IMG_0553.JPG


    Baffles fit. Centre reinforcing frame painted. The grey stuff on the inner-bottom panel is WURTH(German) self-adhesive automotive constrained-layer damping sheet. Similarly applied under the top panel,the rear pane, and to a lesser degree to the sides. Expensive here in Australia.
    http://www.wurth.co.nz/cat/files/assets/downloads/page0198.pdf

    IMG_0551.JPG


    Wadding going in.

    IMG_0566.JPG
     
    Last edited: Jun 19, 2017
    asilker and Ds2000 like this.
  14. holepunch

    holepunch New Member

    Messages:
    26
    THE HORNS

    Refurbishing.

    IMG_0542.JPG


    Housing/sled fit. JBL 2404 Mock-up.Undecided about adding it, as yet.

    IMG_0558.JPG


    HF Assembled/painted. Constrained-layer damping material top, underside and in the hollows of the bells.

    IMG_0559.JPG



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    Last edited: Jul 12, 2017
    asilker likes this.
  15. Djcoolray

    Djcoolray Super Member

    Messages:
    4,635
    Location:
    A rocks throw from JBLM !!!!
    Dude...you don't mess around !

    Looks great....and welcome to AK...!!!
     
  16. holepunch

    holepunch New Member

    Messages:
    26
    IMG_0701.JPG
    416 LF and 802/511b HF in and wired. Ports next.

    IMG_0567.JPG


    DIY port hole-cutter jig and cheap plumbing fittings. The port tubes are a snug fit in the flanges and can be swapped for various lengths for tuning. I still haven't permanently glued the tubes to the flanges as they work well as is, and the tuning can be readily changed by unscrewing the flange fasteners and swapping port tube lengths.


    IMG_0568.JPG


    I made a rough jig to hold the pipe and guide the saw to get square cuts - not shown in next pic.

    IMG_0569.JPG


    Wadding, wiring and ports.

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    IMG_0701.JPG






    Ta-da.. Gee, I keep forgetting to paint the ports. Some grills would be nice.:dunno: Lousy photo, the speakers are background to the model shot.

    IMG_0708.JPG



    If you guys can take any more I can post some early commisioning pics.
     

    Attached Files:

    Last edited: Jun 19, 2017
    mmickk, turnitdown, asilker and 3 others like this.
  17. Rome

    Rome Holsum Honey Buns Subscriber

    Messages:
    37,934
    Location:
    Dallas, Texas
    Greetings to ya & that's an impressive project!

    Rome
     
  18. RobRoy

    RobRoy It's just stuff - but fun

    Messages:
    2,375
    Location:
    Central Kentucky
    Related: In the 70's I sold Hi-fi for a living. Your comments about "in your face" horns really rang true with me. It's why I ended up with bi-amped ESS AMT 1B monitors driven by hitachi separates.

    But one of my salesman buddies had an engineering degree in acoustics and he built his own monsters. Each enclosure included two Altec 15" and a special compression driver. This is from memory and it is from 1977, so I may be fuzzy, especially since we were a bit into herbs in those days.

    Anyway, he asked us to all bring over a favorite album. Well, I brought over my Genesis with Firth of Fifth because of the incredible and deep bass on that one. However, what I never expected was the incredibly POWER of the mid-bass in the piano at the beginning of the song. He had those altecs dialed in like nothing i'd ever heard. it felt literally like being front row center at a concert.

    And yeah, the bass was incredibly deep and clear.

    Maybe I was trying to tell myself, way back then, that i was going to be a bass player...
     
  19. ronscat

    ronscat Active Member

    Messages:
    339
    Location:
    South Georgia
    Nice work there. I know you feel a lot of satisfaction with a job well done! I would love to hear them.
     
  20. Nightwisher

    Nightwisher Farer In The Goldilocks Zone Subscriber

    Messages:
    2,439
    Location:
    South Carolina
    Looking awesome friend!
     

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