One sub or two?

[Beershaun]

The main reason is to better handle room modes. With a single sub you will definitely get a big dip in response at a specific frequency and there is nothing you can do about it with a single sub. With two subs you can place them in separate locations to minimize the null in the room and give you a much more even bass frequency response. You need room correction software and dsp to take advantage of two subs to solve this problem.

 

[alex-z]

For the actual multi-sub optimization, you can do it by hand, although software to help does exist.

https://www.andyc.diy-audio-engineering.org/mso/html/index.html

MiniDSP 2x4HD + UMIK-1 is a cost effective method to manage 4 subwoofers. Genelec GLM is quite pricey for what it does, unless you are already invested into the Genelec ecosystem I wouldn't bother.

In terms of the subwoofers themselves, quad DIY sealed 15" is enough for most rooms. You can achieve an F3 point around 30Hz naturally, which in conjunction with room gain usually gets you flat to 20Hz, and DSP can help out if not.

If cost efficiency is a priority, you could also do two small sealed subs, and a larger ported one to fill in the 20-40Hz region.

 

[onion]

GLM is currently inferior to MiniDSP+REW for multi-sub management - you have to adjust levels manually after the autoEQ process. The subs are effectively managed independently of each other. On the plus side, each sub is paired with a main speaker for automatic phase alignment.

 

[Sancus]

GLM doesn't actually do multi-sub in any meaningful way. You can force it by daisy chaining them but it won't EQ the combined response so I don't think it's worth buying extremely overpriced GLM subs to use that way.

 

[VBSurrey]

Thanks for all the responses guys. Just to clarify - the intended use is for stereo listening notfor home theatre. Anyone using 4 subs for stereo listening please?

 

[VBSurrey]

GLM is currently inferior to MiniDSP+REW for multi-sub management

Is there general agreement on this statement please?

 

[Jim Matthews]

Thanks for all the responses guys. Just to clarify - the intended use is for stereo listening notfor home theatre. Anyone using 4 subs for stereo listening please?

I've done it, with four Moniprice subs. (10", and cheap)

It was a colossal PITA to properly distribute them (I placed them one at a time in my listening position and crawled around the room, no kidding.)

None ended up in a corner, conveniently close to a power outlet.

The necessity of running signal wire and power to each was a chore.

The performance was good, but not worth the hassle.

 

[ferrellms]

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

2 can be better for a couple of reasons - several DB more ultimate dynamic power with lower distortion (moves more air with less work from each box), and, if properly positioned, smoother bass at more listening positions as more room modes at various frequencies are excited by interaction with the room boundaries of multiple low frequency sources, meaning fewer bass nulls and more even response around the room. For a small listening position area (like a love seat), less than enormous requirement for bass (as in movies) and with careful EQ one alone can work just fine. So - yes for your home theater, maybe or maybe not for your study. In any case, EQ is a good thing.

BTW - Genelec is one of the most honest manufacturers due to their position in the pro market where less BS is tolerated as opposed to the home audio market which consists of it.

 

[ferrellms]

GLM is currently inferior to MiniDSP+REW for multi-sub management

Is there general agreement on this statement please?

no

 

[richard12511]

So, one in each corner?
I assume that will require something like Genelec's GLM software?

Actually, GLM only really supports 1 sub atm. If you're integrating more than 1 sub(which is highly recommended), I'd actually skip GLM. Products like DiracLive Bass Management(not to be confused with DiralLive 3.0), Audiolense, Trinnov EQ, and Multi-sub Optimizer will do it. You can manually do really good with a REW and it's new phase alignment tool, but you need something to add the delays it gives you to each of the subs. I've used both miniDSP 2x4HD and miniDSP DDRC88A for this.

 

[richard12511]

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

Reading Toole's book before making any decisions is highly recommended. I very much wish I had read that book before spending any money in this hobby .

 

[richard12511]

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.

I think this is actually the norm when using the Welti approach. The Geddes approach usually sees a bigger jump from 2 to 3 than from 3 to 4.

 

[ferrellms]

BTW - I strongly recommend against spending money on 4 Genelec subs unless you are filling a home theater with explosions. The amount of money needed is far beyond the incremental return. Just because some stranger in an audio forum tells you it works for him is not a good reason to spend that kind of money. Even if you are rich, there is a thing called "opportunity cost" - give some of it to charity or your kid.

Spoken as a stranger in audio forum with a home studio, 50 years of stereo addiction, the best sounding system I have ever heard, has a kid and gives to charity.

 

[richard12511]

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.

The Geddes approach is designed to work in non rectangular rooms.

 

[richard12511]

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.

From what I understand, GLM doesn't handle multiple subs properly. It will no doubt EQ multiple subs if you add them to the grid, but I think it treats them as individual units without considering the overall interaction between all of them. I believe @Sancus ask Genelec support about this some time ago and it was confirmed. I understand it's a feature they plan to add at some point, but may not be a priority atm. Not saying you can't get lucky and get a great summed result via GLM, but if I'm starting new, I would definitely opt for a a program that actually supports multi-sub properly(DLBM, AL, MSO), or do it manually via REW.

 

[richard12511]

4 subs ut shall be. If I go for the Yamaha's (cheap) what software will integrate them please?

I'm a huge 4 sub advocate, but I'd actually recommend against 4 super cheap subs if at all possible. 2 better subs would be better imo. I've had a couple systems with 4 cheap subs, but they just didn't sound all that good(muddy and slow). I now think this was because of the high port tuning in the audible range. What's your budget? I think it's important to get to a minimum level of quality with the sub(HSU has some really great and cheap subs).

 

[Zedly]

 

[richard12511]

GLM is currently inferior to MiniDSP+REW for multi-sub management

Is there general agreement on this statement please?

I own and use both. GLM is easier. MiniDSP + REW is better(talking strictly multi-sub bass).

 

[richard12511]

GLM doesn't actually do multi-sub in any meaningful way. You can force it by daisy chaining them but it won't EQ the combined response so I don't think it's worth buying extremely overpriced GLM subs to use that way.

Should have kept reading before replying .

 

[hege]

You can manually do really good with a REW and it's new phase alignment tool, but you need something to add the delays it gives you to each of the subs.

What do you mean by "you need something"? You can just input everything manually to each Genelec speaker/subwoofer.