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radulescu_paul_mircea last won the day on October 2

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About radulescu_paul_mircea

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  1. B&C 21DS115

    More good news things will come from this. B&C takes the wheel at Eighteensound http://www.proavl-mea.com/#/ondemand/id/3s2NvmQMAC/
  2. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    Here they are!
  3. JTR Speakers Captivator 212Pro Discussion

    I think the noise we are hearing is a form of mechanical non harmonic noise. At the end of the stroke, in a well designed driver, the suspension has to stop the voice coil or any other part to hit another part of the driver. It is doing this by getting harder and harder to stretch until it stops completely. Before it does, some mechanical clipping noise can be heard but it's not really a square wave because the diaphragm is bending a little also at those displacements. In the image one can see what one Powersoft X8 channel can do to a pair of 18TBX100 drivers in an 340 BR enclosure where the maximum excursion allowed was 1.5 mm more than the maximum Klippel recommended protection of 15.4 mm, which is already 4.4 mm over XVar (50% KMS) and where the people using it completely neglected that powerful noise
  4. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    Oh, but they warrant the cost on their own. In anything you put them, that has increased performances. But only with the right amp. There's in fact the problem. Here we only have Powersoft amps that handle very low impedance and high reactivity subwoofers. SpeakerPower amps would be the others, but I can't really get my hands on them easily. Probably some Crests are also good and stable and also Crown amps. But not as good.
  5. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    No, I missed a punctuation mark. They are using the 18SW115-4 driver in the original TH118. I will build 2 identical enclosures to the TH118 , that are now easily found on the web.in those enclosures I will try the ID and IPal drivers to see what are the differencies and if it worths the cost difference. In my sims, the IPal version should go flat to 33 Hz instead of 37 and it should keep the same max SPL because it has more excursion and long term power handling than the SW115.
  6. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    I will soon build two TH118 ,identical enclosures to the original, which I will build only for tests to compare them to the Xoc1 design using both the original drivers, 18 ID and 18 Ipal and also to some other designs with other drivers
  7. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    Some real life tests between 2 Xoc1 TH18 vs 2 L-acoustics SB28 on a clone and on an LA8 amp.measurements,opinions and discussion can be found in the comments https://www.facebook.com/groups/733449990043427/permalink/1471064019615350/
  8. Acoustics Studies

    Soon to come , report about cardioid directivity trough interference from Merlijn Van Veen. I will check it frequently to see what news we will get https://m.facebook.com/story.php?story_fbid=2537646626376057&id=1871382083002518
  9. B&C 21DS115

    http://www.audioxpress.com/article/test-bench-b-c-speakers-21ds115-21-inch-woofer Bench test review. The factory can provide also their own LSI Klippel results that can be compared to these ones and adding that to the tests Ricci did, I can say this is a very interesting driver at a very good price IMO.
  10. Acoustics Studies

    http://icepower.dk/files/convention/The_Active_pulse_modulated_Transducer.pdf I wonder why this hasn't further developed and it didn't get to the market
  11. The Bass EQ for Movies Thread

    That APO EQ brigs some serious distortions and it has some glitches. I used it for a while but when I turned it off, I realized how bad it changes the sound
  12. B&C 21DS115

    The 4 ohm version can be seen on bcspeakers.com. when you select the driver, you have to click on the 8 ohm or 4 ohm icon right beneath the picture.
  13. Ricci's Skhorn Subwoofer & Files

    You are right about the average power. I was referring at that power into both.I didn't get that number from somewhere specific, all I did was to take the TruPower limiter setting for my BC18SW 115 in my Xoc 1 TH18 subs and double them. Off course, my gain strategy is to engage those limiters only on occasions when needed not to keep them engaged constantly.so the average power these get is a bit over half of that. Regarding the content, I was speaking from experience, when in a comparison of my 2 TH18 vs 2 BR with dual 18TBX100 tuned to 36 Hz, those 2 were louder than mine on average because even though the max clean SPL was the same on paper and on measurements, on tehno music, long term the 2 were taking more voltage with less heat, so the limiters were not engaging on them. The kind of music I was referring to was techno,dance, minimal etc.. that music is much more focused in that passband but it doesnt mean there is no content outside of it.
  14. Ricci's Skhorn Subwoofer & Files

    Bigger, for sure!! Now let's think why. the main thing with this is from the fact that putting a horn in front of the speaker, the general sensitivity in the pass band will be increased, and also the efficiency. Grey Bass Reflex 522 L, Black SKHorn 522 L, SPL at 145 V, same tuning frequency Efficency The main issue appears when using more than one and using a specific type of music material. Techno music is most of the time centered around 45-80 hz .there is right where this sub has its impedance minimum. If it is to be chosen between this SKHorn and 2 dual 21DS115-8 in very small enclosures, like 310 litters net each, with similarly big ports as the SKHorn, those would be better equipped to withstand a whole night of using them to their limit. Why? because of the content type. Most of the energy being centered in that band, the RMS limiters for an SKHorn would engage to keep the average thermal power into the sub at under 2-2.2 Kw (which IMO is very risky, given the fact that the excursion is lower exactly where the power input is higher so the cooling is poorer) so even though the peak SPL capability of this sub would be within 2 dB of that couple, in use, those 2 would be much louder than this one because the RMS limiters would not engage if set to the same threshold. also the power compression would be higher on the SKHorn, and extremely low on the 2 dual BR because most of the time the drivers in the BR would see under 1 KW in the 40-75 HZ range and in that range more power will leave the voice coil firstly because the excursion would be higher, so better cooling and secondly the power conversion efficiency would be higher so more energy would be converted into sound instead of heat. In Grey is 2 dual 21 BCDS115-8 310 L net BR Efficiency In Grey is 2 dual BCDS115-8 310 L net BR input power 145V on 2 series Ipal, 160 V 2 drivers paralel, 2 subs parallel In Grey is 2 dual BCDS115-8 310 L net BR Max SPL 145V on series Ipal, 160V on 2 drivers paralel, 2 subs parallel So yes, the two would be heavier, a bit larger, more expensive to make, but would require far less power from the wall and will give more long term output than a single SKHorn. So for people who would carry these around from a gig to another, using them mostly on EDM and Techno, it would be a better solution. it wouldnt sound as clean as the horn, having the driver in front. and also it wouldn't be anything spectacular, but it would be useful for this sort of app which is the most commonly used So here comes the conclusion. Making it bigger would also make it more efficient. increasing the horn side would gain efficiency higher in frequency, increasing the back chamber and/or increasing the tuning frequency a bit would gain efficiency in the lower parts. Off course, making a sub tuned exactly for that genre would be even better, like a Danley DBH 218 horn which keeps the efficiency very high but also it keeps the excursion low for a clean sound, but high enough from the high pass crossover to help the drivers cool down.
  15. Mario Di Cola Isophase

    Does anyone know more about this design? Also, what's your opinion on the short modified transmission line made by Di Cola for their M-Force? Edit: It's called Isopass. And all i can find about it is that it's a driver in front of the other but i don't know if it's a bandpass enclosure or isobaric.