Setting up four subwoofers

[olds1959special]

I’m using a pair of KRK S10’s on the bottom and KRK S10.4’s on the top. I figured it would work because they are the same both 10” with a similar design. I used my 70Hz HPF filters and set the bottom pair of subs to 80Hz and the top pair to 70Hz. Mainly because the 80Hz is clearly marked on the bottom pair so easy to set up. I believe the gain is similar on each pair, with the volume possibly higher on the top subs, which are newer so they should sound better. Anyway, I measured and played with the volume on the top pair until I had a decently flat slope. The bottom pair had already been gain matched so I didn’t want to mess with it for now. Subjectively the sound is good and the bass is very impactful and I can hear the improvement with adding the S10.4’s.

 

[olds1959special]

I gain matched the different pairs.

 

[olds1959special]

I set them all them to 70Hz to match the HPF.

 

[alex-z]

Belief is fleeting, a measurement mic is the proper way to tune a system.

Also, if you are just stacking the subwoofers that might be wasting potential. Usually spreading them to manage your room modes is the most beneficial approach.

 

[olds1959special]

Belief is fleeting, a measurement mic is the proper way to tune a system.

Also, if you are just stacking the subwoofers that might be wasting potential. Usually spreading them to manage your room modes is the most beneficial approach.

I’m just about to take measurements with my ECM8000, but I already used my phone which ime seems to show similar, but less specific and accurate results. Considering I’m not using a DSP and am trying to avoid using EQ, I just picked the 70Hz filter because I had the Harrison inline filter handy, and the new subs have a 70Hz selection, (and 80 and 90Hz.) But my next filters up are 100 Hz so there would be a 10Hz gap, not something I wanted. Then I turned up them up to the same volume setting which was equal to the SPL of the bottom pair. In the process I measured with my phone and was able to achieve a decently smooth slope with the RTA (Audio Tools).

 

[alex-z]

I’m just about to take measurements with my ECM8000, but I already used my phone which ime seems to show similar, but less specific and accurate results. Considering I’m not using a DSP and am trying to avoid using EQ, I just picked the 70Hz filter because I had the Harrison inline filter handy, and the new subs have a 70Hz selection, (and 80 and 90Hz.) But my next filters up are 100 Hz so there would be a 10Hz gap, not something I wanted. Then I turned up them up to the same volume setting which was equal to the SPL of the bottom pair. In the process I measured with my phone and was able to achieve a decently smooth slope with the RTA (Audio Tools).

ECM8000 is quite accurate at low frequencies even without calibration. Use that with Room EQ Wizard for your tuning.

MTG Designs - Measurement Mic Tests

When I was restarting the great waveguide shootout in early 2021 I noticed odd behavior in the distortion measurements of the compression drivers. Specifically I wasn't seeing the amount variation in the 2nd order harmonic distortion from the different compression drivers or horns that I was

www.mtg-designs.com

REW room acoustics and audio device measurement and analysis software

REW is free software for room acoustic measurement, loudspeaker measurement and audio device measurement and analysis

www.roomeqwizard.com

You should give EQ a try. The improvement in sound quality can be significant, many modern speakers/subwoofers include DSP/EQ tuning that is transparent to the user.

 

[pierre]

ECM8000 is quite accurate at low frequencies even without calibration. Use that with Room EQ Wizard for your tuning.

MTG Designs - Measurement Mic Tests

When I was restarting the great waveguide shootout in early 2021 I noticed odd behavior in the distortion measurements of the compression drivers. Specifically I wasn't seeing the amount variation in the 2nd order harmonic distortion from the different compression drivers or horns that I was

www.mtg-designs.com

REW room acoustics and audio device measurement and analysis software

REW is free software for room acoustic measurement, loudspeaker measurement and audio device measurement and analysis

www.roomeqwizard.com

You should give EQ a try. The improvement in sound quality can be significant, many modern speakers/subwoofers include DSP/EQ tuning that is transparent to the user.

Please share the measurements. I need real data to test my mso / dba optimiser. See
https://www.audiosciencereview.com/...-for-speaker-and-headphone.66460/post-2477712 for details.

 

[olds1959special]

Just took a measurement with the LPF settings at 70 Hz on all four subs. (with HPF 70Hz / 12 dB)

 

[olds1959special]

And here's with the LPF turned all the way up on all the subs (to try to fill in the gap in response.)

 

[levimax]

Do you have a way to knock down that big 40 Hz peak by ~ 7dB? with DSP? If so I think you would like the sound a lot better.

 

[olds1959special]

Do you have a way to knock down that big 40 Hz peak by ~ 7dB? with DSP? If so I think you would like the sound a lot better.

Yes, I could try it with Sound Source.

 

[Oddball]

If looking for smoother response and less decay, Dirac ART might help, especially with 4 subs. Orange is average and green are subs. Due to how ART works, other bed channels pretty much follow subs to 150hz.

Not the prettiest ART graph, but definitely shows hot tight the bass range can get with 4 subs.

 

[olds1959special]

With a parametric EQ at 40Hz, 0.5 BW, and -7dB, (Sound Source) with the top subs set to 90Hz LPF and the bottom subs set to 80Hz LPF:

 

[levimax]

With a parametric EQ at 40Hz, 0.5 BW, and -7dB, (Sound Source) with the top subs set to 90Hz LPF and the bottom subs set to 80Hz LPF:

View attachment 499749

Looks better, does it sound better?

