Page 7 of 8 FirstFirst ... 5678 LastLast
Results 91 to 105 of 113

Thread: 4628B curve for Zilch

  1. #91
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by Robh3606 View Post
    Hello martin

    The biggest question you need to answer to figure out what sub to use is what are the peak SPL requirements for them?? Also music will be much less demanding than HT from 40Hz and down so how will you be using them??

    I use a 2235 as my LFE sub in a B380 box and it works fine however it is peak SPL limited on demanding material. I can hit the THX 105db reference level just fine but I am running close to the edge in LFE channel doing it in my room. I am building a second B380 to have a pair for LFE to give me another 6db of headroom.

    If you have a large room or like to listen loud make sure the subs can keep up. You can always add another sub down the line if you need too.

    Rob
    Thank you,rob.
    I'm only considering subs for hifi music use,HT usage is no considered at this time.and i don't need very high SPL in my room at all. i'm just wondering which pair of subs are more naturely and fluently join to my 4628B.
    46 lover

  2. #92
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    If I were you, I would only keep the 4628B and sell the 4699 and 4691 and other cabaret speakers you might have.
    The 4628B Is the only one that really has good component and can be converted to hifi use. I would use subwoofer(s) to assist under 80Hz (real subwoofers, not PA speakers from the cabaret serie)
    I would discard the current passive filter and go fully active. The M533 is a good unit but a digital crossover like a DCX2496, together with some measurement gears, would give you more possibilities.

    Then, you have to change something with the drivers if you want a really good sound, because neither the 2118H nor the 2404H-1 are really good at 3khz.

    You have 3 choices:

    1- remove the 2118H, close its opening, and put a big horn and compression driver on top of the cabinet. Crossovers could be something like 800Hz and 8khz. The horn could be something like a 2397 if you find one. You will need a big horn to reach 800Hz (the E145 is not that great higher than that)

    2- keep the 2118H, and put a small horn on top of the cabinet, with a higher crossover, like 1200Hz and 8khz. A 2307/2308 could do the job. But then you will have a 4 way (plus subwoofers!) and the crossover will be difficult to deal with

    3- remove the 2404H-1 (this is the -1 variant anyway: it does not go that high) and replace it by a small horn and compression driver that is able to go to 20khz. That would be the best option in my opinion. A JBL 2407 (or BMS 4540nd) and a the small PT waveguide from the JBL AC16 speaker (PT-B99HF-1). This is going to be a really inexpensive combo (the 2407 can be found on ebay US, and the horn can be had from JBL Pro and is something like 10$ each), and can sound very good. The crossover point with the 2118H would be around 2.5khz, and you would have to use the CD compensation function of the M553 (horn preemphasis)
    So in the end that would be: E145 up to around 400Hz, 2118H from 400Hz to 2.5khz, 2407 from 2.5khz up to 20khz with CD compensation. That can be done with the M553, fully active.

    Then you just have to add some subwoofers, preferably spread accross the room, and you will have a killer system.
    Pos,my DCX2496 has just arrived,but it seems have no measurement function
    46 lover

  3. #93
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628
    no, the only thing you can do with it (beside crossovers!) is automatic time alignment (which is already quite useful!) with EMC8000 measurement mic. The DEQ2496 has measurement capabilities but a PC would be better.
    If you buy that mic then you only need a mic preamp with phantom power and you can use any PC as a measurement device with something like HOLM impulse.

  4. #94
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    no, the only thing you can do with it (beside crossovers!) is automatic time alignment (which is already quite useful!) with EMC8000 measurement mic. The DEQ2496 has measurement capabilities but a PC would be better.
    If you buy that mic then you only need a mic preamp with phantom power and you can use any PC as a measurement device with something like HOLM impulse.
    Where can i get EMC8000?and a mic preamp?phantom power?
    so complex?!
    46 lover

  5. #95
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628
    sorry I meant ECM8000 not EMC8000 :
    http://www.behringer.com/EN/Products/ECM8000.aspx

    If you want to do time alignement (delays on each driver to get them time-aligned at the crossover frequencies) you jsut need to plug it into the 'C' input of your DCX2496.

    If you want to do real response measurement with this mic then this is more complexe, but you have two choices:
    1- you buy a DEQ2496 and rely on its frequency response analyser (not very precise...)
    2- you buy a usb sound card for your computer, with an integrated mic preamp and phatom power (the ECM8000 needs some power), and you install a free measurement sofware such as holm impulse. This is much more precise than a DEQ2496, but also much more complex...

  6. #96
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    sorry I meant ECM8000 not EMC8000 :
    http://www.behringer.com/EN/Products/ECM8000.aspx

    If you want to do time alignement (delays on each driver to get them time-aligned at the crossover frequencies) you jsut need to plug it into the 'C' input of your DCX2496.

