Subwoofer Eq Suggestions

mike c

mike c

Audioholic Warlord
ok, also try this:

UP the speaker volume (receiver volume) til the speakers AND subwoofer freq. response are at about 80db.

it's possible that the green lined graph at about 70db does not represent what your sub will be able to achieve during higher volume usage. (or it's the greatest subwoofer find of them all! :) )
 
avaserfi

avaserfi

Audioholic Ninja
ok, also try this:

UP the speaker volume (receiver volume) til the speakers AND subwoofer freq. response are at about 80db.

it's possible that the green lined graph at about 70db does not represent what your sub will be able to achieve during higher volume usage. (or it's the greatest subwoofer find of them all! :) )
I'll have to try that on Sunday. I'll just up the volume a bit, hopefully it stays flat :D. I know Jamo makes good stuff, I will be hearing my first SVS on Saturday and am extremely excited!

I will post all results sometime Sunday about all the results from speaker/woofer movement as well as seating and the acoustics/increased volume levels.

You really think that upping the volume by about 7-8db will change the frequency response that much?

I am very new to small system calibrations and thank you guys very much for all the help! It is very exciting and a great learning experience.

Does anyone have any thoughts as to why my response is so low maybe Jamo rates their stuff very conservatively or my square room is doing something right? :confused::eek:
 
OttoMatic

OttoMatic

Senior Audioholic
You really think that upping the volume by about 7-8db will change the frequency response that much?
It probably won't change the response itself at all, unless you run out of gas in the sub, or the sub's amp.

Does anyone have any thoughts as to why my response is so low maybe Jamo rates their stuff very conservatively or my square room is doing something right? :confused::eek:
It could definitely be the room. You can always measure pure tones with your SPL meter and see if they jibe with the REW response. Also, did you calibrate your soundcard?
 
avaserfi

avaserfi

Audioholic Ninja
It could definitely be the room. You can always measure pure tones with your SPL meter and see if they jibe with the REW response. Also, did you calibrate your soundcard?
I did calibrate the card previously and I redid everything today just to make sure. I will pop in my Rives disc and see what happens on Sunday.

I also had one other question for Bryan or anyone else who can field it. What exactly is meant by "non-symmetry" in regards to the graph? I see how it isn't symmetrical but if it was it would basically be flat...
 
OttoMatic

OttoMatic

Senior Audioholic
What exactly is meant by "non-symmetry" in regards to the graph?
I think he's talking about the room shape itself and/or the placement of the speakers and sub with respect to each other.
 
avaserfi

avaserfi

Audioholic Ninja
I think he's talking about the room shape itself and/or the placement of the speakers and sub with respect to each other.
Alrighty, well my room is 14 feet wide by 13 feet 2 inches deep and 8 feet 4 inches high. The listening area is 8 feet 6 inches of the total room area with the rest being used for dining.

Any suggestions on speaker placement for me to play with? Right now the main speakers are 22 inches off the wall and 66 inches apart with my TV stand in between. The sub sits in front of the FR speaker. I plan on trying out a variety of new arrangements this weekend but suggestions never hurt!
 
OttoMatic

OttoMatic

Senior Audioholic
Any suggestions on speaker placement for me to play with?
None from me. Speaker placement is always a struggle in a non-dedicated room (I think you're in a living space, and I don't have a dedicated room either). Too much crap to work around, WAF, other restrictions. Most of us have to "work with what we have."
 
avaserfi

avaserfi

Audioholic Ninja
One last question for now: To find optimal positioning for my front speakers should I just run REW with each speaker alone and find the optimal position then do the other then do the sub and finally see how they integrate together? Also, what frequency range should I focus on?
 
OttoMatic

OttoMatic

Senior Audioholic
One last question for now: To find optimal positioning for my front speakers should I just run REW with each speaker alone and find the optimal position then do the other then do the sub and finally see how they integrate together? Also, what frequency range should I focus on?
Personally, I try to find a good location for the mains by listening in two-channel stereo mode. I try to get good imaging and soundstaging going, etc. I've never tried to place main speakers based on REW measurements. And I've tried a lot of stuff with REW.

Low bass (let's say less than 80 Hz or 100 Hz) is going to be powerful enough to excite the room modes themselves; the higher frequencies generated by your mains just don't interact as much with the room as the sub does. Therefore, locating the sub in different places around the room will have a bigger impact on bass frequency response than will main placement; probably by a lot (again, no experience with intentionally moving around mains to deal with bass/room mode issues). On the other hand, if your speakers are bass-capable, they too, will interact with the room, and their placement in the room will cause frequency response to change.

All that said, I'd focus strictly on the sub. Engage the crossover as you will use it in practice (50 Hz, 80 Hz, whatever you want it to be). Turn off all other speakers. Phase will not matter, because it's only applicable when there are other speakers. Sweep from REW's minimum (which I believe is not changeable right now), and end the sweep at 200 Hz. I think you said your crossover point was 80 Hz, so sweeping to 200 Hz will be fine. Post your graphs from 45 to 105 dB on the vertical (Y) axis and 15 to 200 Hz on the horizontal (X). If you're going to do a series of measurements, plot them on the same set of axes (you've already been doing that).

Once you get your sub response the way you want (either through placement, treatments or EQ), turn the mains back on. You may have an interaction at the crossover point -- play with phase if you can. You may notice peaks and dips, and you may not be able to do anything about them. Of course, you can try moving mains around.

