How much low frequency for the satellites of a 5.1 HT?

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Dear all,

I hope I'm intruding here with my home theater question, it's about how low I have to go in frequency with the satellite channels of a home theater?
I intend to use an Onkio 5.1 or similar receiver, about 100W per channel and I intend to build the in-wall speakers and sub by myself.
The system will be used exclusively for movies and regular TV watching, the stereo system is separate.

The front and center channels will be identical, I try to stay with two way, maybe MTM, as I am novice in XO design.

How much bass do I need to the front-center-left channels, so I can have a clue about drivers selection?

Thank you!
 
It all depends on where the sub is located. If near the screen and between the satellites, you can cross over quite high. Which lets you build quite compact satellites.

The sub can be anywhere in the room and crossing over can be done as high as maybe 140 Hz provided the speakers don't reveal themselves through distortion and noises and the crossover slope is steep.

If the satellites are good, hardly any reason to have a middle speaker. Which saves figuring out how to make a quality speaker in the little space for it and low down.

(Some folks like to boast that their acute sense of stereo is destroyed if the crossover is anywhere over 5 Hz.)

B.
 
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80 Hz, sealed is the THX standard. It makes it easier to match with a 4th order low pass in a subwoofer.



If the speakers are dedicated with room correction, don't bother with baffle step compensation. Let the processor do it, and you'll gain significant headroom.



Best,


E
 
Reading the above posts makes me put more effort also into the surrounds.
I though I would go away with a cheap full range. hmm

OK, I will target L-C-R to 80 Hz, although I had in mind 2x FaitalPro 3FE25 in parallel. This full range drops about -9dB at 80Hz:
snap.png
 
I though I would go away with a cheap full range. hmm
Waste of money. Your L and R will have to play clean and full to 40 Hz, which not a lot of good speakers can manage (if the truth be measured). Obviously your otherwise good FR won't work for 80 Hz but just fine for 140.

There is no "standard" for your room. Depends on speaker layout, etc.*

Possibly in a lab setting, people can just barely exceed random guessing at 80 Hz. But in real life with L and R and a screen in the middle, not a chance you need less than 140 Hz (with clean speakers and steep slopes).

Excepting people who claim they are clairvoyant or have special powers of hearing, many have posted here about being fully satisfied with highish freq crossover.

Why does this discussion recur over and over?

B.
* for decades I had corner horn in a corner far from L and R or sometimes even near my ear. No spatial distortion.
 
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I have read that it is important to create a large diffused sound field for the surrounds, that means using multiple surround speakers evenly spread out in the back of the room, from your sides an backwards and all mounted above ear height, pretty much like sound systems in movie theaters. With multiple surround speakers then small drivers can be used.
 
Reading the above posts makes me put more effort also into the surrounds.
I though I would go away with a cheap full range. hmm

OK, I will target L-C-R to 80 Hz, although I had in mind 2x FaitalPro 3FE25 in parallel. This full range drops about -9dB at 80Hz:
View attachment 726860

If you use the 16 ohm version then you can connect 3 in parallell, and using total of 6 surrounds, 3 for left surround and 3 for right surround
 
Possibly in a lab setting, people can just barely exceed random guessing at 80 Hz. But in real life with L and R and a screen in the middle, not a chance you need less than 140 Hz (with clean speakers and steep slopes).

Excepting people who claim they are clairvoyant or have special powers of hearing, many have posted here about being fully satisfied with highish freq crossover.

.

For LCR I agree, if sub is close to them. Until recently I assumed surrounds were the same and I was pretty satisfied, until I heard what I was missing with surrounds capable of low bass. I was extremely surprised how much things improved going from 100hz xo to 40hz xo. I ended up with 60hz to improve power handling but 40 was better. I wouldn't have believed it before I heard it. I stumbled on a website Making the same argument about bass being localizable from rear surrounds. Wish I had a link to it. They have a bass management system that uses multiple rear subwoofers to supplement the surrounds.
 
