If you haven't heard, Mach5's new 18" driver's T&S specs were released today. I tried modeling up a few enclosures but was running into a problem. To keep the tuning down in the mid teens and the port velocity within reason it was spitting out port lengths over 50"... I probably input something wrong... Anyone mess with this driver in WinISD yet? Any tips or even a screenshot of your driver parameters??
Can't wait to see the real world performance of the UXL-18...
And by the way, I was secretly hoping it would have a tall surround!
Yes, we finally have a reasonably priced 18" sub with performance capabilities. Shown below in 6, 9 and 12 cu.ft, all with 1200 watts input power.
With 1200 watts it would be easy to get away with not using a hi-pass filter. The 6 and 9 cu.ft models reach Xmax at 13.5 hz, the 12 cu.ft model reaches Xmax at just over 12 hz.
Porting would be best done with a slot port, the lengths are easily doable for the box sizes modeled. The 6 cu.ft. model has the smallest port suface area which is 37.5 square inches, that that same area as three 4" round ports. The air speed shown would be a non issue.
With 1200 watts it would be easy to get away with not using a hi-pass filter. The 6 and 9 cu.ft models reach Xmax at 13.5 hz, the 12 cu.ft model reaches Xmax at just over 12 hz.
Porting would be best done with a slot port, the lengths are easily doable for the box sizes modeled. The 6 cu.ft. model has the smallest port suface area which is 37.5 square inches, that that same area as three 4" round ports. The air speed shown would be a non issue.
Looks like a nice driver. I wonder what the pricing will be like on these. 9 cubes isn't even THAT big, and it seems like a pretty strong alignment tuned to 18Hz. Nice xmax at 34mm is a big step up from the IXL at 22mm, and the carbon fiber cone sure is pretty.
Fp: Resonance frequency (in free-air with no added mass) - 20.5 Hz
Qmp: Mechanical compliance loss - 6.8
Mmp: Moving mass - 300g
Cms: Suspension Compliance - 0.20 mm/N
Vap: Stiffness of driver scaled by cone size - 391L
Sd: Area of the cone - 1182 cm^2
Suspension Travel - 35-38mm one way. Somewhere around 70- 76mm peak-peak, depending on how far you stretch the suspension.
This would be a 24" external cube. 1200 watts of power with a hi-pass filter at 10 hz. 1500 grams of mass added to each PR. 115 db at 20 hz plus any room gain provided.
Yes, they are available tomorrow. I keep checking the site. I will place an order as soon as it is ready. I'm in Kansas City, so I figure it would take about a week to get here. I've started construction on the cabinet already. 3/4 birch with the PR sides and the driver sides double walled and flush mounted. 25" squared.
I have to disagree. Yes they model the same and here's where I disagree.
SDX15 - 12 cu ft box tuned to 15hz with 1000 watts input power, Max excursion reached at 13.45hz
Mach UXL-18 - 9 cu ft box tuned to 15hz with 1200 watts input power, Max excursion is reached at 11.98hz
At 21hz the SDX driver is at max excursion where as the mach audio is only at 21mm.
This tells me that the Mach audio has the same spl but with less excursion, smaller box and quite a bit more efficent and no doubt lower distortion too.
This will probably change when the Mk11 comes out though.
In all reality, The Max ouput is similar. The distortion numbers "could" be better, based on the motor topology, But the real thing is we're comparing apples to oranges, and getting results that are within 2% of each other.
All i'm saying is, its very similar to the Maelstrom-x 18, but much less expensive. It really is a good buy.
That 34mm xmax number somewhat tickles my fancy, But i'd love to see how it was measured.
Care to explain how you think it has a 6db dynamic range advantage over the SDX 15? If you are saying that xmax is the limiting factor on a speaker then sure. you're completely right, but thermal is an issue. If you can't get to that xmax without crossing the thermal barrier, you are just wasting it. period.
