Page 2 of 3 FirstFirst 123 LastLast
Results 16 to 30 of 33

Thread: DingDing goes DIY: JBL 2404 mounted inside or outside 2360A and one or two 2123?

  1. #16
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182
    Quote Originally Posted by 1audiohack View Post
    The single pole low pass on a dual woofer system can be a good idea depending on several factors including the upper crossover point and the physical seperation of the drivers involved.

    If you have each woofer on a seperate DSP channel that you can also manipulate the delay between them you can really have some tuning fun.

    I think everyone should build a five way active system at least once but beware, if you don't have some measurement equipment and know how to use it, the probability for frustration seems to multiply by an order of magnitude with each element added.

    Barry.
    That's motivating to read

    The goal is to have the drivers closely together so they connect acoustically, but at the same time there's the visual aspect of having some distance between them (plus symmetry). With Everest and 4435 the distance between the drivers is pretty big. IIRC one of the 4435 woofers are crossed over @ 1khz while the the other comes in @ 100 Hz. If 2123 is incorporated 2226 will never see 1khz besides while rolling off, maybe 300-400 at most, so it may be a better idea to just run both in the same passband due to the low XO in the first place?

    Because of miniDSP it will be fairly easy to try. The drivers will have a separate channel and be time aligned using REW and a calibrated Dayton EMM-6 mic using a soundcard with loopback connection to get correct timing information. Already have that measurement setup and an UMIK-1. Have not done a lot of gated measurements, so that's a hurdle that needs to be won. If the weather is good I can do it outside to get a bigger window.

    Oh yes, this is a big undertaking for someone with my lack of knowledge and it's the first speaker build. At the same time that's part of the challenge and what makes it educational and fun. It may very well be that the sound sucks and I lose some hair over it, but that's OK as long as the project has been educational.

    In the middle of the 4343 restoration and will begin this project once that's done. Was hoping to post some Sketchup drawings and see what you guys think and when the speakers are built I could post measurements and get some guidance on what to do/try given response, phase and so on. If it goes belly up, my 6 cats will have two great houses to play in.

  2. #17
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182
    Quick questions regarding distance from 2123 to 2226.

    Assuming 343m/s speed of sound, and xo @ 400 hz => wavelength = 343/400 = 0.8575m.

    It has to be within 1/4 the wavelength to connect acoustically, right? So that would be 21.5 cm from the acoustic centers of the drivers. That's fairly close.

    Does it need to be 21.5cm from both drivers, or the average distance between them in relation to 2123? Can make a drawing if that question is unclear.

    Is it correct to use the XO point as a basis for calculating maximum distance between drivers? As the drivers overlap after the xo the distance will obviously change with frequency and can and will create lobing, right?

    Can delay in the digital domain do anything to this particular problem within some constraint? Two drivers 10m apart can't sound like one driver no matter how much delay (if you're in the middle) obviously, but if we're talking about 10-20cm off from the maximum distance, will it work well?

  3. #18
    J.A.F.S.
    Join Date
    Aug 2005
    Location
    Back in the audio lab.
    Posts
    382

    Thanks!

    miniDSP is what it is, a super flexible and afforable step stone into active crossover and DSP for the noob. Sonically it's good enough for me, it lacks a display, is very unstable below 25 Hz when you run the 96kHz plugin due to rounding errors in the lower frequencies. It's more stable, but not perfect when running 48 khz plugin. This is important when you're setting your high pass filters, because the unstable filters will give you an overshoot, especially grotesque with steeper filters. Build quality is a little cheap, the software can be quirky sometimes. The lower models are very prone to noise judging from endless threads around the web. The 4x10 HD is also a bit prone to noise, but I'm using passive attenuators line level. You lose a bit of headroom, but a black background is worth it. Furthermore, the output impedance is rather high with 560 ohms. One positive thing is that you can correct things in real time, with other alternatives you have to upload a file everytime you make a change. Having two is a bit of a problem, since you can't operate them simultanously from the same PC. The software doesn't understand that you're trying to communicate with another device etc, but this is not an issue for most people as they're only using one.

    I have learned a lot by using miniDSP and REW. I would not be able to do things like this if it was not for this technology, so I'm very happy. That being said, I will eventually move over to a multi channel dac such as Antelope Orion 32 or Lynx Aurora 16 with a computer to make for even more control. There are options for EQ and filters using open source Equalizer APO under windows, or you can use proprietary software such as Audiolense XO to make FIR filters and use JRiver as a convolver. pos in here also made RePhase which can be used to make FIR filters manually. And he is giving it away for free.