For LCR I agree, if sub is close to them. Until recently I assumed surrounds were the same and I was pretty satisfied, until I heard what I was missing with surrounds capable of low bass. I was extremely surprised how much things improved going from 100hz xo to 40hz xo. I ended up with 60hz to improve power handling but 40 was better. I wouldn't have believed it before I heard it. I stumbled on a website Making the same argument about bass being localizable from rear surrounds. Wish I had a link to it. They have a bass management system that uses multiple rear subwoofers to supplement the surrounds.
As far as spatial localization for music (and I suppose HT), I'll stick with saying up to 140 Hz (with usual further assumptions) is just fine.

Yes, lots of ways to have better bass, but that won't improve spatial localization (which, as I suggest, isn't impaired with a single sub). For example, you could have three subs or you could put your money on a motional feedback sub and get serous earthquake sounds.

In the event that the folks who make HT sound put some different or added bass tracks into the rear speakers, that's a different story. Anybody know?

B.
 
.1 is the sub. 5.1 is 5 full freq channels and a sub channel limited to around .1 of the freq range. Easy way to write it. So 9.1 is 9 full range plus sub.

Thanks. But my question really had to do with how the sound is cut up. Does the ".1" includes the rear bass (since low freq are not spatially localizable at all). And if it does, is that LF feed removed from some or all or just rear satellite speakers? And if not removed from the satellite speakers, how in the world could a quality audiophile get the crossover feeds right?

Actually, I think I may be asking a question that a lot of people wish I hadn't asked since the answer (for most home movie gear) isn't pretty.*

B.
* for ordinary gear, my guess is that the full range (or little bit of LF cut) goes to the satellites and all bass is mixed to the .1. If you are lucky and have poor satellites and if they don't howl when they get too much bass, it all works out OK since movie bass is just hokey made-up feel-good sound. But if you had good satellites (as someone earlier posted) things just get weird and unpredictable.
 
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.1 is the sub. 5.1 is 5 full freq channels and a sub channel limited to around .1 of the freq range. Easy way to write it. So 9.1 is 9 full range plus sub.

It all depends on the bass management and which speakers are designated as full range. You could have all 5 speakers as limited range and have all of the bass out of the subwoofer including the LFE channel. So it's LFE plus any "small" speakers usually surrounds and center with full range mains in a typical dual use music and movie 5.1 set-up.

Rob:)
 
It all depends on the bass management and which speakers are designated as full range. You could have all 5 speakers as limited range and have all of the bass out of the subwoofer...

My A/V amp talks that way but just still a wild guess at how the signals are cut up to the speakers in the cheap modules inside the amp.

Funny, everywhere else in this forum people are psychiatrically obsessive about crossover details of every sort. But with my A/V amp, you just play it by ear.

I don't even know how I would test my A/V amp (using REW or whatever) since it does all kinds of tricks to the feeds.

I wonder how many quality-conscious audiophiles on this forum have a HT serve as their music room?

B.
 
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Thanks. But my question really had to do with how the sound is cut up. Does the ".1" includes the rear bass (since low freq are not spatially localizable at all). And if it does, is that LF feed removed from some or all or just rear satellite speakers? And if not removed from the satellite speakers, how in the world could a quality audiophile get the crossover feeds right?

Actually, I think I may be asking a question that a lot of people wish I hadn't asked since the answer (for most home movie gear) isn't pretty.*

B.
* for ordinary gear, my guess is that the full range (or little bit of LF cut) goes to the satellites and all bass is mixed to the .1. If you are lucky and have poor satellites and if they don't howl when they get too much bass, it all works out OK since movie bass is just hokey made-up feel-good sound. But if you had good satellites (as someone earlier posted) things just get weird and unpredictable.

Most HT recievers have dsp settings for "steering" the bass away from the full range speakers to the sub. Some even let you set the xover freqs.
 
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