radulescu_paul_mircea

I have a version of SKHorn that is larger than the original, it's extremely close to a pair of Skrams in dimensions and it's loaded with a pair of 21" Ipal drivers. I tested it with CEA bursts and recorded the max level of a few more subs, including TH118. Usually, the tests were done with a bridged K20, an ISEmcon mic or earthworks M30, at 4 m and every time the system was calibrated with a B&K calibrator. 2*TH118-8ohm versions on a FP14000 bridged 25, 28, 31.5, 40, 50, 63, 80 Hz values 116, 130.3 , 132.0 , 135.0, 136.3, 139.4, 140.2 dB at 2 m You can compare to SKhorn measurements from data-bass and you'll see it's just about the same level difference as the difference in drivers and enclosure dimensions, meaning about 3 dB overall. You loose that when you go for a more normal 21", but I gained about 2 dB from the larger enclosure in the deep end and larger ports, which I believe will be the case with SKrams. That's the thing, they made the TH118XL that can get you about 6 dB more at 30 hz compared to the smaller version, at the expense of the max level at 45 hz where you get into excursion limit. I believe a Skram loaded with 21DS115 or similar will be a bit lower in output at 30 hz and on par everywhere else wtih TH118XL. another very important aspect is the fact that the sound is so much different! Tapped horns have an extremely clean sound at LF tuning, they have so much more surface than a port so they tend to be cleaner down there , but they don't feel as tight and as punchy as BPHs . in my experience, for very deep bass music, I tend to like TH a lot more, they can keep up better with heat and they sound so smooth! Very large horns are even better, like BC218 but those are just for installs IMO. For all-round use, I'd go either with my dual 21BPH or with simple well designed reflex subs. because right now, reflex with L-Ports like L-Acoustics , but loaded with NTLW-5000 series from eighteensound, tuned to 27 hz, is something one should hear to believe!

I finally got my hands on this driver. The coil is so huge , the wire thickness seems to be 0.45 mm and 4 layers, it's coil is twice the wire amount of B&C21Ipal (of course, not the same efficiency) . It will take loads and loads of power. The excursion reached is probably over 8 cm peak to peak in this video, using a K20 at 16 hz

I believe you will always get a smashing win when going diy vs commercial bang for buck! There's no competition. I went that way too. You need 3 SKhorn to meet 2 BC218 over 30 hz , but under 30hz it will be more of a 2 to 1 ratio. If you went lower, the ports would need to be a lot bigger in length and noise would go down. f132 goes just up to 60 hz. The new Powersoft designs go to 100. I think best bang for buck is SKhorn, best smashing output density and wow factor is EDMSub from Powersoft with dual 30" drivers , which is 2 or 3 times more powerful long term than 1 SKhorn. Ipal drivers don't go that low even though they are beefed up. Eminence is a bit better that low because of the lower fs IMO

Hi! I have some questions for you before I can answer yours. First of all, where are you from ? What is the main purpose you need these subs? Rental, Live events, DJ, club, or home use? what type of music are you mostly working with? yes , I heard BC218 , a pair, they are tremendous subs! But very very large. Really full power at 25 hz I also heard M-Force drivers in F132 from Funktion one and some prototypes from Powersoft before launching. F132 goes as low, at 25-26 hz if I would compare BC218 to F132 I would say they have the same extension, same cleanliness, but F132 is louder and BC218 goes higher,it's easier to integrate without kicks . SKhorn is not tuned as low in native mode. Tuned at 30 hz, the ports are pretty noisy, but the sound is really good. I felt like the sub could benefit from a larger enclosure with larger ports and a bit higher tune, at 32 hz , and that's why I chose to make it that way. In essence it's the same sub, if left at 29 hz tuning, it was maybe 1 dB louder which is nothing. I would go for the original design. If you need it for dance and techno etc, then larger is a bit better but not worth the added weight and volume. but when used with 1/3 of the port closed, it does extend as low as the other two. I think BC218 is 3 dB louder under 30 hz but infinitely more clean . F132 is probably 6 dB louder or so and probably even cleaner. min skhorn I tried lots of drivers, best was RCF LF21N551 but that's not available anymore. I liked it more than 21Ipal, similar power but sounded deeper. Next choice would be Eminence. the new M-Force designs are promising but they are pretty much same as a dual 21" sub, except of EDMsub with dual driver. That's a malefic beast

I was just wanting to post it! They've been working on them for a while, changed the motor a lot

Yes, it happened to me with B&C drivers . You will find my video on YouTube

In the last 2 editions of Voice Coil magazine they measured the Eminence drivers, the 18" and the 21".

Extremely interesting idea about this amp? Are you limiting it to 110V-16A it will you go to 230 V and even more, like 32 A ?

This is not M-Force , it’s a chinese A&D audio driver. Neo motor and 8” coil. I heard the M-Force more than once and it is absolutely amazing. Unfortunately the users had some unlucky situations with them but they indeed perform extremely well! that Funktion one sub is the loudest sub out there !period ! and it digs deep enough to be extremely impressive. It goes louder under 50 hz than 2 SKhorns XL loaded with Ipal and used with other subs from 60 hz up they will have enough headroom. There are a few companies who have 6 and 8 of them in use constantly with great results.

It is in fact a modified version of 18SW100. Slight difference, mostly in suspension

Improve collateral heat transfer from the coil directly to the environment instead of coil to magnet assembly. With M-FORCE is really easy, but with a moving coil, it is really complicated. I really like a more open assembly, like those made by the car audio sub manufacturers. DD Z series comes to mind. Add a cooler and you're done! I own 2 Ipal modules. They are powerful and really good match for a 21Ipal driver. One could get the other into thermal limit of either one of them , depending on situation. The DPC sensor position has to be in the Apex of the horn

In my SKhorn XLs I put them on the inside, to keep the design . They are absolutely needed in pro use, I found anything from sweaters, bottles, shoes, screws to napkins, purses and all kind of things inside

http://www.atelier-der-tonkunst.de/produkte/pol-ddi This is the link to the product. Really good and very low distortion. Capable of taking 200 Vrms at under 1% THD is super useful. I tested it for limiter settings and it works as it should. I will try to get my hand around on how to use it for live Impedance monitoring. That would help me a lot

Found a solution. Instead of using an oscilloscope to look at the voltage, I got a device with -40 dB of voltage gain reduction, with galvanic separation to be used directly with a sound card. I can now use it to get measurements for sound output in paralel with voltage output. I can even use the output of the amplifier as an input reference for transfer function of the speaker alone, with any nonlinearity of the amp eliminated . But I can also measure the amp dynamically, in use, which is a nice feature