    All in all, I think miniDSP 4x10HD is very good for the price, but as far as build quality and attention to detail (such as scalability with several units) it falls through a bit. The instability is also a concern, but the option is that they limit filters to around 20 Hz, and we don't want that. It's better to measure an output and try to extrapolate the correct settings while doing that, as the actual filter you get is not what you see in the GUI. The biquad filters are also awesome, for example if your doing a linkwitz transform or other custom filters. They will be in my system until I get a more advanced setup though, which won't be anytime soon, so yes, I think it's a great device. The company is also very professional in dealing with you.

    Woha, that turned out to be a ramble. Hope it makes sense... LOL.[/QUOTE]

    Thanks for the detailed reply!
    Amazed I'm still alive!
    Tim

  4. #19
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182

    Aluminum in 2446, which diaphragm should I get?

    ^ YW!

    ---

    Just read Truextent's white paper on beryllium vs aluminum vs titanium vs ribbed titanium in large format compression drivers, and was quite pleased to see the performance of the aluminum diaphragms. My 2446 drivers are using ribbed titanium now and looking at the spectral decay in those measurments I think it's quite clear why they are a little hard sounding. The paper seem to favor Be in applications where you're going to boost the high end because of more output and smoother response, but the decay plots indicate that if you're going to use this driver between 1.5-8/10khz range you get very uniform decay with aluminum. This is great news as they are not that costly.

    What aluminum diaphragm would you guys pick for 2446? Wanting to stay clear of ribbed ones judging from the paper.

    Is Radian 1245-8 Diaphragm worth giving a shot?

  5. #20
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,705
    For aluminum, the genuine JBL article, the D16R2441.

    Now that said, if you use aluminum, and if you are not going to run a super tweeter, the lack of that "extra energy" of a ribbed 2450 diaphragm will require you add even more EQ to the top end and in my experience this sounds even more strained than the "noisy" 2450 diaphragms do.

    Are you using a protection capacitor on the 2446's? A 10uF on an 8 Ohm version or a 20uF on a 16 Ohm will get about 6dB out of the mid band and lessen the EQ requirements for the top octave while offering some protection in the process, cheap, easy, and to me it sounds better than 18dB of boost on top.

    If you are for sure going to use 2404's or 2405's with them you could use D16R2440's (still available new) in them and they willl just shut off about 9.5kHz by themselves. That's really about where that long parellel wall slot in a 2360 starts to sound rough anyway. Integrating a 2405 (what I would use) with a 2360 really well is a challenge but this is the combination I liked the best. I have done all of the above by the way.

    It seems no one tests the coated smooth Ti SL's (D16R2450SL) or the D8475Nd diaphragms. Ever wonder why?

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  6. #21
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182
    Quote Originally Posted by 1audiohack View Post
    For aluminum, the genuine JBL article, the D16R2441.

    Now that said, if you use aluminum, and if you are not going to run a super tweeter, the lack of that "extra energy" of a ribbed 2450 diaphragm will require you add even more EQ to the top end and in my experience this sounds even more strained than the "noisy" 2450 diaphragms do.

    Are you using a protection capacitor on the 2446's? A 10uF on an 8 Ohm version or a 20uF on a 16 Ohm will get about 6dB out of the mid band and lessen the EQ requirements for the top octave while offering some protection in the process, cheap, easy, and to me it sounds better than 18dB of boost on top.

    If you are for sure going to use 2404's or 2405's with them you could use D16R2440's (still available new) in them and they willl just shut off about 9.5kHz by themselves. That's really about where that long parellel wall slot in a 2360 starts to sound rough anyway. Integrating a 2405 (what I would use) with a 2360 really well is a challenge but this is the combination I liked the best. I have done all of the above by the way.

    It seems no one tests the coated smooth Ti SL's (D16R2450SL) or the D8475Nd diaphragms. Ever wonder why?

    Barry.
    Wow! Thank you! You sure know your stuff This is a new world for me and the rabbit hole goes deep too, you even match the numbers on the diaphragm to the driver and optimize the position. Yikes! Based on your response here I found another thread you were active in, namely this one: http://www.audioheritage.org/vbullet...in-2445-driver where you describe the matching and optimizing process.

    It looks like the D16R2441 is preferred to the D16R2440 because of the versatility of more hf output. No need to have the driver roll of earlier and the added sensitivity of the latter is not all that important in a home environment I assume, especially when you can lowpass it digitally anyways? Another thing would be if 2360A is replaced with something else and you want some extra wiggle room for the xo. That's an argument to just get the Truext. Be too...

