How a 3 way speaker's woofers behave when it is configured as "Small" for a 5.1 HT system?

swamytk

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Let us assume a Speaker of following:

Speaker: 3 way 4 drivers : 1 tweeter + 3 woofers
Frequency Response: 42Hz to 35KHz
Crossover Frequency: 90Hz/2.2KHz

In above example, given two crossover frequencies (90Hz and 2.2KHz) and 3 woofers in a typical stereo setup: It is my understanding that out of 3 woofers, at least one is for any frequency below 90Hz and rest two are for between 90Hz and 2.2KHz and anything higher than that goes to tweeter. My understanding is that there will be at least one woofer dedicated for below 90Hz. Please confirm this understanding.

With this understanding, connected to an AVR in 5.1 configuration and speaker is configured as "Small" so that LFE can go to Subwoofer. In AVR LFE crossover of 90Hz set - Speaker won't get its share of < 90Hz, so that particular woofer will go silent in this case?
 
My understanding is that there will be at least one woofer dedicated for below 90Hz. Please confirm this understanding.

Yes right.. The bottom driver on FS in this example, would be for 90Hz and below..

With this understanding, connected to an AVR in 5.1 configuration and speaker is configured as "Small" so that LFE can go to Subwoofer.

LFE is different signal, .1 of the audio track.. It has nothing to do with "small" setting..

But, when you set the FS speaker as small, it will route the bass from that speaker to subwoofer..

In AVR LFE crossover of 90Hz set - Speaker won't get its share of < 90Hz, so that particular woofer will go silent in this case?

If you set the FS as small with a crossover of 90Hz, then that dedicated woofer on the floorstander isn't getting that signal for that woofer.. Am not sure if it would be silent, but may produce the sound faintly, which is not audible.. Try it in a demo room and see the difference.. (I have never tried this, but only a guess)..
 
If you set the FS as small with a crossover of 90Hz, then that dedicated woofer on the floorstander isn't getting that signal for that woofer.. Am not sure if it would be silent, but may produce the sound faintly, which is not audible.. Try it in a demo room and see the difference.. (I have never tried this, but only a guess)..
Thanks. In this context can I say that 3 way drivers don't make sense in .1 setup? 2 way should be enough?
 
Thanks. In this context can I say that 3 way drivers don't make sense in .1 setup? 2 way should be enough?
Well not really. The crossover set is a slope and not a cliff. So a crossover of 90hz is not a hard stop, there will be a gradual decay from speaker to the sub. Hence it becomes important to get the perfect crossover setting for each speaker in each room to get that perfect seamless handover between speaker and subwoofer.

Also, 3 way doesn't mean it will go deep down. My kef iq5 are 3 way too, however they do not have great bass extension. In my room almost nothing below 55hz or so. It's the cross over that decides it's 3 way. The cross over is feeding independent signal to the three drivers in my kef.


MaSh
 
LFE is different signal, .1 of the audio track.. It has nothing to do with "small" setting..

But, when you set the FS speaker as small, it will route the bass from that speaker to subwoofer..
Thanks. What is the frequency range of LFE in general and how it is different from Low Frequency bass (42 - 92Hz in this case)? Sorry if it is a very basic question.
 
Thanks. What is the frequency range of LFE in general and how it is different from Low Frequency bass (42 - 92Hz in this case)?

I believe the spec allows for content on the LFE channel to be authored upto 120 Hz. The allowable frequency range for LFE channel is mandated, while the crossover settings are speaker and/ room dependent.
 
In my opinion, they're 2.5 way speakers. The mid and woofers look like the same driver, with the last two compensating for the dropping lf response.

Why do you want to set it to small? Set it to large so that the fronts handle the 60-90hz where you need bass speed, and let the sub handle anything below and provide extension.
 
Let us assume a Speaker of following:



In above example, given two crossover frequencies (90Hz and 2.2KHz) and 3 woofers in a typical stereo setup: It is my understanding that out of 3 woofers, at least one is for any frequency below 90Hz and rest two are for between 90Hz and 2.2KHz and anything higher than that goes to tweeter. My understanding is that there will be at least one woofer dedicated for below 90Hz. Please confirm this understanding.

