RSS315HF-4 12" "The Raven"

For incredible output w/ that setup, build a Bill Fitzmaurice Tuba Home Theater (THT) 15" wide......great output down to around 20-22hz....

Not sure if lilmike has done sims on a narrower F20 for this driver...

JSS

djk, what kind of performance are you hoping for and how big is your room?

Isn't there already a subwoofer called "the raven" ?

Yes there is, Bosso's creation.

James

Thought so. Now we have 2 ;;

You crack me up. He says he's going to build a ~2ft box and, in typical AVS fashion, you reply with "but wait, if you build this ~10ft box, it will be even more awesome". Now I am waiting for the multisub folk to come in and recommend he build 3 more, add another 20A circuit for the amps, upgrade his mains to Pi3's, and look into building bass traps, acoustic panels, and skyline diffusers.

djkest: I suggest you leave this forum now before you go broke and deaf...

The Raven is retired. The name came from the same thought the OP had, it's all black. I kept the original, which is truly one-of-a-kind. The Tumult MKII-based Raven offered more performance per cubic inch than anything I'm aware of and had the only active conductive-convection driver/box cooling system ever. It easily would have topped Ilkka's all-time CEA 2010 subwoofer list, which included some pretty good subs.

I think continuing the Raven moniker with subsequent DIY builds is a great idea.

Bosso

I've built a sealed design using the same driver and amp in one cubic ft. with very good results.

Bosso,

Since two minds were thinking the same thing, maybe this is a type of sign for djkest to start him on a quest to make very nice subs also. If he comes close to your Ravens someday that would be a nice success.

James

Only reason I suggested it is because I have modeled it in the past. I didn't say he had to build it. If he wants lots of output out of a 12" driver, it's an OPTION...in other words, he can consider it...

And your contribution is? I don't see one other than critique. Nice....

AVS forum is known for the notnyt and MK and other systems....he could just as easily have asked this at HTShack and PE Tech Talk and gotten an answer which would have probably made you happier...


djkest,

Yes, outer dimensions of a THT optimized for that driver will be 36"x36"x15". Placement for aesthetic's sake would only work well up against a wall, and could "blend in" with some fake cabinet doors in the front....if it's a tough sell...

If you want to go the sealed route, a 2 cuft box will get you a Q of around 0.7.....and provide a very friendly freq response. The driver will take about 250W before reaching Xmax at 20Hz (and below), about 108dB from 60Hz on up before boundary and room gain. Just as you said, you'd be 3dB down from that at 36.2Hz...If you highpass, you can go louder with more power. With the OAudio's 25Hz subsonic filter engaged, you can get another dB or so before running into Xmax again.

If you go vented, a ~4 cu ft box will get you more output down to 20Hz. OAudio's 300W amp would work well with it's built in 20Hz highpass for a vented box, as the driver will take 300W and just reach Xmax, and the highpass would be necessary to prevent overexcursion below 20Hz. You'd get around 109dB and extend the -3dB point down to 20Hz, again before boundary gain or room gain.

The THT will get you more output than either one, but it comes at the price of space and complexity to build. Without a highpass, it will give 112dB with 150W. Highpass at 25Hz, and that gets you to to 115dB with around 300W.

Those are the options I see with that driver and amp, I'm sure someone can model up a bandpass box with ease....

For low to medium volume music (around 75-85dB), the sealed would be a good way to go. If you see yourself wanting more volume (spl), just build another for an extra 6dB.

If you want the most output, build the horn....

For something in-between, the vented box is an option.


JSS

ROFLZ!!!

I do sound that bad.

"The room it's in now is huge..."

i would suggest a change of plans. you won't benefit from any room pressurization in a large room and with only a single sub to work with, the added extension of a sealed sub will simply be lost.

you want a ported sub because it will produce 6db or so more spl in the 25-30hz region, which is what you are probably really missing right now.

of course, the driver that you selected isn't the best for a ported design. the dayton dvc-385 will be ok with ported and with 500 watts, this will get you 116db at 30hz.

here is a 5 cubic foot enclosure with one 6 inch port that is 20 inches long which gives a tuning of 25hz. at 500 watts input, the cone moves 13mm, which is fine.

