Subwoofer theology!

Hi
I think I had a penny drop moment tonight, during the Carol service. (I used Haverhill and my console for the first time at church and it went well. I loaded it in 250ms sim. dry mode). This might be a stupid question, but....

Would I be right that a sub-woofer is not entirely about adding more bass - it also acts as a filter and prevents the 'normal' speakers getting too bass heavy?

Up until this point in the comfort of my home I had thought there is enough bass in this sound. But tonight I realised that when you boost the audio level to fill a church there is too much bass! I just turned the Low EQ right down on the mixer for this one-off service and got away with it, but I'm keen to understand how to do it properly.

Secondly was 250ms a sensible guess for simulated dry? I didn't have time to experiment too much!

Thanks for helping my learn this side of things. Tim

Subwoofer would normally not pass the low bass to the other speakers fed by it.
There is usually some control of where the filter takes effect.
And surely the subwoofer itself has a volume control?

Subwoofer would normally not pass the low bass to the other speakers fed by it.

Thanks - that is what I was thinking. To be clearer, I don't have a subwoofer, I'm entertaining getting one and asking if I can expect this to at least partially solve the bass-heavy 'problem'.

... I'm entertaining getting one and asking if I can expect this to at least partially solve the bass-heavy 'problem'.

IMHO: Yes and No!

The "Bass-Heavy-Problem"occurs in almost every set-up and is more generally a phenomenon, which can occur with all frequencies as "boosting" and "dampening" mostly in certain sectors of the spectrum.

The reasons for these effects are
- the characteristics of the speaker-system, ( accentuation of frequency ranges: bass? )
- their relative position to the ears of the listener, ( distance, direction,...)
- their relative position in the given room, (corner, floor,...)
- the characteristics of a room ( size,furnishing, reverberance,...and very important, because in most cases the cause of bass-boosting of certain frequencies: the resonance characteristics)

As far as I experienced a good and quick installation of a speaker system in bigger, challenging rooms is a job for acoustic engineers, who studied all the rules and their interdependence. IMHO, we, as amateurs have to replace deeper knowledge by experimenting and obeying some basic rules and finally make use of the equalising features of Our equipment, especially the voicing/intonation feature of Hauptwerk.

Those basic rules have been thoroughly discussed in the internet and might be googled or binged. To repeat them here might be carrying coals to Newcastle.

Amun

[mdyde]

[Topic moved here.]

Thank you for the replies. I did an acoustics module as part of my degree and therefore am not completely starting from cold. It makes sense that the characteristics of the room and speaker placement (both things I didn't have time to do much about) are going to affect things a lot.

I am building a picture up - getting the right speakers in the right place with (probably) a sub woofer as well as a decent stereo EQ unit seems to be the general direction to head in for a church installation.

I wondered if there is any concise advice on the Hauptwerk side of things. Right now I still have basic edition. I understand that Advanced edition would let me send different ranks to different speakers. But taken in context I will probably only be using two pairs of B2031A 's and a subwoofer anyway. It isn't a huge church - it holds about 150. So I'm trying to decide if the Advanced edition would make a huge difference or not?

Also, is there any general advice for getting started with Hauptwerk voicing; I'm assuming the Bass Split tab is rather important to the topic in hand. I might be asking to the Earth on a plate - but surely even the experienced people start somewhere known before adjusting and experimenting.

Thanks again for the help.

It very much depends on how you do your setup. If you feed the speakers through some kind of EQ or straight from the outputs on your sub, then you can filter out the lower frequencies and only have the sub produce them, in which case, you won't have all the speakers trying to throw out low end in addition to the sub. If, however, you simply add a sub to the mix and do nothing to attenuate the signal response of the monitors themselves, then you will just have the subwoofer adding clarity and presence to the mix with all the speakers trying to do it too. In my opinion, this isn't necessarily a bad thing (or rather, isn't necessarily a "problem") if you are using smaller monitors since they can't really produce that end of the spectrum anyway.

Also, is there any general advice for getting started with Hauptwerk voicing

You will find a thorough discussion of the voicing features of HW page 175 ff.
But they only come with the Advanced Edition.

Rgds,
Amun

Thanks, will read up!

What I missed here, is the Fletcher-Munsson curve. You said, that when turning colume up, you have too much bass.
That can be, because at lower listening levels you experience less bass, because of this dynamic freq resonse curve of the ear. So when you compensate for that, it gets too much at higher levels.
(Physiologic volume control was on the older generation of amps...)

Besides, I want to point you towards usnig a DAW ( like Reaper), and doing your mixing, subwoofer mixdown, room equalisation with nearly infinite flexibility......For performances in public I would strongly advice this.

Greetings,

Geert

Also, sometimes placement can be the problem.
For some decades I was a Rodgers technician.
An organist told me that one pedal note stuck out.
I was standing right behind the organ console.
He said, See how loud the G is compared to F# or G#!
To my ears, 3 feet from his, the G was the softest note.
Standing waves.

We moved the subwoofer into a corner, then we
were able to turn down all the low bass stops.
And all notes were equal in all places!
Standing waves, overcome.


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