Subwoofer position

GiddyFish

Active Member
Hi
I'm in the process of redecorating my sitting room so have the opportunity to reroute speaker cables

My current Subwoofer is a Onkoyo SKW-501E I don't have the budget to upgrade this at the moment
I think I need to as occasionally with sudden sounds I get a fuss

I did the subwoofer crawl and it didn't really help with where to place the sub now and when I can upgrade more importantly RCA cable

The TV & amp (Denon avr-x2700h ) is situated across a corner of the room in between outside wall / window and chimney
Under this window is a radiator
I can just fit floor standing Left & Right speakers either side with 2 Atmos uplifters on top
The main seat is directly in front with 2 rear speaker approximately 45 & 135 degrees behind this seat

I have basically 3 options to place the subwoofer

1 In the space behind the TV There is room here without it being in the corner or against the wall
The TV sits on a 3 shelf Glass stand with centre speaker and AMP underneath so not a solid object
I could not test this position
2 To the left of the left speaker this would be in front of a radiator. (Can't go on the right as there an open fire in the way)
3 Directly behind the main seat, this is the current position with RCA cable running under the afore mentioned radiator

If I keep the subwoofer at 3 I have the opportunity to run a longer RCA cable

So my question is it better the place a subwoofer in front or behind the main seat or out of the way behind the Telly?
 

JustinT350

Active Member
Ideally needs a sketch of the room, but it's probably worth having a play about with REW and its room simulator to see what works best. It's surprisingly accurate
 

GiddyFish

Active Member
Lounge.JPG

I looked at REW before posting I don't have a microphone apart from a headset which isn't great
Would the Audisy mic that came with amp work?
Ideally needs a sketch of the room

I've done a rough sketch it's not scale 1,2 & 3 relate to Subwoofer positions mentioned
 

jamieu

Well-known Member
I looked at REW before posting I don't have a microphone apart from a headset which isn't great
Would the Audisy mic that came with amp work?

You don't need a mic to use the REW Room Simulator. Just punch in your room dimensions, your listening position and take a guess at how reflective your walls/floor/surfaces are.
 

GiddyFish

Active Member
OK so I run the room simulator with the sub in the 3 positions I left everything else as default settings

Where might I find information on how interpret the results?

Sub Position 1
SubPos1.JPG


Sub Position 2
SubPos2.JPG


Sub Position 3

SubPos3.JPG
 

Kapkirk

Active Member
After a quick look I see that position 2 actually seems gives the highest and smoothest amplitude across a wider frequency range than p1 although there is a large dip at 63hz. From 70hz onward looks pretty good though. That massive dip between 50 and 65 hz will need addressing though as you are losing a lot of (deep bass) this just may be a quirk of your subwoofer but I would aim to get the graph as close to p2 as possible and try to reduce the dip at 63hz.
The perfect scenario would be to get the the tracing as flat as possible on the amplitude level of between 60-70 and between the frequency spectrum of 35hz-120hz, we are not interested in anything above 120hz for a subwoofer as that is where most other non sub speakers will take over.
Just to give you some idea, most people feel that the strongest bass (frequency that you really feel in the body as vibration) come at between 68-82hz.
 

Conrad

Moderator
Make sure you check the box "align subs individually". Also feel free to play with the delays against each sub and see if the response improves.

A "good" response in room sim is one with the fewest nulls or, failing that, the sharpest and narrowest nulls, ideally very shallow. Peaks can be corrected, nulls can only be corrected with positioning or more subs.
 

speed1268

Active Member
Make sure you check the box "align subs individually". Also feel free to play with the delays against each sub and see if the response improves.

A "good" response in room sim is one with the fewest nulls or, failing that, the sharpest and narrowest nulls, ideally very shallow. Peaks can be corrected, nulls can only be corrected with positioning or more subs.
Would an Antimode help? @Conrad Found it helped in my room:smashin:
 

Conrad

Moderator
I've never used one, but they get good reviews. I don't think I've ever heard someone say that it did a bad job. My issue with them is the lack of manual optimisation, but that might be preferred for others.

If you're not using any kind of room correction or you just using Audyssey or YPAO then it'll probably improve things. If you're using Dirac or ARC then it might not, especially not if you're using DLBC.
 

Conrad

Moderator

Gasp3621

Distinguished Member
Won`t improve much from MultEQ XT32, Tom V. said it`s on par with Audussey as he sells Antimodes and Denon receivers so have done comparisons. However if one has Yamaha receiver (not the latest) or Pioneer/Onkyo then the Antimode could make difference. Antimode = run and forget it. Plug and play! Tom only sells the S-II i think if going with dual subs this model was recommended.
 

Conrad

Moderator
Won`t improve much from MultEQ XT32, Tom V. said it`s on par with Audussey as he sells Antimodes and Denon receivers so have done comparisons. However if one has Yamaha receiver (not the latest) or Pioneer/Onkyo then the Antimode could make difference. Antimode = run and forget it. Plug and play! Tom only sells the S-II i think if going with dual subs this model was recommended.
Good to know. I had assumed that the antimode would do a better job in a multisub set-up.
 

