Running a BK ported and sealed sub together

Sean Pen

Standard Member
Hello all

New user of the forum. Be gentle!

I'm currently running a full Onkyo home theatre setup with Dolby Atmos as follows;

Onkyo TX-NR656 AV receiver/amp.
Onkyo SKF-2800 front corner speakers with Atmos upward firing units
Onkyo SKF-594 centre speaker
Onkyo SKF-594 surround speakers
Onkyo SKW-658 active 8" subwoofers (ported). Two of those.
60" Samsung 4k tv
All that gives me a 5.2.2 setup.

Hopefully see the picture:


Now my question focuses on subs. Back in my youth I used to run some ridiculous car audio setups costing £0000,s. Mainly JL kit which I was delighted with. So I know what's possible given the right injection of cash.

The two 8" subs I run now can only be described as underwhelming. At 80w each its not surprising. I had 1 originally but thought the addition of another would resolve my concerns. Not the case. There ok but not wow!

Reading on this forum and the views on the BK kit led me to the website. I like the look of the kit and the fact I can get boxes in the same material in the same as my custom tv unit. Also they seem to do kit much more powerful than my own.

I use my kit for everything. Weekly movie night with the wife n sprog. Banging out some tunes while working on the house and garden and plenty of gaming. Covering all bases there. Now I'll admit...i like bass. I want to feel it when I throw a grenade on Call of Duty, when mortars fire in a movie. I want it loud, punchy, to rumble and most importantly not sound farty when pushing it on a bit.

My room size is;
12ft wide
15ft long
8ft high

So onto my thread title. Can I run a sealed unit and a ported unit to cover all bases or will that confuse things? I'd like to run twin setups for symmetry. One either side of the tv in each corner of the room. I don't mind spending the cash if the kit will do what I want it to. Max budget 1k.

Would it be better to run two ported or two sealed?

Lastly my amp has two pre outs for subs. Single RCA output leading into the sub input on the power amp. Will this work for the BK kit?

Many thanks for the advice. As I say. Please be gentle. Home theatre is new ish to me.



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Sean Pen

Standard Member
Apologies. Realised a few grammatical errors crept in and this is in the wrong section. Please move to appropriate section of the forum if you wish.

Also. I'd rather not spend the full 1k if I can help it so all options considered.

Thanks again

Sean Pen

Standard Member
I'd probably be tempted to run a pair of the same subs if they're being used simultaneously. It probably doesn't matter that much. At least they'll look symmetrical in your room.

I'm sure a pair of the XLS200's would be a remarkable improvement. I'm not sure the other models would fit either side of your cabinet - worth checking. The P12-300SB is much larger. They're both under £400 each.

You need to select whether you get a downward firing one or forward. Not sure where you are crossing them over, but I've heard a few people say the forward firing ones are preferable, but again theoretically that shouldn't matter.

Thanks for the reply. I'd missed the P12 completely.

Just checked sizes. The P12 units would fit either side very nicely. Couldn't see on the website a way to order front or down firing. Am I missing something?

I'd like front firing as I'm a style junkie at heart and seeing speakers flex is kind of cool.

Deleted member 598831

Ditch the onky ported jobs as they will not be very good. A bk offering will give you cleaner, and more accurate bass response.

Then maybe look to upgrade your front LCR.

Deleted member 598831

Just as a thought, if your after the sound of a ported sub, more like the car audio (My car was used as the demo car for alpine in 2003) Dual bk monoliths forward firing look like they could fit, at 42cm wide?

Sean Pen

Standard Member
42cm width isn't a problem. They will fit between the unit and walls either side.

Im not 100% sure I do like the ported sound. I always favoured sealed setups back in the car audio stuff. I found the bass cleaner and presuming I had enough power the bass would still give the desired effect. I ran twin 12" JL W6 from a monoblock JL amp, in small hatchback it was more than sufficient.

One thing I'm not a fan of with the Onkyo subs is the port noise. When cranked up this can get excessive. (I'm probably over driving them tbh). I'm leaning towards sealed but worried (probably a bit strong to be 'worried' but you know what I mean) that they won't give me the rumble i'm after as described in the OP.

Deleted member 598831

Remember a few sealed subs in a car will give serious clout through the pressure vessel gain, same as room gain. The bk mono wont sound like the piddly little onkyo subs, and they can also me tamed with an antimode, or even bunged if you find they are boomy. If set up correctly (gain and phase), then eq'd properly, then they can be fast and tight just as a sealed sub can be.

Deleted member 598831

If I was in your shoes I would go monolith route, and remember you have a 14 day return period.

Deleted member 598831

@DrHarvey12 runs dual bk mono plus.

He is also very good at advice, and I think he is more qualified to answer the questions you may have.


Well-known Member
As most people have advised, any BK sub would be a significant upgrade to your current set up.

I was (still am :p) a massive bass junkie, particularly in car audio and was powering 2 Kicker L7 15's at one point so I can relate, to a degree anyway.

I can speak on behalf of the The P12-300SB which I upgraded to from a BK gemini. It's a great sub and an even greater price. I only have one and is very 'adequate', especially for the room size. two subs will always sound better than one as you should be able to produce a flatter response across the room.

I personally think two monoliths would be overkill for your room size.

My advice would be get two P12's. At £379 a piece, I doubt you will be disappointed and have some nice change left from your budget.

there is a fairly recent review on here about the P12 too. should give it a read as helped me decide to go for it.

Edit; found it here
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