With this understanding, connected to an AVR in 5.1 configuration and speaker is configured as "Small" so that LFE can go to Subwoofer. In AVR LFE crossover of 90Hz set - Speaker won't get its share of < 90Hz, so that particular woofer will go silent in this case?

This is an oddly spec'd speaker for 3-way. In most 3-way boxes:
- the woofer/s will operate between 40/50 Hz to 400/500 Hz
- mid range from 400/500 Hz to 2-3KHz
- tweeter from 2-3 KHz and upwards
Anyways no point second guessing the speaker designer's methodology and intention.
They must be valid with proper reasoning.

My Marantz AVR runs its calibration and RC magic and always comes back with L/C/R as small.
And the X-over is set at 80Hz. In the "Bass management" tab there are 2 options:
- LFE only
- LFE + Mains

LFE (or .1) is a dedicated sound channel with certain effects encoded into it.
Some FMs have detailed the range as per spec. Sound/movie producers may choose to encode it at a higher level.
This is primarily done so that the L/R/C are unburdened from overworking themselves.
There is bass content in all channels, LFE augments this at higher levels to give the extra kick.
If you don't have a sub in the system to handle LFE, say in a 3.0 or 5.0 system, you will lose out on these effects.
The only sound will be from the main speakers; remember there is bass content in all channels to varying degree.
If there is a sub in the system, LFE is handled by it, admirably or horribly depending on the sub and more importantly, its placement.

AVRs also give you the flexibility to use smaller speakers (book shelf models).
This means the decoder will extract the bass information until specified X-over and route it to the sub.
This is along with encoded LFE. This approach allows users to use their system, monies, space efficiently.
When one has speakers that can handle down to, say 40 Hz, it may make sense to play with the AVR speaker settings.
Choose them as large and individually set the X-over.

In my system, a 3.1, I have chosen to operate L/R starting at 40Hz, C starting at 60 Hz.
Have used LFE+Mains in the Bass management option. Played around with the sub LPF cutoff and settled at 80/100 Hz.
L/R/C is playing full range (as per their spec), not content wise. Sub is augmenting L/R/C bass up to 80/100 Hz.
Sub is also doing encoded LFE. AVR allows for channel level control during movie.
I find some movies need that extra bit of tweaking.

These decisions are made by users, depending on:
- budget (most important)
- AVR capability (most provide a decent buffet of options)
- speaker capability (sensitivity, load, freq response, etc)
- power amplification ("watts", it actually be the instantaneous current available at demanding load)
- sub woofer capability (driver size, extension, "watts")
- listening preference (home listening level or reference level)
- room response (don't get me started here :rolleyes:)

I have learned the hard way that HT is complicated; been playing around with AVRs since late 90s.
Calibration and room correction/EQ definitely help; they remove some of the tough guesswork.

At the end of the day, play around, settle on something and start enjoying movies.
Your home system will never match the real theater; also don't compare with other systems (friends/demo-room).
If you start questioning your decision and your rig, it is a never ending and maddening exercise.

Cheers,
Raghu
 
This is an oddly spec'd speaker for 3-way. In most 3-way boxes:
- the woofer/s will operate between 40/50 Hz to 400/500 Hz
- mid range from 400/500 Hz to 2-3KHz
- tweeter from 2-3 KHz and upwards
Anyways no point second guessing the speaker designer's methodology and intention.
They must be valid with proper reasoning.

My Marantz AVR runs its calibration and RC magic and always comes back with L/C/R as small.
And the X-over is set at 80Hz. In the "Bass management" tab there are 2 options:
- LFE only
- LFE + Mains

LFE (or .1) is a dedicated sound channel with certain effects encoded into it.
Some FMs have detailed the range as per spec. Sound/movie producers may choose to encode it at a higher level.
This is primarily done so that the L/R/C are unburdened from overworking themselves.
There is bass content in all channels, LFE augments this at higher levels to give the extra kick.
If you don't have a sub in the system to handle LFE, say in a 3.0 or 5.0 system, you will lose out on these effects.
The only sound will be from the main speakers; remember there is bass content in all channels to varying degree.
If there is a sub in the system, LFE is handled by it, admirably or horribly depending on the sub and more importantly, its placement.

