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Andy0217

Subwoofer Driver Direction... does it matter

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Calling on the collective subwoofer brains trust...

 

I now have the 2 subwoofers positioned in between the mains with the woofers facing the room...however I have stuffed up on  measurements and have not allowed enough space behind them to run the XLR and power cables,  or make any adjustments, 

 

In hindsight I am sure now after snapping the string line for the front wall frame, I have fixed the bottom plate on the wrong side of the line...I must have been having a senior moment🙂

 

Any  way not much I can do about it now...so my only options are to rotate both subs 90 degrees,...but my question is  should the drivers face each other, or should they be facing the side wall so they are back to back...or won’t it make any difference?

 

I am thinking it shouldn’t make a difference as each sub is dual woofer setup with the second driver facing the carpet, but what would I know...

 

Any feedback appreciated...

 

Cheers Andrew

49548D5A-0607-4FE1-B2B4-9D81C1601C5A.jpeg

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Trust your ears and try in all scenarios with phase switch if there is one in either direction. When you hear the most satisfying bass response, not overblown, out of phase, not enough impact etc, then you have it right.

 

I generally prefer them facing listener for some little extra impact but it’s very subtle and facing sideways may do as well.

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more importantly

 

whats under the covers

is it a diy AT sceen or bought

Quote

 

 

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The LCR's are under the covers...

 

Getting to old and lazy to make another screen, already ordered mine from Rich,   

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Short answer: Yes and no!

 

The direction doesn't matter, except where it changes:

 

1. The orientation - up or downfiring causes cone sag compared to sideways mounting. Some drivers handle this better than others.

2. Clearances - downfiring or rear firing close to a wall both create an air cavity, which impacts the response.

3. Position - if the cabinet is fixed in position, then each direction will engage the room differently - enough to measure and hear a difference.

 

These are all quite minor in comparison to locking in positions that may turn out to be vastly inferior to other options. In many rooms this is make or break.

 

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My experience was positioning my two REL’s ‘by the book’ - that is facing towards listener just didn’t work
Rotating them got me the best result.
I now have one sub forward facing and one 80-degrees to listening position.
Go by your ears🤙

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Thank you all for the info, 

 

With respect to the actual position of the cabinets, I don’t have a choice on this, they have to be behind the screen, so I guess I will have to experiment with the little space I have....

 

And say a prayer while I am at it that I don’t do a hernia as they are real bastards to move around 🙂

 

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If each sub has to be in approximately the position in the pic, and each has to face either left or right ..... then it won't matter a lot which way they face.

 

Don't choose by ear.   If you can measure the difference, you might (unlikely) fine one way is preferred .... otherwise, don't stress.

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you may have enough room for 90 degree XLR and power?

https://www.storedj.com.au/hosa-xrr1015-xlr-f-to-right-angle-xlr-m-balanced-interconnect-cable-1-5ft?gclid=Cj0KCQjwvo_qBRDQARIsAE-bsH91APRIVW5f8atXu4-zVZBinyH5qTh6oTrXMAVZO8746_eX_nonym4aAsmnEALw_wcB

 

https://www.pccasegear.com/products/39830?PPC=Y&gclid=Cj0KCQjwvo_qBRDQARIsAE-bsH-AfHdA1yCRj5b26Rmf1HeaGXEqV6tr1278-CBk9LT_AQzkEkFDp04aApWqEALw_wcB&gclsrc=aw.ds

 

On 24/07/2019 at 8:47 PM, Andy0217 said:

I am thinking it shouldn’t make a difference as each sub is dual woofer setup with the second driver facing the carpet, but what would I know...

If they were designed like that then I'm assuming the designer factored in the appropriate gap between the down firing woofer and the floor, and chose a sub driver suitable for horizontal mounting (usually slightly stiffer suspension so they don't "sag" over time)

A quick interweb search found this

https://www.parts-express.com/resources-woofer-mount-up-down

 

On 26/07/2019 at 8:56 PM, davewantsmoore said:

Don't choose by ear.

agreed - the ear is not very good for achieving the smoothest "in room" bass response - with your investment in such a nice setup, a measurement rig (microphone, stand, a laptop and REW (free software)) would be worthwhile, and not cost a lot (esp if you already have a laptop you could use) but has quite a learning curve to understand what the measurements mean and how to interpret them to get better "in room" bass.

 

It's easy to measure - much harder to work out what to do based on the measurements!