"As far as expectations, I hope it will be better than what I have now, which shouldn't be too hard. It's a 9 year old 10" ported Klipsch (about 1 cubic foot) with 100 W amp."

this will knock the snot out of what you have now. my best guess for what you have now is the red line.

"I think maximum dimensions would be like 36 x 20 x 20"

that is plenty big to build the above design and have some space left over, but not much. :-)

Wrong. My only contribution was sarcasm and funnies...but only for scott I guess.

I'll try to be funny next weekend.

13" internally, 14.5" external looks like it works pretty well.

Horrible day at work.....stain on me. Shouldn't bring it home, I guess....

Yeah, we tend to advise people on the hi side of things, much to the chagrin of well done drywall work.

JSS

curious: did you use screws etc to hold those braces in place or just glue them in place? Not judging just wondering

It will be worth it. Once you have this set up and running you'll never want to go back to a store-bought sub again.

It looks to me like the most conservative switch setting on the Oaudio amp (which has about 4db of boost at 23hz) will cause you to reach Xmax at only 100w or about 106dB. You can tame some of that with a resistor change and/or using the PEQ, but either one will cost you low end performance (the 4db boost does help the response curve).

I really hate to say this after you've started building (your work looks great by the way), but I liked LTD02's advice about the 15" DVC. His 116dB estimate is spot on and the difference in the low end would be significant.

I am so sorry for making you second guess things. The sub you are building will certainly work, and it may be that you are right about rising impedance - I am no expert there. If you proceed just be careful and use the PEQ alot (-7dB or so at 23hz) when you first start cranking it up. I will say that when I checked two subs wired in series it was a much better match up between amp and drivers. A sealed 12" just isn't going to have a lot of deep bass. Great for music, better control, but not deep for LFE stuff most HT guys want. You do have to factor in that I am a convert who believes strongly in ported subs for home theater (not necessarily for music) so you have to consider that. I've gone from two sealed 12" subs to two ported 12" subs (both TC Sounds) and am currently building a 15" ported sub. The way this disease is progressing it will probably turn into two if it works out well. It's like that commercial where you can't eat just one... and you happen to have a big room to fill up with bass.

In WinISD there is a way to model the filters and the info I posted in that Oaudio thread is accurate and I believe I am modeling them right. I think most people who even bother to consider the HPF's effect on the response simply model the amps with a .707 Q and either a 2nd order or 4th order HPF at something like 18hz - and that may be what the latest version of the PE BASH amp is shipping with - I don't know. But a lot of plate amps come with boost and I think it's important to factor it all into the modeling so you don't damage your driver the first night you start cranking it.

The thing is, the 4dB of boost in the 25hz setting seems to do some good things for your sub's response. You can detune the boost with a resistor change and get the filter Q down from 1.42 to 1.0 and that helps the power handling a lot. But the bass extension you get with the boost is reduced too. At that point it wouldn't be that much different than the filter in the PE amp (1db of boost instead of flat - if the PE amp is really flat that is).

If you do decide to start over, take a look at that 15" DVC in 5-6 cu ft. It is really pretty impressive and might be all any mildly insane enthusiast would ever want. Another option is the CSS Trio12 in 4.3 cubic feet tuned to about 20hz - that is essentially what my first ported subs were (I drive two with one Oaudio 500w amp) and they do very well, I just happen to want more.

The more I model with the Oaudio the more I like it, but it does frustrate me that there is so little information out there on the filters and PEQ. Most guys running sealed subs with the Oaudio have good things to say about their resuilts, but a lot of them have very high excursion drivers too so it's hard to say how your combination is going to work out. But it will work - just be careful. And who knows, you may find that it all works out fine and I'm all wet on the modeling.