Help for Poor Beginner - crossover freq. & setup

[Nailzaz]

Hi all,

I ask this question as guy who can't afford much, but wants to make the most of I do have and I have limited knowledge.

Hopefully the forums here can give me some advice.

1. Is it "okay" to use the microphone thingy to have my receiver adjust itself?

I did it and watched some HD movies after doing this and they sound great to me - but I'm not a true audiophile to be sure. My assumption is that it's probably better if I measure the distance of the speakers, etc... but with a toddler & another baby on the way time is limited so is the quality from this auto-calibrating good enough?

2. The auto-calibrating does *not* consider the sub woofer. Granted, I have a cheap and old one, but it can knock the pictures off the wall when I want it too and since I cannot afford another one right now, here are some questions:

a) The back of the sub has a level adjustment. Should that be maxed out and then adjust it via the receiver? I did try this and it seemed a little much and I turned it down - but maybe that's not the best solution.

b) The back of the sub has a Frequency Response adjustment. According to my receiver's manual, it says to turn it all the way up (highest setting) and to adjust it too via the receiver.

So is that the best way to do it it? And more importantly, what's a good place (number) to set the frequency (given my speakers, etc...)?

Thank you guys in advance for your help. You've always been good to help me with my questions and it is appreciated very much.

Sincerely,
Paul in AZ, USA

Here is my system:

Receiver: Sony STR-DG800
Speakers: Bose Acoustimass 6
Sub Woofer: Mitsubishi M-SUB 10

 

[Davemcc]

The auto setup should be fine for a basic setup if you are not too fussy.
On the back of the sub, the volume knob should probably be set to 1/3 or 1/2 depending on the size of the room, then control it from the receiver.

The crossover frequency between your sub and speakers is somewhat problematic. The Acoustimass roll of at the bottom end about 250Hz. That is generally too high for a subwoofer to effectively stretch to reach. Turn the crossover on the back of the sub all the way up and control the crossover from the reciever. It may take some experimenting to find the settings that sound best to you, but try all the crossover points above 80Hz to see what you like.

 

[MDS]

1. Is it "okay" to use the microphone thingy to have my receiver adjust itself?

Yes, it's ok to use the auto setup but in some instances it will not be optimal; eg, they often set speakers to Large when you'd rather have them set to Small. Speaker distances are usually accurate and any EQ it adds can be good.

2. The auto-calibrating does *not* consider the sub woofer. Granted, I have a cheap and old one, but it can knock the pictures off the wall when I want it too and since I cannot afford another one right now, here are some questions:

a) The back of the sub has a level adjustment. Should that be maxed out and then adjust it via the receiver? I did try this and it seemed a little much and I turned it down - but maybe that's not the best solution.

b) The back of the sub has a Frequency Response adjustment. According to my receiver's manual, it says to turn it all the way up (highest setting) and to adjust it too via the receiver.

So is that the best way to do it it? And more importantly, what's a good place (number) to set the frequency (given my speakers, etc...)?

You said you have a Bose Acoustimass so is it that 'sub' you are talking about or do you have an additional sub?

Normally you would set the level on the sub to about 1/2 way up and the frequency (crossover) to it's highest level and then you'd tell the receiver you have a sub and set the xover in the receiver. The appropriate xover depends on the low frequency response of your speakers but 80 Hz is an almost universally good choice.

BUT...the Bose system complicates matters since all the speakers get connected to the bass module and not the receiver. If the Bose bass module is what you are referring to when you say you have a sub, then from the receiver's perspective you do not have a sub and that is why it was ignored during auto-setup. If all you have is the Bose setup, you want the front speaker terminals of the receiver connected to the Bose bass module, front speakers set to Large, and subwoofer=No/Off.

If you do have an additional subwoofer, it gets more complicated.

 

[Nailzaz]

Yes, it's ok to use the auto setup but in some instances it will not be optimal; eg, they often set speakers to Large when you'd rather have them set to Small. Speaker distances are usually accurate and any EQ it adds can be good.



