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Posts posted by radulescu_paul_mircea

  1. The file where I saw you could use the M-force driven by K10 and K20 is in this link



    Also in the next link, at Super Bowl they said they used an M-drive driven by a single K10 (although I suspect it wasn't really used at a very high power)


  2. Thank you for your response. I don't have access now to my PC, but the VHD 221 is measured by me when I opened two for changing drivers and glueing some wood and the simulation is made exactly from those dimensions comparing it with 2 Othorn both using the Ipal driver. The other design is a simple ported band pass horn at under 1000 litters. The tunings are all at 30 hz or so. The K-Array KS 8 is the same as VHD 221 but a bit smaller.I am sure that the ports will compress, and the K-array will be worse but could it be there a mechanisms trough which this compression can be compensated?

    After seeing those efficiencies, I was stunned but after that My thought was that there should be a catch somewhere and it probably is the way HR is simulating multiples.

  3. Ricci,if you still have those bass reflex enclosures made for the 21sw152, you could put the Ipal driver inside to see when and how much those ports would compress and how different those drivers behave.

    Also, regarding the low impedance stability of the K20, on some of the Powersoft datasheets and white papers they say the M-Force driver can work also with K10 or K20. But that one has a RE of less than 0.26 ohms.

  4. Hi all,

    Trying to develop a very powerful and efficient subwoofer, I noticed something interesting. When comparing the Othorn Ipal with other sub designs like K-Array KS8, KV2 VHD4.21 or martin MLX and ASX, I notice that the bandpass and hybrids works better and more efficient than the Othorn. that seems odd since from what I know, TH are more efficient than Bass reflex and shoud be more efficient than band-pass. but not using the Ipal or M-force drivers. You can see in the pics that when using multiples, the efficiency increases very quick and with 4 large ported BPH  enclosure using 2*21 Ipal the output is huge using less energy than with 8 Othorns.

    So whats the catch? Would 2200 sq cm ports avoid compressing at those SPL? 






  5. So when you say you turned them upside down, are you saying the horn mouth is/was closer to the ceiling now?


    Also what ever happened to your monster horn design? Did you ever build one for concept/prototype or no?

    The mouth was closer to the ceiling at first and now it is closer to the floor which is better because I avoided some resonances.

    That monster horn didn't happened because I was waiting for funds that never came... but I will build it eventually, I just I don't know when. I will start building 2 SyntripP to go with the 2 TH18 which I will rent to a club for half a year and with the money I will build the Palehorns for private dub and DnB parties ;)

  6. Yes I did take some pictures and some measurements. The mic was at 2 cm from the grill and the gain from the sound card was 20 dB lower to avoid any clipping as I know the mic can take 113 dB but I don't know how clean the sound card is. The yellow measurement is with the bandpass crossover engaged.

    Couldn't take more measurements with the Xoc1 for now as i have them installed elsewhere for some time.







  7. The BC218 was presented at frankfurt this year and I listened to it in the first 2 days. Unfortunately I wasn't so pleased about them (there were 2 in full moon config) because probably the limitters were not set properly and they were cutting their power to soon.they had the first kick very powerfull but the drop was weak. In the second say, things were better but I know how 6 dual 18 like qsc GP218 sounds and those BC should have beat the crap out of them but they just didn't. I told the boys from Italy my oppinion then but I leaved after second day and didn't managed to listen again. But from what I heard from others after that they did do something because many were impressed of them. Everybody said it was LOUD and DEEP!!! I listened after that the Icubus from Void and 2 stacks with 6 21" +8*15+4*12 can shake the teeth out of your mouth from 40 hz up :))

  8. Hello,

    That is great results indeed. Nice work.

    So you recommend going with the three board CC as measured with your current design? Is that with the B&C-115?

