What is the best way to calibrate a wired subwoofer to a soundbar?

[davetroy]

Hi, everyone,

I have an SVS SB12Plus sub that I'm trying to use with a Vizio S5430 soundbar. The soundbar has sub out. So far, setup has gone pretty well. I have the sub in a corner and it blends very well with the soundbar, meaning they seem like one unit. But considering that the soundbar doesn't have test signals and doesn't allow me to access the kinds of measurements that are generally used when calibrating a sub to a receiver with speakers, I'm wondering what the best way is to calibrate the sub to the soundbar.

Is the best method going to be to listen and toy with the sub's gain (I have the crossover disabled; should I set it at 120, which is as high as it goes) until it sounds right? Or is there a more-efficient method that will yield better results? I do have an SLP meter, but again, I'm not sure I can use it for this.

FYI, the soundbar allows me to set bass levels as well as the subwoofer level, surround level and also DTS TruSurround On/Off and DTS TruVolume On/Off. However, these are not numbered settings; just LED indicators that go from low to high in increments. The SVS manual recommends starting with the receiver's subwoofer output level at about 1/3rd and the sub's gain at 1/4 to 1/3rd before calibrating, but again, would this apply to a sub-soundbar combination, too.

I'm guessing that this is going to be a hit or miss/trial and error situation but I'm wondering if there's a better and/or more-efficient way.

Thanks,
Dave

 

[WaynePflughaupt]

Well if you already have the sub and soundbar sounding “like one unit,” it doesn’t get much better than that. All you need to do at that point is adjust the sub’s level to taste.

However, if you want something of more substance, you might download a broadband pink noise signal and play it through the soundbar and sub separately – i.e. take separate SPL measurements of each. The traditional starting point for home theater is to have the sub 10 dB louder than the main speakers (meter set for C weighting).

If you are unable to turn off the main speakers to hear just the sub for your measurements, you could try the reverse. Turn of the sub and measure the level of the main speakers, then add the sub. The sub will be louder than the main speakers, so the increase in SPL you see will come from the sub itself (the meter is “dumb” - it doesn’t differentiate frequencies, it just registers the level of the loudest sound it “hears”).

Regards,
Wayne A. Pflughaupt

 

[davetroy]

However, if you want something of more substance, you might download a broadband pink noise signal and play it through the soundbar and sub separately – i.e. take separate SPL measurements of each. The traditional starting point for home theater is to have the sub 10 dB louder than the main speakers (meter set for C weighting).

If you are unable to turn off the main speakers to hear just the sub for your measurements, you could try the reverse. Turn of the sub and measure the level of the main speakers, then add the sub. The sub will be louder than the main speakers, so the increase in SPL you see will come from the sub itself (the meter is “dumb” - it doesn’t differentiate frequencies, it just registers the level of the loudest sound it “hears”).

Regards,
Wayne A. Pflughaupt

I think I'll try that. But when you say download a pink noise signal and play it through the soundbar, am I doing this by downloading it to my computer and attaching my computer to the sub via a USB port? I've never done this so I'm wondering how it's done.

I think it's just dumb luck that they're sounding like one unit. I have the sub in a corner about five or six feet from the soundbar (and on the same side of the room as the soundbar). And when I say one unit, I mean that all of the sound seems to be coming from the same place.

What I am noticing is that doors closing, chairs moving, etc. in whatever we're watching sound louder than natural. I'm not sure if that's a phase or volume/gain issue or just the way subs are. But I guess in the meantime, I'll do as you suggest and see if I still have the same issue (which actually doesn't bother me too much).

Thanks,
Dave

 

[WaynePflughaupt]

I’ve never heard of a sub with a USB port, but I may be behind the times. A headphone cable with an RCA jack on the other end will get the signal either into the sub or the soundbar (which will direct the bass portion of the pink noise signal to the sub). The door closing issue may well be that the sub has a peak in response in that frequency range and needs equalization. That would require an outboard parametric EQ connected between the sound bar and subwoofer.

Regards,
Wayne A. Pflughaupt

 

[davetroy]

Thanks again, Wayne. I misspoke. I meant the USB port on the soundbar. It does have one.

Dave

 

[davetroy]

Hi, Wayne,

I'm finally ready to do this. Tried it this afternoon. So, if the soundbar without the sub is reading 60db, I want the reading with soundbar and sub to be about 70db as a starting point? Also, is there a reference level for such a test? For example, should I turn up the soundbAr minus the sub to 75db before adding the sub?

thanks again,
Dave

 

[WaynePflughaupt]

Yes, 75 dB is generally the standard, but anything above the room’s ambient noise floor will work fine. Sixty dB is a bit low...

Regards,
Wayne A. Pflughaupt