Help me correct bass

[Love4sound]

You can't gain match dissimilar subs. I'd recommend level matching from the MLP based on where you're going to put the subs.

Ok this will be even more convenient for me. So use the spl meter and set the gain of both subs at current positions is what you are suggesting right?

 

[liverpool_for_life]

For subwoofer crawl, I was suggesting using the reverse crawl method, as in keeping the second sub in the MLP and moving the mic to identify where do you get the best combined curve.

Ah, okay. Cool.

Phase matching is best done through AVR, unless you want to use Line-in and manually match it.

I incorrectly asked for the procedure. What I really meant to ask was what you mean by phase matching of the 2 subs.

 

[fLUX]

So for gain matching he places both the sub at the same place. I have massive back pain and won’t be able to lift both the subs now. Is there any other way I can do it with both subs at the current location which is one in the front right and the other in the rear left?

Since both the sub use identical drivers and differ mainly on the RMS I think you can just make sure both are outputting the same SPL levels w.r.t MLP. For me gain matching the sub resulted in identical SPLs as both are exact same models (I intend to do it in the way suggested in the video in future to see if it results in any difference), in your case you might need to reduce the 12.17 gain or increase the 10.17 gain to level match them

The method suggested in the above video for heavy subs is as below
i) Keep the Umik-1 or measuring device around 3-4 inches from the first sub driver and measure, adjust gain to your desired SPL level
ii) Repeat the same for second sub and adjust gain knob till you reach the same SPL as first level
Idea behind this is by keeping the mic close to the driver you are eliminating the room modes to the extent possible and will give almost an equivalent measure as measuring different subs at same position.

 

[Love4sound]

Since both the sub use identical drivers and differ mainly on the RMS I think you can just make sure both are outputting the same SPL levels w.r.t MLP. For me gain matching the sub resulted in identical SPLs as both are exact same models (I intend to do it in the way suggested in the video in future to see if it results in any difference), in your case you might need to reduce the 12.17 gain or increase the 10.17 gain to level match them

The method suggested in the above video for heavy subs is as below
i) Keep the Umik-1 or measuring device around 3-4 inches from the first sub driver and measure, adjust gain to your desired SPL level
ii) Repeat the same for second sub and adjust gain knob till you reach the same SPL as first level
Idea behind this is by keeping the mic close to the driver you are eliminating the room modes to the extent possible and will give almost an equivalent measure as measuring different subs at same position.

Ok. I was expecting much better results but little disappointed. Look at the below graphs. One is dual xtz and another is dual subs but 12.17 paired with a 50 watts 6 inch Yamaha sub. I mean what the hell both same performance. I blindly went with the 10.17 thinking if 6 inch 50 wats can give this improvements the 500 watts rms 10 inch will be even better

 

[liverpool_for_life]

So use the spl meter and set the gain of both subs at current positions is what you are suggesting right?

Yes, so that the average level is the same for both. You can attempt to reduce the impact of constraining the bigger sub to the output capabilities of the smaller sub by having the smaller sub closer to your LP compared to the bigger one. This isn't the most technically correct approach, but you aren't going to be playing at levels that expose the deficiencies of this method.

 

[liverpool_for_life]

I mean what the hell both same performance.

Did you place both pair of subs in the same positions in the room as well as keep the MLP constant?

 

[Love4sound]

Yes, so that the average level is the same for both. You can attempt to reduce the impact of constraining the bigger sub to the output capabilities of the smaller sub by having the smaller sub closer to your LP compared to the bigger one. This isn't the most technically correct approach, but you aren't going to be playing at levels that expose the deficiencies of this method.

Yeah that’s how I have placed them. 12.17 is at front and the 10.17 is at the rear next to my seating position. The 10.17 uses the same 500 watts amp that the 12.17 uses. At many frequencies the performance is the same and at certain low bass frequencies the 12.17 is smoother due to the bigger driver

Did you place both pair of subs in the same positions in the room as well as keep the MLP constant?

Yeah same position.

 

[liverpool_for_life]

Yeah same position.

Then the results aren't surprising. The transfer of acoustical energy from your subs to the MLP is the same, unless there are terrible non-linearities in the subs' anechoic FR. You have additional headroom with the bigger sub, but that's not going to show up in the FR. You may/may not hear that difference in content because of the low levels you plan on listening at.

