BWC (Big Woofer Club): Why Big Woofers Matter

Discussion in 'Speakers' started by nishan99, Aug 5, 2020.

  1. spwath

    spwath Hijinks master cum laudle

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    Ok, so I need some actual advice, so coming to this thread.
    I have a pair of eminence kappa 15 woofers laying around. I think it's about time to make an open baffle speaker with them.
    I have a nice pair of scanspeak 1" tweeters from YG acoustics. I would think all I need is some sort of mid. Thoughts on a mid driver for these open baffle speakers?

    I also have my altec horns with Emilar drivers but those are currently in use in my party speakers.
     
  2. Priidik

    Priidik MOT: Estelon

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    There are wide selection of 6'' PA drivers. Get something that has smooth response.
    Also check this out, if you haven't:
    http://www.troelsgravesen.dk/midrange-drivers.htm
     
  3. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    going passive or active?
     
  4. bixby

    bixby Friend

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    @k4rstar Just saw your Heresy post above. Any thoughts on budget acceptable subs for something like those?
     
  5. Josh83

    Josh83 Friend

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    Has anyone heard the JBL L100 Classic? Are they any good?

    I’ve always been curious about them and trying a more efficient speaker, in general. I listen in a monitor-type setup with KEF Ref1s and an SVS sub. I’m only a few feet away from the speakers, so I don’t know if something like the L100 just wouldn’t work right at that distance given the space between the drivers.
     
  6. spwath

    spwath Hijinks master cum laudle

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    Probably passive due to money/less components.
    Ok I'll check that out
     
  7. purr1n

    purr1n Desire for betterer is endless.

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    Lots of stuff moved here to a separate thread. Will be writing a forward to the original post from @nishan99
     
  8. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    are you sure the eminence woofer and the scanspeaker tweeter are the same efficiency?
     
  9. spwath

    spwath Hijinks master cum laudle

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    No, but that could be fixed with an l pad or something right?
     
  10. k4rstar

    k4rstar Britney fan club president

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    if you mean the new ones, they are a big rip-off. a vintage pair of L100 Century for <1k is the way to go for that 70s JBL rock sound.
     
  11. purr1n

    purr1n Desire for betterer is endless.

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    Indeed that is their philosophy, even in the pro market. They want to keep efficiency up but are willing to trade bass extension to do this. A typical 12" model from JBL will get no deeper extension than a 7"-8" model from a consumer audiophile brand. However that 12" is going to be at least 6db more efficient with much lower distortion.

    JBL gets "around" this lack of deep bass extension with ever larger woofers, up to 18" in the pro market. Heck, even their cinema subwoofers are usually rated only down to 22Hz-25Hz as the -3db point. It could be that JBL is less prone to bullshit on their specs, but it does point out their approach.

    I believe JBL's philosophy is the correct one. Most music won't have much below 35Hz. Theatrical content maybe 25Hz. I shudder that Stereophile requires 20Hz extension for their speakers to be in their full Class A Recommended List.

    ORFAS Perpetuating Self Interest.
     
  12. k4rstar

    k4rstar Britney fan club president

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    I didn't know anything about subs when I went shopping for one, except that new ones didn't fit my needs or were overpriced. they don't hold their value very well considering most of them cannot be shipped, so used is the way to go

    I made the following wishlist:
    • 12 or 15in. woofer (despite the title of this thread, this is actually not mandatory. for Heresy we are just wanting a bit of extension and kick to 'relieve' the mains. but I have a large space, for a small space 8 or 10in. sub will also work)
    • class AB amp (because class D sounds like damp poopoo)
    • line level inputs (because I have a pre-amp with an extra set of line outs and wanted to make use of them)
    • good cabinet construction (self explanatory, this is the worst part of a cheap sub)
    • adjustable crossover and output level (the most important point, as it allows us easier setup and using the sub with different speakers)
    once I had my wishlist I went on audiomart and found something that ticked all the boxes, which happened to be a miller&kreisler V75 mkII. M&K is/was a HT company but this sub had good reviews for its day and was USA-made, I found a pair for a bargain price. it was also large enough to plop the Heresy on top of it as a stand, using some hockey pucks and blu-tack for decoupling to make a weird quasi 4-way, but it sounded good!

    this is all I have. my friend doctorjohn uses and likes the Pioneer SW-8 with his Heresy's in the living room. I am not sure if they are still sold https://www.newegg.com/pioneer-sw-8-k/p/N82E16882117402

    there is probably way more useful information on this on the klipsch community forum
     
    Last edited: Aug 8, 2020
  13. purr1n

    purr1n Desire for betterer is endless.

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    LOL, you are probably SOL. The JBLs I have with the 18" woofers ($5000 in 1985) will just cover 35Hz (-3db point), just 3Hz below the 37Hz fundamental of the lowest bass drop on Daft Punk's Doin' It Right. Below that, it drops like a rock. Yes, that's from an 18". However bass is glorious: tight, lean, and mean - sublimely tactile and palpable. Super easy to hear how DACs f**k up in the bass compared to $40k speakers with an array of 9" woofers.

    [​IMG]

    The approach I would take is to grab the big efficient low distortion stuff, even if it only goes down to 47Hz, and cover everything below with a cheap used sub with a steep xover. Of course it's better to get a high quality x2 18" sub, but prioritizing for a budget here. It's easy to throw money at the problem. On a budget, I don't mind sacrificing bass quality below 50Hz to have better bass quality from 50Hz to 250Hz. In fact, I had actually done so with the 15" OBs because I was too lazy and cheap to replace the cheapass Hsu sub.
     
