radulescu_paul_mircea

The thing in the Ipal system that is most important and interesting is the fact that as far as the designer is concerned, there is an electric input and an acoustic output, size and weight constraints and maximum Spl/cost. Using that DPC allows one to choose a desired transfer function and no matter of the inherent nonliniarities of the drivers, that BI is overwhelming them so it is easy to modify the system to match the target response.

Even though this 21Ipal driver is formidable on it's own, I really love what it can do in a complete system, in the pro audio domain. Taking into account only the fact that the effects of aging are largely diminished, can expand the life of one's investment and that is a serious advantage.

Martin audio MLX says its 8ohm driver

 

"DLS18002 18" Driver 8 ohm MLX £1,083.00"

 

https://martin-audio.com/downloads/datasheets/MLXspec.pdf

 

8ohm B&C ipal 18"?

If you look into Ipal AES convention paper, you can see that it "can be matched to any high performance low frequency high excursion transducer, even though it's performance can be maximized if used in conjunction with some specific transducer" and I believe being a matter of cost and profit, it isn't always the best choice to make the best one can do, because for 3 dB extra, it is better for them if you buy an extra box than to spend more to use the best driver.

I never opened a MLX sub so I cannot know, but they definitely use the Ipal module controlled by their own software

The KV2 specs for the sub's continuous output when two are used is spot on! 141 dB from a pair and 147 from the Ipal version with 34 Hertz extension is the most sincere spec I'be seen for a while ) that's if you don't read the rest )

The Martin ASX user manual is more than interesting. it said about the driver being capable of a 30 mm one way stroke and 152 dB SPL, even saying to limit the peak output if one cannot keep the minimum distance at 4 meters.

We, DIY-ers have some things to compete with now, not only bass reflex subs

That package is quite good, and possibly even better with the Ipal driver module combo. Also a design a bit larger with a bit lower extension could be a game changer for me.

Yes , those ports are huge , as are also those in VHD sub, but even with those sizes I measured about 2-3 dB compression at vent running. But for a fact I know that a part of that is because of the power amp because although I had 2 K8, an X8 and a K20 with me that I installed on another location afterwards, I only used the VHD 3200 because of the special connections and I didn't have the time to change them.

The VHD sub is measured as you can see in REW and the simulated response usinng basic band pass crossover looks almost Identical. The sub was measured outside on a beach close rangeand also at 10 meters with no object around closer than 20 meters. the graph is close mic.

When I was comparing the efficiency and output of the KV2 vs Othorn i was comparing 1 VHD 2.21 IPal vs 2 Othorn Ipal.

The other sims are fictive, based on what I think the Martin Asx looks like inside, but larger with 2 drivers inside. first would be with Ipal and second with M-force.

My main question is if the Ipal technology has a way of compensating for the port compression at very high output.

From what I know, a Helmolz resonator works well when alt the air mass from the port is resonating. when turbulences occur the efficiency drops and after a certain air speed the sistem tends to be nonliniar and the speaker starts to behave almost like in a leaky sealed enclosure with a higher tune and a good cooling system, but that port will not really help the driver to get more sound . That is why I always thought FLH and TH are more suited for extreme SPL than Bass reflex or Band pass. But then I thought that this tech from Powersoft could have some methods trough which they can overcome this problems or compensate for them in a way.

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

http://www.powersoft-audio.com/en/docman/911-m-force-kit-guide/file

 

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)

http://www.fohonline.com/news/14257-powersoft-drives-audio-for-super-bowl-50-entertainment-performances-with-120-k10-amplifiers-and-m-force-powered-subwoofers.html

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.

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.

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? 

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

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.

I turned the subs upside down on their wall brackets and I managed to get rid of that large peak.

I will soon build a pair of Othorns or maybe Palehorns :-P with 18Sounds 21ID using the Ipal Mod and also a K10 to compare the output. I wanted to build them with 21Ipal but I will get these for free to test them for a year so I can't complain...

The 18Sounds 21ID is exactly the same as 21NLW9601 but with a lower RE voice coil. The distributor in our country asked the Factory representative directly and that was the answer they gave me.

If you use the Direct program from Danley and set it to continous you can see what those subs are really capable of. Set a mic in the sim at 10 meters and play with them and see the response on the graph. There are real repetable real world measurements. And for the speakers you can use Program setting because they can go a bit higher than continous setting shows

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 )

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

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.

So, after spending some time with both the Danley TH118 and the xoc1 th18, I can say that there is no major difference between them. Only one dB more from Danley before it starts to distort badly, but I couldn't hear the difference.

Here are the measurements taken close mic, in the exactly the same position, on the wall bracket, inside the pub.

 

 

 

Hello,

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,

Hello,

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

We should ask sine123, he has more info. He told me that they had been thermalling that night. For now there is no info about them on their site. They will officialy launch it in about a month.

This big, to be more accurate

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.

 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 

153 aprox, including power compression from 32 Hz up But damn, it's expensive :-/

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...