Geez, I just wrote this whole thing thinking that you are trying to fix your sub frequency response. You've ordered an SMS-1 but it's not there yet... Duh! Anyway, it still all applies, from my point of view. Get the sub right first, and then integrate the mains, etc.

You'll have even more fun when the SMS-1 gets there!

Good luck!
 
avaserfi

avaserfi

Audioholic Ninja
Thanks for all the help Otto. I'll try all the suggestions everyone has given and report on them as soon as I do it.

Learning is a huge deal to me so I would like to learn more about proper speaker placement through trial and error not just by reading besides it will be nice to have the frequency response as flat as possible before the sms-1 anyways. Plus its always nice to improve system performance for free :).

I think I have my mains set pretty well, but I will try to play with them some more and also work with my woofer as well.
 
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B

bpape

Audioholic Chief
One last question for now: To find optimal positioning for my front speakers should I just run REW with each speaker alone and find the optimal position then do the other then do the sub and finally see how they integrate together? Also, what frequency range should I focus on?
Ding! Reastically you can't find final positions like that since when you do both together you'll get some interaction. BUT - what it will do for you is show you very clearly what moving each speaker forward and backward, side to side, etc. does for frequency response. Then when you start playing with seating position and sub position, you'll know how you can 'fix' things.

You're going to find some things that will change drastically as you move the seating (mic) position. You'll find other things that don' change at all. Note those. The ones that don't change will need to be dealt with via speaker/sub/phase/xover changes.

Yes - non-symmetry referrs to the fact that the speakers are not set up basically equally straddling the centerline of the room. In this situation it can't happen. That's just reality. I was simply trying to explain why some of the anomolies might be happening. For instance, when you do the single speaker measurements, I think you'll find the bass response quite different for the left than the right speakers simply because of boundary issues.

Speaking of that - when you do the individual left and right measurements, run them full range even though you'll be cutting them off at 80Hz. Xovers are not brick walls. There will still be energy below 80 from the speakers. We need to know what it is going to be.

Bryan
 

Buckle-meister

Audioholic Field Marshall
...before the measurements that are posted were taken I changed all my crossovers to 80 except my center which is at 100...
Are you measuring with all your speakers playing? This would be done for the purpose of achieving as flat as possible a surround response (as opposed to 2-channel response). Is this what you're aiming for? :confused:

...you have put in the calibration file for the SPL meter right?
Mike, the calibration file, at least for the RS meter, has virtually no effect in the low frequencies being discussed here. :)
 
avaserfi

avaserfi

Audioholic Ninja
Are you measuring with all your speakers playing? This would be done for the purpose of achieving as flat as possible a surround response (as opposed to 2-channel response). Is this what you're aiming for? :confused:
All the graphs are from stereo mode so I am just working with my mains and sub. Not as worried about the surrounds, for now at least, I will probably at least play with that later.

edit: Again, thanks to all that have been helping me out with this. I have learned a huge amount about subwoofer placement and speaker/room interaction in general and I am sure there is still much more for me to learn. I set aside time tonight to test my speakers and possibly my sub. Although I have been pretty happy with my main speakers placement it can't hurt to adjust and see any differences obvious by this thread the sub location is still very much in open air.
 
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Buckle-meister

Audioholic Field Marshall
My strong suggestion to you is pull it all down...Once you get the seating position, speaker positions, and sub positions the best you can in terms of frequency response, THEN start SLOWLY putting treatments back up...
I agree with all but one part; putting up (certain) treatment after first fixing the listening, speaker and sub position. I mean isn't it an almost given that the bass traps will be required and that they must be placed in the corners for maximum benefit and so shouldn't they be placed in the room from the outset?
 
B

bpape

Audioholic Chief
The problem is that if you put them in first and they're doing their job, they're going to mask some problems and make it harder. This is also why we do them a little at a time. If we find the best place without causes and issue when they're in, then we shift a little and find a place that doesn't hurt much raw but doesn't cause an issue with treatments fixing one thing and messing up something else.

Bryan
 
Warpdrv

Warpdrv

Audioholic Ninja
Well I see your getting your SVS, and your SMS-1 soon....

Download this manual from the Outlaw site... and read it though.... Its the best out there for the SMS-1.

Looks like things are shaping up pretty well there on the Room Treatments....

Nice job.... I haven't come back to this thread for a while... got long... heheheh

Anyways... Looking forward to seeing some more of your room plots...
Remember that to post the SMS graphs, you can only take a pic with your camera to post it up... :)
 
avaserfi

avaserfi

Audioholic Ninja
I actually am not going to be getting the SVS, it was something I was contemplating but decided to get a SMS-1 rather than a BFD and SVS (space is tight). I am going to start taking down the panels and adjusting all my speaker/seating positions soon so I will probably post some pics tonight.

The SMS-1 arrives on tuesday so expect some graphs to be posted by wednesday :).
 
avaserfi

avaserfi

Audioholic Ninja
Frustrated!

So I disconnected my mains and just worked with the sub got that to look pretty good then I turned the mains back on...yuck. No amount of moving, within limits, seems to help this craptacular frequency response... This is without any of the panels I made up and both the subs and mains cross overs set to 80. I tried moving the mic to see if that would change anything as well as the speakers...its not helping. I am confused :confused:.


Black is with mains

 
avaserfi

avaserfi

Audioholic Ninja
Play with phase at all?
Just makes it worse :(

Got it looking like this after some serious minor changes in phase and boundary gain (more the latter) brown is just the sub the other is both mains and the sub:

 
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