Jump to content

radulescu_paul_mircea

Members
  • Content count

    201
  • Joined

  • Last visited

  • Days Won

    12

Everything posted by radulescu_paul_mircea

  1. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    Nice!! SW152 is the best choice except IPal. I worked with PD2151 in some different alignments. Huge efficiency, even higher that the IPal drivers. Low MMS and very high BL. They can take a lot of voltage I low order alignments , they are very well suited to 4th order bandpass. They are conservatively rated at 1000 ( in comparison to other well respected brands) but they can really take 400 watts thermal dissipation, but they cannot dissipate that much heat as one IPal driver and the excursion is limited. Very linear, better than most in craftsmanship,
  2. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    It seems Danley is using electrical series on their TH812 subwoofers
  3. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    I wanted to post this picture from last night. They are way more powerful under 45 Hz than 6 Electrovoice Xsub. I used them all in a configuration where I had a null in the DJs spot and a good spread across the venue. With any song that had serious content under 45 Hz, if I turned mine off, the 6 dual 18 were at least 10 dB lower than the whole setup. I love their sound !
  4. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    I don't have 2 ohms 21Ipal drivers. They do not exist for now. The power of the IPal module is exactly what a 21Ipal driver is able to handle in a well ventilated enclosure. I'm not that impressed either. But I don't have access to SpeakerPower amplifiers in Europe, especially with the taxes we have around here . It wouldn't really be a good competition for the price I can get the modules or other amps.
  5. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    No, they are single voice coil drivers. But there are 2 drivers in the same enclosure. The difference in resistance gives a small variation. That variation will change the electromagnetic parameters a bit. The variance in the magnetic field intensity adds to that. Then the mechanical parameters of the soft parts will change the general impedance curves between different drivers in identical enclosures. If this drivers are linked in series, being reactive loads, they go haywire even with small variations, because they ask for different voltages and amperages but also with different electric phase angles and this way the variance increases. Then at the onset of large nonlinearities in KMS and BL , the difference can increase quite a bit or decrease if you are lucky. But the difference in load is a difference in temperature, a positive feedback occurs in a worst case scenario. I work with my subs in a pro audio environment and they get used to the limits often. I need to get rid of this problem and the only way is by using them in parallel, with one amp per driver. This sub loaded with 2 21Pal presents a 2.25 ohms minimum load, 3.7 average in series so I would need an amp that can be stable at 1.1 ohms minimum at very low frequency and high power, meaning I'm left with 2 IPal modules per unit. From an economic point of view, it is not very good, I would be better with 2 separate single driver enclosures, where I would gain efficiency, output and portability at the same time. But a dual 21 dual IPal module ultrasubwoofer sounds very fun for fixed installations.
  6. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    Off course I did flip the Voltage meters to take them out of question, I changed the polarity, I changed the frequency, I put them in parallel on the same channel or different channels. The voltage difference exhibits only when linked in series. It is way way worse when they are free air, when they are not loaded by the enclosure like under port tunnig. The excursion difference is pretty obvious when I have the hatches open. I never tested their TS parameters. 2 of the drivers are not with me for now , they went to warranty, one of the remaining will go soon. The same thing happens with the ID drivers, the voltage is extremely different when measured but in this enclosure one driver had 1 hour of break in before loading, the other didn't. After 10 hours of high level music, the difference diminished but it was present still, at about the same level as with the IPal drivers.
  7. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    I am referring to electrical series not acoustical. I confirmed my theory by Akabak first and then I measured the voltage at the drivers connectors and they differ by up to 6 V when driven with 80 V. So one driver gets 37 V and another 43 V at the same time measured at 38 Hz where driver excursion is maximum. I'm going to test them as you said Sunday. Outdoors with drivers in series and parallel impedance and magnitude.
  8. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    If you look at the measurement I posted since I built these 2, youll see they all are a bit different, especially between 32 and 45 hz. The first ones are with the drivers in parallel, the last ones are with drivers in series. A different Q behavior... Look also at the response of one enclosure vs 2 of them, the ports get better with 2, a higher Q and at least 1 hz lower extension. Off course some of them differ because the space where I measured them is different and no matter what post analisys I use, some reflections will get into the final impulse response, otherwhize I loose resolution and accuracy down low. these differences account for about +- 0.5 to 1 dB sometimes.