    Last edited: Aug 8, 2020
  14. bixby

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    Thanks for the info, yes M&K made lots of very nice stuff over the years.

    I guess I should have never sold this one: https://www.audiocircle.com/index.php?topic=124850.0

    I never did get it integrated into my systems over the years and felt it should have a useful home. I still might not be able to use a sub come to think of it. I do not use a pre but rather go direct dac to amp with dac volume control, no way to high pass the mains without some creativity I suppose.
     
  15. Priidik

    Priidik MOT: Estelon

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    Looking at the simulation for better candidates of 18'' woofers in 250L vented box (on the floor, against a wall) the ones I would choose to be able to produce quality bass up to 70 Hz are not going to be -3 dB @ 18 Hz without dsp. More like @ 25 Hz.

    KillAllLife in music propaganda. The compromise is never worth it for music. When one has to have all, it takes at least a three way + 18'' stereo subs. To be safe, 4x18''.
     
  16. purr1n

    purr1n Desire for betterer is endless.

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    On the open baffle questions a few have asked about:

    PAP used to sell custom Eminence woofers for OB, and they were about perfect with some who preferred slightly different. I think @sphinxvc and @Serious may be using the Eminence Beta 15s in place of the PAP. Some background on this topic first:

    For OBs, we are looking for higher Qts and lower Fs. It's matter of tradeoffs and some things are counter-intuitive. In general, lower Qts driver, with bigger magnets, are considered to be "higher quality" or perhaps better damped or controlled. Higher Qts drivers are looser, and thus are more often used in sealed boxes to serve as an air cushion for damping.

    One would think that lower Qts drivers would be ideal for OB, but OB changes the dynamics (both figuratively and literally). The problem is that inherently hightly damped woofers in an OB just don't wanna move that much, hence they roll off massively. (@spwath: you paying attention here). I'd say that drivers suitable for OB range from 0.45 Qts to 0.80 Qts. The PAP customs are about 0.75 Qts if I remember correctly.

    A lot of folks build their OB from Eminence Alphas which have a whopping high 1.26 Qts. On a decent sized 2' baffle, it actually yields pretty decent bass down to 45Hz. However, what we don't hear on DIYA is that this driver sucks. (There is a lot of shit on DIYA that gets talked up that sucks, like 15" wide-banders). It's everything that makes RobS' sayings right. That magnet is simply too small to be able to control anything. OJneg built OBs based on Alphas and hated them for being uncontrolled and loose.

    Going back to @sphinxvc and @Serious (and also myself), they opted for the Beta 15's Qts 0.58 instead of the PAP customs because they felt the Betas had better control. The downside is a 5-10 Hz less bass extension. Since PAP withdrew their custom 15" OB drivers from DIYer purchase, the Beta 15 is probably the only realistic cheap choice right now for OB. For 18", there is the JBL 2241 with 0.4 Qts, but JBL = $$$.

    Alternatively, Linkwitz opted for a very low Qts smaller 10" diameter super long throw super high spec Seas subwoofer and relied on EQ to address the OB bass drop. He not only engineered around the problem, but also threw money at it. These kinds of woofers are expensive! Personally, I stay away from long throw because that means big rubber surrounds and stiff spiders. That means that some initial energy gets absorbed or lost into heat before the cone starts moving. I like super responsive drivers. Think Honda Civic auto with torque converter designed to save fuel vs BMW M with an individual throttle body for each cylinder.

    In terms of OB, folks think they sound light-on-their-feet and fast. This is a direct result of the darn thing not being in a box with an air-cushion (and also without sound bouncing all over the place inside the box before bouncing out through the cone back out). Normally we think of "fast" bass as being well damped, but it's not always this way. "Fast" drivers need to be let loose and not always constrained. There is a reason most people who do OB never go back.

    Short of OB, the only other way I would have it is a mega box. Bigger boxes have less box coloration because there is a lot more room inside for the sound to bounce around and die before being reflected back out. There is a reason why those $130k Magico speakers, despite their heroic construction, steel frames, sandwiches, still sound like the music is coming out of a box. Sure the cabinet is inert, but it's still a bunch of relatively small cones in a small box. Mega box of course means high VAS, which means big woofers.
     
    Last edited: Aug 8, 2020
  17. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    thats normally not ideal. but at the very least the mids and woofer should be relatively the same efficiency.
    for example, ive picked the audax pr170mo mid which is 96db efficient, to mate with a hivi rt2ha which is 95 db to mate with a omega pro 15a which is 96 db efficiency...
     
  18. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    ive heard probably 10 different jbl l100 vintage. I think they are some of the worst speaker ive ever heard.
    the new jbl l100 is a serious step up
     
  19. purr1n

    purr1n Desire for betterer is endless.

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    Padding down a mid or high is OK. Padding down the lows, a woofer is a bad idea, or poorer idea. Main problem is finding a mid that will keep up with the lows. Consider the inductors will also have an R component. This is crucial to keep in mind when designing XOs. Low R inductors = $$$. All this is why I don't blame people for going DSP.
     
  20. spwath

    spwath Hijinks master cum laudle

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    Looks like my eminence kappa 15s have a qts of 0.33, so maybe too low.
    Also have eminence Delta 12s under my bed, those have a qts of 0.43.
    Maybe something could work...
     

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