Finshed my 18" sub .......Old school fosgate and HPSA 1000

[Deadof_knight]

OK here are the pics ..it turned out very satisfactory. Im just having some timming issues have to spend some time moving it around. But she goes Boom pretty impressivly. :D box Dimensions 27.25 x 16 x 18 internal with a cubic ft amount of 4.54.:D

[Deadof_knight]

Double wall construction on the baffle plate and floor plate. Good bracing Put an entire roll of r-13 yellow in it. I also put an additional set of binding post so I can run another sub in parallel in the future. (overkill)



http://www.polkaudio.com/forums/attachment.php?attachmentid=32238&d=1205976376

[Early B.]

Very nice.

Got any other specs yet, like how deep does it go? What are you replacing and how does it compare?

[engtaz]

Very nice. How did you come up the the baffle dimensions.

engtaz

[Deadof_knight]

Im going to borrow The HiFi shops RTA when I get back from business trip to Napanee Canada. I am it using in conjuction with my Velodyne. My Velodyne is a 500 watt 15 vented and does pretty good, dont know the frequency yet. But the 18 goes way deeper than the 15. My wife says its messing with her breathing. I just grinned cause it hits hard Ive got it crossed over at like 50-60 hz............The baffles board I just looked up the fosgate specs and kinda copied it but I like to double thick the actaul baffle board it most of my boxes. Use of T-nuts on all fasteners...

[GV#27]

Very nice work on the box construction DOK.;)
when I get back from business trip to Napanee Canada. Napanee! whats in that little place?
Thats about an hour east of me.

[engtaz]

Cool

engtaz

[Deadof_knight]

Napanee has a Goodyear plant there, I service all the North and South American plants. I have a 2 day service there as they have 2 of our machines.

[ben62670]

Good job. I have finally learned in recent years what a good box can do for sound. Do you have an SPL meter? SVS has a chart that corrects the readings in the lower frequencies. I did not realize this when I did my sonosub, and was so disappointed by the number. Corrected put a big smile on my face:)

[Deadof_knight]

What kinda numbers should I expect, ? If I could get the timming down the room should rumble I mean a set of 1.2s a 15 and an 18 should wreak havok on the pictures.....

Thanks for the complements ...after seeing everyone elses boxes Im like oh hell this has got to be perfect!

[ben62670]

The best thing to do is download True RTA. Get the free version. Run it at different frequencies, and right down the SPL numbers. If you don't already have an SPL meter you should get one. DIY rocks. If you are any good at wood working people should give it a shot. I use a GFA-555 bridged for my sub, and it puts out 850@4ohms. Manufacturers have to keep in mind shipping weight when building. We can brace the piss out of a large box, and dig a little deeper for much less money. I am not a huge fan of plate amps. PE has plate amp though that has a good power supply, and it also come in a standard amp config just like a regular amp.
Enjoy
Ben

[ShinAce]

If you use an SPL meter to calibrate, measure from a few listening positions. The variations in response below 100 Hz can be huge when moving a mere 12".

If your sub is at the front of the room, have the meter facing the side walls.

[Deadof_knight]

Thanks in advance for the Tips and any more you guys have it will be something like thursday or friday before I test........

[Deadof_knight]

OK here is what Winisd beta says for now

http://www.polkaudio.com/forums/attachment.php?attachmentid=32238&d=1205976376

[Deadof_knight]

So GV where are located I just drove back to Toronto a lil bit ago ..... Im assuming your somewhere around Kingston ?

[GV#27]

Im in Peterborough which is approx 100 miles north east of Toronto.

Atleast you got to expierence the 401 HWY on a good weather day.

[venomclan]

Nice work.

[Deadof_knight]

yes the drive was clear and my timming was great no traffic !!! woohhooo just getting outa Toronto can take forever on a bad day. not too mention NO snow !!!!

Back to some suggestions ... I posted winsid beta specs. looking at the graph its pretty poor but listening to it is totaly different ....

[Deadof_knight]

Somebody else run the specs and give your two cents ?

[ShinAce]

If you want to dig deep, you're looking at a bandpass box. If you do that, you'll lose a lot of that RF 'punch'.

Keep what you have now, it's good.

[Deadof_knight]

Either that or big a monster BOX ! I do like the punch it delivers. I was hoping Ben might step in here and yak some about this .... I do have to say though it knocks the socks off my Velodyne 15 .... If get them in unison it should be a sweet sound ....I guess that have the fun it tweakin it all. I went today to try an get some formica for the box having a little trouble finding glossy black though .Im thinking a black marble is my next choice...Then get the grill done and maybe look for a Fosgate badge of sorts

[dorokusai]

The bracing is a bit odd but I'm sure there was a method to the project. I may have missed it but what are you going to veneer it with? It looks pretty cool, have fun!

[ShinAce]

Btw, next time you double up on the baffle, cut the outside panel hole as 18" and the inside panel hole as 17". Flush mount is king, ;)

[ben62670]

Here is the correction chart for a Rat shack meter.
http://www.svsound.com/questions-faqs-rscomp.cfm
In room is where you need to test. You really need a meter to get these boxes right. I may be tossing my sonosub in favor of a box that looks like a coffee table. Trim, handles, false hinges, and all. Back to square one. At least I know where to go with volume, and port size.

[Deadof_knight]

Ah I see what your taking about Shine very nice idea Im wanting to do my grill, I think I have enough wood left I can still do flush just slap another layer on there ,,,,The damn thing is heavy as hell whats another 5 lbs Doh !!! I just checked out the formica deal I found Black gloss Formica almost 3 dollars a square foot OUCH! have to buy 4 x 8 minimum sheet !!!! But it will look good and match my TLs pretty close.

