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Lilmike's Cinema F-20 - Page 8

post #211 of 1695
Thread Starter 
Regarding amps.

Anything that delivers 300 watts to a 4-ohm load is sufficient to drive the MFW. I did not test above 300 watts, as that has exceeded the thermal rating of the driver by ~33%. I noticed no complaints, so I'm pretty sure that 300 watts is OK. The AV123 MFW-15 amp was 350 watts if I recall, so anything in this range is fine.

Many of the smaller pro amps will work very well, most provide a little more power than we need, but the driver should be OK.

I like highpasses at 20 Hz, for reasons I explained earlier.

Should have the flange details up later tonight.
post #212 of 1695
I'd like to add a couple of completed F-20 pictures. I apologize for the crappy quality as they were taken with an iPhone. But you get an idea of the sheer size of this thing. Its pretty TALL! I am super happy with the ease of the build as I kept a timer of the total hours I spent to build and it took right at about 8 hours to get to this point. I figure theres 2 more hours worth of finish work and shes ready to roll.The driver is breaking in as I type this and I should be doing test tomorrow night.







post #213 of 1695
Quote:
Originally Posted by turdlepoker View Post

Check with ERICH on here and ask for a shipping quote. If he will ship international, I highly doubt it's $190. That's the difference in the price between the MFW and the Dayton (at the price you stated).

Yes I'm waiting on a reply but just in case shipping is ridiculously high I was just asking if the Dayton will give me identical performance. BTW I don't have a problem with the price I would pay for the Dayton's at all but if I can get the MFW-15's for a bit less that's even better.
post #214 of 1695
Thread Starter 
SWEET! There's another one on the way!

Build looks excellent!!

Come on now - it is only 5 feet tall.....that's shorter than my Shiva cabinet....and this one gets louder.....

@ crabra:

The Dayton DVC works fine.
The Ref HF does too. The Exodus Tempest X2 is a monster in this.

As it turns out, lots of drivers work well in this horn, it sort of worked out that way. I really did design it for the MFW-15.

@ everyone

Updated the Zip in Post #1 with another sketchup showing the detail of the flange assembly. Other than changing the other filenames for consistency, there were no additional changes.
post #215 of 1695
Lilmike, I'm not sure if you mentioned this already but I figured, I would ask you directly.

Did you caulk fill the spaces between the gasket on the MFW? Looks like it won't seal completely without doing so. Just curious if you did.

Thanks :-)
post #216 of 1695
Quote:
Originally Posted by lilmike View Post


..

@ crabra:

The Dayton DVC works fine.
The Ref HF does too. The Exodus Tempest X2 is a monster in this.
As it turns out, lots of drivers work well in this horn, it sort of worked out that way. I really did design it for the MFW-15.

Thanks, Those drivers are all available down here. The most expensive being the Tempest X2 of course. You say it's a monster in this horn, what does it have over the MFW-15 and DVC? For me it would be about $100 more than the DVC and not sure about the MFW-15 yet but probably twice as much.
post #217 of 1695
Thread Starter 
Quote:
Originally Posted by turdlepoker View Post

Lilmike, I'm not sure if you mentioned this already but I figured, I would ask you directly.

Did you caulk fill the spaces between the gasket on the MFW? Looks like it won't seal completely without doing so. Just curious if you did.

Thanks :-)

Yeah, I did.

I used little pieces of the PE speaker caulk.
It's not exactly called out, but I mentioned that in the build instructions...

Caught a couple of typos - new instructions posted in Post #1
post #218 of 1695
Thread Starter 
Quote:
Originally Posted by crabra View Post

Thanks, Those drivers are all available down here. The most expensive being the Tempest X2 of course. You say it's a monster in this horn, what does it have over the MFW-15 and DVC? For me it would be about $100 more than the DVC and not sure about the MFW-15 yet but probably twice as much.

Double the Xmax and 3X the power handling means that the Tempest X2 will put about 6 dB on the MFW in this cabinet at 21 Hz.

The Tempest X2 models at over 120 dB, at 21 Hz 1M groundplane, within xmax at full power. Not at all shabby for a single 15" driver. While there were two on the shelf last time I saw Kevin, my wallet is still definitely feeling the recession. I hope to test the Tempest X2 in this cabinet soon.

The DVC is also an excellent choice, it puts about 4 dB on the MFW, but runs out of linear excursion at 500 watts. The DVC's voice coil is actually a smaller diameter than the MFW's, but the DVC has a little more xmax and somewhat higher power handling.
post #219 of 1695
I am curious if anyone has tried two of these together yet. I have the first one half way built down in the garage and was thinking of a second to help balance. Or maybe it is just me. I will have to hear the first one in position and Get it EQ'ed to get an impression.
post #220 of 1695
Lilmike,

Just out off interest how much bigger would this need to be to get a tuning off about 17hz with a tempest x2 driver or even a shiva.

