Hello from Northern CA

Discussion in 'Introductions and Member Systems' started by musical, Aug 11, 2018 at 5:17 PM.

  1. New member in the greater Sacramento area just want to drop by and say hello. I'm an audio hobbyist who like to tinker and try out new -to-me gear, especially vintage gear. I like RF as well, not just AF. I have a number of hobbies, but of all the hobbies I have dabbled in, I would have to say audio is the most rewarding and the most cost effective. My current gear include Carver, Sansui, Kenwood, JBL, Altec, Infinity, Pioneer, among others. Among my upcoming projects, I bought a used pair of Altec 9849-8A speakers in fully working condition a while back, and am planning to some improvements to them (at least recap and repaint) when time allows. Yeah, finding the time to do this project and other projects is a major challenge for me. I'm still in the info collecting phase at the moment, and hoping to learn as much as I can from this site when I finally get around the Altec to do the actual improvement work.
     
    Last edited: Aug 11, 2018 at 5:42 PM
  2. Mortsnets

    Mortsnets Junior Member

    Hi musical, have fun with the Altec, qny pictures? What is RF and AF?
     
  3. airdronian

    airdronian Junior Member

    Welcome !
     
    musical likes this.
  4. AF is audio frequency, basically anything that works in the audio frequency range, usually 20Hz-20KHz (but technically can be up to 100Khz); while RF is radio frequency, anything that deals with frequencies higher than 100Khz, for example like your radio tuner.

    Here're couple of pics of my Altec 9849-8A:

    IMG_1695.JPG
    IMG_1697.JPG

    Yes, I'm definitely looking forward to listen to these Altecs when the improvements are done.
     
    John Frum likes this.
  5. Prime Minister

    Prime Minister Site Owner Staff Member

    Welcome aboard!
     
    musical likes this.
  6. Quite interested to see what you do with the Altecs. In all these years, I don't think I've seen even one 9849 project. There would seem to be a number of possibilities there.

    GeeDeeEmm
     
  7. Yes. I want to do all improvements and restoration that I can without screwing up the "spirit" of these Altec Studio Monitors - that is no plans to turn them into some sort of virtual DIY speakers, and to do them all when I have them opened up. I think the improvement work will probably mostly along the line of cleaning, maintenance, and restoration, rather than major things like changing entire drivers or XOs or cabinets. I think these major parts are good as they are (except that the XO need recapping, of course). From readings on various place on the Internet, including here, so far I think my plan includes the following:

    1. Restoration of the cabinet - repaint / refinish. Any recommendation for paint to match the factory "utility grey" paint? I thought about using a polyurethane paint for more durability and resistance to liquid, but I have some concern about working with this type of paint due to its toxic vapor when wet.
    2. Recap - any recommendation of type and brand capacitor?
    3. Cleaning all contacts and switches
    4. Address any cab sealing / air leak issues if needed
    5. Adding some kind of stubs, risers, or feet to cab to protect the new paint job.
    6. Evaluate condition and amount of acoustic fill / damping material, and address if there's issue.
    7. Cab is braced, but is that enough?
    8. Change out and upgrade the resistors?
    9. Upgrade the internal wiring to larger gauge wires?
    10. Rehabbing the grill - not totally necessary, but have thought about other type of grill cloths. Any thoughts on this?

    Anything else?
     
    Last edited: Aug 12, 2018 at 6:36 PM
  8. In order:
    1. If you have the skills, veneering them in a nice walnut or mahogany would be very nice. Otherwise, I wouldn't hesitate using the poly paint. Just ensure that you have adequate ventilation. No sweat.
    2. Any quality capacitor will do. There are many who have capacitor preferences, but this is impossible to determine without personal experience. Others may give you their preference, I have none.
    3. Very important. Amazing number of problems stem from simple dirty contacts.
    4. Natch
    5. Internet is riddled with a number of suitable rubber feet, etc that will do the job. Castors, too.
    6. Rarely a problem, but be sure to stay with the original scheme/material. Damping is becoming another Audio Urban Legend on the order of cables. Everybody has an opinion - usually wrong. :chin
    7. Bracing. This is one area where it's literally true that more is better. We want to listen to the sound of the speaker system, not the box. There is a caveat, though: adding lots of interior bracing also reduces cabinet volume, and that's a bad thing. The ultimate answer is to brace outside the cabinet by adding another layer of plywood/mdf, thereby doubling the cabinet wall thickness. Lots of attractive possibilities with this approach, but I'm sure this is beyond your intentions.
    8. Rarely necessary, but resistors are cheap. Why not?
    9. Again, rarely necessary (and only in the case of corrosion), but wires are cheap in the lengths needed for interior use. Easy, fun, and you'll feel an odd sense of accomplishment.
    10. Oh, heck yes. The world is your playground when it comes to grill cloth. Big improvements possible here. And don't forget name plates on the grill, too.

    And I'm thinking that the 9849 would be an excellent candidate for bi-amping and using a mini-dsp. This would allow you to perform beautiful equalization, time alignment, and all the other worthwhile and fun things you can do with a mini-dsp. Very small expense for a ton of fun and enjoyment.

    Keep us updated on your project.

    GeeDeeEmm
     
    musical likes this.
  9. Thanks for the thoughtful feedbacks there GeeDeeEmm. There’re couple of projects ahead of this one; hoping to get to this one before the end of summer.
     

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