    No protection, no kids, Not long since I got them and been running without a cap. Been reading up on cap or no cap, and a lot of folks have run without it for years and have had no problems. When my amps power off, I simply let the music play and they slowly fade out, so no dc, crackle or pop when turned on or off. Protecting against power outtage, maybe put a UPS on that amp.

    Really tempted to give the D16R2441 a try. Seem like they hoover around $200 each new from various retailers, maybe possible to get a used pair in the marketplace here too.

    2405 really "belongs" in 4343, but I can use it to see how it fares compared to 2404 and get a second pair if they're that much better. Some people say they prefer 2404 with 2360A, so hoping for that.

    All this being new, guessing based on that other thread the D16R2450SL may not be popular because of the added mass of the aquaplas and as a result possibly poorer impulse response?

  7. #22
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,705
    Hi;

    I don't run caps for protection either, not even on my Be loaded drivers but on these large format constant directivity horns I find that they sound better to me with a single cap sized right for some mid band attenuation and less agressive EQ.

    If you look at the directivity charts for the 2360 you will note the collapse in the vertical response to about 20-25 degrees above 10kHz. You can use a 2404 crossed in right about 9-10kHz to maintain the directivity but it is just hard to get a 100X100 degree super tweeter to play that loud and do you really need that energy bouncing off the ceiling? This is about the vertical dispersion pattern of a 2405 at 10K anyway and since you can't really use a 2404 in the center of the mouth of the 2360, I have had better luck integrating the 2405. Below the 2360 as you have pictured.

    It is of interest to me that JBL used the D8R475 in the M9500 horn in a 2450 motor with no super tweeter, in a statement speaker system. They measure and sound very good too. I am not trying to sell you anything, it is just my opinion that those diapragms are dynamite for Only $210.ea USD.

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  8. #23
    Senior Member audiomagnate's Avatar
    Join Date
    Jan 2011
    Location
    Colorado and Georgia
    Posts
    1,014
    Quote Originally Posted by 1audiohack View Post
    Hi;

    I don't run caps for protection either, not even on my Be loaded drivers but on these large format constant directivity horns I find that they sound better to me with a single cap sized right for some mid band attenuation and less agressive EQ.

    If you look at the directivity charts for the 2360 you will note the collapse in the vertical response to about 20-25 degrees above 10kHz. You can use a 2404 crossed in right about 9-10kHz to maintain the directivity but it is just hard to get a 100X100 degree super tweeter to play that loud and do you really need that energy bouncing off the ceiling? This is about the vertical dispersion pattern of a 2405 at 10K anyway and since you can't really use a 2404 in the center of the mouth of the 2360, I have had better luck integrating the 2405. Below the 2360 as you have pictured.

    It is of interest to me that JBL used the D8R475 in the M9500 horn in a 2450 motor with no super tweeter, in a statement speaker system. They measure and sound very good too. I am not trying to sell you anything, it is just my opinion that those diapragms are dynamite for Only $210.ea USD.

    Barry.
    Just a data point, I don't use protection caps because I have tested both ways and I swear they change the sound. I have had an active four way system without protection for years and never had a problem. I'm careful and no one else touches my system.

  9. #24
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182
    Quote Originally Posted by 1audiohack View Post
    Hi;

    I don't run caps for protection either, not even on my Be loaded drivers but on these large format constant directivity horns I find that they sound better to me with a single cap sized right for some mid band attenuation and less agressive EQ.

    If you look at the directivity charts for the 2360 you will note the collapse in the vertical response to about 20-25 degrees above 10kHz. You can use a 2404 crossed in right about 9-10kHz to maintain the directivity but it is just hard to get a 100X100 degree super tweeter to play that loud and do you really need that energy bouncing off the ceiling? This is about the vertical dispersion pattern of a 2405 at 10K anyway and since you can't really use a 2404 in the center of the mouth of the 2360, I have had better luck integrating the 2405. Below the 2360 as you have pictured.

    It is of interest to me that JBL used the D8R475 in the M9500 horn in a 2450 motor with no super tweeter, in a statement speaker system. They measure and sound very good too. I am not trying to sell you anything, it is just my opinion that those diapragms are dynamite for Only $210.ea USD.

    Barry.
    Ok, will try with and without a cap then. Was not intending to use a cap even if Be is chosen because of what audiomagnate says in regards to SQ. It would suck big time if they were blown, but at the same time YOLO and it feels wrong to spend that much money to get the best diaphragm and limit the result with a cap.

    Good points regarding the vertical dispersion and integration of the tweeters, had not thought about that.

