Subwoofer integration at both high and low volume

[fudun]

Hi, I know I have read something about this before, but I can't remember the exact terminology for this. So googling didn't help much.

In short, my system sounds great, but I only get the right subwoofer level at the volume I calibrate at. If I play at a lower volume, the sub disappears, and at higher volumes it overpowers the monitors.

My setup is Neuman KH-80 monitors + Kali WS 6.2 sub

At the moment it is run through a Topping DX5, with sub passthrough handling the crossover. I am about to add my old MiniDSP DDRC-24 to the mix, probably removing the Topping DAC.

I set my monitors' output level to 94 dB, as anything higher resulted in an annoying hiss, and I suspect this is the reason for them to have a less steep volume curve than the sub has. So how can I make my sub follow a similar curve so I can have one calibration working for both high and low volume? Would like to figure this out before I start calibrating anew (UMIK-1/REW/Dirac)

 

[Svend P]

You could solve it with a surround reciever that has Audyssey Dynamic EQ

 

[sigbergaudio]

Could it be that at louder volumes your monitors hit their limiters, so the sub is getting louder but not the monitors?

Another common reason for this experience is that the bass response from your sub isn't even, so some frequencies sound overpowering, but the overall volume of the sub isn't actually loud enough. This could be resolved by manual or automatic EQ. What crossover are you at?

 

[fudun]

Thanks guys. I know some receivers have functions that handle this, but I won't add one to this setup

I do not think I am anywhere near the limit of the speakers. I calibrated at 68 dB which is quite loud sitting less than 1 m from the speakers. Currently running the crossover at 80 Hz because that's what the sub does, but I am planning for something higher when I add in the MiniDSP.

I know this is a general problem when it comes to how audio is perceived, and the reason why some systems have a loudness option. But it is much more pronounced in this setup than any other I have had.

Edit: The sub response is actually quite even. I just switched to a new desk and moved the desk a bit so I am going for some new measurements soon. But either way, the problem is more related to the sub's volume curve being steeper. I belive if my sub had a sensitivity setting in addition to the gain, it could have solved this.

 

[sigbergaudio]

I suspect you have a peak in the bass response somewhere. Say that is 10dB (random number) and somewhat wide, then you'll end up setting the level of the subwoofer based on that, resulting in a subwoofer that has an overall level in all other frequencies (except at the peak) that is 10dB too low. This will make it seem too soft at low levels, while the peak will be more dominant the louder you play, giving the impression that the subwoofer is too dominant.

If you can either use Dirac or do measurements and manual adjustments when you get the MiniDSP, you will probably end up with a better result.

 

[fudun]

Well I did some work on flattening the response when I set this up. Using REW+APO for this. It might be that the problem is only related to peaks/room modes, but either way it changes with sound level. When I set up the miniDSP here I will get some improvements as I can control the crossover better and do separate adjustments to the response curves of the sub and monitors.

But I would still like to figure out a a to decrease the sub's dynamic or what it is called. I think the miniDSP/Dirac might have a compression setting, but I don't know if it does what I am looking for. The MiniDSP has been gattering dust for a while, so can't really remember. And at the moment I can find the mini USB cable I need to set it up...

 

[aschen]

This is just equal loudness anatomy of hearing at work right? Remember the loudness contour button on ye olden equipment? It eqed up bass and treble at low volumes to compensate for changes in hearing sensitivity. Is there a modern DSP equivelant?

 

[fudun]

In this case I feel there is something more at play. It seems like the subwoofers sound level increase so much faster than the monitors as you rotate the volume control.

 

[Devnull]

Have you measured at different volume levels? Until you do you won't know if it's your perception of what you're hearing, like aschen suggested, or if your subwoofer is operating non linearly.

 

[fudun]

Good idea. I'll make a set of measurements later this weekend

 

[LTig]

In this case I feel there is something more at play. It seems like the subwoofers sound level increase so much faster than the monitors as you rotate the volume control.

I think this is the loudness contour. The lines for equal loudness are much closer to each other in the low bass.

 

[fudun]

Might be. I have had a lot of different setups over the years both with and without subs. This in particular seems much more affected by the issue, so I don't think it is just my perception of the sound. I will make some measurements that may or may not prove that the actual sound level measured in decibels change at a different pace in the subwoofer vs the satellites. But I would still like to find a way to adjust the sound level curve of the sub, or whatever is the correct term for what I am looking for.

 

[OldHvyMec]

It VERY common for people not to match the efficiency of the sub drivers with the main speakers in play. 90% efficient mains with 85%
efficient subs is a great example. When you get it right at normal listening levels say 75-80db and then turn it up the subs can't keep up.

It happens all the time with horns that are very efficient, 98-105 and then people buy a box subs at 85 or so. You have to match the subs
to the mains, it's as simple as that OR you'll be turning the sub up and down from now on. All my current subs are 90-95% at 4 ohms
and the mains are 93% at 4 ohms. All the way from the bottom and all the way to the top they are matched.

It's looked over by most, while thinking what a deal they got on the 75-85% subs on sale. It has nothing to do with DSP, EQs or room
mechanics unless you save 4 or 5 different settings for different volumes. I always found it was easier to match speakers when I built a
set.

Two of the subs I use that are off the shelf that work very well are GR OB 12" servos at 90%+ and PEs HO44-10 at 91%.

