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Ricci

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Everything posted by Ricci

  1. It'll be an Alpine Type R 15", an MTX 9515-22, a Peerless STW-350 and 2 MTX 9515-44's. I'm not ready to sell any quite yet though. Still have to test em. Edit: I can sell one of the MTX 9515-44's. See price below.
  2. Ricci

    B&C 21DS115

    You can completely ignore the winisd recommendations. In fact you should also ignore qtc for the most part. IMHO. I never use it for design work anymore. Start with a size that is practical to build such as a 17" or 18" cube and use that calculated volume for modeling. Use the model to determine an appropriate amount of power to use. Don't worry if the excursion below 20Hz seems to go beyond Xmax at low power. It will due to a very low qtc alignment. The DS series drivers are almost impossible to bottom out and it takes WAY more power than winisd will show to push the driver beyond 20mm
  3. They have the same amount of total displacement effectively. The 21Ipal is a little more efficient.
  4. It's 5 Listed as "Measured Complex Inductance Parameters" under the individual "Drivers" page.
  5. 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
  6. That sounds about right. Might be useful for HT if you find you aren't using all of the headroom a pair will provide.
  7. 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.
  8. Excellent...I may have to buy one of these units for my tool kit.
  9. 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.
  10. 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
  11. Interesting. Are you planning to do any testing of this setup? What is "the device"?
  12. 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 p
  13. 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.
  14. Looks good man. Are you building a pair of these or just 1? You forgot to post tuning with one of those ports stuffed.
  15. These don't look right to me. The response shape looks off. Are you using the generic LE (red Le) function?
  16. 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.
  17. 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?
  18. 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.
  19. 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.
  20. 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
  21. DXF files uploaded to the first post...
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