Small subwoofer build for the livingroom

[TEK]

Hi

I expect that I will need a sub in my livingroom to get some fundament in the bottom, below the in-kahn-neatos.
It will be used at normal sound levels, but will have to fill a quite big livingroom.
Outer size should be limited to 50x50x50 cm.

I'm looking for suitable elements/setup for this. I'm located in Norway, so scandinavian or european drivers is fine.

Any recommendstion?

[dar47]

That size any 12" will do but I'm running a Seas 10" ROY(yummy) in my large living, dinning, kitchen area and Seas is very close to you.:W

[csmielke]

I just finished building a sub with the CSS SDX10 subwoofer and two Scan Speak 26W/0-00 passive radiators in about 47.5 liters. With room gain its solid into the mid to low 20s. You can pick the plate amp to go with it. I just finished dialing it in and I'm really pleased. Jon is working on a couple of designs with the same configuration.
Chris

[JoeAngelicchio]

I just finished building a sub with the CSS SDX10 subwoofer and two Scan Speak 26W/0-00 passive radiators in about 47.5 liters. With room gain its solid into the mid to low 20s. You can pick the plate amp to go with it. I just finished dialing it in and I'm really pleased. Jon is working on a couple of designs with the same configuration.
Chris

Any pics Chris?
Joe

[TEK]

I have heard many that talks about the SEAS ROY drivers. As far as I have understood the L26RO4Y seems to be preferred by many.

Seas does not seem to have any sub element larger than this 10". So if I want to go for a larger element I will need to select a different supplier.
As mentioned before, my mains will be the in-kahn-neatos. They have one 8" each. So it's a open question if I should target a 12" woofer or stick with a 10".
When I check a bit closer it seems like I should be able to get a 15" woofer into a cabinet sized 50x50x50cm (50cm is approx 20"). It might be favorable to target a smaller box...

I see that many uses passive radiators with the SEAS ROY as well, same as you do with the CSS SDX10 Chris.

In my case the sub will be placed into a corner with walls behind it and to the right of it, and with a stereo bench right to the left of it.
Any passive radiators will be pointing downwards or into a wall. The main driver will be pointing out into the room.

Is passive radiators a pro in this situation?

[csmielke]

Tek,
You might be better off without the PRs in your case if they are right up against a wall. I did mine with the woofer facing forward and PRs on each side. Jon just did a thread on a 15" from Parts Express in a PE cabinet (I thought it was 3 cu') He also used a Hypex Ds4.0 400 watt plate amp. That is also a sweet combination which will move a lot of air. Here some photos of the one I completed.

[5th element]

Dayton's Ultimax drivers should not be ignored.

[Face]

Dayton's Ultimax drivers should not be ignored.

I'm very happy with the pair of UM18s in my living room.

As for PRs, they shouldn't be used down firing.

[Hdale85]

Yea I like my Ultimax 15, just don't use a plate amp lol. They are such crap, mine died after like 7 months of use.

[TEK]

Yea I like my Ultimax 15, just don't use a plate amp lol. They are such crap, mine died after like 7 months of use.

That soundedmlike a bit much generalization.
I have 3 sub's with plate amps, all are working greate and have done so for many years.

[TEK]

OK, I have checked some more details.
I started to calculate the internal volume of a sub that is 50/50/50cm and the result was above 100liters. That's not a small sub.
So I did some more exact measurements.

The sub will be placed into a bench and will be formed so that it fit's the size of the rack, and then painted white.
The result is that this means that the outer dimensions of the subs top will be 41,5cm x 41,5cm. The sub will be 40cm high, and raised 5cm above the floor.
I then design the sub to have 2cm thick walls in general and a baffel that is 3cm and some internal bracing.
This will result in a internal volume of approximate 47 liters when not taking the driver(s) themself into account.

I have the following possible configurations:
- 1 forward or downward firing element, ported
- 1 downward firing element and forward firing PR
- 1 forward or downward firing element, closed
- 1 forward firing and 1 downward firing element closed

The size of the cabinet allows for a maximum of a 15" driver, both forward firing and downward firing (but then it will not be much else than the driver in the cabinet).