Thanks Ben hey I wanted to go the Sonosub route but I only have really one place to put this bugger and thats under my stairs. Sonsub route would really light up the stairwell probaly turing the stairwell into a horn loaded sub and blow the door off!!!!

The bracing explaination On the one side you see is just a short piece I wanted to connect front and back plates with the top and bottom , In the center that worked well, on the right side it worked well. on the other where the amp is I had the amp in the way and that is just what I came up with. Im still thinking of using two oak 1 inch rods Like I normally do just to the right and left of the speaker. This should firm it up a bit, THe small pieces by the amp shore up that area because in my opinion the 3 /16ths amplate needs help . I ve doubled the front baffle the bottom plate the only piece that vibrates a little is the top. Its enough to walk a remote off of it ( I wanted 1 inch mdf didnt want to wait for it to come in) To cover it again is about the same amount of work if I use rods.....So Im up in the air.

Also The box volume is within the realm of what Fosgate said to be min and max 3 min 5 max I came from the car audio craze of the 80s and I liked the kicked in the gut bass So this project has turned out to my liking pretty good Allthough I thought it would fair a little better frequency wise. My boy says that its just plane unnessesary !!!!! As he drivee off with his P2 12 and 500 watts in his Tahoe :p

[ShinAce]

The thing about the low freq extension is; that sub can displace a LOT fo air, so by setting an EQ properly and keeping the volume to reasonable levels, you can extend the reach of the sub.

If you do mount it in the corner of the stairwell, you will be horn loading the box. Horns have an inherent bass cut-off freq as well. This one will probably be higher in frequency than the sub's natural cut-off. For that reason alone, I ask that you try it with caution, paying careful attention to the very low notes. If it does work to your satisfaction, consider slapping a sheet of drywall on the staircase to get rid of the jagged egdes.

Have fun!

p.s. Shin is japanese for god version. It's from Street Fighter where akuma becomes god akuma, or Shin Akuma. I use this name because of the influence SF had on me and the fact that Ace is usually taken. Ace is just the name I use to record high scores. It all has meaning, but very little.

[Deadof_knight]

Well the stairwell is completely sheetrocked allready but Im thinking of casing the subwoofer area so its its own cubical. and stop the bass comming out the door or the stairwell. Plus Im fighting the sub being behind the couch..... typical home problems and keeping friendly with the wife!

[Deadof_knight]

Ill take pictures later to give you an idea of what im dealing with .

[ShinAce]

Looks to me like a nice grill on that sub would make it a coffee table.

My personal sub is a 4th order bandpass box with isobarik(or clamshell) 10's. Total box volume is around 4 cubic feet. I used 1/2" plexiglass as a top and glues mylar film to the inside walls. It's crazy enough for me, and most people don't even realize I have a sub. Usually, I have 2 arcade joysticks chillin there;blocking the view.

Here's the best pic I can find right now. I'm in bed with a chest cold and not getting up anytime soon.

[Deadof_knight]

What kinda subs you got in that coffee table there ?

[ShinAce]

Random. Max Pentivent 10". PV1020/4 or sumthin like that. I ended up measuring the T/S specs and they're not bad. I don't have the specs in winISD anymore, but they're -3dB around 20 Hz and 70 Hz in the box. They can take 110 WRMS and I'm feeding each 80. It was convenient because I wanted something to fill in the 20-60 Hz range and the bandpass design came out perfect as a table.

A long time ago, a buddy asked me to build him some 3 ways for parties. I used that 10" because it would work and take the bass. He bailed and I swapped the 10's in the towers for pioneers and used those 2 to make a sub. It's the same loudness as a single 10", but half the box size. I kept the towers(and gave up my bookshelves+a sub) which are pretty decent. Two 5" crown midranges in a D'Appolito with the tweeter.

[Deadof_knight]

I understand the Isobarics just havent tackled one of them yet. I bet its nicely controlled even if it is a bandpass, being that its a push pull Looks nice not real big and you dont notice it. I was never a fan of bandpasses because guys were always building the 6db boxes and they just didnt sound good LOUD as hell but ......
Now that Ive seen a coffee table in use might just have to jump off and try it !!

[ShinAce]

For home theater, where you need some real low end rumble, and the punch of the bass is coming from the mains, it fits the bill nicely.

For music, I'd take a decent vented 12" anyday.

[Deadof_knight]

OK i was worried about phase and a whole lotta other stuff was even going to tack on 2 10s to boot to the eighteen so i could still keep some midbass. I finally stuck the big beast under the stairs (still havent got it formicad yet ) Gotta work too. Well I just listened too it and.(UNDER the STAIRS) I set it up to start with right next to the 1.2s and it was pretty darn impressive But thats not where I can have it . So I stuck it under there too make momma happy and let her have the living room back. (wow) Im probably gonna put my Velodyne in a whole different setup now Damn ! That puppy gits it!!!! I dont need a RTA too hear that kinda difference. Be nice too know but eeeehhhh Im just going to enjoy it for now. Now I think Im gonna build a a set of fifteens muhahahah for what ever reason. I think I need intervention this has got too be a syndrome of somekind damn sure an addiction.

The eighteen picks up where the 1.2s start to roll off. Ive got the sub set up just loud enought to hear and feel and the sound stage is still forward and doesnt muddy the mid bass. Im one happy camper now.

MUhahahha!!! ladida!!

[GV#27]

I think I need intervention this has got too be a syndrome of somekind damn sure an addiction.

Its too late there is no intervening now,you are headed down that slippery slope and no one here can help you with your plight.Good luck.

[ShinAce]

YES! Learn the ways of the dark side.