Page 1 of 2 12 LastLast
Results 1 to 15 of 26

Thread: Sub Question....

  1. #1
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181

    Sub Question....

    Ok I have a couple questions for the pro's here. I have a three way horn system, half JBL half other's. I have a mid-bass (100hz-500hz), cd horn 500hz-rolled off), tweeter (6000K + ). For subs I have 2 2235's. I put them into a pair of L45 flair cabs and blocked the holes just to test them, but am unsure how to wire them into the system. My preamp only has one output and I tried the tape out into a cheapo electronic car crossover at 100hz. Problem is they sound mushy and I can't blend them at all with my other drivers. I want to blend both subs into the stereo . I have a 200 watt Acoustat TNT amp for output. I also tried an integrated amp and plugged into an aux input from the crossover and used the volume knob for gain but things got mushy.



    Any ideas here...is the crossover the problem, the cabs or using the tape out, or all three?

    I really new to this so please bare with me.

  2. #2
    RIP 2010 scott fitlin's Avatar
    Join Date
    Apr 2003
    Location
    Brooklyn NY
    Posts
    4,343
    You have two problems, the first and foremost is you arent getting a proper signal to the xover from the tape out, you need a master out to supply the requisite preamplified signal and drive level. Second is the crossover, car crossovers are generally inexpensive and not so great. The proper xover will have better drive, cleaner signal, and better, make that far better accuracy.

    For a crossover I can recommend several models, depending on your budget.

    If you really want to do this economically, and get really nice sound, you can get a Crown VFX-2A off Ebay. Then you can cross your subs over at 100hz, and overlap your full range wherever you wish. You can let the full range cabs run all the way down, or to 40hz or 30hz, or whatever you choose. The VFX also has balanced ins with user definable gain, that comes in handy, too. You will have to use your amplifier input level controls, as the VFX has no output level attenuators, but this will work.

    And yes, I agree with Zilch, you do want to run your subs in stereo!
    scottyj

  3. #3
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    From L45 Flair dimensions, BB6P calculates a box just over 5 cuft.

    If you've closed off all openings, inculding the ports, you're running closed box, the black curve below.

    BB6P suggests tuning that box to 24.6 Hz (red). A single 4" ducted port 7.25" long will do that.

    If you have the ports closed off, open them. I don't know what size or length port is in L45, but if you'd measure it, I can determine the present tuning, which may be just fine.

    Tape outs should run them through your additional amp, but you'll have to control the volume separately with that. You also need a crossover, as you already know.

    Ideally, your single preamp out should go to an active crossover like M552 or 5235 running your two amps.

    Also, everything has to be phased correctly for them to blend worth a whit....
    Attached Images Attached Images  

  4. #4
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Quote Originally Posted by lpd
    I have a 200 watt Acoustat TNT amp for output. I also tried an integrated amp and plugged into an aux input from the crossover and used the volume knob for gain but things got mushy.
    You plugged into the aux input from what crossover? The cheapo car audio one? I don't get that. Is it an active crossover? How is it powered?

    Is the Acoustat a stereo amp? You'll want to run the subs in stereo, if possible....

  5. #5
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181
    Zilch,
    Thanks for the reply. There are ports in the cabs that are 6" X 8" in length. All other holes have been covered. Is the port too big?

    I have two outputs on my cd player as well which can be used at the same time (its a McIntosh MCD7007). I used the variable into my pre into the amp for the three way horns. I used the fixed output into the car xo and then into the Acoustat amp to the subs in stereo. I also tried the tape output on the preamp, but the only way I can control the volume of the subs is with the xo levels which aren't very accurate to say the least. I'm powering the xo with an adapter. Any thoughts on the 5234A crossover? I hvae one but the cards I have are 1.1K. Would it suffice or should I look for a 5235?