 

[fLUX]

Ok. I was expecting much better results but little disappointed. Look at the below graphs. One is dual xtz and another is dual subs but 12.17 paired with a 50 watts 6 inch Yamaha sub. I mean what the hell both same performance. I blindly went with the 10.17 thinking if 6 inch 50 wats can give this improvements the 500 watts rms 10 inch will be even better

Can you try measuring by keeping crossover in AVR to about 250hz and I believe you have already set the bass management to : LFE instead of LFE + mains.

There is a high chance your measurements are aided only by the 12.17 and the 2nd sub is not coupling/adding up resulting in similar response for both the subs, you can try the following and see if it helps
- Try varying the phase dial on the sub placed at the rear and see if it results in a better graph.
- If the 2nd sub can be placed at alternative positions, try crawl method using the 10.17 as it would probably be lighter to move around

If you can get a Minidsp2by4HD it will certainly be good as it allows you to make changes to the time alignment and phase & obtaining a good combination for the right result and then EQ'ing the same to trim the peaks and apply some minimal boosting to the dips.

Also I would say that while the frequency response might have been similar for both the options you tried, the quality of bass via the XTZ would be in all likelihood be much better than the Yamaha 6 inch sub.

 

[Love4sound]

Then the results aren't surprising. The transfer of acoustical energy from your subs to the MLP is the same, unless there are terrible non-linearities in the subs' anechoic FR. You have additional headroom with the bigger sub, but that's not going to show up in the FR. You may/may not hear that difference in content because of the low levels you plan on listening at.

Ok so I could have just added a Yamaha sub and saved 50k right?

 

[Love4sound]

Can you try measuring by keeping crossover in AVR to about 250hz and I believe you have already set the bass management to : LFE instead of LFE + mains.

There is a high chance your measurements are aided only by the 12.17 and the 2nd sub is not coupling/adding up resulting in similar response for both the subs, you can try the following and see if it helps
- Try varying the phase dial on the sub placed at the rear and see if it results in a better graph.
- If the 2nd sub can be placed at alternative positions, try crawl method using the 10.17 as it would probably be lighter to move around

If you can get a Minidsp2by4HD it will certainly be good as it allows you to make changes to the time alignment and phase & obtaining a good combination for the right result and then EQ'ing the same to trim the peaks and apply some minimal boosting to the dips.

Also I would say that while the frequency response might have been similar for both the options you tried, the quality of bass via the XTZ would be in all likelihood be much better than the Yamaha 6 inch sub.

Ok let me experiment more then.

 

[liverpool_for_life]

Ok so I could have just added a Yamaha sub and saved 50k right?

Maybe. Maybe not.

However, what is virtually guaranteed is that you're unlikely to see a difference in in-room FR, just because you changed subs. Bass sources are just that. Bass sources. Any difference in their capability can only be heard/felt if you can efficiently transfer the acoustical energy they generate to your MLP. If you don't change where the bass sources are and you don't change the position where you measure, you will see no meaningful change in the measurements that show how efficiently that acoustical energy generated by the subs is transferred to your MLP. That's just the physics of bass reproduction in small rooms.

 

[Love4sound]

Maybe. Maybe not.

However, what is virtually guaranteed is that you're unlikely to see a difference in in-room FR, just because you changed subs. Bass sources are just that. Bass sources. Any difference in their capability can only be heard/felt if you can efficiently transfer the acoustical energy they generate to your MLP. If you don't change where the bass sources are and you don't change the position where you measure, you will see no meaningful change in the measurements that show how efficiently that acoustical energy generated by the subs is transferred to your MLP. That's just the physics of bass reproduction in small rooms.

Ok May be the 500 watts rms ported xtz not meant for my room and next I should try a 300-500 wats sealed sub.If u see here the volume is set way low and just a point above minimum which can also be a factor for low performance. At this level audyssey sets the gain in avr at -3.5 dB so may be I should calibrate again increasing the gain in sub such that audyssey sets the gain at -8.0 or -10 dB. And also currently i have set the eq and port tuning to be performing well in the lower region. I need to experiment with the mid and upper frequency port tuning and eq options to see if it can improve the mid region

 

[liverpool_for_life]

Ok May be the 500 watts rms ported xtz not meant for my room and next I should try a 300-500 wats sealed sub.

Your in-room response issues have little to do with amp power, ported vs sealed etc. They have everything to do with where they're placed, where you sit and whether you've made the effort to integrate them for a better response (manipulating delay and applying EQ, including external PEQ).

You have the measurement capability. I forget if you have a minidsp or not. If you do, use it to get a better result before looking for different subs. You're certain to face similar disappointment, if not.

