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Post by paintedklown on Sept 30, 2014 17:22:38 GMT -5
I think you've got it right. Start out with the sub and mains set so they are at about the same level at the crossover frequency. (If either dominates things at that frequency too much, you won't be able to tell when the non-dominant one adds or subtracts from the dominant one.) Adjust the phase for the most output at the crossover frequency. Now go back and make sure you have the crossover set so the sub "meets" the mains cleanly, with minimal dip or bump. (This would have been hard to do, and wouldn't work very well, until the phase is more or less right.) Now that the crossover is set right, go back and tweak your sub level (if necessary). Keith, since I am a total moron when it comes to this stuff, I would like to ask some clarifing questions. 1. I assume you are using an SPL meter and playing a test tone at 80hz with the crossover on and the sub turned off, and measuring the SPL level of your main speakers, then turn off the mains and measure again (at 80hz) with only the sub playing? I am a bit confused how you can tell if the mains and sub are at the same level. 2. With both the sub and mains at the same level for the x-over point (80 hz in this example) we then turn BOTH of them on and adjust the phase of the subwoofer until we get the MOST output (measured by our SPL meter)? 3. Then go back and change the x-over point? I'm lost as you can see. Please be aware that I need "An idiots guide to basic subwoofer setup".  I don't care if I do look like an idiot though. I have ALWAYS wanted to learn how to get this right because I feel it really opens up a LOT of speaker buying options if I can get a smaller tower or large bookshelves of a higher quality (for the same money) instead of waiting for a magical full range tower that costs as much as bookshelves but sounds as good as a flagship model would. LOL! |
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Post by Boomzilla on Sept 30, 2014 17:27:30 GMT -5
1. Use the SPL meter -
2. Yes
3. No - Leave it alone
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Post by paintedklown on Sept 30, 2014 17:29:36 GMT -5
1. Use the SPL meter - 2. Yes 3. No - Leave it alone Thanks Boom. Would using an SPL app on my phone suffice for such a project, or would I have to get a real SPL meter? Does it need to be calibrated in any way? |
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Post by pedrocols on Sept 30, 2014 19:38:10 GMT -5
Don't ask me how many times I need to go back and forth to adjust the sub level and play the test tone and then go back to my listening position...I have two subwoofers so I have to do it twice and after I match the two subwoofers crossover and spl....fun, fun, fun... If you have a Radio Shack meter and a way to input into a laptop. Then this becomes much easier to use REW's RTA. (plus you get a bigger screen) Tony Yes. I use a Radio Shack meter and is in fact pretty handy. I have REW and a MiniDsp UMIK-1 but I like the walking back and forth...  |
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Post by deltadube on Sept 30, 2014 19:45:25 GMT -5
1. Use the SPL meter - 2. Yes 3. No - Leave it alone with the phase aligned I thought it would be ok to change the cross over settings.. eg from 80 to 120.. cant see this effecting phase.. how do you phase align the 2nd sub? cheers |
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Post by Boomzilla on Sept 30, 2014 20:11:16 GMT -5
OK - Once the phase is aligned, it remains aligned for any frequency you wish to cross over at. If you have two subs, I'd phase align the right sub with the right speaker, etc.
A cell phone app is adequate for this task. It won't be as accurate as a true SPL meter, but it will be just as accurate as the Radio Shag meter for far less $$. In the treble, the RS meter is more accurate, but in the bass, they're both execrable.
The cell phone apps come "pre calibrated" for the phone you'll be using them with.
Cheers - Boom
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Post by pedrocols on Sept 30, 2014 21:19:23 GMT -5
OK - Once the phase is aligned, it remains aligned for any frequency you wish to cross over at. If you have two subs, I'd phase align the right sub with the right speaker, etc. A cell phone app is adequate for this task. It won't be as accurate as a true SPL meter, but it will be just as accurate as the Radio Shag meter for far less $$. In the treble, the RS meter is more accurate, but in the bass, they're both execrable. The cell phone apps come "pre calibrated" for the phone you'll be using them with. Cheers - Boom If you have two subs you might want to align the phase of the subs with each other.If you don't they will cancel each other. |
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Post by Boomzilla on Oct 1, 2014 0:30:50 GMT -5
If you have two subs you might want to align the phase of the subs with each other.If you don't they will cancel each other. I think I disagree. The two subs can be "in phase" with each other at any point of the compass. For example, with the subs in 180-degree phase to speakers (yet IN PHASE with each other), there will be a HUGE dip at the crossover frequency. However, if the two subs are in phase with the speakers (and the speakers in phase with each other), then the phase difference between the two subs will be minimal. |
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Post by ansat on Oct 1, 2014 7:27:24 GMT -5
If you have two subs you might want to align the phase of the subs with each other.If you don't they will cancel each other. I think I disagree. The two subs can be "in phase" with each other at any point of the compass. For example, with the subs in 180-degree phase to speakers (yet IN PHASE with each other), there will be a HUGE dip at the crossover frequency. However, if the two subs are in phase with the speakers (and the speakers in phase with each other), then the phase difference between the two subs will be minimal. I will partially agree with boom. Adding a second subwoofer really complicates things. This is where you start to use phase as an eq tool to flatten the overall response and overcome your room. Using a rta or rew rarely do you have 2 subs in phase in practice when trying to flatten the response. When perfectly in phase you start to see really wild swings and any troubles in the room can be amplified further. Tony Sent from my SM-G900P |
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Post by audiobill on Oct 1, 2014 7:58:13 GMT -5
And the critical last step of fine tuning by ear.......
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Post by pedrocols on Oct 1, 2014 8:12:30 GMT -5
If you have two subs you might want to align the phase of the subs with each other.If you don't they will cancel each other. I think I disagree. The two subs can be "in phase" with each other at any point of the compass. For example, with the subs in 180-degree phase to speakers (yet IN PHASE with each other), there will be a HUGE dip at the crossover frequency. However, if the two subs are in phase with the speakers (and the speakers in phase with each other), then the phase difference between the two subs will be minimal. Agree. You misunderstood my argument. I first flatten the subwoofer response with a antimode and then I align the phase of the subwoofers with each other to get the most spl at the cut off frequency (with no speakers playing). Secondly, measure speakers response at the same frequency cutoff by themselves(with no subwoofer playing). Thirdly, I play test tones at the cutoff frequency on the subwoofers to match the spl of the speakers at the selected cutoff frequency. Lastly, I play the test tone with both speakers and subwoofers and, if necessary, reverse the phase until I get the the higher spl at the cutoff frequency. I do this procedure utilizing two 15" subwoofers with Magnepan speakers and it works pretty good and I have good integration. |
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Post by Boomzilla on Oct 1, 2014 8:34:29 GMT -5
Thanks, pedrocols - That explains it well!
Boom
PS: How much does the DSPeaker help?
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Post by pedrocols on Oct 1, 2014 9:17:32 GMT -5
Thanks, pedrocols - That explains it well! Boom PS: How much does the DSPeaker help? You're welcome. Well, what the DSpeaker is doing is basically getting rid of the peaks. |
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Post by Boomzilla on Oct 1, 2014 10:24:32 GMT -5
Audibly?
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Post by pedrocols on Oct 1, 2014 11:05:06 GMT -5
I only use Dspeaker for the subwoofer and audibly to my ears is very smooth. Even heavy bass seems to be coming out of the mains. |
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Post by pedrocols on Oct 1, 2014 11:08:51 GMT -5
Of course it could always be better but there is only so much you can do about it when your listening room is your living room.
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