    Thanks

    peter

  6. #6
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Quote Originally Posted by lpd
    There are ports in the cabs that are 6" X 8" in length. All other holes have been covered. Is the port too big?
    6" diameter? Are you sure? 'Cause it looks more like 3" or 4" in this pic:

    http://www.lansingheritage.org/image...-l45/page3.jpg

    5234A is fine. You need to find or make some 80/100 Hz cards for it. 12 dB/octave would be best. A forum member may be able to provide blank cards for you.

    I'd think at this point your problem is the crappy crossover, and the fact that you have no high-pass on the three-way, plus possible phase issues.

    Somebody says "Mushy," first thing I think is phase....

    [Zilch don't wear no lab coat. Nope. ]

  7. #7
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    8,170
    6" diameter? Are you sure? 'Cause it looks more like 3" or 4" in this pic:
    Hello Zilch

    You could but a half dozen systems in that cabinet. Depends on the woofer installed as you know.

    Hello Peter

    Is that a 12V active crossover??? What slopes?? High and low pass ?? You should be able to drop the crossover in between the amps after the preamp just like the 5234 you plan on using. With 100Hz crossover and those woofers in phase you are going to have a good amount of coupling going on if they are staked or close enough to each other. You get coupling and boost around 100Hz and it certainly does muddy things up a bit especially if the crossover doesn't roll off the midbass box. Where does your 100Hz box roll off??? Is the box good to say 60Hz or so?? Where is the F3??? With room loading you may be getting a significant amount of additional extension from that box even if sealed. 12dB could do it, you can certainly try I would look for a set of 18Db cards if the 12dB doesn't work. I know it didn't work for me in my application I ended up using a 24Db network. How are you setting this all up?? You have something to measure it with???

    Rob

  8. #8
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181
    Quote Originally Posted by Robh3606
    Hello Zilch

    You could but a half dozen systems in that cabinet. Depends on the woofer installed as you know.

    Hello Peter

    Is that a 12V active crossover??? What slopes?? High and low pass ?? You should be able to drop the crossover in between the amps after the preamp just like the 5234 you plan on using. With 100Hz crossover and those woofers in phase you are going to have a good amount of coupling going on if they are staked or close enough to each other. You get coupling and boost around 100Hz and it certainly does muddy things up a bit especially if the crossover doesn't roll off the midbass box. Where does your 100Hz box roll off??? Is the box good to say 60Hz or so?? Where is the F3??? With room loading you may be getting a significant amount of additional extension from that box even if sealed. 12dB could do it, you can certainly try I would look for a set of 18Db cards if the 12dB doesn't work. I know it didn't work for me in my application I ended up using a 24Db network. How are you setting this all up?? You have something to measure it with???

    Rob
    Rob,
    It is a 12V crossover, until I find a set of cards for the 5234A or another sub crossover that is more useful. Slopes....not sure about those specs. The room is a rectangle with the three ways on the long wall centered on the wall about 7 feet apart. One sub is on a short wall corner loaded about 16 inches from the back wall and the other is on the same wall as the three ways, but 2 feet on the side of the right three way horn setup. I have the crossover set at 100hz. Three ways are good to about 80 hz I think, but I have no measuring tool to really tell. F3???? Not sure what this is. The midbass horn has a port its like a smaller version of an A7 with a port on top. I plugged the port to remove some of the rolloff/muddiness. Plroblem is I don't have a tool to set it up...any suggestions?

    I also moved the one sub on the one corner of the short wall to the otherside which really smoothed things up. Placing two subs is much trickier than I thought...any ideas here?

    Cheers,

    thanks Zilch/Rob!!!

  9. #9
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Quote Originally Posted by Robh3606
    You could but a half dozen systems in that cabinet. Depends on the woofer installed as you know.
    If it's 6" diameter, they're tuned to ~33.5 Hz according to BB6P, i.e., more like 4430, a good tuning for 2235H, of course, but not a sub.

    I'd look to installing the 4" diameter tube (ABS pipe here, typically,) inside the present port, or in one of the other holes, preferably in a reversible manner....