Regards

 

[LTig]

Efficiency is not relevant but maximum reachable SPL. If the mains can play louder than the sub the sub will clip when its limit is reached.

The only constellation where efficiency matters is when you use a passive crossover for a passive sub, which is very unlikely nowadays.

 

[OldHvyMec]

Efficiency is not relevant but maximum reachable SPL.

Only if you want to get up and down every time you change the volume and adjust the sub. That is the exact problem the guy is describing.
Match the speakers and you don't have to boost or L-pad the individual drivers except for the given room they are in.

It's kind of speaker building 101. Match top to bottom and left to right for a good starting point.

What does maximum SPL have to do with normal listening levels and how efficient the speaker is? They are normally measured at 8ohms 2.83v/1M
4ohms is higher but there is usually a sacrifice in distortion and the problem with valve gear liking 4 ohm drivers.

I've dealt with this problem back to the first subs used in the 70s. Jensen Imperials, Klipsch, Altec Lancing, you had to use pro drivers or you needed
a remote on the sub amp. Infinity RS series are all matched. Mains to subs. VMPS, heck even GR research keeps their sub/mains close.

Regards

 

[Devnull]

I wasn't grasping what OldHvyMec was saying so I threw together a quick experiment. Used a 8 inch coax on my living room floor and one of the living room subwoofers. Put some simple guessed at crossovers into a soundweb 9088iis DSP and 10dB of attenuation for the tweeter and ran the output to my subwoofer amp and to a 2 channel crown amp for the mid and tweeter. Attenuated the input signal by -25dB, -15dB and -5dB.

I know the graph looks terrible but I made no attempt to clean things up or balance the outputs between the drivers, I just wanted the crossovers to protect the drivers.

I'm not seeing what OldHvyMec said should happen. The subwoofer with 2 86 dB driver's keeps up with the 95dB mid and the attenuated 105dB tweeter. When the signal goes up by 10dB the output goes up by 10dB across the all 3 drivers

 

[LTig]

Only if you want to get up and down every time you change the volume and adjust the sub. That is the exact problem the guy is describing.
Match the speakers and you don't have to boost or L-pad the individual drivers except for the given room they are in.

This will not solve the problem. Actually I don't understand your reasoning. Once you match the sub and the sats to play at equal levels (by whatever means) changing the sound level of the music does not change it. These are linear systems.

If the sub plays too low at low SPL this is the expected behaviour according to Fletcher Munson. Use a loudness control or similar to fix it.

 

[OldHvyMec]

Look it's pretty simple and I'm sure you can see when drivers that match in efficiency at one meter and a given voltage will act in kind to one another in a build.

I learned a long time ago you don't build problems into the speaker you have to compensate for with EQ, balance, and resistors.

You choose the same ohm rating and USUALLY build very close to the individual sensitivity/efficiency of the drivers in a 2-3-4-? way speaker.

Do you understand that? I usually build a lot of flexibility into the speakers I build, because of the difference in 99% of other rooms. Most
rooms are different. I like adjustability on the mids and highs in a 3-4 way. (L-Pads).

If you have a main speaker built that way, why wouldn't you match the sub the same way, if your speakers didn't have a sub system onboard?

Do you think they would throw in a 79% sub driver in with a 95% efficient bass, mid, high driver? Does that make since to you?

It pretty simple to stay out of trouble, but it can be expensive to get out of trouble. Matching drivers is a good place to start. Like I said
it's 101 speaker building. Match your components. You cannot make chicken soup out of chicken $hit.

Why would you need a remote on a sub unless the drivers weren't matched? It's sure not to turn one on, ay?

Use a loudness control or similar to fix it.

Usually "variable loudness" (trim as Mac now calls it) is for low volume listening usually, It cuts the added gain at 1/2 way up the volume pot or before.
What about the other end at high volume when the sub is at 80 db and the mids and highs are at 100db?

When drivers are matched there is no tone control in the picture except for how the source was recorded. Ballance is for mismatched components
left to right (or ears), not top to bottom. Some manufactures actually match left to right, believe it or not, it wasn't common at all 1950-2000. Probably
still isn't. I don't know, I don't buy other manufactures stuff to often, and that is one of the reasons why other peoples speakers aren't high on my list
with the exception of a few I like to tinker with. Infinity and VMPS are two that I like. I've built over 100 sets through the years. I've learned
a lot, from actual hands-on speaker builders.

Some things you just don't argue with unless you like fixing things. I've certainly done my share of that (fixing things).

Regards

 

[Keith_W]

Different efficiency of the subwoofer driver and the rest of the speaker would be a problem if all of them were connected to the same amplifier. But most subwoofers are powered, so the efficiency does not matter. What matters is that both speaker and sub respond to the input in a linear fashion. This can be easily tested by taking a sweep at 65dB, then repeating the sweep at 75dB, 85dB, and 95dB.

 

[LTig]

Look it's pretty simple and I'm sure you can see when drivers that match in efficiency at one meter and a given voltage will act in kind to one another in a build.

I learned a long time ago you don't build problems into the speaker you have to compensate for with EQ, balance, and resistors.

You choose the same ohm rating and USUALLY build very close to the individual sensitivity/efficiency of the drivers in a 2-3-4-? way speaker.

Do you understand that?

I do, but here you talk about building a passive speaker while in your posting further up you talked about matching a sub with the satellites. @Keith_W had said it all above so I'm not gonna repeat it.