What input power did you model the tempest x2 on?

Also how important is it on this design to cut the correct angles where the piece meets the next piece. Is it possible to keep the wood straight cut when building this.

cheers

Graham
post #221 of 1695
Quote:
Originally Posted by lilmike View Post

Double the Xmax and 3X the power handling means that the Tempest X2 will put about 6 dB on the MFW in this cabinet at 21 Hz.

The Tempest X2 models at over 120 dB, at 21 Hz 1M groundplane, within xmax at full power. Not at all shabby for a single 15" driver.

Exactly why I am getting the xls 1500 So when I available I can get one of these and blow the doors off!!


Quote:
Originally Posted by Rob Flanery View Post

I am curious if anyone has tried two of these together yet. I have the first one half way built down in the garage and was thinking of a second to help balance. Or maybe it is just me. I will have to hear the first one in position and Get it EQ'ed to get an impression.


Im doing the same, building one, seeing how it sounds, then having a second ready to go if necessary


Hey turdle, so you just took scraps and mounted them underneath the access panel screwed onto the side it seems? How do you plan to seal up the access panel door to the rest of the cab?
post #222 of 1695
Thread Starter 
Quote:
Originally Posted by gperkins1973 View Post

Lilmike,

Just out off interest how much bigger would this need to be to get a tuning off about 17hz with a tempest x2 driver or even a shiva.

What input power did you model the tempest x2 on?

Also how important is it on this design to cut the correct angles where the piece meets the next piece. Is it possible to keep the wood straight cut when building this.

cheers

Graham

I sort of discussed that here. I have the F-24 fold done, I'd be happy to post it up if people are interested. It basically gives you 3 Hz and costs you 3 dB. No free lunches. Once I'm at 20, I'll take dB over additional Hz personally.

Shiva X2 is not a good driver in this cabinet. I have a home for those coming soon - just need some shop time (and it is supposed to rain this weekend).

Thought I said that the Tempest was modeled at a kilowatt in, which is the thermal limit.

PL is good stuff, but can't work miracles. Miters help a lot. The smaller the gap, the stronger the joint will be. There are only 3 joints that have to be mitered, and I drew them in for a reason. I did not like the look of things without the miter cuts. Tip the shoe on the circular saw, clamp your guide in place and go - it is not that hard to do.
post #223 of 1695
Thread Starter 
Quote:
Originally Posted by Rob Flanery View Post

I am curious if anyone has tried two of these together yet. I have the first one half way built down in the garage and was thinking of a second to help balance. Or maybe it is just me. I will have to hear the first one in position and Get it EQ'ed to get an impression.

Just one here.....I only have one driver....

Hope to drag it inside and audition it properly this weekend, should have some help on Sunday.
post #224 of 1695
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

......
Hey turdle, so you just took scraps and mounted them underneath the access panel screwed onto the side it seems? How do you plan to seal up the access panel door to the rest of the cab?

That is discussed in Step 8 of the plans. I posted a new drawing of what I did in the Zip file with the Sketchup plans in it.

Here is the exterior:



Here is the interior:


Hope this helps.
post #225 of 1695
The MFW's are only $70 a throw and 120db + at 21hz for that kind off money I am thinking off buildiing two and see how it goes. They should still be good for HT even with a 20hz tune and even better for music.

I don't own a circular saw and would probably loan one. I need to go back through the thead and download the sketchup and cut sheet files.

Would this still work ok with 3/4 mdf?
post #226 of 1695
Thread Starter 
Quote:
Originally Posted by gperkins1973 View Post

The MFW's are only $70 a throw and 120db + at 21hz for that kind off money I am thinking off buildiing two and see how it goes. They should still be good for HT even with a 20hz tune and even better for music.

I don't own a circular saw and would probably loan one. I need to go back through the thead and download the sketchup and cut sheet files.

Would this still work ok with 3/4 mdf?

A hand-held circular saw is the fundamental tool needed to make this. A decent one is less than $100 US, you can get a perfectly serviceable cheap one for half that.

MDF??? Maybe.

I'll never know. I hate working with MDF. The dust is awful, it is less sturdy than plywood, and it is heavier. I'd use OSB over MDF personally.
post #227 of 1695
Plywood is really expensive here in the UK. Are there any particular types off ply that is more suitable than others. I have never used ply before.

I have found this stuff.

http://www.building-supplies-online....uce-3582-p.asp

Not cheap. I don't mind mdf or the dust. If this would be fine in mdf that would be ok to me. My current subs are very heavy so these would be a breeze in comparison.
post #228 of 1695
Quote:
Originally Posted by gperkins1973 View Post

Plywood is really expensive here in the UK. Are there any particular types off ply that is more suitable than others. I have never used ply before.