[cjd]

I have a 10" Dayton HO in an up-firing configuration in about that volume (12x12x30 minus a bunch of volume for the plate amp) ported to ~28Hz. It's excursion limited to be sure.

In this case you'll probably get the best extension with a long throw 15" like the Ultimax paired with a good EQ - which will be worth having for room issues anyway.

I should also add, you might be surprised. I forget to turn the sub on in my HT occasionally (or my wife does) and it's only when I realize I should be feeling something that I notice it's off - usually. Not always...

[TEK]

Thanks cjd.
I'm planning on using my receiver (Marantz SR7005) to set the crossover point, but a separate amp I have (400w@8ohm) will drive the sub. The receiver have room correction, but I doubt that it will be able to adjust the lower end for a sub designed to be eq'ed.
So if I'm going to lift the bottom end using eq I will have to add some external box to eq the sub.

Any suggesten to what that box might be?

[cjd]

I've been beyond happy with the performance of the MiniDSP (balanced, in my case) - combined with REW you almost have no work to do - it calculates biquad filters for you based on targets and live measurements. It's also tiny (I mounted mine to one rail at the back of my rack, and gives you enough output channels to let you add subs - say you find you need hide a different sub somewhere (and tune separately,) you can. I'm only using a single input, but am using both outputs to drive the subs I have in the front wall and under the stage in my HT. The dual placement helps a ton with room issues.

I notice I didn't mention it, but I envisioned a sealed setup. Other folks make great long-throw subs so don't feel limited to Dayton if someone else is a better deal for you. Do the power calculations on your amp too - you don't want to be clipping it. As long as it drives 4ohm you'll probably find it enough, though. Depends how low you want to go.

If you have Excel, Jeff B's woofer box calculator has a nice section that lets you explore a driver with active EQ on the low end and verify required power input, etc.

[csmielke]

TEK,
You might also check out the SDX12 big brother to the one I used. In a 40L enclosure you get an F3 of 29hz and QTC of .6. These run $289 ea. Jon, CSS audio is running an Xmas sale on the SDX10s buy two get $100 off or $257 for two. If you guys are serious about a couple of the designs you and Steve had in mind it might be a good time to grab them?
Merry Christmas all,
Chris

[TEK]

cjd - MiniDSP is outside the budged for this build.

I came across this application note for the SEAS L26ROY Driver.
It seems like they recommend SEAS L26ROY with a passive radiator (SL26R). Looking at the application note it's like it was made for my box...

http://www.seas.no/images/stories/design/pdf_datasheet/L26ROY_Application_Note.pdf

With this design I would not need to EQ the lower end and can probably just let my receiver apply room correction to the sub to get a decent result.

So, I think that I will just go for the SEAS L26ROY and SL26R.
The only issue for me is that one driver must be facing downwards and one forward. Is that an issue? I would think that the SL26R could be facing down and the L26ROY forward.

Edit: The cost for both SEAS L26ROY and SL26R will be 350 usd delivered to my doorstep.
(It might sound like many of the dayton and other elements may compete with that, but remember that I will have to pay shipping to Norway as well as 25% tax for anything I buy abroad, and probably approx 20 usd in handling)

[cjd]

Your project and money, so you definitely get to choose how it goes. I figured an option left out is worth less than one dismissed. the Seas setup looks quite good too. They make great drivers.

[tktran]

The only issue for me is that one driver must be facing downwards and one forward. Is that an issue? I would think that the SL26R could be facing down and the L26ROY forward.

I have built a 10" subwoofer with a downward facing passive radiator, using 18mm MDF stock.
The driver was the popular Peerless XLS 830452, which has slightly less excursion than the SEAS L26ROY.

It was in a tiny 1cu foot box, and worked well, with some caveats:
At high levels, the subwoofer would hop around, due to the high "thrust" of the downward facing radiator.

You may not experience this problem, because your cabinet may be significantly heavier than the one I built
and it also depends on the level of excursion from the passive radiator. For music levels it wasn't an issue for me.
For home theatre- dinosaur footsteps, explosions, the subwoofer certainly moved around.

In my situation, if I were to build a 10" subwoofer with a passive radiator in a small box (1cu foot), again,
I would make the cabinet heavier (heavily braced 18-25mmmmDF, or put the drone on the opposite side to the active driver.