Search results

  1. G

    DIY sub for Neumann KH420

    A net volume of 48l is just about right for 2x BMS 12S330. Fb, Qtc around 60Hz, 0.5. I'd guess the drivers would consume 9-10l volume, so that would make it 58-60l box. Check out the box volume calculator in Vituix. Maybe 12mm wall thickness is already adequate, with double thickness on the...
  2. G

    Compression drivers?

    I'm not an expert either. Which geometry does wide horizontal and narrow vertical nicely? I vaguely recall that Greg Timbers said that the vertical orientation of the biradial horn on the JBL Array 1400 is actually the right orientation, something along those lines. For example Limmerhorns...
  3. G

    JBL L82/L100-inspired bookshelves

    If I have the dimensions of the L82 right, I'd estimate the cabinet's net volume to be around 27l. You'd need more of a subwoofer type 10" with lower Vas than those you've listed. and also low Fs. Like the subwoofer version of the SB29: SB29SWNRX or the Peerless XLS-P830452. It seems to me right...
  4. G

    Compression drivers?

    I like the response of the RCF ND650 in the factory datasheet better, and I guess would consider the poly surround a plus. Among others the Lavoce HD1403 horn looks nice, 80deg horizontal, the B&C ME90 is nice as well.
  5. G

    DIY shoeboxes with drivers + external amp and active xover?

    This would work with a 3-way. For example looking at the Faital 6RS140 mid-woofer: a small sealed box with net volume of 2.5-3l would result in a 2nd order high-pass response with Q=0.5, same as a LR2 crossover slope, with -6dB at 136.5Hz. Use a matching LR2 low-pass on a woofer below and that...
  6. G

    Crazy PA Coaxials for Hifi

    The 10" and 12" ones from BMS have a pretty smooth FR. Also their 44mm voice coil compression drivers are specced for a low crossover frequencies, based on that they should work well for a 1kHz crossover. I was curious how a passive crossover would look like for the 10", gave it a try in...
  7. G

    Crazy PA Coaxials for Hifi

    Of course they're not "time aligned", like the ones from Genelec, Kef, etc. which are most likely are. ..and a cross section drawing reveals the horn profile in the ones without a horn.
  8. G

    $2k DIY subwoofer, oh my

    Is this dual opposed, but with the drivers reversed? Is this equivalent of single driver open baffle solution? Or is there a benefit to the back wave coming from the gap in the middle? (In case it's dual opposed.)
  9. G

    BEST 10inch subwoofer for sealed enclosure?

    So what is the size and volume of the cabinet? Apart from shallow sub drivers, the B&C 12TBX100 is a quite shallow conventional driver. Based on the low Vas and Qts two of them could work in the same volume as two 10" woofers. Based on the Fs, the Fb would be a lot higher, so I guess it might...
  10. G

    Best 15inch/38cm woofer units?

    With the right driver, a 3-way can be built with a very small back volume for the mid cone driver. This is interesting because small is easier to build, and box resonances of a small a mid chamber are going to be high in frequency, even up to 1kHz, which is easier to mitigate probably. Very low...
  11. G

    Best 15inch/38cm woofer units?

    Right, taking the B&C 15SW115 (a high-end model) for example, the nominal sensitivity rating is 96, so a 95-97dB mid cone would be needed. Maybe preferably a 6" for directivity matching at tweeter xo frequency, but such high sensitivity 6" drivers don't have a lot of Xmax, might not be a problem...
  12. G

    DIY Mini-Unity Horn. Am I crazy?

    The 5" BMS 5CN162 has been tested here: https://www.hifi-selbstbau.de/datenbler-mainmenu-40/koaxialchassis-mainmenu-62/604-bms-5cn162?showall=1 I think that's pretty good FR for the HF. Same goes for the 10", seems to have a pretty even FR as well on the data sheet.
  13. G

    DIY Mini-Unity Horn. Am I crazy?

    The HF driver in the BMS 10C262 is specced in the datasheet as 1000-20000Hz, recommended xo 1200Hz. Such an xo frequency, say 1100Hz would be a pretty good one, as in same beam width of LF and HF. Based on the TS params, and if define 3 for the value of Ql, which is said to model an aperiodic...
  14. G

    DIY Mini-Unity Horn. Am I crazy?

    Do you mean using that 8" coax "synergized", i.e. a Synergy horn but with the cone of the coax being the mid instead of separate cone drivers. 8" is going to need a lower xo, because for a larger cone, the band-pass chamber one can actually construct is going to have a lower roll-off. I think...
  15. G

    Woofer Stands/Module

    I'd go for something that plays cleanly even extending above 1kHz. Plugging the ports on the bookshelf speakers, you might be able to get a low end roll-off on them that's low Q, and if so, in the simplest case that could be combined with a 1st order HPF, which could be a line-level one (a cap...
  16. G

    DIY Mini-Unity Horn. Am I crazy?

    The BMS 4550 is what could be called the 'original' Synergy Horn CD, right? It's capable of low xo, stated officially on the spec sheet. (I think I've read somewhere that its FR around 1kHz has a shape to it that is used in Danley's designs. Just saying, not necessarily important overall.) If...
  17. G

    Recommend for pair of 12" sealed passive subwoofers

    Wouldn't you just target 0.577 or 0.5 as the best values for the Q of your closed box. I dig the the BMS 12S330 because the sim shows Fb=72, Qtc=0.58 for just 16l net volume (probably a 19l box, 300mm cube). That Fb might be still okay for LT with an additional HPF if taking the small size over...
  18. G

    I2S isolation

    Could be 5x dual LVDS receivers and 4x DIT4192 for example. I think creating a board for that is going to be more involved than buffering AES lines from the FPGA. At Mouser 4x DIT4192 chips cost 26EUR, the smallest ULX3S costs 105EUR, ex VAT though. (It has a HDMI connector on board. I wonder...
  19. G

    I2S isolation

    I thought the plan was to receive 4x I2S over LVDS and turn that into 4x AES to feed the inputs of the Okto8 DAC. Though post #17 says the HDMI box might not output multiple I2S channels, and there's a Raspberry Pi mentioned before the DAC. (For signal processing? CamillaDSP?) If the Raspberry...
  20. G

    I2S isolation

    Sounds like you're planning to design a PCB for this. Approaching it from the input side, If the goal is to feed multi-channel to the Okto8Pro DAC via its AES inputs, signal transformers could provide isolation. Somewhat of a heavyweight solution probably, but an FPGA could be used to convert...
Top Bottom