LSC

Yeah so much to learn especially when it comes to limiting and how manufacturer specs are calculated.. I reckon they should also state true RMS figures besides the aes and program power ratings.. Found myself quite limited in regards to limiters as I'm using a DCX2496.. might need a proper upgrade to be able to limit in multiple ways I'm also very pleased by all the input provided and will try to implement the limiting settings jay michael tried last weekend Also very intriguing idea of an impedance measuring-limiter device, maybe that'd help lots of people..

Okay sweet, easy does it! No just kidding sounds complicated but if that's a DIY approach of a feedback system then it's worth digging into.. Didn't read anything about measuring impedance with a soundcard but my soundcard has lots of ins&outs so channel count won't be a problem. How does one accomplish coherent IQ demodulation? Also, radulescu_paul_mircea, if you're reading this, what's your approach for limiting when it comes to prolonged bass notes on a regular basis?

Oh, I see.. ..different test signals vs. Real life conditions.. 😐 I guess I need to work out a limiting scheme for music with snappy transients in bass and one for music with continuous low notes.. And the power consumption of the amp is a big one for me as well as I like to keep things efficient.. Such a headache, I wish there'd be a limiter that measures the changing resistance of the coil as it gets warmer and then adjusts accordingly.. Some kind of a feedback loop

I'm not sure if I don't understand but the figures you calculated are way higher (not lower) than 700w? Am I missing something? Are we talking about sines coming from the amp? Sry for being confused and thanks for caring and elaborating!

Well well.. Thank you all so much for your input! I see that this is a complex topic which I really want to master one day.. Lots of different opinions and ways on this one.. I will try and implement limiting based on your suggestions/DSP capabilities Wondering how to set it though.. 400w long term seems so little and >1000w seems like a bit much but thats also what I thought the driver should be able to handle Also nice to hear a feedback on the temperature sensor idea, I thought of mounting a contact sensor onto the magnet to read out the temperature from time to time.. Maybe that'll be the safest bet for me as my DSP is limited in it's limiting capabilities and the opinions vary quite a bit ;( But I guess that's guesswork also as the temperature inside of the magnet is probably higher and I don't wanna find out how hot it gets before failing again.. I think I will try 3 different measures: 1. Never letting the signal be clipped by the DSP 2. Trying different limiters (short attack for kicks that are too loud, long attack for prolonged sinewaves) 3. Adding a temperature sensor to the magnet that let's me read out the temperature from outside the box Please keep on giving suggestions, I'm really soaking up input on this as it's very sad to not hear the beautiful skram bass in my living room anymore.. don't want it to ever happen again haha Also.. If there's anyone from the bass music scene that has experience in limiting, please let us know how to set a limiter without having a major drop of power during long notes.. if that's even possible?

Wow thanks for your thorough reply! Very eye opening.. It gives me something to work with and puts my (can't really blame the dj) abuse into perspective.. I assumed that the RMS rating states how powerful a sine wave can be for 2 hours continually ☹️ Silly me.. Oh well there's always a first... and more to learn haha.. Is there any literature on that? Also if there's any more input on how to set this combination up for bass heavy content then that'd be very appreciated! Will go from ricci's recommendations but maybe someone else who has experience in limiting right for low crest factor signals wants to chime in Also does anyone like the idea of temperature sensors? Apart from being impractical they would allow us to really know how the driver is doing regardless of how sophisticated the limiting works..

Sooo I created a thread in "bass gear" about the loss of a big voicecoil sitting in a skram and how to prevent this from happening again. It was the second time I used my skram and I was using a NX6000 amp. I'm posting this here as well to give a little bit of a heads up on how these things can happen even with moderately powerful amps and how to avoid them. Please learn from my mistake and treat your skram's nicely http://data-bass.ipbhost.com/topic/771-burnt-a-costly-drivers-coil-with-a-pricey-ampfollowup-and-prevention-of-costly-mistakes/

