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One sub or two?

VBSurrey

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#1
Hi Forum

Where did the notion that two subwoofers are necessary come from. Every sub I have looked at from the affordable Yamahas to the pricey Genelecs have two analogue XLR inputs (L+R) and two XLR outputs for the studio monitors (L+R).

In fact Genelec who call themselves ‘the world leader in studio monitors ‘seller bundle which they call a stereo bundle comprising

2X8320 SAM monitors

1 X 7350 subwoofer


Is there any evidence that two subs are required or is this just another case of audiophile folklore?


Appreciate any feedback


Kind regards
 
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#2
There is a whole chapter in Dr Toole's book explaining why multisub works. I think there is a paper from T. Welti and A. Devantier about how big the difference is between one and two and how there is an improvement having 3 or 4 over 2 but not as big a jump.

If you are dealing with a single seat you can get by with a single sub once you optimize location and EQ. For a wide sofa it is better to have two subs to properly EQ the bass region over the extended area. For multiple rows four subs are actually recommended.
 

eric-c

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#4
maybe goes without saying but ideally, the subs of are identical models. I use four identical subs in each corner of the room. it has been a while since I read the T Welti paper. I recall, you an also put the subs at the mid points of each wall but you will lose a lot of the room gain plus it is not a practical to have big subs mid point on the wall.
 
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VBSurrey

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Thread Starter #8
4 Genelec subs would be interesting from a cost perspective.

Room size
4 metres wide
5.4 metres long

Ceiling height 2.4 metres. Ground floor room so concrete base with screed over. Carpeted with underlay. Dedicated lstening room with just a single seater couch

Ordered the Floyd Toole book from Amazon

Gretaly appreciate all the responses
 

onion

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#9
Yes, you need some sort of digital processing to allign all 4 of them together.

Could you maybe better describe the listening position(s), what you aim to achieve, the room size .etc
I found that adding the 4th sub made a great improvement, even without proper alignment. For my room, the quality improvement going from 2 to 3 subs was less than going from 3 to 4.
 

abdo123

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#11
4 Genelec subs would be interesting from a cost perspective.

Room size
4 metres wide
5.4 metres long

Ceiling height 2.4 metres. Ground floor room so concrete base with screed over. Carpeted with underlay. Dedicated lstening room with just a single seater couch

Ordered the Floyd Toole book from Amazon

Gretaly appreciate all the responses
4 subwoofers are a bit of an overkill for a single seat, but it's a great way to get reference quality bass.

you will find entire chapters in the Dr. Toole's book on subwoofer placement and sub-bass reproduction, and the GLM integration will make it a breeze to manage.
 

Wes

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#12
Double your pleasure
Double your fun
With Double-Sub, Double-sub
Double sub ...

If you enjoy room modes then stick to a single sub

or stick your single listening position into an oddball, uncomfortable spot in the room
 

sergeauckland

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#13
With my previous 'speakers (Meridian DSP5000), I used a pair of D1500 subs located directly alongside the main 'speakers, thus in effects creating a 'full range' pair. My room has too many corners i.e. isn't rectangular, so room modes (except for the floor-ceiling mode) aren't what's normal, so I've never seen the point of multiple subs in my arrangement.
With my current 'speakers, I don't use subs at all as there's adequate bass extension without them. My listening is mostly classical music and Jazz, I never watch movies so have no use for LFE.

S.
 

win

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#15
If you want a project, then multi-sub optimizer is a freeware program that gives great results.
 

eric-c

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#16
I use four subs as my old theatre had three rows of seating and this helped provide smoother bass response across all rows. My current theatre I have two rows but still use the same 4 subs. :) I would not go for four subs for the sake of going for four subs. If clean bass extension is important to you then two high quality (can go deeper with less distortion) may serve you better than four subs for the same cost.
 

HooStat

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#17
I think you can use less expensive subs than Genelec, particularly if you are going to use 4 of them. I don't think GLM handles multiple subs, so you are going to have to do some work on integrating them. Others have done this, so hopefully they can comment.
 

JustJones

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#18
I use 2 Genelec 7350 subwoofers paired with 2 8351b and GLM manages them. I know Genelec recommends the 7370 with those monitors but in my room the 2 7350 provide all the bass I want and cost was a factor as Genelec subs are pricy. I'm pretty sure GLM will recognize more than 2 subwoofers.
 

Jbrunwa

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#19
My room had a couple steep nulls using one 15" sub no matter where we placed it. Because the nulls were at 36 and 68 Hz, we did not need a massive second subwoofer. Adding a small second sub, an SVS SB-1000 Pro with their Soundpath wireless adapter allowed us freedom to place the sub in a location to eliminate the room nulls.
 
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