You said you have a Bose Acoustimass so is it that 'sub' you are talking about or do you have an additional sub?

Normally you would set the level on the sub to about 1/2 way up and the frequency (crossover) to it's highest level and then you'd tell the receiver you have a sub and set the xover in the receiver. The appropriate xover depends on the low frequency response of your speakers but 80 Hz is an almost universally good choice.

BUT...the Bose system complicates matters since all the speakers get connected to the bass module and not the receiver. If the Bose bass module is what you are referring to when you say you have a sub, then from the receiver's perspective you do not have a sub and that is why it was ignored during auto-setup. If all you have is the Bose setup, you want the front speaker terminals of the receiver connected to the Bose bass module, front speakers set to Large, and subwoofer=No/Off.

If you do have an additional subwoofer, it gets more complicated.

This is good advice, thanks.

First, yes I do have an additional sub and old Mitsubishi 10(?). You said that would complicate things? How so? I did noticed that the auto calibration set the Bose speakers to large and I manually set them to small.

Should I still set my sub at 1/2 power, full frequency & 80 hz?

Thank you again, very much for your help.

Paul

 

[MDS]

The Bose bass module acts like a subwoofer (although it cannot go as low as a dedicated sub) and will separate the frequencies for itself vs those it passes on to the satellites so when used with a receiver you want it set to Large so it gets a full range signal.

When you have a sub connected to the receiver sub pre-out, normally you'd have other speakers attached to the other speaker terminals. When you set subwoofer=yes and set a xover frequency, the receiver sends the sub only the frequencies below that frequency and the rest to the other speakers. To accomplish that you need to set the other speakers to Small.

Now here's the rub if you have the Bose and another sub but no other speakers attached to the receiver. From the receiver's perspective you have a 2.1 setup because the Bose is connected only to the two front speaker terminals. You need to set the front speakers to Large so the Bose can get the full range signal and do its thing with splitting the signal between the bass module and the satellites, but if you do that there is nothing to send to the subwoofer from the receiver's sub pre-out. The receiver sends bass to the sub only for those channels set to Small (which there are none) unless the receiver also has a 'double bass' type function (it goes by different names in different receivers). If it has the double bass option set it to On and you'll get bass from the subwoofer.

If you were to set the front channels to Small to utilize the subwoofer, then the Bose will only get the frequencies below the xover and the satellites will most likely be silent because the bass module has a very high xover point (something like 200 Hz).

 

[Nailzaz]

This does get more complicated and I'm a little confused, please bear with me.

It looks like the passive sub for the Bose is more or less a "pass through". In otherwords, I looked at the back and the manual and there are connections to the reciever for all of the speakers (not just two) - if that makes sense.

Maybe if I give you the specs you could tell me how you would proceed? For example, I'm confused now on setting up the size of my speakers via the reciever (small/large). I should note that I have an older Accoustimass with doesn't have a sub out connection.

So here are my components, specs and links:

- Receiver: Sony STR-DG800
(I don't believe this has that 'double bass' setting you mentioned)

http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&productId=11040213&langId=-1

- Mitsubshi Sub 10
This old sub is what I have and I couldn't find any mention of it on the web, except for this one site - but it does have the specs:

Model Description:
Amplified Subwoofer
Features:
Black diamond gray cabinet finish, bottom-firing, ported type
60W amplified power
10" polymer woofer
Level control
Auto standby
Phase switch
1-touch, phono jack input
Specifications:
Crossover : 50-200 Hz variable
Frequency Response : 38-200 Hz

http://www.bcs.tv/store/model_detail.cfm?id=788677

- The Bose®Acoustimass®6 Series II Speaker System
This is a discontinued product, but I found a manual for it - however it only mentions what to set the speakers to (large/small) but doesn't seem to say what the frequencies are.

http://www.bose.com/pdf/customer_service/owners/og_am6.pdf

Given this information, I would like to know how you would set it up. Currently I have all of the speakers set to small, sub=yes and I set the powered sub to 1/2 power, full freq and adjusted my reciever to 80hz.

