Page 1 of 2 12 LastLast
Results 1 to 15 of 23

Thread: Basic Ohm question

  1. #1
    Senior Member
    Join Date
    Aug 2004
    Location
    Redwood City, CA
    Posts
    215

    Basic Ohm question

    What would be the result if I mixed an 8ohm woofer with a 16ohm compression driver using a 16ohm crossover. ie 130a and 2441. Would I be guessing correctly that the woofer would be somewhat muted?
    Robin

  2. #2
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,715
    You can and we do mix drivers of various impedances with no problems. The crossover is the critical point. Do you have the network schematic? Is it a JBL network?


    Widget

  3. #3
    Senior Member
    Join Date
    Aug 2004
    Location
    Redwood City, CA
    Posts
    215
    Hi Widget,

    The crossover is a JBL 3115 and I thought I might try a pr. of 130a 8ohms woofers that are available. My LE15s have a rub and may get a full reconing.
    Robin

  4. #4
    RIP 2009
    Join Date
    Feb 2004
    Location
    Rohnert Park, CA
    Posts
    3,785
    Quote Originally Posted by rloggie
    The crossover is a JBL 3115...
    The 3115 is spec'd for 8-18 ohm LF and 16 ohm HF, so you should be good to go: http://www.jblpro.com/pub/obsolete/F..._Networks1.pdf

    Did you pick up those 130A's recently on craigslist?

    John

  5. #5
    Senior Member
    Join Date
    Aug 2004
    Location
    Redwood City, CA
    Posts
    215
    Yeah, those are the ones. They may be gone already but I've emailed to find out. I talked to the guy right after they appeared but couldn't get away to pick them up. We'll see if he calls back tonight.
    Robin

  6. #6
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,715
    The problem isn't the impedance mis-match... the problem will be the sensitivity difference between the LE15A and the 130A. The new woofer will have significantly greater output above 100Hz than the LE15A had.


    Widget

  7. #7
    Senior Member
    Join Date
    Aug 2004
    Location
    Redwood City, CA
    Posts
    215
    Quote Originally Posted by Mr. Widget
    The problem isn't the impedance mis-match... the problem will be the sensitivity difference between the LE15A and the 130A. The new woofer will have significantly greater output above 100Hz than the LE15A had.


    Widget

    Since neither of these speakers list sensitivity in the library how does one know the differences on paper?? Or do you know by experience?
    Robin

  8. #8
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,715
    Quote Originally Posted by rloggie
    Since neither of these speakers list sensitivity in the library how does one know the differences on paper?? Or do you know by experience?
    In this case I do have experience with both... but the info is also in the library.

    http://www.lansingheritage.org/image...ome/page15.jpg
    Attached Images Attached Images  

  9. #9
    Senior Member
    Join Date
    Aug 2004
    Location
    Redwood City, CA
    Posts
    215
    I see. These would go into the Hartsfield cabs. I wonder what the original 150-4 sensitivity was?? It seems to be cut from the same cloth.

    http://www.lansingheritage.org/image...-150/page1.jpg
    Robin

  10. #10
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,715
    Can't help you there... but if the LE15As were sounding right, the 130As won't.


    Widget

  11. #11
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Do we consider K/E145 an option for Hartsfield?

    Their response is closer to 150-4C than LE15A is, no?

    [Thinking "Everest" here....]

  12. #12
    Senior Member
    Join Date
    Jul 2003
    Location
    Orange County, CA
    Posts
    3,593
    Quote Originally Posted by rloggie
    Yeah, those are the ones. They may be gone already but I've emailed to find out. I talked to the guy right after they appeared but couldn't get away to pick them up. We'll see if he calls back tonight.
    I have a pair of 130As lying around if you are interested. I would even trade them for a NICE power amp than can be used in mono. This be them:


  13. #13
    majick47
    Guest

    OHMs

    While your on the topic maybe someone can answer my question from their practical experience with L pads. I have some 3106 crossovers for 2405 tweeters (16 ohm) and noticed the L pads were marked 8 ohm. Would the 8 ohm L pads diminish the output of the crossover or have any other negative impact?

  14. #14
    Senior Member louped garouv's Avatar
    Join Date
    Jun 2004
    Location
    formerly "the city where imagination takes precedence over fact"
    Posts
    2,152

    same question

    but this time with ALtec N800 Xover and 515Bs (16 ohms)....


    I think that the combo w/ 511B (802-8G loaded) sounds fine but what do I know...

  15. #15
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Quote Originally Posted by majick47
    While your on the topic maybe someone can answer my question from their practical experience with L pads. I have some 3106 crossovers for 2405 tweeters (16 ohm) and noticed the L pads were marked 8 ohm. Would the 8 ohm L pads diminish the output of the crossover or have any other negative impact?
    8-Ohm adjustable L-Pad is correct. If I were making it out of fixed resistors, I'd build around 10 Ohms:

    http://audioheritage.org/vbulletin/s...2&postcount=51

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 8 ohm speakers on a 4 ohm amp?
    By rcpmac in forum Lansing Product Technical Help
    Replies: 12
    Last Post: 03-05-2007, 08:29 AM
  2. HELP! with 2404H-1 replacement diaphragm 8 vs 16 ohm....
    By randy1kenobi in forum Lansing Product Technical Help
    Replies: 5
    Last Post: 10-16-2005, 04:28 AM
  3. Non-Searching Newbie Question solution?
    By Regis in forum Forum Feedback
    Replies: 7
    Last Post: 05-04-2005, 07:12 PM
  4. Isn't refoam enough? basic restoration question
    By Steve K in forum Lansing Product Technical Help
    Replies: 9
    Last Post: 04-14-2005, 10:12 AM
  5. Reading Lpad circuit with 120/240Ti
    By DavidF in forum Lansing Product Technical Help
    Replies: 4
    Last Post: 12-30-2004, 03:06 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •