Jump to content

TUMULT DIY for Synergy setup...some pics *edited


kramskoi

Recommended Posts

Just thought i'd post some pics of my object of obsession since November of last year. What was then only envisioned, is now coming to fruition. I'm hoping it will be a nice match with my Synergy sb-2 system. I went straight from 8", all the way to what is arguably the best 15" driver available. The cabinet is a little over the top but i can rest assured that it is quite dead.

The 2" front baffle will shortly become over 3" because the builder made the driver cut-out too wide for my taste. A 68 pound driver needs as much wood to adhere to as possible. The walls are 1-1/4" and there are 4 internal braces at 3/4". I've added some foam to the inside but that will be all. The only sound coming from this box is the cone, needless to say!

I built an impedance analyzer and i've determined the exact Fb of the box. I will need this for the Marchand Bassis, which will be used to blend the sub into the room. I spurned the idea of an LT circuit...too much trouble and not enough options.

The spring clip terminals will also get the axe shortly. I just needed to be able to test the impedance analyzer with the enclosure. I was'nt sure if i'd built it correctly.

I'll probably get either the ep1500 or 2500 to bring the beast to life and safeguard against clipping. I'll see then, if i need a Behringer BFD. The box measures 21.5" cubed and 3.3 cu. feet (net) internal volume.

Anyways, here are some pics:

post-19343-13819283642492_thumb.jpg

Link to comment
Share on other sites

You need to use the file attachment feature at the bottom in order for

your pics to be visible to everyone else on the internet (gotta upload

them to the internet - right now they're linking to the file on your

harddrive). You can do one pic per post and it automatically gets

attached to the bottom after you post your message.

Link to comment
Share on other sites

i'll tell you what it's NOT!...that's 14 5/8" like my builder did!...stick with 14 1/8" and if it's too small just hull it until it fits.

I'm about to glue another 1 1/2" to the front baffle so i have yet to do the cut out but i'll probably go with 14 1/8", as noted above.

I think adire calls for 14 1/4" for the tumult driver. Trust me, to see this driver is one thing, to actually lug it around is another. It's pretty massive. It will need as much wood to adhere to as possible. The consensus for a 68 pound driver is to use t-nuts.

I'll let you know how it comes out after i cut the hole. I'm not sure about the hole layout.

Link to comment
Share on other sites

yeah, whew! is right...i did the cut out, today, at 14 1/8" and the driver still moves around (1/16" on each side)...14" would definitely work best.

I'm not going to do another baffle, 14 1/8" will have to suffice. I don't understand why these drivers are'nt real world tested though.

I hope that 1.5" will be enough to secure it properly.

Link to comment
Share on other sites

Thanks Jay. The beast sealed up fine. This caused me the most worry over the past few days. I used black weatherstripping (wal-mart) and the included rubber gasket. No problem! I did'nt even bother screwing the new baffle...i think titebond will suffice...it's pretty darn strong!

The enclosure was a b**** to lug around. I did'nt weigh it but i'm pretty sure it's over 100 lbs. I have a few bumps and scrapes from bossing it around. It's definitely a two-man lift now.

With my enthusiasm (and patience) for sanding and painting on the wane, i put just three coats of black lacquer on the box. I may add more later once i clear my head.

The 3.5" front baffle puts a "serious" muzzle on the driver...the cabinet is whisper quiet!

I tested the sub yesterday, and i was seriously impressed. I'm running the sub-out from the yamaha to an older RCA rt2280 receiver via the "multi-channel-in" mode. The RCA sub channel is rated for 80 watts @ 8 ohms/.9% THD @ 1kHz (40-20,000 Hz). I'm not sure how much actual "clean" power i'm getting at 4 ohms but i was surprised by the level of output. I should have some real power by next weekend, then i'll secure the Bassis and BFD to finish the project.

In my 1,800 cu. ft. space, i recorded a "clean" 90 dB @ 20 Hz...6 meters from the sub. This is near the back wall at one of two listening positions. I also scored 104 dB @ 28 Hz (~2 meters) and 81 dB @ 16 Hz (6m near rear wall) ,uncorrected, from a digital RS meter. All this from a substandard receiver. I can hardly imagine the output of the ep1500 at it's mono-rated 1400 watts. It's going to be an interesting weekend![:D]

post-19343-13819283813914_thumb.jpg

Link to comment
Share on other sites

holy crap uncorrect at 6 meters!!! I think it is about 6-10 db for

every meter away!!! but on the other half that concerns me is the fact

that you have not screw the sub in. I think that if you get up there in

excursion that you may actually pop the sub out onto the floor which is

NOT GOOD! BTW you used titebond???? Ummm that is going to be a

permanant fix then ! You should never have used titebond to glue the

woofer shut. Yes it is great for sealing but what about servicing the

sub or so?

Link to comment
Share on other sites

Ooops, now i've done it...*giggle*...no,no, no Jay. I meant the front baffle. Had to add another 1.5" because of cut-out errors on the original baffle. I used eight (#6) 2" wood screws to secure and seal along with the weatherstripping. I'll tighten it a bit more until it settles. It's pretty airtight as is though. ZERO resonance from the cabinet so far!

I was thinking about using 3" screws for additional support of the new front baffle but titebond is really all i need. After the first 30 minutes of bonding, i was unable to move it at all! No way would i seal the driver with titebond!...lol...sorry for the confusion.

My room is on the small side and it has a unique shape. There is a cubby hole which is 6' wide X 10' deep. With the sub sitting corner-loaded in this hole, that part of the room acts as sort of a bass horn. I recorded the 104 dB (28Hz) as it opens into the larger part of the room. I also have the advantage of being able to totally seal the room if i need to. The 20 Hz and 16 Hz readings were taken at >6 meters. The sub is sitting behind the LCD and side-firing. The rear wall reinforces the bass wave so this probably influenced the readings. All of the readings are uncorrected. Not too bad for less than 100 watts of power.

I was so impressed with the output of the sub (with the little RCA) that i've taken the klipsch ifi and the m&k out of service. I'll be sending both to ebay shortly.

The tumult sounds as articulate as the 8 inchers it has replaced. It pounds at the appropriate moments and is silent otherwise. I expect even better with the marchand bassis on tap for on-the-fly Q adjustments. The only bummer is that i'm back at work so i can't play around with it.

I think that positioning and the anti-resonating cabinet has subdued my 75 Hz room node to the point that i can run the crossover at 80 Hz instead of 60. I can already see rb35's in my future...probably next year.

For a final tidbit...i was able to exceed, handily, the combined output and clarity of both the previous subs combined...it's not even close! And with less than 100 watts...incredible![:o]

Link to comment
Share on other sites

thank god! I thought well you know. But the screws, I am going to buy

the machine screws from mcmaster-carr and I already brought some

hurrican nuts 10-32 for the baffle. The measurements are crazy! Also I

am glad you like it and the tumult is one of the ultimate subwoofers

hence 100 watts is all it is needed to kick the ifi and m&k ***

btw woodglue like titebond and such is stronger than the wood itself

surprisingly. Glue two pieces of mdf and then try to break it with a

hammer, the wood will break but not the bond

Link to comment
Share on other sites

holy crap uncorrect at 6 meters!!! I think it is about 6-10 db for

every meter away!!!

You lose 3dB for every doubling of distance. So at 2m you are 3dB down

from the rated sensitivity at 1m. At 4m you are 6dB down and 8m is 9dB

down, etc etc...losses in an enclosed room are actually less due to the pressure loading and reverb in the room.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...