I have found this stuff.

http://www.building-supplies-online....uce-3582-p.asp

you want to make sure that you have something that is going to be the most resistant to warping over time, and is strong. Birch, and auruco plywood seem to be the favorites. I used aruco ply for mine and it truly is much easier to work with than MDF
post #229 of 1695
Mike, thanks for the additional drawings, it is smooth sailing for me now so stoked to get home and get to work on this guy. im already envisioning buying three more sheets for box #2 with a set of tempests. MMMMM
post #230 of 1695
Quote:
Originally Posted by lilmike View Post


Yeah, I did.

I used little pieces of the PE speaker caulk.
It's not exactly called out, but I mentioned that in the build instructions...

Caught a couple of typos - new instructions posted in Post #1

Thanks for the reply. I'll probably just squirt in some basic over the course tile and window caulk. I figure it should be just fine.
post #231 of 1695
Quote:
Originally Posted by lilmike View Post

Double the Xmax and 3X the power handling means that the Tempest X2 will put about 6 dB on the MFW in this cabinet at 21 Hz.

The Tempest X2 models at over 120 dB, at 21 Hz 1M groundplane, within xmax at full power. Not at all shabby for a single 15" driver. While there were two on the shelf last time I saw Kevin, my wallet is still definitely feeling the recession. I hope to test the Tempest X2 in this cabinet soon.

The DVC is also an excellent choice, it puts about 4 dB on the MFW, but runs out of linear excursion at 500 watts. The DVC's voice coil is actually a smaller diameter than the MFW's, but the DVC has a little more xmax and somewhat higher power handling.

WOW! The Tempest has a good bit to offer. The question is if the extra money is worth the extra DB and if you will use it in the real world once the sub is properly calibrated???

Either way, the extra 6db would scream!
post #232 of 1695
Quote:
Originally Posted by beastaudio View Post


Hey turdle, so you just took scraps and mounted them underneath the access panel screwed onto the side it seems? How do you plan to seal up the access panel door to the rest of the cab?

Exactly as you described.... Once you cut out the Access Hole in the side panel, per instructions you will have a 3/4" overhang to attach boards too. Just cut 4-1.5" wide boards with scraps to the specific length (they don't have to be perfect as the PL Premium will do its job). Just apply the PL to both sides where it will make contact and from there you will just insert a few screws and it will pull it tight. Just be sure to wipe up the PL squeeze out as if you don't the panel wont have a flat surface to sit on. Once you start the project you will see how it all goes together.

Link to gasket: http://www.parts-express.com/pe/show...number=260-542

And as for installing the access panel door... You just put some speaker gasket down on the flange (try to do this in one piece from start to finish to minimize places for leaking) then just screw the panel down to flange. I don't recommended regular drywall screws for this as they have a tendency to countersink and leak.


I purchased these from Lowe's for $5.97. Due to their design they just pull themselves tight and don't usually countersink. These worked great on a THT project I did.

post #233 of 1695
Thread Starter 
Quote:
Originally Posted by gperkins1973 View Post

Plywood is really expensive here in the UK. Are there any particular types off ply that is more suitable than others. I have never used ply before.

I have found this stuff.

http://www.building-supplies-online....uce-3582-p.asp

Not cheap. I don't mind mdf or the dust. If this would be fine in mdf that would be ok to me. My current subs are very heavy so these would be a breeze in comparison.

That is decent ply, a bit expensive though. I can get equivalent material for $23 US a sheet. For this build, I used shop-grade birch ply. It was ~$30 US/sheet, but I did a bit of shopping to find that price. MDF is typically under $20 US/sheet, but I have not bought any in years. I used to build everything out of MDF, but switched to ply/OSB about 5 years back. I won't use MDF again.

I prefer OSB to MDF, quality OSB is lighter, stiffer, and about the same price. It glues far better too. Finishing is harder, but I typically only use it for paint-grade or test cabinets, so that is a minor concern.

If you want to try MDF, I think you'll be OK. Others have made horns of MDF and had no problems.
post #234 of 1695
I do not think my wife would be happy if I built one of these as I am looking at a smaller design of lilmike's......however, the output of this thing is SO INCREDIBLY TEMPTING!

But it would block a window....maybe it could be a "raised platform"

mwahahaha!
post #235 of 1695
Thread Starter 
Quote:
Originally Posted by turdlepoker View Post

Exactly as you described.... Once you cut out the Access Hole in the side panel, per instructions you will have a 3/4" overhang to attach boards too. Just cut 4-1.5" wide boards with scraps to the specific length (they don't have to be perfect as the PL Premium will do its job). Just apply the PL to both sides where it will make contact and from there you will just insert a few screws and it will pull it tight. Just be sure to wipe up the PL squeeze out as if you don't the panel wont have a flat surface to sit on. Once you start the project you will see how it all goes together.

