Subwoofer calibration question

Grimster74

I know this has been discussed many times before but I have to ask again. When everyone calibrates their subwoofers, do you calibrate them in line with your front speakers (75db) or do you tend to want to run them a little hot (78db or above) I myself run them in line with the fronts but I often wonder why I spent so much money on subs and it seems as though I'm only using 5% of there full potential.

Ricardo

for movies (only task of my sub), I run it hot...78-80

If you also use it for music, then that might be too high.

Grimster74

See, that is the one thing I like about the Outlaw 990, it has the 2 channel subwoofer offset option which makes it really nice when going from movies to 2 channel music listening.

millerman 3732

I run my sub 3-5dbs hotter than the rest of my speakers, depends on what I'm watching.

Schwingding

Don't think of it as not using their full potential, rather that your room doesn't require as much gain. If you had the same sub in a larger room you'd have it turned up more with the same SPL reading.

If you are after audio that matches what the original intent of the creator was, you'll match SPLs all the way around, and then treat the room for dips and peaks in the room's frequency response.

Still, it seems that many sub owners run their subs a little hot. Me - mine are about 3 db higher than the rest of my speakers. I just prefer it that way, even though the gain on my subs is still below 1/3 of full.

McLoki

I calibrate flat and then play music and adjust (final calibration) by ear. (usually ending up about 3db hot or so)

Michael

Lowell_M

I'm 5db hot right now for both music and HT.

Sansui

Schwingding wrote:

Don't think of it as not using their full potential, rather that your room doesn't require as much gain. If you had the same sub in a larger room you'd have it turned up more with the same SPL reading.

I'm expecting a SPL meter (and the Avia DVD from SVS) for X-mas and after reading your reply to Grimster74 I thought of something. Evidently a SPL meter' output readings are in "db's". From what I've read here over the last two weeks people say to set the speakers for a reading from 74 up to 80. Evidently "they" use a setting between those numbers. If there is a "right" setting, what should I be trying to set them at?

If the SPL meter's output is in db's doesn't the volume setting on the amp play an important part in setting all the speakers? I have an Oknyo amp and the volume setting is a numeric format (0 to 79). When in DD/THX mode I listen to it at around "44" (listening to the "RM-10" package from Polk, love them!). If the volume plays in important part when setting the speakers, what should I set my volume at?

PolkWannabie

Anywhere in that range ( 74 - 80 ) is ok ... I usually do mine at 75 but the number is arbitrary ...

Volume setting only plays a part in that you'll need to turn it up enough to generate the reading you selected on the meter ... The actually setting on the preamp or amp or receiver is otherwise somewhat irrelevant.

Sansui

PolkWannabie wrote:

Anywhere in that range ( 74 - 80 ) is ok ... I usually do mine at 75 but the number is arbitrary ...

Volume setting only plays a part in that you'll need to turn it up enough to generate the reading you selected on the meter ... The actually setting on the preamp or amp or receiver is otherwise somewhat irrelevant.

So if I guess if I pick 80 I'd turn the volume up enough so that my center speaker is read at 80 and then adjust the other speakers to 80 also?

MillerLiteScott

Turn the volume up till your left and right MAINS read your desired db level. Then adjust all the other speaker levels to your desired level to match the mains. Adjust your sub to be @ 3-5 db higher to suit your taste.

This is my understanding.

Sansui

MillerLiteScott wrote:

Turn the volume up till your left and right MAINS read your desired db level. Then adjust all the other speaker levels to your desired level to match the mains. Adjust your sub to be @ 3-5 db higher to suit your taste.

This is my understanding.

Thanks! I'll set the MAINS first.

Schwingding

MillerLiteScott wrote:

Turn the volume up till your left and right MAINS read your desired db level. Then adjust all the other speaker levels to your desired level to match the mains. Adjust your sub to be @ 3-5 db higher to suit your taste.

This is my understanding.

Mine, too.

