Subs without Phase control?

[xtreme02gt]

What if I have two subs now but they don't have a phase control knob. How would I get them in phase " IF " they are out of phase? Or would they be in phase no mater what? How would I do it?

I know the eD A2-300's have phase control, but the one I have in the living room and the other that will be putting in the living room don't

[crazyBLUE]

Originally Posted by xtreme02gt

What if I have two subs now but they don't have a phase control knob. How would I get them in phase " IF " they are out of phase? Or would they be in phase no mater what? How would I do it?

I would think if there was 2 same length RCA cables connecting the subs , that there would be no problem . I'm sure Big Daddy will have something to say if I am wrong .

[pokefan]

I'm not sure exactly when you would need phase control since I don't have a use for it but if you had to switch it with no other options you could pull the sub and switch the + and - terminals.

[Driver_King]

Originally Posted by xtreme02gt

What if I have two subs now but they don't have a phase control knob. How would I get them in phase " IF " they are out of phase? Or would they be in phase no mater what? How would I do it?

I know the eD A2-300's have phase control, but the one I have in the living room and the other that will be putting in the living room don't

The only thing you'd be able to do is run an auto-calibration system to get the phase set in the receiver or you can manually set the average distance from the subs to your listening position if that auto calibration is not an option.

[xtreme02gt]

Originally Posted by pokefan

I'm not sure exactly when you would need phase control since I don't have a use for it but if you had to switch it with no other options you could pull the sub and switch the + and - terminals.

No, I mean I want to make sure both subs sound the same. Not one louder than the other, or one of them a little out of sync with the other sub.

BTW: Both subs are the same. Same size, same brand, same power!

[xtreme02gt]

Originally Posted by Driver_King

The only thing you'd be able to do is run an auto-calibration system to get the phase set in the receiver or you can manually set the average distance from the subs to your listening position if that auto calibration is not an option.

I don't know if it is... I have the Yamaha RX-V765 and it has dual sub set-up. But I don't know if it will calibrate both subs. How can I find out if it will?

[erict]

Originally Posted by xtreme02gt

I don't know if it is... I have the Yamaha RX-V765 and it has dual sub set-up. But I don't know if it will calibrate both subs. How can I find out if it will?

The only way to properly setup two subs is to do them independently using an spl meter.

[ryandubbz]

switch the positive and negative terminals around on one sub

[Driver_King]

Originally Posted by xtreme02gt

I don't know if it is... I have the Yamaha RX-V765 and it has dual sub set-up. But I don't know if it will calibrate both subs. How can I find out if it will?

It won't calibrate each subwoofer individually but will calibrate both as one. The way auto calibration systems work is by relaying test tones through your speakers to the calibrated mic back to the receiver where algorithms, EQ's, and filters are intelligently applied to sort through the different possible situations and determines which settings should be used. You will need to calibrate each subwoofer to 75dB at listening position with an SPL meter before calibrating with the auto calibration system to get the best results.

[xtreme02gt]

Originally Posted by Driver_King

It won't calibrate each subwoofer individually but will calibrate both as one. The way auto calibration systems work is by relaying test tones through your speakers to the calibrated mic back to the receiver where algorithms, EQ's, and filters are intelligently applied to sort through the different possible situations and determines which settings should be used. You will need to calibrate each subwoofer to 75dB at listening position with an SPL meter before calibrating with the auto calibration system to get the best results.

Ok, how do I do that? With this receiver the volume knob still works with the pink noise, so I can turn the pink noise as loud as I want to.. So how do I set the subs to 75db?

[ryandubbz]

Originally Posted by xtreme02gt

Ok, how do I do that? With this receiver the volume knob still works with the pink noise, so I can turn the pink noise as loud as I want to.. So how do I set the subs to 75db?

you will need to buy an spl meter, you can get one at radioshack for about $50. Theres alot of members on here who use this one from radioshack, Digital Sound meter

[erict]

SPL meter.

http://www.radioshack.com/product/in...uctId=2103667#

[kareface]

Originally Posted by xtreme02gt

Ok, how do I do that? With this receiver the volume knob still works with the pink noise, so I can turn the pink noise as loud as I want to.. So how do I set the subs to 75db?