GiddyFish

Active Member
That massive dip between 50 and 65 hz will need addressing though as you are losing a lot of (deep bass) this just may be a quirk of your subwoofer

Any idea how?
I increased the surface absorptions for the floor and that flattened the line somewhat

As I don't have means of taking actual measurements are there ball park figures for different surface absorptions
A carpeted floor will absorb sound differently from Double Glazed Window, Brick walls and Plaster boarded ceiling but I don't know what values are. and google didn't help.
I get these will differ from room to room

Also feel free to play with the delays against each sub and see if the response improves.
Increasing this number also flattens the curve but I'm just guessing what this number is based the length of cable from the AMP

Are they your only options? Would something in the back corner work? A back corner placement with a little delay gives you an improved response with minimal nulls:
That position is in a fixed cupboard

It could possibly go between the cupboard and the couch but needs moving every time I needed in the cupboard so it might be good for acoustics but not very practical

So unfortunately those are really my only options see rough sketch above
Would an Antimode help?
Not sure what 1 is nor what it dose. if I had the cash to buy 1 I'd probably upgrade the sub first the let the Demon AMP Audyssey setup to configure it

At this stage just trying to find the best place to put the sub I have so I can run cables whilst decorating being mindful an sub upgrade is probabley needed when fund alow
 

Conrad

Moderator
Any idea how?
I increased the surface absorptions for the floor and that flattened the line somewhat
I wouldn't do this. You'll be very unlikely to affect the response below 100Hz with absorption, unless you're planning on putting panels in that are many feet thick.

As I don't have means of taking actual measurements are there ball park figures for different surface absorptions
A carpeted floor will absorb sound differently from Double Glazed Window, Brick walls and Plaster boarded ceiling but I don't know what values are. and google didn't help.
I get these will differ from room to room
Leave them on the defaults. You'll be fine with those in a "normal" room. As long as you're not in a glass box or a recording studio it'll be a pretty close match.
Increasing this number also flattens the curve but I'm just guessing what this number is based the length of cable from the AMP
No, it's timing of the sub, not physical distance. You can affect the acoustic distance of a speaker by adjusting its delay or phase, this will change when the speaker/sub plays relative to the other speakers. With speakers you want them adjusted so that all the sounds arrive at the same time. With subs the wavelengths are so long that this matters less and you can delay the sub so that sounds arrive in a way that's complimentary to the other speakers and has no audible effect.

That position is in a fixed cupboard

It could possibly go between the cupboard and the couch but needs moving every time I needed in the cupboard so it might be good for acoustics but not very practical

So unfortunately those are really my only options see rough sketch above
Ok, I'll take another look.

Not sure what 1 is nor what it dose. if I had the cash to buy 1 I'd probably upgrade the sub first the let the Demon AMP Audyssey setup to configure it
It's a device that corrects your subs response. For one sub Audyssey is probably doing about as good a job as you'll get.
At this stage just trying to find the best place to put the sub I have so I can run cables whilst decorating being mindful an sub upgrade is probabley needed when fund alow
What sub have you got now? Instead of an upgrade you might consider a second sub. It might be worth wiring for that now while decorating anyway, the amazon basics sub cables are super cheap and perfectly fine.
 

speed1268

Active Member
I wouldn't do this. You'll be very unlikely to affect the response below 100Hz with absorption, unless you're planning on putting panels in that are many feet thick.


Leave them on the defaults. You'll be fine with those in a "normal" room. As long as you're not in a glass box or a recording studio it'll be a pretty close match.

No, it's timing of the sub, not physical distance. You can affect the acoustic distance of a speaker by adjusting its delay or phase, this will change when the speaker/sub plays relative to the other speakers. With speakers you want them adjusted so that all the sounds arrive at the same time. With subs the wavelengths are so long that this matters less and you can delay the sub so that sounds arrive in a way that's complimentary to the other speakers and has no audible effect.


Ok, I'll take another look.


It's a device that corrects your subs response. For one sub Audyssey is probably doing about as good a job as you'll get.

What sub have you got now? Instead of an upgrade you might consider a second sub. It might be worth wiring for that now while decorating anyway, the amazon basics sub cables are super cheap and perfectly fine.
Fwiw pre set the psa via antimode( on normal mode)then ran ARC and I get good bass well integrated into the system but I don’t get that pressure that folk talk about and slam into your chest type thing! Are the two separate and I’m wanting too much! As advised to the OP put details into REW and placed sud at the best point!
Should this be enough for myself and the OP or do we need to do more?

Thanks speed
 

Toobad

Active Member
The Onkyo SKW-501E weighs 9.1kgs, has a 8" driver and outputs 80W. The is absolutely nothing wrong with getting it to be the best it can be but this unit is what one would expect to find in a budget "home theatre in a box" bundle so expectations will need to be lowered accordingly. I suspect you would pay around £60 - £80 at the most for a used example on eBay.
 

GiddyFish

Active Member
a budget "home theatre in a box

Yeah I've had it ages it was part of a 5.1 set
When I upgraded the rest of the speakers was advised it was OK
Most of the time I think it dose the job however for high end Audio movies such as Greenland it can't cope with the loud bangs so the other speakers distort, mainly the rear right for some reason

When my budget permits I will upgrade it and will be looking for suggestions
 

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