 

@Paul Spencer - who has responded in this thread - provides room measurement and calibration services and is based in Melbourne (well "outer" Melbourne) - I've never had Paul measure my room, but I can vouch for his skills and knowledge as he designed my speaker setup - PSE144 top end, TD18 midbass and T20 tapped horn sub.

 

As Paul says - subs' positions in the room - much more than front firing/down firing/rear firing - can make or break a room.

I get that you have limited location options for your subs - they have to go behind the screen - but they may work better elevated above the LCRs (just an example).

 

For me (yes I'm a bass nut), getting the bass right in any room is more critical than anything else - you're building such a nice room, it deserves great bass!

 

Plonking 2 subs in the most convenient spots is not the best approach to achieve good "in room" bass.

My recommendation would be to engage a professional to position your subs - you have options in Melbourne, but Paul is well regarded by myself and others here on SNA...

 

...and get a measurement rig also - you'll learn about room acoustics through the process and you'll likely want to tweak later (eg new treatments, new gear etc etc)

 

cheers

Mike

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90 degree plug looks like a good idea, also, can't buy yourself 75mm by punching a hole into the plaster behind where the plugs need to go?

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Hi Chaps, 

 

Thanks for all the feedback, as it turned out I was able to slice a channel in the batts behind each sub for about another 75mm and I have fitted the XLR cables into both rear panels without any issues so all good,

 

With respect to the power cables, I have ordered 2 power cables with right angle IEC plugs, so all sweet on that front too, 

 

On the positions of the subs, I am somewhat hamstrung with location as they have to remain behind the screen, but elevating them might be an option...will look at getting someone in such as Paul to do an assessment. Down the track, 

 

Thanks and Cheers

 

 

 

 

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The position isn't ideal in terms of spreading out room modes.

 

But from memory the drivers shouldn't face each other as that could lead to cancellation.

 

One of the old tricks about breaking in speakers was to have them firing at each other as the cancellation reduces output and keeps neighbours happy.

 

I would have them back to back.

 

But given the time and effort you have expended in your setup I'd expend a little more and buy the UMIK mic from minidsp.com and download REW.

 

It'll take an hour or so to learn how to use it enough to take decent measurements of your subs.

 

If you are a Mac guy Fuzzmeasure is even easier.

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On 14/08/2019 at 7:46 PM, sfdoddsy said:

It'll take an hour or so to learn how to use it enough to take decent measurements of your subs.

agreed - learning how to take good measurements doesn't take long at all.

It's how to interpret those measurements and make informed decisions to change things that subsequently measure better that's the difficult part.

 

No question @Andy0217 needs to invest in his own measurement rig, and myself and others on SNA will try to assist in interpreting all measurements/graphs posted - but Andy will get a better result much faster with professionals engaged earlier.

 

There's plenty of examples here on SNA of long threads on interpretation of room measurements - lots of opinions and serial discussions of "try this/try that", which could be circumvented by a professional doing multiple measurements, analysis and changes in a single session.

 

I've spent many hours measuring and analysing the measurements of my room and other rooms - I have a reasonable handle on how to measure and what it all means - if I was starting from scratch I'd recommend jump starting that process by getting a professional in from the beginning.

 

cheers

Mike

 

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On 14/08/2019 at 7:01 PM, Andy0217 said:

Thanks for all the feedback, as it turned out I was able to slice a channel in the batts behind each sub for about another 75mm and I have fitted the XLR cables into both rear panels without any issues so all good,

Watch out for rattles  ;)

 

On 14/08/2019 at 7:01 PM, Andy0217 said:

On the positions of the subs, I am somewhat hamstrung with location as they have to remain behind the screen, but elevating them might be an option...will look at getting someone in such as Paul to do an assessment. Down the track, 

 

If this is where the subwoofers are going to be located - you mentioned before there was little wiggle room (their direction doesn't matter) then that's where they'll go.

 

If you can put them "anywhere" ..... then yes, measure.

 

Otherwise there's nothing more you can do except EQ them correctly.     Use your AV receivers bass management solution, and everything should be automagical.

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On 16/08/2019 at 10:21 PM, almikel said:

if I was starting from scratch I'd recommend jump starting that process by getting a professional in from the beginning.

This.

 

Putting the subwoofers where they are behind the screen was either "a decision you had to make" (fair enough, go with it) ..... or a "potentially bad decision that you can undo  (in which case, do the work, or get help, to make a better decision).

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