You'll be calibrating 2 subs. Depending on which of the RS meters you'll need to get the offsets, especially for calibration below 200hz. Bring the volume levels till your front are around 75db at a range of frequencies. Start with a frequency that is less likely to be off, 800-1000. Once you get them about to 75 DB, you should then calibrate each sub individually to around 69db. Turn on both of the subs to make sure they sum to 75.

[jlafrenz]

Originally Posted by xtreme02gt

Ok, how do I do that? With this receiver the volume knob still works with the pink noise, so I can turn the pink noise as loud as I want to.. So how do I set the subs to 75db?

Set the volume to a point around where you like to watch movies at. Then at that volume level make sure all the speakers are putting out 75db by using the gain/trim setting in your receiver. Do not touch the actual volume know once you start level matching.

Also, kareface has a good suggestion if you do one sub at a time by setting each one to about 69db.

And remember, feel free to adjust your subs from this point to tailor it to your liking.

[xtreme02gt]

Originally Posted by kareface

You'll be calibrating 2 subs. Depending on which of the RS meters you'll need to get the offsets, especially for calibration below 200hz. Bring the volume levels till your front are around 75db at a range of frequencies. Start with a frequency that is less likely to be off, 800-1000. Once you get them about to 75 DB, you should then calibrate each sub individually to around 69db. Turn on both of the subs to make sure they sum to 75.

So how do I calibrate 200hz or 800-1000hz with just pink noise?

If I understand it right, using a SPL meter with the pink noise from the receiver, that just calibrates levels right? I will need some kind of cd or dvd with other test tones to calibrate Hz right?

[drummerboy_2002]

The phase control is mostly meant to fix the difference between filter "orders". Every "order" shifts the phase by 90 degrees. These days, most manufacturers try to stick to 2nd and 4th order filters, which is why some subs only have a 0 and 180 degree switch, rather than a continuously variable phase control knob. If the subs are out of phase, it will most likely be fixed by swapping the positive and negative leads on one sub, like mentioned above. But, you'll need to find out which sub is in-phase with the rest of your speakers and alter the other one.

[jlafrenz]

Originally Posted by xtreme02gt

So how do I calibrate 200hz or 800-1000hz with just pink noise?

If I understand it right, using a SPL meter with the pink noise from the receiver, that just calibrates levels right? I will need some kind of cd or dvd with other test tones to calibrate Hz right?

Yes and no. If you are just doing a basic calibration to level match, all you will need is pink noise test tone and the SPL meter. Some discs have various tones at certain frequencies so that you can fine tune things a bit more. This can be helpful with subs because the Radio Shack SPL meter has a bit of variance at certain levels. It is very little around 80Hz which is a recommended setting. It is more important when people use REW or other program to plot their sub frequency in a chart and then use it to some sort of EQ to level out the frequency response. My suggestion is to start with basic calibration and then move on to the more in depth tuning of your sub.

[kareface]

Originally Posted by xtreme02gt

So how do I calibrate 200hz or 800-1000hz with just pink noise?

If I understand it right, using a SPL meter with the pink noise from the receiver, that just calibrates levels right? I will need some kind of cd or dvd with other test tones to calibrate Hz right?

Oops, I'm accustom to having a laptop for calibrations, lol. If you have any computer in the house you can download a free noise generator. However you can just use the stock receiver tones as most will play a few ranges to give you a good average. The problem with the stock tones for the sub is you won't be able to compensate for the accuracy of the SPL meter. You can get an idea of the frequency the test tones generated at by turning down the crossover on the sub until the noise goes away (or starts getting quieter). I doubt it'll be below 50hz, but if it is you might want to calibrate with the computer for better accuracy.

[xtreme02gt]

So dose the RCA cable length has nothing to do with it? So I can have one that is 6 feet and one that is 15 feet?

[erict]

Originally Posted by xtreme02gt

So dose the RCA cable length has nothing to do with it? So I can have one that is 6 feet and one that is 15 feet?

Yes.