Having very rough response below ~ 300 Hz is normal in an untreated room, but your response is rough above 300 Hz which is not typical. Is this measurement taken with a stationary Mic? If so I would try RTA with MMM (moving microphone method) as you will get smoother and more useful information.

 

[olds1959special]

Looks better, does it sound better?

Having very rough response below ~ 300 Hz is normal in an untreated room, but your response is rough above 300 Hz which is not typical. Is this measurement taken with a stationary Mic? If so I would try RTA with MMM (moving microphone method) as you will get smoother and more useful information.

There's definitely less bass boom now. I measured with a stationary ECM8000. I will try MMM, thanks.

 

[olds1959special]

With the HPF filters removed completely, and adding a parametric EQ at 40Hz and 75Hz, 0.5 BW, and -7 and -6 dB respectively, with the top subs set to 90Hz LPF and the bottom subs set to 130Hz LPF, I was able to get this:

It seems there is less of a dip in the upper bass region, and for some reason the highs look better now.

btw, I am using them stacked in a L/R setup because I don't have space to put the subs anywhere else. Also, I like stereo bass.

I'll be trying the MMM soon.

 

[Hear Here]

I’m using a pair of KRK S10’s on the bottom and KRK S10.4’s on the top. I figured it would work because they are the same both 10” with a similar design. I used my 70Hz HPF filters and set the bottom pair of subs to 80Hz and the top pair to 70Hz. Mainly because the 80Hz is clearly marked on the bottom pair so easy to set up. I believe the gain is similar on each pair, with the volume possibly higher on the top subs, which are newer so they should sound better. Anyway, I measured and played with the volume on the top pair until I had a decently flat slope. The bottom pair had already been gain matched so I didn’t want to mess with it for now. Subjectively the sound is good and the bass is very impactful and I can hear the improvement with adding the S10.4’s.

It appears to me that you are looking for a complex and difficult system to get right. Instead of mains plus 4 subs, why not keep things simple and get a carefully selected pair of genuinely full-range speakers that will work beautifully in your room and forget the notion and complexity of adding subs?

Consider what TYPE of speaker will work in harmony with your room (conventional box, horns, electrostatic, omnis. etc) and then look for one that can deliver the full frequency range. Then optimise your room's acoustics - paying attetion to carpets, curtains, soft furnishings and maybe room treatment. Then just sit back and enjoy music without the hassle-factor you appear to be inviting.

If you really want 4 subs, then consider the only (as far as I know) preamp that has multi-sub Dirac Live and Dirac Live Bass Control DSP to pull it all together - the NAD M66. That’s the preamp I currently use although I don’t take advantage of its DL or DLBC features as my full-range speakers sound better without either of these DSPs or the addition of subs. Good luck and bonne noel.

 

[olds1959special]

It appears to me that you are looking for a complex and difficult system to get right. Instead of mains plus 4 subs, why not keep things simple and get a carefully selected pair of genuinely full-range speakers that will work beautifully in your room and forget the notion and complexity of adding subs?

Consider what TYPE of speaker will work in harmony with your room (conventional box, horns, electrostatic, omnis. etc) and then look for one that can deliver the full frequency range. Then give appropriate attention to your room's furnishings - carpets, curtains, soft furnishings and maybe room treatment. Then just sit back and enjoy music without the hassle-factor you appear to be inviting.

If you really want 4 subs, then consider the only (as far as I know) preamp that has multi-sub Dirac Live and Dirac Live Bass Control DSP to pull it all together - the NAD M66. That’s the preamp I currently use although I don’t take advantage of its DL or DLBC features as my full-range speakers sound better without either of these DSPs or the addition of subs. Good luck and bonne noel.

It’s not complicated, I don’t think, I like stereo bass and auditory envelopment, as well as a controllable bass boost, and it sounds the best now I think, going “double-bass” with no crossover, but then adjusting for the most offensive peaks from room modes. SoundSource does the job with its PEQ.

I’m running all four subs at their highest possible LPF setting (90Hz and 130Hz) and have them gain-matched.

The four 10” subs are just big enough to fit right next to the speakers and not get in the way of the room too much, like a larger sub would, and since they are powered I don’t need any more amps.

 

[Hear Here]

How odd that you mention "stereo" when talking about bass as its source location can't be detected by our ears. In most amps that offer sub outs, the output is a mono mix from both left and right channels. If you are placing 2 subs close to each main speaker, I guess they will contribute nothing towards adressing any room mode problems. As far as I can see, all they can possibly do is to add bass depth to your main speakers that are presumably incapable of delivering this bass without supports from subs.

No problem there, but my own approach is rather different, I don't want to clutter my room with subs (they are never attractive) so I have big main speakers capable of delivering the full audio range without adding subs. OK, there's still no attampt to counter room modes (I think this isn't a significant problem in my particular room since paying attention to carpets, furnishings, etc), but it means I have a very simple system that requires no more taxing setting up problems than placing the mains in optimal positions.

 

[goryu]

How odd that you mention "stereo" when talking about bass as its source location can't be detected by our ears.

There are several lengthy threads here on this very subject that you might want to read...