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Showing content with the highest reputation since 07/10/2020 in Posts

  1. 2 points
    I did. The old 7560's which I believe were the same as the Crown M600 and a couple of other re-badges. It's been a long time but it was something like 1500w burst into 4 ohm and 1000w for a very long time and would do it at 20Hz. Doesn't seem like much these days. These aren't really amplifiers intended for "music" signals. These are industrial grade equipment for labs, measurements, running motors, MRI's, etc. HEAVY loads. They do audio just fine but are WAY overkill for bumping some music. Kinda like taking a Mack tri-axle dump truck to pick up 100lbs of mulch. I love how they rate their amps and provide all of the engineering specs. Compare their data sheets to those for Behringer or Yamaha amps. This is how gear used to be spec'd. I wish it still was. Amps really should be rated in terms of voltage and current capability into various loads at different frequencies IMHO. A 7810 or 7796 is a monster power source even if some 20lb amps produce more power on paper. The ratings are MUCH different. Yes they are heavy as hell. They have to be. You'll never get this type of ruggedness and sustained power output out of a 20lb amp. If I was filthy rich I'd have a stack of these installed on 3 phase to run the subs, just because.
  2. 2 points
    Thought I should update this thread as I went ahead and built a pair of VBSS subs to live with my Danleys. The hype is real, these are fantastic sounding subs considering their inexpensive cost to build. They wont crack the stucco on my ceiling like the Skrams did, but for listening to music at moderately loud listening levels I couldn't have wished for a better outcome. Thanks for the help everyone, the project was a success! And I didn't blow a bunch of money I didn't need to spend in these strange times. Aesthetically I think they make for a great match with the Danley's as well. https://imgur.com/gallery/R1JSs05
  3. 1 point
    Discussion of JBL's most powerful differential drive woofer should go here. This is an oldie but a goody. It's an expensive bugger like most of the woofers I test these days but it is still a cut above most of the 18" units on the market. I always wanted to test one of these just to see how good it is. I don't expect many people to go out and buy these for a project at those prices but it is still a common driver to see in the industry in a lot of JBL's top Pro subs. I figure giving it a run through here should help give insight into the capabilities of the various JBL subs using the 2269H. It doesn't have the crazy efficiency and motor force of the drivers coming out in the last 5 years, but it does seem to offer quite a bit of power handling and raw displacement capability. It's too bad you never see these on the second hand market for a few hundred dollars like you can pick up other legacy JBL units for. It might be an option then. The retail price is a killer. It really doesn't seem like these would be that expensive to produce either with JBL's economy of scale and having been around for so long. https://data-bass.com/#/drivers/5cd9d5e8bd4b990004557d17
  4. 1 point
    Here's my random thoughts. Shorting sleeve is mentioned but the 1kHz Le rating is way up there at over 2X the Re. Also the shape of the impedance curves shown indicate a very sharp increase in impedance vs freq above the minimum imp above resonance. Indicates a lot of inductance also. Heavy 5" coil and a huge motor with lots of steel. They have not posted the Zma data for download yet, which would allow it to be analyzed with Bolserst's semi inductance excel program to back out the semi Le specs for modeling. Shipping weight is listed at 115lbs. I suspect these drivers are in the 90-100lb range. Two or 3 times as heavy as the pro 21's. Can't see anyone using the Vortex 21 for pro audio work with that kinda weight. Drivers that heavy are a PITA to deal with especially in multiples. Imagine a double 21... Both drivers seem to be nearly identical. They model almost exactly the same except that the Vortex has slightly higher efficiency and upper bass due to the lighter mms. Most of that is probably just from switching surround types and perhaps the cone or dust-cap. The rest of the spec comparison and specs lead me to believe that the motor, frame, coil and spiders are identical. It's possible that the roll surround is much better behaved at high excursion than the traditional pro type (less noise more linear). If not I don't see a reason to pick the Kraken other than if you want that type of look. The Vortex is higher sensitivity and efficiency with apparently the same amount of excursion and it's a tiny amount lighter. Judging from the cutaway pics it looks like the top plate is about 15mm and the coil is about a 45mm wind height. Coil overhang would give 15mm overhag with no adder. 1/3rd gap adder would put it at 20mm one way which is close to the claimed spec. The coil would leave the gap at 30mm one way. Unless there is a lot of fringe field and overshoot the maximum excursion is done there and also sound horrendously distorted by that point. Of course I'm speculating based on an un-detailed drawing but this should be close. Spiders don't appear to be mirrored. There is mention of a warning system to prevent damage. I believe this is the ring shown under the bottom spider sticking up above the top plate. Looks like the bottom spider will contact this a few mm before the bottom triple joint would contact the top plate. This will probably sound very bad but not be immediately damaging. It looks like the bottom spider triple joint would contact the top plate around 30-32mm in. I'm guessing the spider will contact the ring around 27 or 28mm incursion based on that. Since the coil would leave the gap completely at 30mm I don't think it will be easy to push these drivers that far anyway. Spec wise I think these look good. They have a low Qts and high efficiency. EQ is used on everything these days and the goal is usually more bass from less space. The pricing also looks good especially in multiples. My biggest gripe would really be the 100lb weight followed by the question mark of how bad the inductance is.
  5. 1 point
    I've decided to order one of the cvr d-3002's to see whats up with them. I don't have the equipment to bench test but I can do some a/b listening tests vs my K10. Ill report back
  6. 1 point
    Thank you for clarifying that for me, I will keep on doing what I am doing. SME, thanks again for your input. Phase alignment has been one of the biggest rabbit holes I've fought with over the last few years but I feel I've finally got a reasonably repeatable process that is giving me good results. peniku8, yeah I know know its not ideal but with this covid thing im trying not rack up too much dept for new sound gear. If/when things get back to normal Ill figure out something proper. I dont let anyone touch my gear so not worried about the random factor playing in. I did order one of those cvr amps, ill let you guys know what I think. Doing some bush camping in a couple weeks and taking some gear with me so will be able to ring it out a bit.
  7. 1 point
    I'm actually heading to our local makerspace woodshop this weekend to cut up panels for another 4 of these. I gave a couple of my music nerdy friends a demo and they immediately asked me to build pairs for them. For less than 1k Canadian you can build a pair with a berry nu3k included in the price. Unreal value for the dollar.
  8. 0 points
    Josh, I'm starting to see the advantage of your designs over typical bass reflex...thanks for your contributions btw. One replacement driver came in. Same issue. Not as bad but still clearly audible. I'm going to try to fix it myself. Glue through the fabric and doping around the edge surface. If all else fails it looks like a SKRAM or similar hidden driver design is in my future. Thanks for all the comments guys.
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