radulescu_paul_mircea

What would that weigh?

http://www.pksound.ca/products/gravity-30/#1480026407865-fd911a0d-385b Another M-system platform sub. Bandpass

I have good internet connection ) best in Europe for sure (1Gbps connection for 10$ a month via fiber optics ) Yes, Bassboss is BassMaxx renamed because that was a trademark so he couldn't use the name anymore. His approach for using BR for 22-60 hz and Horns for 40-100 with an excellent integration is very similar to a bandpass horn approach.

Another brand that I know off of using this design principle (except KV2 ) is Traktion Sound , a small company with some interesting looking subs and speakers. http://www.tractionsound.com/loudspeakers/bps221-harpia.php They have a separated sub for 30-40 hz with dual 21", probably very efficient in the pass band and another for the rest of the range ,smaller with dual 18".that is probably a very good approach for best efficiency.

How the hell I missed this thread? Daaamn! I am working at some Bandpass subs and as you know they are the best option with good drivers now. I think I have simed more then 2000 iterations with all drivers possible from the worst to the best, to the impossible ) Band-pass horn in Othorn dimensions on the market ALERT! http://www.bassboss.com/subs/vs21-rum-punch-sub/ About 2 db less than the othorn though. I would probably not try to have the smallest enclosure and go for larger cab, ports and horn to get most of the drivers and amp there because they cost much more than wood and food for the people that carries it ) probably 50*40*25 or something.

Of course you would. But it would be more expensive.

So Audiholics measured and reviewed the sub already http://www.audioholics.com/subwoofer-reviews/svs-pb16-ultra-subwoofer/measurements I thought Ricci did the measurements for their subs

I know this is a DIY project and most of the satisfaction and value of the speakers is in the designing and building process. But for 5000$ for a pair of square speakers with a limited output and connections why not go to the market's best bookshelf speakers ever made: Devialet Phantom Gold? Fully digital,with wireless transmission,optical input, fancy remote, very very stable connection. The bass drivers are low impedance with a tech similar to IPal, the amps and power source are much beafier the the Ice modules, you get 103 dB at 45 hz from a pair in room at 2 meters, it looks really nice. The drivers have about 13 mm xmax and 16 mm xvar.the mids and tweeters are coaxial, proprietary design. The graphs are measurements in room at 1 meter made by a guy on the devialet forum. I have sold a bunch of these. I had Beolab 90 in our shop and on moderate levels one could hear no big difference. Again, I love DIY but it has to offer a much bigger performance/value to worth the headache

So taking that much power even in a very high efficiency system the heat will accumulate very fast. Using the metal wings attached to the motor one can increase the heat transfer but it is not as efficacious as forced air. And using the TruePower counter from Powersoft K10 generating around 1.2-2 Kw per channel drawing on average 3.1 Kw from the wall, to see how quick and how high 4 BC 18PS76 per channel will heat up, in 45 minutes of bass heavy music I ended the test because I got around 35 degrees Celsius increase. So putting only that power in 8 vented drivers I could get that temperature increase. Now imagine 2 KWh in a single 22 kg motor.

I believe the problem is the lack of active cooling . In a normal driver the moving of the coil creates air currents and that exchanges the heat between the driver and the medium but here they use only convection. In the F32 from Funktion one I believe they use the driver as per the image attached with a small chamber of air and in a horn enclosure using 8 of them which behaves more like a full horn.that raises the impedance for a good bit. The thermal inertia is very high so even though it is hard to increase the temperature, it is also as hard to decrease it . The M-Drive can generate around 5000 watt long term and 2000 watts thermal equilibrium so in 2 minutes you increase the temp with 20 degrees Celsius

Here is another sub using the M-Force/drive combo. Cool looking, fairly compact and probably LOUD. I wonder if it is a bandpass, transmission line or a TH...

I wonder if that app also takes measurements like the Elac one?

I am now playing with these babies and I have a SVS fan client with 3 Ultras installed and we listened to both of them for days now. He will probably end up buying the speakers but also will probably be the first PB16 client. As for the dimensions, could the 16" be in fact an 18" but measured only from the suspension edges?

From the image there it seems its ferrite magnet. The spider could be good enough. It doesn't look to be 15" ,more like 12. But when you look at the Ipal driver's spider you can see it is not that huge but it can allow sufficient excursion and control for the application.

Hi guys, It appears to me that Ricci has another cool sub to test. https://www.svsound.com/products/sb16-ultra 8" edge wound voice coil ! That said something!

I don't like to hijack your thread, cause it is not related to testing procedure you use, but this datasheet has some serious measurements and they even describe whats signal they used http://www.audiocore.co.uk/wp-content/uploads/2015/10/APA-Detailed-Power-Specs-Jan-2016.pdf It deserves a look at least

The room is 4*4 meters in an apartment building. The level I can get with those subs is formidable, using the amp bridge to drive them both but I took out one of them because it gets scary very quickly and I stay with rent :-D With some processing I got flat from 21 hz, and I try not to exceed sane, normal levels

It seems now I can also put my system list here: -2 monitor audio rx2 -2 xoc1th18 with 18SW115 -1 Teac AR-650 -1 Crown xls2002

I would love to see a clone tested this way

Here these dudes say they use 13 Kg of new N48 on their single 32 sub, 8" voice coil. Sick! http://alphard.audio/general/product/id2793

Keep up with these test! Your test, Ricci's and some others from the DIY community helped me to convince a client to get the best possible. I know it is not directly related with Luke's measurements, but I wanted to share a review with you about the Powersoft X4 (and for X8 at the same time, being 2 of htem in a single package) http://www.powersoft-audio.com/en/docman/1012-x-seriestestrevieweng/file That is a resonably way of review-ing amps IMHO

In a sealed burst test, I think other important factors besides excursion and thermal compression,are the break-up of the diaphragm, the softness of the adhesives and other small factors that doesn't have an effect at small signals but once you push ove a threshold, those effect starts to accumulate with other nonlinearities.

I got the number from here :-P http://www.rockfordfosgate.com/products/details/t3s1-19 Right at specs. :-) easy to miss if one doesn't look. There is a video on youtube with a better drawing but it is not a clear 3d model.

Yeah,for that kind of money I would settle with the video. They say it uses over 3 Kgs of magnet and that got me thinking that it couldn't all be only in those pillars. The "flower power" arrangement for the magnets looks good but are a little inefficient, from what I know.

So, after rereading all I could about these drivers, I noticed a something about the magnet structure. In the link at around the 1 minute mark that guy said it uses a single magnet in the center of the voice cool. https://youtu.be/Q83fnT6wsSI But Ricci said it has 6 pieces