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Everything posted by Ricci

  1. New CEA 2010 in room Measurements.

    I have been doing most of the commercial subs in my room as well for quite a while. Mostly as a data point on the room acoustics effects I have and how distortion is lowered in the deep bass. Mic is at head position at the main seat and subs are placed in the same corner each time. Only valid for my room and that exact placement.
  2. (8) Ported Incriminator Audio Judge 21" build

    Finally! I bet you will be glad to have this project off of your plate and be able to fire up all 8.
  3. Othorn Plans

    It should be fine. Response shape may be a hair different but not a deal killer by any means
  4. That is good to hear Nick. I decided not to see that in the theater so I could fist watch it at home. Looks like it has some good 12 to 25Hz energy. My buddy also said the visuals are stunning.
  5. New SVS Ultra 16"

    Looks like it is time to try that K20 out on the next big woofer across the bench. Judging by the slope of those curves it looks like the 70% BL point is going to be around 20mm.
  6. The Bass EQ for Movies Thread

    John how much time does it take you to go through the process above?
  7. New SVS Ultra 16"

    I went back and looked at the Tymphany STW-350F specs and they are totally different from the specs that ITR posted from a PB16 driver. Originally I thought that these drivers would be quite similar or were at least using a similar build platform. After looking again there is very little similar between them at all. The frames are different, the STW-350 is 15" OD but the SVS appears to be 16" OD. The STW-350 is using an overhung topology with a 7.4" diameter coil. SVS says they are using an underhung 8" nominal diameter. That being the case both the surrounds and spiders would be different. The overall motor / gap / coil geometry would be much different as well. In fact it seems like perhaps the only parts shared would maybe be the motor case and backplate. Although the motor outwardly makes the drivers seem like close brothers it appears that they are more like estranged 3rd cousins. Modeling the 2 drivers using the parameters provided shows that they behave as differently as you would expect. The SB16 driver should be a completely different 3rd driver design. I must say this has gotten me interested in testing the SVS 16's again.
  8. New SVS Ultra 16"

    Thanks. They are not what I expected. I just checked and this would've tied the 21Ipal as having the stiffest suspension I've ever encountered.
  9. New SVS Ultra 16"

    Welcome to the forum... Just to clarify...These specs are pulled from what driver? What jumps out at me is Qts = 0.87 BL^2/Re = 118 n0 0.186% Cms=0.039 Extremely tight suspension + 500g mms and a relatively low strength coil / motor system results in a very inefficient driver. Very odd set of design tradeoffs IMHO.
  10. Here's the design I'm going to be using to replace my Othorn. It's been "almost" done for a long time now but I finally made an effort to wrap it up to the point that it is ready to build. Originally I was going to go with another TH design I was calling the Palehorn to replace the Othorn but I wasn't quite happy with it. I stumbled on this type of cab a few years ago while doing a billion simulations of different cabinet designs. You can read some of that in the M.A.U.L. thread. I originally planned to try this design first since it was smaller and cheaper to produce but circumstances led to the bigger more complicated M.A.U.L. getting done first. Since this style of 6th order bandpass / horn cab worked quite well and on target with the bigger design, I used what was learned there to make a few tweaks to this and finally wrap it up. I'll add a lot more info later, but here are some pics to start with. If anyone feels froggy and wants to have a go at building one of these let me know and I'll send the plans. Simplified design layout. Add bracing, drivers, hatches, hardware to taste. PDF and DXF Plans Skhorn 221 print.pdf Skhorn 221 print.DXF
  11. JTR Noesis 215RT Measurements Discussion

