Page 1 of 5 12345 LastLast
Results 1 to 10 of 47

Thread: Broke down. Got a duplex.

  1. #1
    Senior Hostboard Member
    Broke down. Got a duplex.


    Alien_Shore's Avatar
    Join Date
    April 25th, 2012
    Location
    Virginia
    Posts
    731
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    2 Post(s)

    Broke down. Got a duplex.

    I gave in and picked up a beat up 604E. Sent it off to Bill to have him give it the GPA treatment.

    Woof T/S:
    604elfts

    Vas:
    604elfvas

    Horn T/S:
    604ehfts
    - Mike

  2. #2
    Senior Hostboard Member Panomaniac's Avatar
    Join Date
    May 25th, 2006
    Posts
    1,811
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Broke down. Got a duplex.

    Cool. Let us know how it is when it gets back from Oklahoma.

  3. #3
    Senior Hostboard Member voice of the theater's Avatar
    Join Date
    February 25th, 2009
    Location
    Upstate New York
    Posts
    1,412
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Broke down. Got a duplex.

    Nice! Please keep us posted. I'll bet that speaker sounds amazing after you get it back from Bill/GPA. BTW, I'm inventing a triplex speaker. Altec 15" Biflex woofer with h.f. driver/horn (not to be confused with a triflex?)....
    Being of "Sound" Mind

  4. #4
    Senior Hostboard Member donaldpatten's Avatar
    Join Date
    September 26th, 2004
    Posts
    336
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Broke down. Got a duplex.

    Congrats

    Welcome to the Duplex family
    Are your magnets alnico or ceramic
    I noticed the woofer R is about 7 Ohms. I expected to see about 12. What V.C. Are you getting on the new GPA?

    Don

  5. #5
    Senior Hostboard Member
    Broke down. Got a duplex.


    Alien_Shore's Avatar
    Join Date
    April 25th, 2012
    Location
    Virginia
    Posts
    731
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    2 Post(s)

    Re: Broke down. Got a duplex.

    Ummmm,
    I got it back from GPA yesterday - those measurements reflect the "GPA treatment"...
    It's a huge mother - 604E so it's Alnico.
    And yes, Don, I expected the same thing from the woofer VC - Bill told me he was putting in 16 ohm VCs for both HF and LF...

    I only had time last night to very briefly hook it up through the Behringer dcx2496, as I don't have a XO for it yet. No cabinet either. It sounded...meh. The mids were very clear, and I think I got a glimpse of what everyone talks about that "point-source" sound - some extremely revealing details from the recordings, but as you'd expect I guess from an unmounted speaker it was utterly lacking any low end. I need to throw together a passive XO (plan to use Markwarts design as a starting point). But it is curious that the Woofer R is reading like an 8ohm VC is in there. Some of the other T/S params match very well with what is posted on Todd's list, while others are off by quite a bit. Does the MM number look right? I thought it was curious that DATS came back with a number that essentially equaled the amount that I applied to the cone to calculate the Vas. The math for that doesn't work out...
    - Mike

  6. #6
    Senior Hostboard Member Panomaniac's Avatar
    Join Date
    May 25th, 2006
    Posts
    1,811
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Broke down. Got a duplex.

    Ah, those are after - sorry! I'd say Mms looks low, that's a light cone. But I'm not sure. I'll see if I can dig up files on some GPA reconed 604s (ferrite) I had here.
    From the plot, it looks like an ohm woofer and horn to me.

  7. #7
    Senior Hostboard Member Earl K's Avatar
    Join Date
    December 5th, 2002
    Location
    Toronto
    Posts
    507
    Follows
    0
    Following
    0
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    4 Post(s)

    Re: Broke down. Got a duplex.

    Quote Originally Posted by AlienShore
    I gave in and picked up a beat up 604E. Sent it off to Bill to have him give it the GPA treatment.


    From your measurements, it appears the "GPA treatment" is to turn a 16 ohm 604 into a 10 ohm 605 ( if that DAT measurement is to be believed ) .

    Time will tell if your measurements hold water ( fyi, others using WT3, which was the G1 version of DATS , had many problems with it, maybe DATS is better ??? ) .

    The current measurements
    tune up quite well ( if accurate ) using a 9.5 cu' enclosure tuned to 25hz .


  8. #8
    Senior Hostboard Member
    Broke down. Got a duplex.


    Alien_Shore's Avatar
    Join Date
    April 25th, 2012
    Location
    Virginia
    Posts
    731
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    2 Post(s)

    Re: Broke down. Got a duplex.

    Quote Originally Posted by Earl K View Post
    From your measurements, it appears the "GPA treatment" is to turn a 16 ohm 604 into a 10 ohm 605 ( if that DAT measurement is to be believed )
    Yep - that's what it looks like. I sent GPA an email - we'll see if they reply.
    In the meantime, do you recommend another (more reliable) method for testing T/S?
    - Mike

  9. #9
    Senior Hostboard Member Earl K's Avatar
    Join Date
    December 5th, 2002
    Location
    Toronto
    Posts
    507
    Follows
    0
    Following
    0
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    4 Post(s)

    Re: Broke down. Got a duplex.

    WT2 is more reliable than WT3/DATS ( different maker with a different way of measuring ) .

    REW has a TS parameter measurement area ( you need to wire-up a small box ) that uses the same method as WT3 .

    Personally, I wouldn't bother GPA with this type of thing until you've gotten similar measurements from at least one other measuring program.


  10. #10
    Senior Hostboard Member Earl K's Avatar
    Join Date
    December 5th, 2002
    Location
    Toronto
    Posts
    507
    Follows
    0
    Following
    0
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    4 Post(s)

    Re: Broke down. Got a duplex.

    - Every once in a while it is worth the diy hobbyists time to check ( recalibrate ) the validity of ones measurements by using another method ( really , it's simply part of the scientific method ).

    - For TS parameters ( when checking these "all-in-one" devices ) one can use the old standby method outlined here !

    - I believe that verifying Re, Fs & Qts ( Qms, Qes ) is enough to know where ones device stands .


Page 1 of 5 12345 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
This forum has been viewed: 20968996 times.