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what's the ultimate sub build? :)


Paducah Home Theater

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Anybody ever heard these?  

 

http://www.istonline.ca/mach5_ftw_21.html

 

 

Very popular drivers.  Any idea when they'll be in stock?

 

 

Didn't know they were out.  Is that a 96.9 db sensitivity at 1 W / 1M???  The way its stated looks like it but I don't know why it is labeled "LP".  I'm assuming it wouldn't be all that great for music though.  

Edited by MetropolisLakeOutfitters
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Firing into the laundry room may not shake the house anymore than another location.  What shakes the house is the long bass waves.  Just like the car you can hear a block away.

 

Right now I have somewhat of a buffer, basically there is a laundry room and mud room between the theater room and the rest of the house plus every wall is insulated and the ceiling is double insulated, so it filters it surprisingly well.  If I fire it into the laundry room, due to having open architecture, if I forget to close the door there is literally a clear shot straight from the subs to the bedrooms, plus who knows what will rattle if four 18's are firing directly up against a washer and dryer just inches from the sheet metal.  I'm afraid of the rattling more than anything.  I could almost be talked into the ceiling installation although it doesn't seem like that would be very friendly on your insulation in terms of your heating bill.  

Edited by MetropolisLakeOutfitters
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it doesn't seem like that would be very friendly on your insulation.

 

I only had one issue insulation wise.  My house was blown originally with cellulose and the living room has a peaked roof.  The vibrations actually caused the insulation to sluff off the peak.  I was never a fan of cellulose as it's basically treated shredded newspaper and whoever did the original job was light in a bunch of areas.  I had it reblown with fiberglass and never had another problem.

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it doesn't seem like that would be very friendly on your insulation.

 

I only had one issue insulation wise.  My house was blown originally with cellulose and the living room has a peaked roof.  The vibrations actually caused the insulation to sluff off the peak.  I was never a fan of cellulose as it's basically treated shredded newspaper and whoever did the original job was light in a bunch of areas.  I had it reblown with fiberglass and never had another problem.

 

 

I was mainly worried about heat loss through the subs.  Or do you bury it in insulation?  

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It does not get cold in Texas like Kentucky winters, lol.  I would have love to do an IB but backed out due to the basement ceiling tiles  possibly popping up and down.  I wish I had a separate heating / ventilation system but, the wife is pretty good not to complain much.  She knows sound rules!!!

Edited by derrickdj1
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The suspension is extremely stiff on those drivers.  I'd wager the graph would look significantly different after break in.

 

I noticed they used a 4 cu ft box as well.  I believe that's the MINIMUM size box you can put it in.  Ficar recommends 4-8 cu ft for sealed.

 

I would think they broke in drivers before testing them. If they are pro's they did. Driver T/S specs are based on drivers which are broken in.

 

The difference in 4 cu ft and 8 cu ft with this driver is marginal at best:

 

we5caSDl.jpg

 

 

 

 

 

 

Here is the graph. Is it something I did wrong??

 

Don't know.  Did you select dual voice coil?  Was the Qts and Qes calculated?  They look way off.  I don't have winisd on this computer.

 

Some of the information on their site was wrong. The biggest thing was the CMS. They had it as .73mm/N, which is way off.  This caused the WinISD calculations to be way off as demonstrated above. Also, I had entered the RE as 1.4 and it is 2.8 since there are two voice coils. Oops...

 

Here is the new graph. It looks a lot better, and is now -3db at about 25Hz. Much better...

 

That Fs is still way too high. That driver should be down in the high teens. That's also causing your Vas to be way too low.

 

For comparison, the Ascendant Ava 18 I mentioned above has a Fs of 18Hz and a Vas of  407 liters, and the SI HT18 has a Fs of 17Hz and a Vas of 412 liters. Vas is a function of Cms * (Sd)^2, so something in the 1xx liters range is very low for an 18 unless it is incredibly stiff. :)

 

We may be in a bit of luck. Data-bass measured and actual Q18 in 2012. I have entered that data into WinISD and run a new graph. The article is here: http://www.data-bass.com/data?page=system&id=98&mset=108

 

The fs was in the 30hz range with that version of the driver, and the vas was even lower than the one from the website. It is all a bit confusing, but at least a third party has offered some hard numbers:

 

 

 

The suspension is extremely stiff on those drivers.  I'd wager the graph would look significantly different after break in.

I do know that they've gone the multi-spider route lately, perhaps that's what's going on to some extent. Even then, a Vas of 110L for an 18" driver is extremely unusual unless it's car audio specific: small box, high power. The Q line is (was) intended to be their non tiny enclosure 2kW/ea offering. Perhaps times have unfortunately changed. If they've really gone the high stiffness route, then nein for HT use, unfortunately :(

 

But I guess the market drives the product. :)

 

Unless something new comes up, I tend to agree. These may have been the ultimate, but I think the drivers Carl is using in his IB would destroy these in LFE.

 

 

Mustang - granite is about 44" x 128". I paid a deposit so they wouldnt cut it. Im only charged on what I use.

 

What about a LilMike LilWrecker under a 44" x 90" section of that? It would leave a 7.75" overhang on the near sides and 10" on each end. I drew a picture:

 

1Y4JjB5.jpg

 

The LilWrecker is a beast of a tapped horn sub. 

 

Here is a nice (low cost) build of a LilWrecker:

 

Folded Tapped Horn Subwoofer Tuned to 17hz

 

Here is a LilWrecker compared to an F20 size wise...

 

3682Ithl.jpg

 

Actual LilWrecker measurements:

 

f58f557f_lilwrecker25201m.jpeg

Edited by mustang guy
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The height is my first concern, been planning on it being about 20" high due to having to put a center on top of that.  This could work if I could put the center behind the screen.  

 

I have room for two of those behind the seats though and I know ported subs sound really good down low in that location.  Is there something that could go up front and compliment one of those sitting behind me?  Or two as far as that goes?  :)  

Edited by MetropolisLakeOutfitters
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The F20 is 20" high. If you could find a place at the back of the HT for a second F20, you would have a kickin setup. It's good to something like 22Hz. About the same as a THT, but with more output potential.

 

Note: there are lots of people here who use F20's in their HT. You should be able to get a lot of feedback on it. There is a build thread or two here also.

Edited by mustang guy
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