  9. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    I put my camera inside many times. it does appear to have a problem there. Also the behavior is different when drivers are in parallel, the response between 32-39 hz is 1 db higher in sensitivity, but this I still need to verify again. when the hatches are open and i pass a sine wave anywhere under 50 hz, the drivers excursion is visible and the difference can be very big, like double somewhere under Fs. I'll instal the Ipal modules on them loaded with ID and I have decided shorten the ports to go to 32 Hz instead of 28 Hz as it is now. I wanted them to be 30 hz, I thought they ended up at 29 but 28 is definitely too low, especially for the 18Sound ones. I need to cut 16 cm out of them to be able to get close to where I want them to be but I have a vertical brace in my way. from the experience with the BR with RCF and from sims, going to 32 Hz will increase the output by about 3 db under 45 hz, the output at 30 will be the same and under that it doesn't matter anymore, because the place where they will be installed doesn't need anything that low. Again, I'll have to say about the sound of it, it is absolutely fenomental. The impact that 2 of these have is awesome. I'm in the process of designing and building another set of 2 slightly modified but the same dimensions. I can't wait to hear them together. I took a measuerement between front and back. Unknown voltage, 2 subs one on top of the other, equitemporal distance, so the distance are matche in impulse delay, not in ruler. very good directivity!
  10. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    I did the measurements again to directly compare the 21ID Vs 21IPal Measured at 4 meters, normalised to 2 meters CEA2010 2 m K20 bridge BPH221 ID 4 ohms 20 Hz 104.6 25 Hz 126.2 28 Hz 132.2 30 Hz 133.4 31.5 Hz 133.1 35 Hz 133.1 40 Hz 137.0 50 Hz 141.2 63 Hz 140.1 70 Hz 142.0 80 Hz 143.2 100 Hz 144.5 BPH221 Ipal 2 ohms 2 meters 20 Hz 105.8 25 Hz 126.9 28 Hz 134.5 30 Hz 136.6 31.5 Hz 137 5 35 Hz 135.4 40 Hz 138.6 50 Hz 140.7 63 Hz 142.8 70 Hz 144.0 80 Hz 144.6 100 Hz 145.1 I love these tests. The amp asked for huge amounts of power at 28 Hz where the port is tuned. I've seen 720 V peak to peak and 110 amps on the output with series IPal before the 20A breaker dropped. I can say that the drivers in series are a problem, a big one IMO. Very different excursion at 35 Hz between them, that's why the output is lower there
  11. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    It was the 451. The suspension is more linear and a bit softer. But the glueing seems way better applied and engineered
  12. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    All the measurements were made outdoor ground plane. One space where I measured the TH and F121 , a wall of the building was 14 meters away but the rest of the space is a lake and a field. I truncated the impulse response to eliminate as much of the load as possible. 17 meters the reflection came 100 ms after so I had very good resolution and clean response down to 10 Hz. The space where I measured Stasys XV2 that I will not publish, the BR with RCF , the SKhorn XL and others is a very large space where the building behind and on one side was at 25 meters and the other 2 sides were empty for more than 100 meters. I switched from MC2 to clone and X4 because I own a clone, a K20 and I have 2 X4 for an install that I could use but the MC2 was installed in a fixed place where Funktion and TH are installed. I am using REW for generating and measuring the output, Focusrite soundcard, earthworks M30 calibrated mic , a class 1spl calibrator , a Behringer calibrated mic for comparison purposes. Unfortunately one of the RCF drivers kicked the backplate with the coil former and it isn't in the perfect shape right now. I will soon test the SKhorn XL with 21ID , each driver on a K20 channel to see the numbers. Probably next week.
  13. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    Br221RCF 33hz bridge FP14000 clone 2 meters CEA2010 20 Hz 106 25 Hz 121.3 30 Hz 131.9 31.5 Hz 134.7 33 Hz 136.9 35 Hz 139 40 Hz 141 50 Hz 142.4 63 Hz 140.6 80 Hz 140.8 100 Hz 141.5
  14. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    CEA 2010 measured at 2 meters F121 MC2 E45 bridge normalised to 2 meters 25 Hz 108 30 Hz 115 31.5 Hz 117.1 35 hz 120.8 40 Hz 127.1 50 Hz 132.3 63 Hz 134.5 80 Hz 136.2 F221 measured at E45 BRIDGE normalised to 2 meters 25 HZ 114.7 dB 30 HZ 121.4 31.5 HZ 123.5 35 HZ 128.9 40 HZ 135.2 50 HZ 139.4 63 HZ 141.5 80 HZ 141.8 100 HZ 142.9 1*TH18 xoc1 measured at 4 METERS MC2 E45 BRIDGE normalised to 2 meters 25 HZ 110.4 30 HZ 123.3 31.5 HZ 125.1 35 HZ 128.2 40 HZ 129.3 50 HZ 133 63 HZ 134.3 80 HZ 134.8 100 HZ 136.6 2*TH18 xoc1 measured at 4 METERS MC2 E45 BRIDGE normalised to 2 meters 25 HZ 116.8 30 HZ 130.3 31.5 HZ 131.9 35 HZ 135 AMP LIM 40 HZ 136.3 clip 50 HZ 139.2 63 HZ 140.2 80 HZ 140.4 100 HZ 142.7
  15. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

