Snell SUB1800's

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Hey guys,

I just got a pair of Snell SUB1800's for a very good price, and now im lookin for a cabinet to throw em in. Any ideas for cabinet size and vent diameter/length? Also, have you guys heard anything about these subs? They retail for $2500 each and theyre made by a pretty high end company, so I'm guessing theyre gonna be awesome.

Thanks.
 
I have heard these before, they are awesome subs. The only trouble is, the boxes were immense. They were over 8 cu ft. (actually checking Snells website, the dimensions are 45 x 21 1/2 x 17, but they don't mention port size). IIRC, there was one or two 4" ports in each beast. My best suggestion would be to build an 8 cube box (that somehow fits in your room) or an appropriate length of sonotube and a couple 4" flared ports and start tuning. They look like with a an fs of 17, they could take a 20hz box tuning.

John
 
Hey John,

I called Snell today and they told me the port is a 25" square with a length of 25", but that doesn't make much sense to me. That seems like an extremely small port, but is it becasue they are in such a large box? They also told be the baffle is 1.5" thick, what does that mean? Also, once I get these 2 monster boxes built, do I go about tuning them using different baffles or keep playing with port length? Sorry I seem so uneducated, I'm real new to this stuff, I just got an amazing deal on these drivers that I couldn't pass up, and now here I am.

Oh and pedroskova, yep I mean it as in Champ Cay, they've always been my favorite series, closely followed by F1, if they could ever pass each other lol.

Thanks so much for all the help
 
CARTRulz said:
Hey John,

I called Snell today and they told me the port is a 25" square with a length of 25", but that doesn't make much sense to me. That seems like an extremely small port, but is it becasue they are in such a large box? They also told be the baffle is 1.5" thick, what does that mean? Also, once I get these 2 monster boxes built, do I go about tuning them using different baffles or keep playing with port length?
Thanks so much for all the help


Hmm, maybe that was a square (slot) port. It was a while ago I heard them, but I don't think math has changed since then. If they publish that the box size is 45 x 21 1/2 x 17, I think it would be quite difficult to use a 25 x 25 port. If you don't have access to someone with a woofer tester (or some way to ascertain the Theil/Small params of the sub) and you don't have exact plans for the box, I would shy away from slot or square ports. They are harder to tune. Please keep in mind you don't have clone the original exactly, your design can be better if properly executed. I would suggest poking around on some of the forums for proper subwoofer box design, but in a nutshell, here are some tips. This is a BIG box, it will need proper bracing and/or thick walls. The baffle is the board that the woofer is mounted to, 1 1/2" would be a good thickness. This may mean laminating two pieces of MDF (or Birch ply) together. You may want to make the whole box 1 1/2" thick. You will definately want some bracing, how much is up to you, but basically, the more the better.

I would suggest reading at Mission Possible DIY They have some RL-p 15 projects you might want to look at in terms of how to build massive sub boxes.

As far as ports, like I said maybe two 4", one 6". It might be easier and cheaper to use 6" PVC pipe and just cut till it tunes up right. Also, build one box, get everything tuned, then build the other. Until the box is finished, because of the scale, you might want to think about mounting a set of casters on the bottom, you can always replace them with spikes when everything is done.


John
 
Hey guys,

So I got of the Snell's built and I gotta say, I'm pretty dissappointed. Its in a 8.5 cubic foot boz with 2 ports of 4 inch diameter and about 28 inches in length. Even with the thing kickin its just not at all what I expected. Could it possibly be my amp? I mean, its rated for 600-1000 watts, and right now ive got an old technics reciever rated at 115 watts/channel pushing it. I mean, im sure the cone is moving to its Xmax, but would the reduced wattage affect sound quality? Should I try making the ports any longer? Ive got the box made out of 3/4 inch birch ply, doubled (laminated) on the front and back so its 1.5", and the thing is braced to hell with 2x4's. Its also lined with insulation thats attached with spray glue. Any helpful hints would be great, as I'm kinda stuck, and I'd expect a little more from subs that go for $2500 brand new.
 
Never mind. I removed most of the insulation and took off the ports and now the thing kicks. Does that make any sense? Ive got just like 2 6" ports that are 4" in diameter and the amount of air that is moving out of them is absolutely incredible, and it sounds awesome for music. But I'm guessing its gonna suck for movies, so I gotta play around with the ports and get the correct length thats gonna be a compromise. Now I gotta build the other!
 
Sorry I didn't get back to you sooner. I'm glad you figured out the problem. Most folks tend to shy away from heavy insulation in a ported speaker. Tuning the ports might take a little time, but it will pay off in the end. The power might make a bit of difference, but I heard them underpowered as well, and they still rocked (I think it was 200w to each one). I hope you enjoy your new subs.

BTW, you might look to a pro amp to power these monsters. Crown or QSC will make something in your power range that will be more affordable. They say that anything less than 10% of distortion out of a sub is inaudible, so a pro amp having marginally higher distortion than a home amp shouldn't be a problem. FWIW
 
Hey John, or anyone else,

I've been searching and cant seem to find the T/S Parameters for these Snells. Do you have any ideas? I only ask because then I could run them in something like WinISd Pro and come up with some port lengths to help me out becasue right now I'm completely lost. Should I just buy an SPL meter from Radio Shack and a test tone DVD and go from there? If so, do you have any tips on how to use that to my advantage for tuning?

Thanks a bunch.
 
You could call Snell, if they give you the T/S params, you've got it made. Other than that, I remember reading somewhere how you tune a ported box with a ohm meter and a tone cd, but I forget where. I think the impedence spikes at the port tuning freq. I'm a sealed box guy myself, so I don't pay close attention to that stuff.

Putting a few calculations together, I think that 2 - 4" ports in a 8.5 cube box, minus the ports should tune to around 18 hz with 22.5" long ports. 6" long ports should give you a 30Hz tuning, which is a little high for these subs. Try 22.5".
 
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