I took the time to model both, The SDX will be pretty close to xmax at 21hz at 1000w input. The Pi can handle almost 1200w, but, factoring in maximum SPL off the two drivers keeps them within 1-1.5db of each other. (this is with the SDX 15 at 1000W, its rated power, and the PI at 1200W) It doesn't matter how much xmax is left on the driver when you are pushing its thermal limits. I also happen to know through experience that the 1200w thermal rating on the mach 5 drivers should be closer to 1000. I own an 18" IXL 2.2, My brother in law has it in his car, wired for 1300w at 1 ohm, in a 4 cubic foot sealed box, The leads to the voice coils burned off with the gain at half, and he NEVER gets the full 1300w out of the amp.
I had a similar experience with a mach 5 audio MAW15. Running off one channel of my QSC RMX 2450, not bridged, (i beleive at 8 ohm thats only a rating of 500w rms) i popped my maw15, rated for 500w rms.
I personally would never run a Mach 5 driver PAST its rating. They are amazing drivers below their rated power, and bang for the buck a very high value product. Just not for feeding them GOBS of power.
I took the time to model both, The SDX will be pretty close to xmax at 21hz at 1000w input. The Pi can handle almost 1200w, but, factoring in maximum SPL off the two drivers keeps them within 1-1.5db of each other. (this is with the SDX 15 at 1000W, its rated power, and the PI at 1200W) It doesn't matter how much xmax is left on the driver when you are pushing its thermal limits. I also happen to know through experience that the 1200w thermal rating on the mach 5 drivers should be closer to 1000. I own an 18" IXL 2.2, My brother in law has it in his car, wired for 1300w at 1 ohm, in a 4 cubic foot sealed box, The leads to the voice coils burned off with the gain at half, and he NEVER gets the full 1300w out of the amp.
Out of interest, what cab sizes did you do those models with and how did you arrive at those sizes. One way to solve hitting a thermal limit before xmax is to simply increase your box size. Now I realise you may not have that luxury, but until cab size is accounted for as well, you cant claim a driver has hit its thermal limit before reaching xmax because I could model any driver to do that if its cab was far to small.
I do realise what your saying and agree, but the enclosure size is also an important factor in relation to what your saying here. If you modelled with 'optimal' enclosure sizes, what were they and how did you conclude they were optimal.
I modeled three drivers in the same enclosure with the same tune.
14 cubes with a 15hz tuning. AKA, LLT.
The box is huge, which should allow it to hit xmax faster, but it still doesn't.
The SDX 15, the mach 5 ixl 18.2.2, and the mach 5 UXL-18
Long story short, in the same box with same tune, the biggest difference was 2db between the ixl 18.2.2 and the UXL-18, the sdx 15 was dead center between. with the 1200w the pi driver hits about 22mm xmax. I wouldn't want to go bigger to get the extra xmax, 14 cubes is large enough.
I modeled three drivers in the same enclosure with the same tune.
14 cubes with a 15hz tuning. AKA, LLT.
The box is huge, which should allow it to hit xmax faster, but it still doesn't.
The SDX 15, the mach 5 ixl 18.2.2, and the mach 5 UXL-18
Long story short, in the same box with same tune, the biggest difference was 2db between the ixl 18.2.2 and the UXL-18, the sdx 15 was dead center between. with the 1200w the pi driver hits about 22mm xmax. I wouldn't want to go bigger to get the extra xmax, 14 cubes is large enough.
But then if the driver is optimal in the larger cabinet then your cabinet is the restricting factor. Larger cabinets lead to cleaner output as the cabinet effects drop off, something which is detailed in Steve's LLT guide. It is strange though as you have spotted, the low QTS of the driver should help the driver remain clean sounding, while the considerable motor force would make it a good option for smaller cabinets.
If you put this driver in a smaller sported cab, and I mean smaller in the proportional sense rather than physical, then it should sound cleaner than some other options out there. The stiff suspension and good strong motor should combine pretty well to make the driver pretty accurate all round. Ive no doubt the driver is a high quality one, and it would be interesting to get my hands on one for sure. Looking at the models its a great driver for just about any and all cabinets, and suitable for people wanting a big driver in a smaller sealed cabinets, or for people wanting a large LLT with a sound character akin to a low Q sealed system.
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