  10. #10
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181
    I'll check the port and get back to you. Maybe I'm wrong on the measurements. If not I'll try to install a 4 inch one and see what happens.

    cheers,

    peter

  11. #11
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181
    Port is 4" and 9" inches in length. Should I take an inch or two off or leave it as is.

  12. #12
    RIP 2011 Zilch's Avatar
    Join Date
    Jun 2004
    Location
    Berkeley, CA
    Posts
    9,963
    Leave it. You're tuned to ~23 Hz, good for sub to 75 W, 112 dB @ 30 Hz.

    Also, I'm looking up the cards for your crossover, and I find that you'll have to load your own for 100 Hz. The proper component values are in the manual.

    The only "standard" one listed for sub is 80 Hz, 18 dB, which I use here myself....

  13. #13
    Obsolete
    Join Date
    Apr 2003
    Location
    NLA
    Posts
    12,193
    Quote Originally Posted by Zilch
    they're tuned to ~33.5 Hz according to BB6P, i.e., more like 4430, a good tuning for 2235H, of course,
    Some things I just can't sit by and watch transpire. Where is the thumbs down emoticon? I think I've posted at least a dozen times to tune the 2235H in the 28 Hz to 30 Hz range. There's a long history of trying all kinds of volumes and tunings with this driver over the past 26 years and that's pretty much where it all shakes out. Tuning aggressively like the stock 4430 never seems to work real well in the typical room and tuning too low ends up with smacked mass rings and torn suspensions. Of course, feel free to do whatever you want when the day is done.

    Have you heard the crack of your mass rings today?

  14. #14
    Senior Member lpd's Avatar
    Join Date
    Jun 2003
    Location
    Beautiful BC
    Posts
    181
    Quote Originally Posted by Giskard
    Some things I just can't sit by and watch transpire. Where is the thumbs down emoticon? I think I've posted at least a dozen times to tune the 2235H in the 28 Hz to 30 Hz range. There's a long history of trying all kinds of volumes and tunings with this driver over the past 26 years and that's pretty much where it all shakes out. Tuning aggressively like the stock 4430 never seems to work real well in the typical room and tuning too low ends up with smacked mass rings and torn suspensions. Of course, feel free to do whatever you want when the day is done.

    Have you heard the crack of your mass rings today?
    Well you can't give me @@$#@ without an explanation of how to tune the 2235 to 28-30hz hehe I don't have a clue what to do. I appreciate your thoughts on this.

  15. #15
    Obsolete
    Join Date
    Apr 2003
    Location
    NLA
    Posts
    12,193
    Here is a pretty easy way for a DIYer to tune a box.

    http://www.danmarx.org/audioinnovation/impanalyzer.html

    Dan put that article together years ago and it's basically how we had to do it back in the old days when dinosaurs roamed freely and computer time cost big bucks.

    You can also pick up http://www.partsexpress.com/pe/showd...number=390-802

    These techniques should be in any DIYers repertoire. Start simple and read http://www.lansingheritage.org/html/...979-manual.htm and http://www.lansingheritage.org/html/...enc-manual.htm

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. LE15 Surround Question / compression Driver question
    By mech986 in forum Lansing Product Technical Help
    Replies: 5
    Last Post: 05-20-2006, 03:53 PM
  2. A serious question.
    By Rolf in forum Forum Feedback
    Replies: 61
    Last Post: 04-05-2006, 02:20 PM
  3. Question re: Olympus Speaker Ports(?)
    By henflet in forum Lansing Product General Information
    Replies: 3
    Last Post: 01-19-2006, 12:03 PM
  4. Non-Searching Newbie Question solution?
    By Regis in forum Forum Feedback
    Replies: 7
    Last Post: 05-04-2005, 07:12 PM
  5. JBL 3110 crossover question and aftermarket diaphragm report
    By molecularman in forum Lansing Product Technical Help
    Replies: 4
    Last Post: 04-24-2005, 07:51 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
  •