# Thought #2...how many with capable mains...



## hearingspecialist (Mar 15, 2010)

are running them as "Small" vs. "Large" even when both are crossed over to 80hz for THX style listening??? I have always run them as "Large" even though I still cross them over at 80hz and they are tuned to 32hz. I was playing with the settings at lunch while wasting time at home and switched them to small still crossed over at 80hz. I heard a very different presentation of the sound with the same listening material and now really wonder what the measurable differences will be with the "Large" vs. "Small" both crossed over at 80hz?

Anyone want to take a stab? :nerd:


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## Kal Rubinson (Aug 3, 2006)

If set to LARGE, they run full-range regardless of the crossover setting. Depending on the processor and settings, the bass below crossover may also be sent to the sub resulting in double bass.

If set to SMALL, the bass below crossover is diverted to the sub and the main speaker is rolled off.

Very different, as you have heard.


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## hgoed (Mar 22, 2010)

From what I understand, running small will prevent the larger driver on your mains from having to produce the lowest frequencies, theoretically improving the midrange.
Running full-range could sound better in the mid-bass if you've got decent mains. 

It may also depend on your sensitivity to low frequency directionality. At 80Hz, we're not supposed to be able to tell, but I'm pretty sure that's not accurate for everyone. 

Why not listen to both and see what you prefer?


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## koyaan (Mar 2, 2010)

The difference will depend on a couple of things. I know my old Denon AVR had a setting that sent both LFE and main bass to the sub even if the mains were set to large. If the mains were set to small, crossed over at 80hz, the bass below 80 and the LFE went to the subs only. Of course, that made a diffrence. With a traditional 80hz crossover, the major difference would be the quality of sound from your mains below 80hz compared to that range from your sub.


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## Jason_Nolan (Jul 4, 2008)

I think Kal summed it up pretty well.

I used to have Definitive's with 18" powered subs and a JL F113 subwoofer. The definitives were capable of producing down to 20hz, but the JL had much better bass and I could locate it for smoothest response. I was of the impression of the more woofers the better the bass.

I quickly learned that you have too much modal interaction by letting both 18's interfere with the JL and set them to small, crossed over at 80hz. This produced a much smoother response. I'd say in almost every circumstance that this will be the case. It's very difficult to get two subs that are not colocated to play well together. Without getting into the physics of sound too much, when sound waves of different lengths play at the same time at different locations, they meet together at certain frequencies at different phase angles and can either cause a peak, or a null. 

I'd bet that your sound, although different, is now better that you set your mains to small with the sub.


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## Jungle Jack (Jul 28, 2009)

Hello,
I am definitely a proponent of setting the Crossover to 80hz. In addition to the above excellent points is the fact that the best place acoustically for Speakers is almost never the best place for the Subwoofer and Bass.

The advantages of setting to 80hz are myriad including placing less stress on the AVR allowing it to focus on the Highs and Midrange. This allows you to have higher overall SPL's while running a much lower risk of the AVR of going into distortion.

Moreover, there are very few Speakers out there that are truly capable of going down to 20hz. And they are unbelievably expensive to boot. My Mains are rated down to the low 30's by virtue of having 200 Watt ICE Amplifiers in each Speaker to drive the Woofer, but I still use an 80hz Crossover. My Surrounds (MartinLogan Vistas) are rated down to around 40hz, but do not have built in Amplifiers for the Woofer. 

Thanks to having very powerful Amplifiers, I could easily set the Surrounds to 40hz with no worries about distortion, but again where they are placed is not advantageous for Bass whereas my Depth Subwoofer is placed for the smoothest and deepest Bass Response.
Cheers,
JJ


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## Binary (Nov 23, 2009)

I have fairly large main speakers, Cerwin Vega M100 Towers. They make great party speakers, but can be a little bass heavy.

I've found that my favorite "range" to cross over is actually 50hz. my mains/surrounds are all capable of 50hz reproduction. I use a DCX2496 to cross over the mains that i leave set to "large" and put a 4th order filter on them at 35hz, this gives me a small overlap in the 35-50 range which is where my sub actually has a small dip in response. (about 1.5 db max drop) My center is set to small, as are the rest of the surrounds. But i find that for regular television or anything recorded in 2 channel. this really makes it sound cleaner, and since my mains are no slouch, they integrate with the big subwoofer without much hassle.

I use the behringer dcx as well to add a bit of boost at 50hz (3db) this helps bring the output of the 50+hz range to that of the subwoofer. and then it blends in nicely. Im a bit of a bass junkie.


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## nova (Apr 30, 2006)

I have to agree with the others to a certain point. My L & R speakers are pretty capable down to 27Hz but with a little experimentation I find that my room and my ears prefer them to be run as small and crossed over at 60Hz. So my opinion is that 80Hz and small is not always the best for all rooms/systems.


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## Integra8 (Jan 1, 2011)

Interesting thread! When I ran Audyessy, my front 3 speakers were set to 40hz. After reading many posts I backed it off to 80hz, now at 60hz and still experimenting. How accurate is Audyessy in this regard? My speakers are Paradigm M-9s, appox 12+ years old.

Jeff


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## LeeH (Feb 18, 2011)

Why is the crossover "standard" at 80hz? Does it have to do with directionality (i'm sure somewhat), the point at which amp power starts to really get drained by low frequencies or what?