    Kinda off topic from the 215RT... In general if I was selling subs or speakers I'd probably aim for a flattish response to 30-35Hz and a gentle 6 to 12dB/oct roll off below there. Rooms vary a LOT but if you look at the broad trends vs individual samples most rooms seem to have some moderate boost by 20-25Hz and a large amount by 10Hz. Mine has about 3.5dB at 20Hz and about 14dB by 10Hz. There are always those examples that don't and you have your usual room issues such as the dip in the 12-17Hz range that occurs in a lot of rooms, or the peak near 40-60Hz for seating placed near the center of the room. A lot of companies go for the flat full or half space bass response. It's really a matter of preference and design choices.
  12. Discussion of JTR's mammoth main speaker should go here.
  13. FV25HP measurements are viewable now.
  14. Test data and notes for the F18 18" sealed sub and its brother the FV18 vented sub are both viewable on the main site now. Please place any discussion or comments here. Thanks,
  15. FV18 results posted...
  16. Do you have Alpine? How much is a SWS-15d2 or an SWR-1522D? $400 is a lot for a UM18.
  17. How much is an Ultimax in Belgium? How much is a 21" B&C? I'm just curious. There may be other driver options that make more sense given his location.
  18. Maximum horn compression ratio?

    Yes we are in agreement. We dove a bit deeper than expected. Again. But it happens. Yep extra mass or lowering of Fs shofts the max efficiency point down in freq. What were we supposed to be discussing? Horn compression in the throat? Ha.
  19. Maximum horn compression ratio?

    SME, Yes mass and suspension compliance affect Qts. Higher mass and stiffer suspension both squelch efficiency. No need to worry about those if strictly comparing the motor and coil systems with BL^2/Re, but in many cases what people compare is off the shelf drivers. There the Mms and compliance matter and those are factored into the final Qts value. Resultant Fs also shifts the efficiency maximum. As will the final enclosure design, etc. We really can't just look at Qts though due to complex inductance effects on these types of drivers.
  20. Maximum horn compression ratio?

    Dave, BL rating means nothing alone. That does not tell you the effective efficiency or "strength" of the motor /coil system. Resistance also has to be considered at minimum. BL^2/Re Or just look at Qts Technically the normalized inductance should also be considered as it effectively saps the efficiency and raises Qts. You need to include 3 parameters at minimum. BL, Dcr and Le. Or like I said just use the easy button and compare Qts, though that doesn't consider Le effects.
  21. Maximum horn compression ratio?

    Compared to an 18Ipal almost everything has lower motor force / efficiency. Of course the HST 18 has like twice the displacement capability though.
  22. Maximum horn compression ratio?

    I see that you also have a throat depth of just over 2". Have you seen how tall the surround is on an HST? Are you sure this enough to clearance the surround at full excursion? Im not sure how a surround like that will fare in a high pressure horn loaded app. It might be fine but I have never seen it tested. Things to consider.
  23. Maximum horn compression ratio?

    I will look at this when I get a chance. Very busy at the moment getting some more tests ready to upload. Off hand. Interesting fold. Have you considered weight of the cab and internal pressures at high output? Bracing of the panels etc? Check the particle velocities, acceleration forces and pressures at the throat and exit. They will likely be extremely high with such a high compression ratio. Also absolutely model with the Le option checked which derates motor force some.
  24. Replacement AVR / processor

    I'm still using the old Onkyo 886 myself. Probably get the Denon DN-700AV when I do change unless something better comes along. Related to the clipping with WCS signals... Most of us with big, capable systems, by default have HE / sensitivity. I've done a lot of gain investigation with my current components. My REF playback is at -7 on the master with my FL and FR channels at -15 channel trim. This is largely set by the high sensitivity of the CF-4 speakers and the extra hot input sensitivity of the Emotiva XPA-5 amp. The sub channel runs about 3dB hot at -7 trim with my K20 input sensitivities at minimum. The Onkyo will spit out over 12v through the SW jack without clipping but I do not know what point it would occur internally with a WCS. Back when I did all of that testing I did not have an easily accessed WCS signal. K20 clipping occurs well below 12 volts input. I could always increase the input gain on the amps if needed but I don't run REF +15 on the subs virtually ever. Is anybody actually running their processors at (0) for assumed REF with the channel trims near 0 or higher? You really shouldn't need to with high capability speakers but this makes me curious.