Sansui

Thanks for the info. Now that I have a little bit of knowledge on this SPL meter thing I should be considered dangerous...

Deadof_knight

I have found that in comparison to my front I run my sub 15" -6 db on movies and flat on music. That said I run a 10 and a 12 at the same time at one setting. Somtimes the 15" is sometime turned all the way down to -12 and my living room is rather large and has vaulted ceilings.

mjhughes

I think that a blanket +3db for calibrating a subwoofer is just an arbitrary number with no relevance to anything. Every room is different and no one calibration fits everywhere. What you need is flat response in the entire system, this will let the music or movies play as they were recorded without your system adding distortion or coloration.
Download these test tones, http://www.hsuresearch.com.au/Setup.html and using a Radio Shack meter, play the tones and adjust your sub and speakers LP and HP filters and levels so the all tones are as close as possible in level. Use the the excel chart on that link to plot the readings from the RS meter. You may well end up with system settings that don't fit the standard 80hz crossover settings that everyone is obsessed with, but a flat response is a flat response. It will take some time but the results are well worth it. I think that subwoofer test tones built into av recievers are a waste of time, and also the sub test tones on Avia and VE. The built in test tones are fine for setting main, center and rear speaker levels(also Avia and VE), but not for the sub. Avia does have a usefull sweep from 200hz to 20hz which is great for seeing where problems may lie in you room.

McLoki

If you want more test tones (for calibrating a BFD or something similar) you can get them here....

There are spreadsheets that have the correction values already put into them, but be sure they are the values for your meter. (different radio shack meters have different correction values. - I did not know that until I purchase my most recent meter)

Michael

mjhughes

Wow there's a lot of tones on that link! The excel spreadsheet on the link I gave is apparently adjusted for the inaccuracies of the Radio Shack meters, but I have also read that the inaccuracies may not be to relevant anyway, as even very expensive meters start to get inaccurate down low. Always use your ears too for what sounds best. Measuring can help make sure you aren't too far off in your settings.
The other thing I'd recommend is using the Polk sub setup method using speaker wires, or pre-out to the sub, and setting the main speakers to "large" and subwoofer to "no" in the AVR. What you lose in efficiency in the L&R main channels is more that made up for by bypassing bass management on them, which degrades the sound greatly in my opinion. Setting up the Polk way and having a flat(ish) response in the entire system, means that you won't need to adjust the sub settings for music and movies.

McLoki

mjhughes wrote:

The other thing I'd recommend is using the Polk sub setup method using speaker wires, or pre-out to the sub, and setting the main speakers to "large" and subwoofer to "no" in the AVR. What you lose in efficiency in the L&R main channels is more that made up for by bypassing bass management on them, which degrades the sound greatly in my opinion. Setting up the Polk way and having a flat(ish) response in the entire system, means that you won't need to adjust the sub settings for music and movies.

You should always experiment with this, but the polk method is more for sub/sattelight combinations and non-adjustable crossovers in your AVR. (just my opinion of course)

For the vast majority of normal speakers, you are much better off calibrating the sub (or subs) so it (they) are flat. Then use your avr settings with all speakers set to small 80hz crossover and sub to on. This of course is mainly recommended for home theater uses. You may or may not want to adjust your settings for music playback.

Once again - don't be afraid to experiment and ultimately use what you think sounds best reguardless of hookup method or crossover setting.

Michael

schwarcw

McLoki wrote:

You may or may not want to adjust your settings for music playback.
Once again - don't be afraid to experiment and ultimately use what you think sounds best reguardless of hookup method or crossover setting.

Michael

Good advice there Michael! I use the test meter to calibrate the system just to see where the channel levels should be. I write these down.

Then I tune it by ear for multi-channel music. Some of the SACD or DVD-A music sounds pretty good in multi channel if the system if "tuned". If you tried to listen to multi-channel music on a system tuned for a home theater, you would never listen to multi-channel music again.

PolkWannabie

What is tuned for HT .vs. tuned for Multi Channel music ?