    The reason I got 2360A was that they came with the 2446's and was a bargain, about $170 each with the original 2506b brackets and everything. All in very good condition too, although the horns have some minor scratches and stuff which will be fixed before spraying. Point being that 2360 may be substituted for something else, as I was really after the 2446 drivers. This makes me inclined to jump on the Be diaphragms, because those will give more flexibility if this project fails and the drivers will be used in another application where more hf output is preferred. It seems like most people gravitate towards those diaphragms and everything else is just a temporary stop. Trying out a bunch of different ones may well become more expensive than just getting the best sooner rather than later?

    D8R475 is interesting too, but I must admit that the most enticing to me right now is your recommendation for D16R2441 and ofc. Truextent's Be. D16R2441 because both 4343 (w/2420) and 4430 (w/2421A) use aluminum and I really like the sound from those. Be because I've yet to see one negative thing mentioned about them except for the price.

  10. #25
    Senior Member ivica's Avatar
    Join Date
    Jan 2008
    Location
    serbia
    Posts
    1,633
    Quote Originally Posted by 1audiohack View Post
    For aluminum, the genuine JBL article, the D16R2441.

    Now that said, if you use aluminum, and if you are not going to run a super tweeter, the lack of that "extra energy" of a ribbed 2450 diaphragm will require you add even more EQ to the top end and in my experience this sounds even more strained than the "noisy" 2450 diaphragms do.

    Are you using a protection capacitor on the 2446's? A 10uF on an 8 Ohm version or a 20uF on a 16 Ohm will get about 6dB out of the mid band and lessen the EQ requirements for the top octave while offering some protection in the process, cheap, easy, and to me it sounds better than 18dB of boost on top.

    ...

    It seems no one tests the coated smooth Ti SL's (D16R2450SL) or the D8475Nd diaphragms. Ever wonder why?

    Barry.
    Hi Barry,

    Very interesting experience and suggested way of using CD horns with 4" diaphragm JBL driver.
    Especially as You prefer 2450 ribbed Ti vs 2441 aluminum (either used without UHF driver).
    What about 2445 (non-ribbed) Ti diaphragm ? Is it somewhere "in-between" these two ?
    Some of the measurements I have done either SL or Be (Trex) decline the FR response over 10kHz more
    rapidly, so I believe that the large amount of EQ would be needed if wanted to reach 16kHz.
    Ribbed diaphragm seems to operate up to 12~13kHz before break, I wonder what would be their behaviors
    if being SL-coated.


    regards
    ivica

  11. #26
    Senior Member
    Join Date
    Jun 2013
    Location
    wny
    Posts
    107
    I'm doing the same thing. I am gonna try 2 x 2404's under ea 2360 .

  12. #27
    Senior Member
    Join Date
    Sep 2013
    Location
    Flat Earth
    Posts
    182
    Quote Originally Posted by dezmond View Post
    I'm doing the same thing. I am gonna try 2 x 2404's under ea 2360 .
    How will you mount them? I was thinking about making some sort of wooden jig that can be attached to the holes in the 2360 and then have 2404 mounted to that.

    Basic concept

    Name:  2404-mount.png
Views: 341
Size:  4.9 KB

    This way the cables for 2404 can be hidden behind 2360. Have also been thinking about making the mounting piece for 2404 detachable from the 2360 mount so I can make new ones depending on the driver I end up with. Maybe also allow for rotation to adjust positioning through measurements from sweetspot.

  13. #28
    Senior Member
    Join Date
    Jun 2013
    Location
    wny
    Posts
    107
    I will show a picture later tonight. I have them on each side of the 2506b bracket tilted down slightly. I am using jbl as4731 cabinets .

  14. #29
    Senior Member
    Join Date
    Jun 2013
    Location
    wny
    Posts
    107
    Here some pictures -
    Attached Images Attached Images    

  15. #30
    Senior Member
    Join Date
    Jun 2013
    Location
    wny
    Posts
    107
    Not saying its the best way, just trying it like this.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2397's mounted inside an enclosure?
    By Doc Mark in forum Lansing Product General Information
    Replies: 11
    Last Post: 12-13-2013, 07:28 AM
  2. 811b mounted verticaly
    By rudy sesztak in forum Lansing Product DIY Forum
    Replies: 3
    Last Post: 05-13-2011, 06:47 AM
  3. Rear Mounted Port Tube Location
    By Uncle Paul in forum General Audio Discussion
    Replies: 11
    Last Post: 09-18-2005, 08:41 AM
  4. Side mounted woofers/subs
    By Robh3606 in forum Lansing Product DIY Forum
    Replies: 1
    Last Post: 08-22-2003, 02:06 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
  •