Subwoofer measurement

[johnyM128]

Hellou my friends,

sealed subwoofer 10´´, behringer inuke 3000dsp, low pass at 80HZ

so i bought ecm8000 and try to do first measurement - i apply it for subwoofer. Iam pretty not sure, if all is ok bcs there is extremely big gap at 35hz.... iam wondering if there is problem with behringer emc8000

First measurement, no correction/eq, smoothing 1/6

First measurement, no correction/eq, smoothing 1/48: big drop at about 37hz

Second measurent: eq on INUKE DSP turned on, smoothing 1/6

Second measurent: eq on INUKE DSP turned on, smoothing 1/48 - still big gap at around 35hz.... at inuke dsp i have +7db at 35hz!!!!

Any ideas? thanks you very much!

Jan

 

[welldun]

looks like the dip at 35hz could be just be a null at that listening position. This issue is most likely caused by the room. Due to the rooms dimensions there will be areas where you will have peaks and nulls in the frequency response. To test things out, you can either move the subwoofer to a new location and test again, or move the listening position and test again. Worst case scenario, you would have to move both.

 

[johnyM128]

looks like the dip at 35hz could be just be a null at that listening position. This issue is most likely caused by the room. Due to the rooms dimensions there will be areas where you will have peaks and nulls in the frequency response. To test things out, you can either move the subwoofer to a new location and test again, or move the listening position and test again. Worst case scenario, you would have to move both.

Thanks for your reply!

Is it goot solution to add another subwoofer to cancel null at listening position?

thanks you very much!

Jan

 

[welldun]

Thanks for your reply!

Is it goot solution to add another subwoofer to cancel null at listening position?

thanks you very much!

Jan

The simple answer... yes! but like everything else, there are other things to consider depending on what the goal is. Tell us about what type of room you are trying to setup. Is it a music listening room with one seat and two speakers and a sub? Is it a home theater setup with multiple seats and full surround... etc.?

Let us know what the purpose/use of the room is and what equipment you already have, and we will then be better able to help.

 

[johnyM128]

Its standard living room in the apartment... one couch near rear wall. I have HT, but when listening music, using just stereo + subwoofer
Now, subwoofer is placed against couch, +/- in the middle near TV. I was wondering, if it should be better adding another subwoofer oposite to one i have.
thanks!

 

[welldun]

Its standard living room in the apartment... one couch near rear wall. I have HT, but when listening music, using just stereo + subwoofer
Now, subwoofer is placed against couch, +/- in the middle near TV. I was wondering, if it should be better adding another subwoofer oposite to one i have.
thanks!

Ok I see. First off, I hope you're enjoying your setup so far. I'm all about getting the most out of what I have before deciding to add more.
Having said that. Since you are using the system for music and HT (like many of us), you would be best served by making sure that your seating is properly placed. If your couch is near the back wall, you can end up sitting a bass heavy zone that can affect the quality of the sound. I know that your question is about potentially adding another sub, but let's first make sure that you are maximizing the use of what you currently have. Adding more gear doesn't always enhance things. If you were to add another sub and place it in the wrong spot, you can end up creating cancellations that would make it sound like you don't even have a sub. This is why proper placement of speakers, subs and seats is key and will make all the difference. Depending on the size of your room, most of what you will hear for your speakers and sub(s) will be dictated by the room itself. If it's just you in the apartment, then you have the luxury of only needing to calibrate the system for one main listening position (MLP). That means that just one subwoofer that is properly placed and time aligned could be all you need.

Let's do this... Tell us the dimensions of your room so we can start to understand how the room will affect your listening experience. Have you used the Harmon Room mode calculator? If not, I would recommend you download it and use it to see how the room (based on its measurements) is affecting your sound. Here is the link Harmon Calculator ,save the file as an Excel file (don't open it online because it might start to ask for a password). Add your room dimensions to the worksheet and it will give you an visual representation of which frequencies affect your room and the location where they peak as well as where they cancel each other and create a null. Once you have that info, you can start to adjust your seat and or speakers and sub to make sure that you have them all in the best locations. You want to avoid areas where they peak and you also want to avoid the nulls. You can then check the effect of these change by using REW and your mic. This is all a bit of a process even if you know what you are doing, but in the end it can really help you get the most out of your room and gear.

 

[MediumRare]

Stop stop stop! Your post EQ graph looks great. You can’t hear that dip at 35, it’s too narrow. It looks excellent, overall. Plus, boosting more than 6 dB puts a big strain on your amp and risks clipping, which is a far greater problem. Show us the spectrum with your mains and let’s see how your crossover is going.

 

[AustinJerry]

Couple of comments. First of all, please consider posting sub response measurements with a more appropriate horizontal scale. Sub measurements are typically 15-300Hz, and the horizontal scale should be set to the same values. Here are examples:

Note that these two examples are of the same measurement. The second one is much easier to analyze. And also note that sub measurements should typically be presented with no smoothing.

Second, about that dip. I agree with MediumRare that it is narrow enough that it is likely not audible. If the dip is a room mode, then no amount of PEQ boost is going to fix it. By applying boost, you could cause damage to your equipment. There are several ways to address or alleviate a dip like that. The first step would be to move the sub around to various spots in the room, re-measure, and see how placement affects the response curve. The second step would be to add one or more additional subs. Additional subs will always result in improvements. In fact, it is extremely difficult to get acceptable (good) bass with only one sub. Take a look at this analysis of the benefits of multiple subs: http://www.avsforum.com/forum/15-ge...495869-austinjerry-s-set-up.html#post23859810. And remember to experiment with placement!