 

[fLUX]

Ok May be the 500 watts rms ported xtz not meant for my room and next I should try a 300-500 wats sealed sub.If u see here the volume is set way low and just a point above minimum which can also be a factor for low performance. At this level audyssey sets the gain in avr at -3.5 dB so may be I should calibrate again increasing the gain in sub such that audyssey sets the gain at -8.0 or -10 dB. And also currently i have set the eq and port tuning to be performing well in the lower region. I need to experiment with the mid and upper frequency port tuning and eq options to see if it can improve the mid region

I did the following for setting up the measurement process
i) Set crossover to 250hz in audyssey
ii) Set number of subs to 1 (was 2 before) and changed the gain to 0. In your case since there is no minidsp 2by4 HD you will still have 2 seperate subs connected
iii) Play around with the port tuning by blocking the alternate ports , same ports , one port in only sub so forth. For me I found the best setting by blocking the left port (assuming i am behind the sub) and no port for the front sub.
iv) Measure the response each time you play around be it the phase on the sub or the port tuning. I would suggest to keep the inbuilt PEQ/filter options to off on XTZ initially till you experiment with above.

If you feel the response obtained via measurements is good enough then turn the frequency filter in audyssey for subwoofer to a higher level than your crossover for the subs to kick in so that no eq'ing happens via audyssey.

 

[Love4sound]

Your in-room response issues have little to do with amp power, ported vs sealed etc. They have everything to do with where they're placed, where you sit and whether you've made the effort to integrate them for a better response (manipulating delay and applying EQ, including external PEQ).

You have the measurement capability. I forget if you have a minidsp or not. If you do, use it to get a better result before looking for different subs. You're certain to face similar disappointment, if not.

Ok so you are saying no matter how good of a sub I get the room response is going to be similar. Since I have already spent so much I think investing in a mini dsp is a good idea in a dual sub set up. May be it will do a better job then audyssey

I did the following for setting up the measurement process
i) Set crossover to 250hz in audyssey
ii) Set number of subs to 1 (was 2 before) and changed the gain to 0. In your case since there is no minidsp 2by4 HD you will still have 2 seperate subs connected
iii) Play around with the port tuning by blocking the alternate ports , same ports , one port in only sub so forth. For me I found the best setting by blocking the left port (assuming i am behind the sub) and no port for the front sub.
iv) Measure the response each time you play around be it the phase on the sub or the port tuning. I would suggest to keep the inbuilt PEQ/filter options to off on XTZ initially till you experiment with above.

If you feel the response obtained via measurements is good enough then turn the frequency filter in audyssey for subwoofer to a higher level than your crossover for the subs to kick in so that no eq'ing happens via audyssey.

Yeah no mini dsp and I am planing to get one as I feel it’s worth the shot in a dual sub set up. Like u said I’ll try experimenting different port tuning options. Right now I have the right port closed for both subs(standing infront of the sub)

 

[fLUX]

Ok so you are saying no matter how good of a sub I get the room response is going to be similar. Since I have already spent so much I think investing in a mini dsp is a good idea in a dual sub set up. May be it will do a better job then audyssey

Yeah no mini dsp and I am planing to get one as I feel it’s worth the shot in a dual sub set up. Like u said I’ll try experimenting different port tuning options. Right now I have the right port closed for both subs(standing infront of the sub)

Minidsp certainly does a good job matching the curve to your target curve, provides more option than audyssey and in combination with REW offers endless possibilities. Plus you can configure multiple target curves and switch between them (on the go if you have a remote or via a usb out to PC/Laptop)

 

[Love4sound]

Minidsp certainly does a good job matching the curve to your target curve, provides more option than audyssey and in combination with REW offers endless possibilities. Plus you can configure multiple target curves and switch between them (on the go if you have a remote or via a usb out to PC/Laptop)

Ok guess it’s time to order a mini dsp then. Does it come with the cable u need to connect with avr or needs to be purchased separately?

 

[liverpool_for_life]

Ok so you are saying no matter how good of a sub I get the room response is going to be similar.

For the love of all that is holy in the name of subwoofers, yes. Yes. YES!

Since I have already spent so much I think investing in a mini dsp is a good idea in a dual sub set up. May be it will do a better job then audyssey

No maybe. I can guarantee you that it will. Or I'll take the minidsp off your hands, no questions asked.

 

[fLUX]

Ok guess it’s time to order a mini dsp then. Does it come with the cable u need to connect with avr or needs to be purchased separately?

You will need one extra RCA cable to connect from subwoofer1 preout on AVR to minidsp 2by4hd input & existing 2 subwoofer cables will go to output of the device. You get a micro-usb cable along with the minidsp