Thank you again and although I'm broke - your advice is worth me at least buying you a StarBucks or something - so if you have a PayPal email you want to send me, I'd be happy to donate for this help.

Paul

 

[MDS]

OK, so this version of the Acoustimass is slightly different than the ones I've seen (I don't keep up with Bose).

Based on the chart in the manual everything I've said so far still applies except that it suggests setting the Center to Small. All other channels must be set to Large and Subwoofer=No as mentioned earlier. I'm sure there is a reason they suggest center=small but I have no idea why.

If you follow that diagram, you can set all channels to Large except the Center which you set to Small. If you set subwoofer=Yes in the receiver, the only info that will get sent to the sub is center channel signals. That will probably work ok since movies have the majority of sound info in the center channel anyway.

I'd follow the Bose recommendations but turning subwoofer=On/Yes in the receiver will at least get the bass for the center channel sent to your sub. The Double Bass feature is relatively new in the last few years but all brands implement it under a different name (Onkyo = Double Bass, Pioneer=Plus, Yamaha=LFE+MAIN). If you don't have the double bass feature there isn't much you can do to utilize an additional subwoofer in conjunction with the Bose.

 

[Nailzaz]

My wife just went to bed and I ran the auto calibration again and the reciever changed the speakers to "large" - all of them.

If you don't mind, I have 3 questions.

1) I'm not clear about the center speaker being set to large/small and the powered sub being on or off. Should I keep it at "large" + sub=on? Or are you suggesting that I change the center=small or something else? I feel silly asking this stuff and again, thanks for the patience.

The next two questions are somewhat unrelated, but I'm curious...

2) Would you recommend turning the reciever EQ on or off?
There's a bass and a treble +/- if I do

3) The default setting for the sub woofer is 0db - is it a matter of preference to increase/decrease that or do you have a recommendation?

I think this is the last of my novice questions.

Again, thank you

 

[MDS]

1) I'm not clear about the center speaker being set to large/small and the powered sub being on or off. Should I keep it at "large" + sub=on? Or are you suggesting that I change the center=small or something else? I feel silly asking this stuff and again, thanks for the patience.

The way bass management in a receiver works is that any channels set to Small will have the frequencies below the xover redirected to the sub. Since the Bose bass module also does that, you usually want them all set to Large so it gets a full range signal. I have no idea why the manual suggests Small for the center unless it doesn't touch that channel and allows the receiver to deal with it.

If you set sub=On, it won't affect any channels set to Large as by defnintion any Large speakers get a full range signal. It would affect the center if it is set to Small because it would redirect the bass below the xover to your sub.

The next two questions are somewhat unrelated, but I'm curious...

2) Would you recommend turning the reciever EQ on or off?
There's a bass and a treble +/- if I do

I do the calibration manually so I don't use any Auto-EQ. The simple answer is if it sounds good to you, leave it.

3) The default setting for the sub woofer is 0db - is it a matter of preference to increase/decrease that or do you have a recommendation?

The level setting on the sub itself and the level in the receiver work together. You can have the sub turned up high and the level in the receiver turned down or vice-versa. You can only know what combination works best if you are calibrating manually to reach a certain SPL. But, in general you want the receiver level set to 0 dB or higher. If the receiver level is set below 0 dB, the auto-on feature of the sub may not work reliably because the level of the signal sent to the sub is too low to trigger the auto-on.

If you want to use the auto-setup routine, I'd start with the receiver level set to 0 and the sub volume at about half way up. If the auto-setup routine completes without error, you are good to go. If not, you have to mess with the level on the sub and the receiver's sub level. It's preferable to keep the reciever's level greater than or equal to 0 dB and increase the sub level in that case for the purposes of making the auto-on feature work reliably.

 

[Nailzaz]

With this, I'm off to turn up some HD 5.1 content (until my wife wakes up) to see how it sounds.

Thank you again! It is very gracious of you to take the time to help me out.

Paul

 

[MDS]

No problem. That is what we are here for. Hope you get everything sorted out to your satisfaction.