Sooo here we go.. As the title suggests I've somehow managed to fry my first pro audio speaker... Not really proud of it but I thought I'll make it a new topic so me and others can learn from my mistake and maybe some of the more experienced members here can give us a lil rundown on how to set the limiters right. So let me describe what happened: I was having a lil snooze around 4 at night when someone came up to me and said that the dj requests some help... I went and had a look at the amp rack to find my NX6000 turning on and off because of protection mode.. I couldn't believe it but after sticking my nose into the vents of my skram I had to face the reality that my beloved 21ds115 which seemed so indestructible had burned it's coil x( I fully deemed this impossible as the NX6000 puts out 1.8-2kW sines and it was a techno night, so no prolonged sinewaves like you'd have with dubstep or bass music in general... Butttt; now I know better and I suppose it was just getting hotter and hotter as the night passed by and thermal build-up was getting too much at some point?! Or could it be that steep filters are just better than the 12db BW I was using as high pass filter? Could it be that the DJ made the signal clip and the DSP somehow produced a harmful signal? Now to the prevention of this happening again.. Does it make sense to add a temperature sensor to the magnet of the driver which can be read by a handheld thermometer or perhaps even an arduino to monitor the temperature and adjust accordingly? Can someone please explain how to set limiters in the right way so nothing can get hurt but no bass resources gets wasted? ...I already thought of running sines, measuring them at full amp throttle and set the limiters according to the RMS rating of the driver but that seems (seemed haha) like overkill.. Please share your thoughts and tips fellow bass lovers so I can assess what went wrong and how to avoid it next time as this was a quite traumatizing thing to happen on the second occasion I had my skram out and about.. Thanks in advance, Nathan

The first test session with both was so good, lots and lots of undistorted bass leaving the mighty box.. Effortless and natural as many said before about your hybrid designs! It hammers every note down to the point where it feels like big slaps of air hitting you. If one dares to stick their head close it literally is breathtaking. Seriously. Much respect and thanks again to you Ricci for taking your time to design this subwoofer and for making it available to the DIY community! Please PM me with your paypal/banking details so we can send a donation your way!! Outdoor measurements couldn't be taken yet due to rain but I can try to get some 1Watt/1m/nearfield indoor responses if wanted. If someone wants to have a listen please don't hesitate to ask about my whereabouts in Germany.. Cheers, Nathan

Powersoft K20... some day hopefully NX6000 for now...at least I won't have to worry too much about limiting with one per channel, right? So keen to get&post some measurements soon, output is definitely huge as one could say!!

Second one almost done 😍 received_705947329803410.mp4

After a couple days of building.. first one is closed and sounds sweet so far (no real testing or measurements done yet but will get to that before the end of the month hopefully The Build was coming together quite nicely but it was still a bit challenging because we're limited toolwise and also woodworking-skill-wise If you just take your time and think through every single step twice (or more hehe) then this shouldn't be too hard to build though.. Here's some pictures of the progress so far, please be nice guys, second time building (and woodworking really..)

Okay that's good news, will go without the T-Nuts.

So good to see yous building already!! Liking your tweaks for easier construction without CNC, Jesal! Did you use 18mm ply for the vent dividers and does that even matter much (change of tuning freq.)? Also is it possible to just mount the driver without T-Nuts? They caused a lot of hassle in our last builds and we feel like we don't really need to take out drivers often..

Print is looking sweet as, big ups to josh!

Oh yeah it's very important to shut down the reactors at times.. 😜 https://en.wikipedia.org/wiki/Scram

Veerry understandable, Jesal and good to see that you care for your lonely skhorn in a way of constructing some little siblings! Keep us updated! Plenty of wood has been ordered, that's how far I got today x)

Any chance I could get a PM with the plan so I can order the wood? Couldn't find the measurements on the pics of post 2 somehow EDIT> noticed that prints will still take time, was confused by jesal already having the dimensions as it seems 😇

Hello First of all i wanna thank you for designing these awesome subs! I can imagine how much work you have put into the design and I really appreciate that you share your designs freely and support the DIY community with pro audio subwoofer designs that are able to compete with the big brands. I'm proud to be able to say that we will be making 2 of them loaded with 21ds115`s within the next few weeks. Maybe our party collective has the honour to be the first to build a pair of these beauties in Germany They will be used mostly outdoors for Bass Heavy music. We will make sure to take some pictures during the build and post measurements afterwards! Cheers, Nathan