AVRs also give you the flexibility to use smaller speakers (book shelf models).
This means the decoder will extract the bass information until specified X-over and route it to the sub.
This is along with encoded LFE. This approach allows users to use their system, monies, space efficiently.
When one has speakers that can handle down to, say 40 Hz, it may make sense to play with the AVR speaker settings.
Choose them as large and individually set the X-over.

In my system, a 3.1, I have chosen to operate L/R starting at 40Hz, C starting at 60 Hz.
Have used LFE+Mains in the Bass management option. Played around with the sub LPF cutoff and settled at 80/100 Hz.
L/R/C is playing full range (as per their spec), not content wise. Sub is augmenting L/R/C bass up to 80/100 Hz.
Sub is also doing encoded LFE. AVR allows for channel level control during movie.
I find some movies need that extra bit of tweaking.

These decisions are made by users, depending on:
- budget (most important)
- AVR capability (most provide a decent buffet of options)
- speaker capability (sensitivity, load, freq response, etc)
- power amplification ("watts", it actually be the instantaneous current available at demanding load)
- sub woofer capability (driver size, extension, "watts")
- listening preference (home listening level or reference level)
- room response (don't get me started here :rolleyes:)
Well written, a lot of information. This kind of reply makes me come back to HiFiVision regularly. Hats off to you, @raghupb !


I have learned the hard way that HT is complicated; been playing around with AVRs since late 90s.
Calibration and room correction/EQ definitely help; they remove some of the tough guesswork.
At the end of the day, play around, settle on something and start enjoying movies.
Your home system will never match the real theater; also don't compare with other systems (friends/demo-room).
If you start questioning your decision and your rig, it is a never ending and maddening exercise.
Pretty much summarized what I am supposed to do! Thanks.
 
Let us assume a Speaker of following:



In above example, given two crossover frequencies (90Hz and 2.2KHz) and 3 woofers in a typical stereo setup: It is my understanding that out of 3 woofers, at least one is for any frequency below 90Hz and rest two are for between 90Hz and 2.2KHz and anything higher than that goes to tweeter. My understanding is that there will be at least one woofer dedicated for below 90Hz. Please confirm this understanding.

With this understanding, connected to an AVR in 5.1 configuration and speaker is configured as "Small" so that LFE can go to Subwoofer. In AVR LFE crossover of 90Hz set - Speaker won't get its share of < 90Hz, so that particular woofer will go silent in this case?

Hello Swamytk :)

Actually a crossover of 90hz in itself doesn't state much. There is also something called as cross over slope. It could be 6 or 12 or 24 db. And there is also something called as a octave .

An octave is a doubling or halving of frequency.

So 90hz crossover will do the below:

1. With a 6 db cross over slope it will -6db at 45 Hz
2. With a 12db crossover slope it will be-12db at 45hz
3. With a 24db crossover slope it will be-24db at 45hz.

But what is important is that a crossover starts cutting off signal loudness even before that 90hz set frequency . So a 6db slope is -3db at 90 Hz. A 12 db slope is already -6db at 90hz, and finally a 24db slope is already -12db at the same 90hz cross over frequency.

So when integrating subs, speakers and preamps.. one has take these parameters into consideration..

A sub with a high pass filter of -12db at 60 Hz. Is actually -6db at 60hz. And will gradually taper out to -12db at 120hz.

So the idea is to get the sub and speakers both at -6db at this cross over frequency of 60hz. So that -6db + -6db = 0db...which is the base level.

For the above to be achieved one has to pay attention to the crossover slopes in every components. The sub, preamp and speakers. And do some basic mathematics as per above to get that +0db at the cross over point.

So coming to your question, even though you have set the crossover point at 90hz, there is still a signal going to the bottom most bass driver. Depends on the slope of the crossover again. It could be -3 Or-6 Or-12 6db at 90hz. But there definitely is a signal going right upto 45hz , which is a half octave of the set cross over frequency of 90hz, depending on the slope of it. All the best :)
 
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