  16. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    2* TH18 xoc1 8 ohms driver at 28.3 V@4 meters Vs 1 SKHorn XL 14.1 V 4 m. And compared to F221
  17. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    Another important fact are the distortions. For the same input voltage, 28.3V , between all 5 designs, 2*TH, 1*F221, 2*BR29hz RCF, 2* BR29Hz Ipal, 2*BR33Hz RCF and 2* SKHorn XL, the last one is the best one, with under 2.5 % distortion from 31-110 Hz. Compared to F221 that has up to 7%, or BR33hz RCF that goes to 5.8% at 40 Hz.. the proportion of the orders of harmonics are also very different and the ones with the drivers close to the surface have their own sound signature. I believe what I can hear is probably some very small air turbulences across the drivers diaphragms and suspensions and other things because of the fact that the acoustic impedance mismatch will always have a part of the air molecules wiggling over the surface, slipping away to the edges. Also any noise from the driver itself is not masked, but that is just it.
  18. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    @Ricci I messed up the phrasing on that. I meant that the RCF loaded enclosure with 29 hz tuning lacked punch and depth. The enclosures with RCF and 21Ipal are the same. After I changed it to 33 Hz, increasing the surface with 30% and decreasing the length with the same percentage, it improved quite a bit, but still no comparison to SKHorn XL, which indeed is absolutely devastating in that category! New tuning in green. It makes sense what you said about loading. TBH I don't think the main problem lies with the port losses, but with the magnetic strength and damping. Off course, the performances of a reflex enclosure is in fact simple to deduce from measurements and Sims and also is pretty simple to design properly. How it will sound though based on that,you could never really know until.you build it. I found something interesting regarding group delay and linearity. If it is my feeling that a lower group delay is good, but it makes things sound thin. A higher and more even group delay will exacerbate the lower frequencies and it will make them jump into attention.
  19. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    Add 6 dB for 2 meter results. CEA 2010 4 meters 1*F1218 ohms MC2 E45 bridge 25 Hz 102 30 Hz 109 31.5 Hz 111.1 35 hz 114.8 40 Hz 121.1 50 Hz 126.3 63 Hz 128.5 80 Hz 130.2 1*F221 4 ohms E45 BRIDGE 25 HZ 108.7 dB 30 HZ 115.4 31.5 HZ 117.5 35 HZ 122.9 40 HZ 129.2 50 HZ 133.4 63 HZ 135.5 80 HZ 135.8 100 HZ 136.9 1*TH18 8 ohms 4 METERS MC2 E45 BRIDGE 25 HZ 104.4 30 HZ 117.3 31.5 HZ 119.1 35 HZ 122.2 40 HZ 123.3 50 HZ 127 63 HZ 128.3 80 HZ 128.8 100 HZ 130.6 2*TH118 8 ohms 4 METERS MC2 E45 BRIDGE 25 HZ 110.8 30 HZ 124.3 31.5 HZ 125.9 35 HZ 129 AMP LIM 40 HZ 130.3 clip 50 HZ 133.2 63 HZ 134.2 80 HZ 134.4 100 HZ 136.7 The results I got with one and 2 F221 this summer were not ok, something was absorbing a lot of power under 60 Hz. I got +6 dB now from them today in comparison at 25 and 30 Hz. But still no match for a single SKHorn XL. It seems that it is very close to 4 TH18 at 30 Hz and 3 of them under 100 Hz.
  20. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    635 Liters net reflex enclosure, 1680 sq cm port, 40 cm length measured in the same place, same mic, same calibration, same windowing. I am very surprised that the Bandpass SKHorn XL loads the driver that low. The enclosure is very big and I don't like how it sounds on music, it lacks the real kick. But the deep end is very powerful and clean.
  21. radulescu_paul_mircea

