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Everything posted by Ricci

  1. They have the same amount of total displacement effectively. The 21Ipal is a little more efficient.
  2. It's 5 Listed as "Measured Complex Inductance Parameters" under the individual "Drivers" page.
  3. I'll reply a bit more later but let me say that when modeling for maximum output, otherwise known as "Bench Racing", there are a number of limitations about simulations that should be kept in mind. 1.) Sims are usually greatly simplified and usually lack a variety of effects that occur in the real world like non linearity in the drivers BL, suspension, thermal effects in the voice coil, port and other air flow related losses, etc. All of these cause compression of the output. 2.) Sims are only as good as the data input. 3.) Amplifiers are not constant power devices, they are constant voltage. Speaker impedance varies with frequency. 4.) System output is usually limited by a number of different factors. Driver excursion, amplifier voltage, amplifier current and the resulting amplifier power are the main limitations. Which limitation kicks in first depends on the frequency range. There are also other factors such as vent compression, PR excursion limitations and thermal compression or power handling of the driver to consider. Horn Response allows a good approximation of max output based on entry of a number of these parameters. This is what Peniku was showing in his simulations. Limiting by wattage isn't really the best way to go about it. 5.) Power handling and xmax ratings are not all created equal. 6.) Eq can modify the driver excursion profile and which frequencies run the amplifier or driver into the limits first.
  4. That sounds about right. Might be useful for HT if you find you aren't using all of the headroom a pair will provide.
  5. I'm assuming sales were slow at the prices these went for. I haven't seen anyone else on the forums post about having an SHS-24. I figured a few would've been bought during the closeout sale. I always get at least a pair of drivers.
  6. Excellent...I may have to buy one of these units for my tool kit.
  7. Ahhhh. I think you're right. Unfortunately according to the SI website that may be the case for these drivers, which is a shame. I wonder how many were sold at the sale price last holiday season. Perhaps it'll be a small batch as requested type of deal. I need to get my ass in gear and figure out what type of cabs I'm going to build to test these. I still have the giant sealed cab from the original HS-24 testing. I'm tempted to see if I can somehow cram 2 or 3, 6" aero-ports in that cab without too much trouble.
  8. What John is describing is very similar to how I do it. One difference is I run the sine wave looped back through the RTA and monitor the THD. It should be well below 1%. Once it starts to clip you'll see the harmonic content jump abruptly and THD shoot up over 1%. It usually happens very abruptly. If the device has a clipping indicator you may find this happens well before or well after the indicators. You do have to make sure that this is the output voltage clipping and not the input though. To reiterate a voltage divider will probably be required. I cheat and use one of my DCX2496's in the chain usually. They will take an input of >10 volts before clipping and can easily reduce the signal to something that your SC input can handle when looped back. Go through the components one piece at a time starting with the AVR, then adding the EQ unit and finally the amplifier. You want to eventually get the highest voltage cleanest signal that you can to your amplifier and then set the amplifier so that it is the first thing that clips. This also helps keep your electronic noise floor as low as possible. Definitely disconnect all speakers. They aren't needed for any of this testing.
  9. Interesting. Are you planning to do any testing of this setup? What is "the device"?
  10. Ricci

    Sub Advice

    It's best to start out by defining some things. DIY can definitely offer some advantages and cost savings but the tradeoff is a higher amount of sweat equity and possible increased difficulty in integration and setup. Like More mentioned some of your goals are at odds with each other. What is your budget? What size can you subwoofers be? Define some hard limits on the dimensions. How loud do you plan to listen? Are you wanting front row concert or EDM show levels or just good clean low end at moderate levels? The best bang for the buck amplifiers are external rack mount pro amps. Plate amps cost more and must be accounted for in the enclosure design and build. Your post makes it seem like you would like the amp to be placed with the subwoofer where you have a pre-existing RCA cable. I recommend using XLR balanced cables where possible especially if going DIY. long runs of RCA unbalanced can have issues with noise.
  11. Don't worry about it. It's kind of on topic anyway. Personally I am not a fan of MDF. I don't like working with it and it doesn't hold screws well. Also it hates moisture. I'd rather use a cheap Arauco ply or similar if the 13ply void free stuff is too expensive. I've done a number of cabs out of cheaper ply materials and they've turned out fine.
  12. Looks good man. Are you building a pair of these or just 1? You forgot to post tuning with one of those ports stuffed.
  13. These don't look right to me. The response shape looks off. Are you using the generic LE (red Le) function?
  14. It's not stuffing. It knocks down high frequency radiation from bouncing around inside of the cab. You may think low passed subwoofer = no high frequency radiation but that's not entirely true. Distortion, mechanical operational noises, internal standing waves in some cases, air noise, leads vibrating against cab walls, etc...Anyway I've always lined my vented subs because it does knock down these junk noises a bit. Try snapping your fingers or knocking on the side of the cab with no lining and then with some lining, with your head inside.
  15. Sensitivity will measure low on a dual opposed cab when measured from 1 location. I've got an article on this subject on the main website. Can you post your model inputs and the physical characteristics of the cabinet?
  16. I'm not surprised. It's probably used as a tactic to sell Atmos & get higher penetration into the market by how much obviously "better" it sounds. Or perhaps they have 2 different mixing teams working on the tracks separately? Resulting in 2 different mixes? That seems like a monumental waste of time and money though. For coherency and efficiency you'd want to change as little of the mix as possible between formats. One would think at least.
  17. Honestly some stiff foam cut to shape works just fine for an easy route. Similar to what the ID MFG's do for variable tuning.
  18. There are 4 ports when all are open= Divide the Ap (port area) of 725.76cm2 / 4 = Each port has an area of 181.44cm. Multiply 181.44 by the number of ports that are open and input into Ap. Also some volume from the vent is added back into the enclosure when blocked. Add 14.42L to the enclosure rear chamber volume (Vrc) for each port that is closed off. 3 port operation = an Ap of 544.32 and a Vrc of 216.15 2 port operation = Ap of 362.88 and a Vrc of 230.57 1 port operation = Ap of 181.44 and a Vrc of 245
  19. DXF files uploaded to the first post...
  20. I'm surprised they ran like that. It's not making sense to me how they would have a complete circuit using both positive terminals in stereo mode? It's kinda hard to make sense of what you are describing. At the end of the day if the amps and speakers both still work afterward then there's nothing to worry about. Just pay more attention next time!
  21. Ricci

    Eminence NSW6021-6

    Looks somewhat similar to a design I had a few years ago but ended up going in another direction. IF it's the one I've seen a few screenshots of. Good luck in the endeavor. As far as this Eminence driver goes I hope they get their stock built up soon. I need that 2nd pair eventually.
  22. SME's post is spot on. It takes careful investigation to figure out where clipping is occurring. MiniDSP's are not known for having robust voltage headroom on either the input or output. EQ complicates matters. Many receivers will clip the sub output internally under a WCS signal and well below maximum output voltage. The amp is the easy part of the gain stage. Most have clip indicators and as long as the gain control is up a few clicks from the minimum the input won't clip before the output.
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