I'm just looking for the logic behind the standard. I will be revisiting my setup when I incorportate some AV123 Rocket 850 signatures into my system.


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## hearingspecialist (Mar 15, 2010)

Crossover recommended frequency 80hz:

THX recommends this frequency for pure sonic pleasure and other codecs also also use that frequency to support their LFE processing. :nerd:


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## gdstupak (Jul 13, 2010)

My mains are crossed over at 40hz. 

For 2 weeks I listened with everything crossed over at 80hz but just didn't care for the sound of it. I would probably use the 80hz crossover if didn't have a good amp for plenty of power and eq's to dial-in the sound.


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## Jungle Jack (Jul 28, 2009)

Hello,
It is all about what sounds best to you. I am using some of the most powerful Amplifiers out there, but still cross over at 80. Much of this is due to the fact Electrostats need to be out in space several feet away from any Walls. This is almost always not the best place for a Subwoofer and achieving the best possible Bass.
Cheers,
JJ


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## Theresa (Aug 23, 2010)

hgoed said:


> From what I understand, running small will prevent the larger driver on your mains from having to produce the lowest frequencies, theoretically improving the midrange.
> Running full-range could sound better in the mid-bass if you've got decent mains.
> 
> It may also depend on your sensitivity to low frequency directionality. At 80Hz, we're not supposed to be able to tell, but I'm pretty sure that's not accurate for everyone.
> ...


"DECENT?" Some of the best "mains" only go down to 60 or 80Hz. With a sub and satellites you get better imaging AND bass. As for directional cues I read that in testing some could hear them as low as 60Hz and some not until 120Hz. The vast majority not until 80Hz and above. An advantage of dual subs, one on each side, is that it removes this issue.


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## Binary (Nov 23, 2009)

My preferred crossover is around 50-60hz, as steep of a filter as possible. I find that when the subwoofer starts putting out the 80hz range its very easy to localize for most people, and it actually pulls the image towards the subwoofer. 50hz is great. my mains are solid to mid 30's so by using this, i put the image where it belongs, have amazing two channel sound, and the sub is only used when needed. Its nice to not have that bloated midbass range.


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## Jungle Jack (Jul 28, 2009)

Hello,
80hz is considered by the majority of HT Experts to be a point where the Subwoofer should not be localized provided the Subwoofer is Level Matched.

That being said, if you are noticing it at 80hz, it is great that you have Speakers that will allow you to crossover lower than 80hz. I too have Speakers that go far below 80hz both in the Mains and Surrounds, but still choose to use an 80hz Crossover. Another reason is that with Electrostatic Speakers, they really need to be out in space to sound their best which is almost never the best placement for a Subwoofer.
Cheers,
JJ


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## Binary (Nov 23, 2009)

I know those electrostats you have have a woofer box attached to the bottom. I know what you mean about a lack of bass in room as they are getting no reinforcement from boundaries, however, its because of the nature of the electrostats that the woofer is even there. Without that woofer, I doubt those electros would go to 80, and if they did, it wouldnt be all that pretty. Because your electros are somewhat weaker in the lower ranges, a higher xover works.

I happen to have some very large towers with 15" woofers in them tuned for ~28hz. i'd say apples to apples, my mains have better bass than your martin logans, but you've got me beat hands down once you cross that 80hz range.

If you've got mains that can truely do 50hz, where they are placed, then 50hz is the recommended crossover in my books. Granted, it takes a fairly large main to do 50hz at reference level, and often the mains are bigger than the surrounds, but they all cross over in the same range. So you'd need a full set of speakers good for 50hz cutoff in order to take advantage of the lower crossover.

My sides are a custom vented CSS SDX7 MTM box tuned to 30hz, and my rears are good to 50hz. I am fairly lucky in having surrounds that can be driven hard.
I wouldn't be surprised if my MTMs could push out the same kinda bass as your mains.


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## Jungle Jack (Jul 28, 2009)

Binary said:


> I know those electrostats you have have a woofer box attached to the bottom. I know what you mean about a lack of bass in room as they are getting no reinforcement from boundaries, however, its because of the nature of the electrostats that the woofer is even there. Without that woofer, I doubt those electros would go to 80, and if they did, it wouldnt be all that pretty. Because your electros are somewhat weaker in the lower ranges, a higher xover works.
> 
> I happen to have some very large towers with 15" woofers in them tuned for ~28hz. i'd say apples to apples, my mains have better bass than your martin logans, but you've got me beat hands down once you cross that 80hz range.
> 
> ...


Hello,
Indeed. The 25,000 Dollar CLX is quite large and is not a hybrid and only goes down to around 60hz. And indeed on the ESL Hybrid Models, even with the biggest ones, the Panel ends at 200hz. Full Range Electrostats would be unimaginably large and even MartinLogans 100k Statement e2's used a Tower of Woofers.

However, with the Vantages having 200 Watt B&O ICE Power Amplifiers powering Aluminum Woofers with heavy Magnets, the Bass Response is actually quite good when used without a Subwoofer. Considering they cost around 6000 Dollars, they should be able to play cleanly down to 35hz.

Regardless, most Subwoofers do sound their best not 5-6 Feet out into the middle of the Room like the way I have my Vantages setup. I also think the quality of the Subwoofer can also come into play in regards to audibility at 80hz.
Cheers,
JJ


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