    iPAL enclosure details

    Yes, the DSP is pretty old design, it is focused mostly on reaching the 2 microseconds latency to be able to use the DPC sensor and not on SNR. This means it is not suitable for cinema sound systems
  22. radulescu_paul_mircea

    iPAL enclosure details

    It is the DSP, it is made for outdoor pro audio usage, where the signal to noise improves
  23. Hello guys, I was triyng to build a pair of Othorns before Christma2s but my plans didn't go that well because it seems I can't find nowhere to buy ( for now) a pair of 21's fron B&C or 18sounds. So, now i still want to build a pair of subs and I was looking in other projects. First I saw the Xoc's Th18 and then the Keystone which I like it more because it is easier to build and it kinda looks cool When I compared the Spl results from Walter's measurements I saw it can reach around 130 dB/1m GP and has a FR down to 35Hz.same with Th18. Othorn on the other hand goes 8Hz lower and it reached a max Spl of around 137 dB/1 m. Also, on the specs of TH118 from Danley they say it has 137 dB cont. Taking into acount the compression for the driver in the Keystone, at 1800 watts as Walter measured that seems to be a very real, easy to verify value. Also I trust Ricci's measurements so if he says his sub gives that Spl, it does. So, now, the questions: 1. Is the 21sw152 driver that much more powerfull to gain 6 dB more at higher freq than the 18sw115, even if it is tuned 8Hz lower 2.where does Danley take their nubers from? Because from what i see, the xoc1 design is preety much the same and it has around 6 dB less continous output 3. Is there a company that takes into account power compressio? Because I can't find any 4. Which should be better in a small space af around 300sqm beetwen 2 Keystone or 2 Othorn both with 18sw115. Paul
  24. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    The new sub design in grey vs this one including some power compression effects added as eq , 140*140*70 cm so 40% larger. I put 2 vs 2 because from my experiments with subs the response doesn't go lower when multiples are used but they can take more power with less excursion and distortions, so it is a bit closer to real world results. I'll use 7075 alluminum braces to save volume, add stiffness and decrease weight. The drivers will have 2 additional ways of cooling so in normal full power usage, it will closer to 2 SKH larger, but the same number of drivers and amp channels as one.
  25. radulescu_paul_mircea

    Ricci's Skhorn Subwoofer & Files

    The idea behind this build is to learn. I started my company to sell subs, because here in this part of Europe, there is a very deep lack of powerful high quality bass Mostly I wanted to see people's reactions, the power density, the extension, to see if the weight and dimensions are a big problem. They are now installed in a basement where we got them by hand. I wanted to see about the power compression, port noises, chuffing, I have learned how and why to install protection grilles, handles, wheels, I wanted to see if I can improve their performance in any way without any other compromise except cost and complexity. I wanted to learn about braces, hatches, accessibility. These gave me a good insight on all of these These subs will be loaded with 21ID and Ipal modules and will permanently stay in rent in a small club where people love good sound. Based on what I learned, I'll continue my other designs and after all 4 designs will be ready and I'll have a stock of 4 of each, I'll publish the specs, measurements, graphs , technical details , pictures and videos and I'll start selling those.
×