Link to gasket: http://www.parts-express.com/pe/show...number=260-542

And as for installing the access panel door... You just put some speaker gasket down on the flange (try to do this in one piece from start to finish to minimize places for leaking) then just screw the panel down to flange. I don't recommended regular drywall screws for this as they have a tendency to countersink and leak.


I purchased these from Lowe's for $5.97. Due to their design they just pull themselves tight and don't usually countersink. These worked great on a THT project I did.


Those are similar to what I used, they work great. Predrilling through the panel helps to make sure things pull tight. But - I didn't bother.... I just spun the screw in part way, then reversed the driver and spun the screw in the hole in reverse to open the hole up, then tightened it up.

Lazy man's pre-drilling....
post #236 of 1695
Thread Starter 
Quote:
Originally Posted by Kimeran View Post

I do not think my wife would be happy if I built one of these as I am looking at a smaller design of lilmike's......however, the output of this thing is SO INCREDIBLY TEMPTING!

But it would block a window....maybe it could be a "raised platform"

mwahahaha!

T-6 design/build thread is coming. Came up with a different shaped fold that I'm playing with (taller and skinnier), but may set that aside for the short term and get this design out there for folks to play with too.

The T-6 is within a dB or two of the F-20 at a watt. People (myself included) have measured SPLs in the low to mid teens with the prototypes.

Seriously, other than the size, the most significant difference between the two is that last 1/2 octave. The T-6 does not go below 30 Hz, but, the T-6 is 1/3 the size of the F-20, and really only gives up that last 10 Hz of extension.

Highpass the T-6 properly so that the driver does not complain when trying to reproduce things it can't possibly do, and I doubt you'd really miss the last 10 Hz for most content.

Sure, it leaves some on the table. At least there is room left in the room for that table when you build a pair...
post #237 of 1695
I like the T6's and think that as a pair they represent some real bang for the buck in performance.

That having been said...

I drug the F20 into the theater this afternoon. It has been drying for the last 16 hours and should be pretty much ready to go. The key word here is drug. This thing is heavy. There are moments when I am thankful for my size. My wife couldn't have budged it.

This horn has no manners. It is not polite. The quality of the build is crude to say the least. I used up alot of plywood that would have otherwise set in the garage for want of a current project. There is nothing dainty about the sound either. This is not a sub. This is the kid in 4th grade that kicked the dirt out of you every day and took your lunch money. I had it fired up to break it in for a couple of hours and then gave it a bit of juice. I am sure that at some point my heart will start again. It felt like I was smacked in the chest by a 2X4! Nice design Mike. I am sure once it is EQ'ed and set properly it is going to be nothing less than spectacular. I am now looking upstairs at the Living room for a home for my T6's, and the bedroom and kids playroom and garage and bathroom and... for locations for the Anarchys.

If you want to impress your friends and kill anyone that wears a pacemaker this is the horn for you. It pack alot of wampum. Now I just have to drag it out the back door onto the deck tomorrow and give it a coarse sanding and a coat of flat black latex. This thing has taken our theater to a new level. Breathless, effortless Bass.
post #238 of 1695
Quote:
Originally Posted by lilmike View Post

Sure, it leaves some on the table. At least there is room left in the room for that table when you build a pair...

That is the coolest way I have seen anyone describe the difference between a FLH and a TH in this forum. Bravo!
post #239 of 1695
Mike,

This is the guy I'm holding out for; understand this one is further-out.

If you have not sourced a driver yet, and have a target driver in mind, please ping me via PM. I'd like to contribute to the cause.

You and Erich are assets to our community and shouldn't eat these investments alone.

Larry

Quote:
Originally Posted by lilmike View Post

Cinema T-16 (a little further out, model is done, fold is sketched, but I currently have no suitable drivers to test with, though I am working on that too...)
Tapped Horn, 16 cubic feet, F3 ~17 Hz, 15" drivers, less than 3 4X8 sheets of ply. As with the T-12, widths will be varied on this one, and it might also get a stretch, this all depends on the results.
post #240 of 1695
I was thought I was going to build a mess of Anarchys for my HT. But now you guys have come up with this one!

My dedicated HT is 17x26x9 with an attached hall for a total of about 4,400 ft^3. I'd guess two would absolutely kill my poor little B&W ASW1000. Is four overkill? I'd use a B&K AV5000 MKII that I have lying around - it's rated at 145x5 into 4 ohms. Also plan on using a MiniDSP.

Good stuff - you guys rock!
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