    If you want to do real response measurement with this mic then this is more complexe, but you have two choices:
    1- you buy a DEQ2496 and rely on its frequency response analyser (not very precise...)
    2- you buy a usb sound card for your computer, with an integrated mic preamp and phatom power (the ECM8000 needs some power), and you install a free measurement sofware such as holm impulse. This is much more precise than a DEQ2496, but also much more complex...
    I heard that Bag-end comany have this technology,is this T-A very important for my 4628B?
    I think that how to coordinate every drivers sound level in 4628B when active crossover and tri-amp is more important for me.Is that right?
    46 lover

  7. #97
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628
    yes you are right, level matching is much more important.
    Also, if you go active and remove all passive parts, put a cap in serie with your 2404s to protect them in case of problem (bad parameters on DCX, amp problem, ...). Something around 15uF or 20uF should be good.

  8. #98
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    yes you are right, level matching is much more important.
    Also, if you go active and remove all passive parts, put a cap in serie with your 2404s to protect them in case of problem (bad parameters on DCX, amp problem, ...). Something around 15uF or 20uF should be good.
    Thanks for your remindering!
    Then how to match these drivers level?By what method?
    46 lover

  9. #99
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628
    measurement with a PC is the best method, but with a simple SPL meter and some test signals (from a PC or a test CD) you can already do basic level adjustments.

  10. #100
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    measurement with a PC is the best method, but with a simple SPL meter and some test signals (from a PC or a test CD) you can already do basic level adjustments.
    Pos,could you please give me some more detailed information on this?some examples\some threads on this forum.
    Thank you
    Martin
    46 lover

  11. #101
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628
    You can plug your PC to your sound system and use WinISD to generate some test tones at different frequencies, and then you can use any SPL meter to check the resulting SPL trough your speakers.

    First thing would be to connect all the drivers directly to amp (with a protection cap on the 2404), and dial the same crossover point as the original 4628 passive network in the DCX2496, with LR24 slopes as a start (800khz et 3khz I think?)
    Then you plug you computer to the DCX2496 inpout, and try different test frequencies in the mid band of each driver (lets say 400Hz for the E145, 1.5khz for the 2118, and 6khz for the 2404), and you adjust your amplifiers to get the same SPL for each on the SPL meter (same position, lets say 2m from the speaker, at ear level).

    When that is done you knwo your levels are ok and the system should sound similar to its passive version, and you can start tweaking...

  12. #102
    Senior Member ratitifb's Avatar
    Join Date
    Feb 2006
    Location
    France
    Posts
    653
    Quote Originally Posted by pos View Post
    and try different test frequencies in the mid band of each driver (lets say 400Hz for the E145, 1.5khz for the 2118, and 6khz for the 2404), and you adjust your amplifiers to get the same SPL for each on the SPL meter (same position, lets say 2m from the speaker, at ear level)...
    i'm afraid when using pure tones in a non anéchoïc room It'll be preferable to generate narrow band noise centered on the frequencies you have suggested

  13. #103
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    France
    Posts
    2,628

    Lightbulb

    yes you are right. At least all these frequencies are likely to be above the schroeder frequency in martin's room, so that should not be that bad, but larger band signals would definitely be safer.
    Can you suggest a software that would easily generate these band noise signals?

  14. #104
    Senior Member ratitifb's Avatar
    Join Date
    Feb 2006
    Location
    France
    Posts
    653
    Quote Originally Posted by pos View Post
    Can you suggest a software that would easily generate these band noise signals?
    Adobe audition (Cool Edit Pro in the past ...)

  15. #105
    Senior Member martin_wu99's Avatar
    Join Date
    Jul 2007
    Location
    Xi'An,China
    Posts
    1,479
    Quote Originally Posted by pos View Post
    yes you are right, level matching is much more important.
    Also, if you go active and remove all passive parts, put a cap in serie with your 2404s to protect them in case of problem (bad parameters on DCX, amp problem, ...). Something around 15uF or 20uF should be good.
    Pos,I‘v made six balanced cables for active crossovering my 4628B in my spare time,but still lack two 15-20uF caps,what's the votage of the caps?Do they have to in serie with 2404s permanently?

    Thank you

    Martin
    46 lover

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Response Curve for LE-14A, H
    By muddyspeaker in forum Lansing Product Technical Help
    Replies: 0
    Last Post: 01-24-2005, 11:18 PM
  2. 4315A Impedance Curve?
    By johnaec in forum Lansing Product Technical Help
    Replies: 10
    Last Post: 12-01-2004, 11:56 PM
  3. JBL LE15A Weird Impedance Curve - Need advice
    By scorpio in forum Lansing Product Technical Help
    Replies: 3
    Last Post: 08-09-2004, 12:54 PM
  4. 2426/2370 response curve file
    By sebackman in forum Lansing Product Technical Help
    Replies: 0
    Last Post: 02-22-2004, 07:44 AM
  5. 077 impedance curve
    By stimpiew in forum Lansing Product Technical Help
    Replies: 5
    Last Post: 05-28-2003, 11:01 AM

Posting Permissions

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