    Kind Regards,

    Yes, I am glad I built this design and it seems that the cone correction was a good aproximation. But, since the last year I started to improve sound systems in clubs and venues and I used and heard lots of them. And after listening this month subs like Outline Lab21, JBL VTX G28, Coda, Aurasound, The Danley BC218 and this weekend the KV2 VHD 2.21 and 4.21 I realized that when you can go flat to 30 Hz or lower, everything changes and the music is more incisive and enveloping. And more FUN! So now I want to build the Othorn or something larger and more powerfull that can go at least flat to 32hz. And I think the jump from 77 Kg to 100+ kg will not be that much, eapecially when I instal the system.for long periods of time
  9. No, it is all-pass. But the sub is at 3 meters from the ground and there is a glass wall behind the subwoofer. Also, a part of the ceilling is made from drywall so there is a big loss in low frequency but it is a small space so there is lots of headroom to spare. And I found out that the 53 Hz peak is from a vent hole resonance and the thing is that there are two exactly in the same position from both subs.




    I am also building some TH18 XOC1 cabinets. I will be trying the 18IPAL and comparing to the standard 115. Do you have details of the throat V boards you have made from your throat picture?

    Thanks in advance,


    I have a problem with it. Try to put only two pieces instead 3 because I have a big hump at 53 Hz yhat I belive it is from that cone correction.fs at 35Hz and more than 1 dB sensityvity bellow TH118. So it is not that close.. IT IS possible that I made a mistake when building it. I will take some measurements after the Easter camparing the original with this one

  11. Right on topic, Funktion One will soon release a FLH with single driver using the M-Force motor and a custom made 32" diaphragm and it will be BIG :)

    In the presentation of the "novel approach" the bandpass enclosure reached around 145 dB from a single enclosure with single driver. I am curious what did F1 manage to squeeze from it. And I bet it has a very high compression rate.

  12.  But unfortunately for me wood is the most costly thing here. Wood sheets cost about 100 per sheet or more. So thats why I have never gotten started on any of my larger horn designs yet.


    I do find it fascinating that your design has very similar SPL as mine. I was hoping for 140db out of one driver using the IPAL but the downside is you need a monster amp to power this driver. SO no go yet.

    Yes, the I was thinking to use the M-drive module for both drivers. 

    The wood is a bit expensive here to but I managed to find a guy who knows a guy who knows another..you Know ;) so I can get a 5*5 BB/CP ply for 30$. As for starting to build the Giant Sub, I will wayt until someone take's the bait and gives me the funds to try this sort of projects.


    Now I will post some measurements I made with REW for the subs

    This are the two subs with 2 Arcline 6 from void at 4 meters on axis (near the bar where most people stay)



    Xoc1 left side 1 meter



    Xoc 1 right side 1 meter


    Sub has 29 hz 18dB/oct HP BW and 48dB/oct 100 hz LP 

  13. Single with dual 21Ipal. I am a Powersoft dealer so with some effort I could get the Ipal at the same price as the MRSP od the 21SW152. But i had to slightly twitch the Re of the driver to get a more linear response.I have to learn Akabak to sim this box because it will be expensive and I don't want to funk it up ;)plus the DPC from Powersoft . I have to learn a lot ...

    I've just compared the two th18 with 2 nexo ps15 and i can say that they really sound the same. Mine were used on a btidged powersoft K6 in paralel 4 Ohms and the nexos with NXamp4*4, one per ch. Mine seemed to have more directivity and was shakind things more at 31 hz. I couldn't take measurements at high SPLs vecause mi mic starts clipping at 112 dB...:(

  14. Yes, it really is the going thing. Modifiing the parameters of the drivers, I managed to squeeze some serious SPL from a single enclosure and a devastating power from 4.

    I hope I will get this project approved, because the client want's either 16 QSC GP218 with 8 PL380 (around 55000 Euros incl. taxes) or 4 of mine active which will cost him a little more than half of that and will need a much smaller power generator for them, also.

    Single large FLH with 34 hz, 3 order BW at xmax with around 8KW/driver


    4 pieces 31hz, 24dB/oct BW at x-max, around 7Kw/driver


    16 QSC GP-218 with 1400 watt/ driver at xmax









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  15. I know it is imposible to say what one wants. Now lets think. I will use 2 subs with 2 tops made with 2 B&C 15 coax with mostly dance music indoors in a small place. I will build for sure a pair of Othorns until summer but for now I have to build something that i will use with one INuke 6000. So I am mostly inclined to do a pair of keystones.

    But, for start, I am curious about how come the Othorn got 7 dB more than the Keystone. AND 8 hz extension.

    I will also instal in a small Pub next month a pair of TH118 with 4 SH 100 with their branded Crest amps and I should see what they are made of.

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