KEW

KEW

Audioholic Overlord
In the past, I have read posts which discuss the importance of using the same subwoofers.

I would like to get some thoughts on this.

I have the option of 4 15" sealed subs with limited placement options, Or I can use 2 15" subs combined with two smaller subs which would give more options (such as having a couple close to LP as ShadyJ has been recommending lately).

What are the concerns of mis-matched subs?

FWIW, I will be using miniDSP on these.
 
speakerman39

speakerman39

Audioholic Overlord
In the past, I have read posts which discuss the importance of using the same subwoofers.

I would like to get some thoughts on this.

I have the option of 4 15" sealed subs with limited placement options, Or I can use 2 15" subs combined with two smaller subs which would give more options (such as having a couple close to LP as ShadyJ has been recommending lately).

What are the concerns of mis-matched subs?

FWIW, I will be using miniDSP on these.
Kurt, according to Dr. Earl Geddes it is best to use (3) subs in a room. Even, when say one or more is sealed and the other(s) is/are vented or of different sizes. Here is a link to his paper and video:


http://seriousaudioblog.blogspot.com/2012/05/two-great-articles-on-multiple.html


Not saying that I am in agreement, but I do find it interesting to say the least. Here is a paper where Harmon recommends (4) subs:


https://www.harman.com/sites/default/files/white-paper/12/11/2015 - 06:12/files/multsubs.pdf


http://www.harman.com/sites/default/files/white-paper/12/11/2015 - 06:25/files/LoudspeakersandRoomsPt3.pdf



Hope this is helpful to you! :):):)


Cheers,

Phil
 
Last edited:
S

shadyJ

Speaker of the House
Staff member
Quantity of subs don't matter too much, whether 2, 3, or 4. What matters is the response at listening position. The more subs you add, the flatter your response can be, and the less need of equalization. Geddes has his approach, Harman has theirs, and there have been others, but the goal is mostly the same.

As for near-field, some people really enjoy that effect, others do not care for it. I say give it a try to see how you like it. There have been theories bandied about that near-field can feel a lot more powerful even for the same SPL, but I haven't seen any scientific substantiation of that, merely some educated guessing. I am not saying that isn't true. I don't know for sure.

Regarding mismatched subs, it doesn't matter very much so long as you never reach any of the individual sub's limits too soon. A problem with wildly mismatched subs is a weak subs can reach its limit much sooner than a powerful sub at which point it starts generating a lot of distortion and degrades the sound overall much more than if the system had not included the weak sub at all. If all your subs have roughly the same performance characteristics, that won't be a concern.
 
speakerman39

speakerman39

Audioholic Overlord
Kurt, at one point I owned (4) of the SVS SB12's. Had (2) up front like I had the S1500's AND the other (2) directly behind my seating position. The low end did sound a bit smoother, but the SB12's were no match for the dual S1500's inmho. I also placed (2) of the SB12's to the left side behind my seating position to very little difference albeit near-field. Here are a few pics for you:

upload_2017-10-29_20-39-17.png


upload_2017-10-29_20-39-53.png


upload_2017-10-29_20-40-39.png


upload_2017-10-29_20-41-32.png


upload_2017-10-29_20-42-46.png



Of course things are totally different now. But, the (4) SB12's were no match for the dual S1500's. As you know my preference is on music and that I prefer sealed subs. Anyways, hope that this is of some help to you.


Cheers,

Phil
 
lovinthehd

lovinthehd

Audioholic Jedi
Phil, are you sure it wasn't partly due to placement choices? Symmetry don't mean much to a sub....
 
speakerman39

speakerman39

Audioholic Overlord
Well, given that my room is rather small placement was and still is an issue. However, I just preferred the sound of the dual S1500's as to the smoothness of the (4) SB12's. The low end was smoother sounding with the way the SB12's are placed in my pics. When I co-located (2) of the SB12's to the left side behind my seating position albeit more near-filed, there was very little difference. Over all, the dual S1500's were much more to my liking. In a bigger room that could easily change. Who knows? For the time being, I am not even using a sub. :):):)


Cheers,

Phil
 
lovinthehd

lovinthehd

Audioholic Jedi
Well, given that my room is rather small placement was and still is an issue. However, I just preferred the sound of the dual S1500's as to the smoothness of the (4) SB12's. The low end was smoother sounding with the way the SB12's are placed in my pics. When I co-located (2) of the SB12's to the left side behind my seating position albeit more near-filed, there was very little difference. Over all, the dual S1500's were much more to my liking. In a bigger room that could easily change. Who knows? For the time being, I am not even using a sub. :):):)


Cheers,

Phil
Was that avr XT32/SubEQ equipped? Or did you use something else to account for the different sub distances?
 
speakerman39

speakerman39

Audioholic Overlord
Was that avr XT32/SubEQ equipped? Or did you use something else to account for the different sub distances?
No, I was using XT 32 w/ SUB EQ HT. I even used my RS SPL meter to double check levels before running Audyssey. Dialing in the phasing was the trickiest part. Never got around to doing any measurements though. Could kick myself for not doing so.


Cheers,

Phil
 
lovinthehd

lovinthehd

Audioholic Jedi
No, I was using XT 32 w/ SUB EQ HT. I even used my RS SPL meter to double check levels before running Audyssey. Dialing in the phasing was the trickiest part. Never got around to doing any measurements though. Could kick myself for not doing so.


Cheers,

Phil
Thought you had one, couldn't remember, thanks.
 
D

DubPlate

Audioholic Intern
In the past, I have read posts which discuss the importance of using the same subwoofers.

I would like to get some thoughts on this.

I have the option of 4 15" sealed subs with limited placement options, Or I can use 2 15" subs combined with two smaller subs which would give more options (such as having a couple close to LP as ShadyJ has been recommending lately).

What are the concerns of mis-matched subs?

FWIW, I will be using miniDSP on these.
I don’t know much about subs, but I do have some experience using mismatched subs. One of my two subs is much more much capable than the other. Auto setup had a hard time with this, increasing the trim on the less capable sub into distortion. I had to dial each back to -11, and instead use the gain on each sub to level match. That tightened things up quite a bit.

I can also confirm what shadyj is talking about, while watching movies that dig really low, the less capable subs gives out first, and I can sense a shift in bass that mimics movement, to the more capable sub.

Other than that though, no issues for me with mid-bass.
 
S

shadyJ

Speaker of the House
Staff member
To the comment that more subs mean less EQ'ing, I should add that works not just for the listening position, but for every location throughout the room. The ideal would be to use so many subs that all the modes are randomized out, and you get a good response everywhere. The ideal would be no need for equalization whatsoever.
 

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