LINEAR VOLUME FREQUENCY RESPONSE QUESTION

[Lab_Experiment]

A brief history of my experience of different subwoofers:

COMMERCIAL BIG NAME SUBS: PLAY ONE NOTE AND ONE VOLUME. I rented a popular brand 15 or 18 inch powered sub (cant remember) but at 70% volume I could hear bugs walking across my floor. At 75% I wouldn't be able to tell if there was a war going on outside. This was a serious problem. I was nothing short of disgusted. I also had the same experience going to a "rave" from a big name dubstep artist that used a different brand of big name commercial bins.

SYSTEM I BUILT: EvErY VoLuMe is GREAT. I bought some amps and I built two sealed boxes each housing 4 12" subwoofers. First thing I did was play a 30hz sinewave being volume modulated with a low frequency oscillator. My faith in music tech was restored after having been drug through the mud for a while.

I will be honest I'm a bit terrified to build anything that isn't a sealed box with drivers larger than 12". Not because I am a poor craftsman, but because I never want to spend money and get a similar behavior to what I've experienced with the commercial subs.

 I am particularly worried because RICCI said that weaker subs do not perform in his boxes in this quote talking about the othorn:

"Most people that build the Othorn's do seem to use the recommended 21 or 18" drivers but there have been a few who have used much more affordable / weaker drivers that simply do not perform right in that cab and won't allow it to perform like it should."

I have a few questions:

1. Has anyone had a similar experience as I have?
2. Was the unilinear volume response amplifier related or speaker/box related?
3. If I build a SKHORN will it only sound good when I'm pushing 4000 watts?
4. Should I go with a different strategy than buying two 21SW152's and building a SKHORN if I want to sacrifice maximum SPL for low frequency extension and a linear volume response? I do NOT care about linear frequency response because I am not your average meat head, I am a wizard, self trained in the arts of Ableton Live.

Linear Frequency response is not the same beast as Linear Frequency Volume response. If you're replying please understand the distinction. I know it can be confusing.

[peniku8]

6 hours ago, Lab_Experiment said:

Linear Frequency response is not the same beast as Linear Frequency Volume response. If you're replying please understand the distinction. I know it can be confusing.

What you're talking about is compression and expansion.
There are a lot of factors that can cause compression in subwoofers (a change in input gain results in a *smaller* change in output change), like the voice coil getting hot (impedance rises, so the same amount of voltage generates less power; also known as power compression), air velocity in the port getting too high (port compression), the driver reaching excursion levels where the magnetic field strength gets lower (over excursion) or simply the amps' limiters kicking in, to protect the drivers from destroying themselves.

To express the effects of compression with your wording it could be something like:
-volume change from 70% to 75% is very large
-volume change from 75% to 80% is small
-volume change from 80% to 85% is imperceptible

Since you describe the opposite effect, if I undersood you correctly, this doesn't apply, since you're seemingly describing expansion.
There is only one cause of expansion in subwoofers that I am aware of and it is minute.

So, if expansion doesn't happen inside a speaker, what's the thing you're hearing?
I think the explanation is fairly simple: it's the lack of compression. You're not used to hearing capable systems that can reproduce content with their full dynamic range, in which case the SKHorn would be one of the worst choices, since it's one of the most capable subwoofers out there.

Another explanation would be bad deployment and what you were hearing at "75% volume" wasn't the subs being super loud, but everything distorting badly (which will be perceptually louder, since our hearing is more sensitive at higher frequencies and distortion will mostly produce frequencies higher than the stimulus).
Most venues and festivals I mix have underdeployed systems and/or are badly set up. The last festival I mixed at had a stack of 3 2x15" subs on either side of the stage. All three cabs were different, which was the first point of concern, but the biggest issue is the physical deployment: you get terrible lobing and super uneven bass response across the audience (see my recent post on AudioScienceReview on this topic).

I haven't experienced the effect you're describing. Most of the time I'm fighting compression and uneven response across the audience.

The issue you're describing can have many causes, but "subwoofers being overly dynamic" it is not.

7 hours ago, Lab_Experiment said:

2. Was the unilinear volume response amplifier related or speaker/box related?

My answer to that question would be "source content" as per the explanation above (lack of compression; habitual).

 

7 hours ago, Lab_Experiment said:

3. If I build a SKHORN will it only sound good when I'm pushing 4000 watts?

The difference between 1000 watts and 4000 watts will be 6dB in theory. In practice, some compression will have set in at 4000 watts of input power and it will be less than that at certain frequencies.

[klipsch]

The only thing bad about skhorns is that they are like the Lay's potato chips commercials - one, two, three just begets wanting one, two, or three more. 

That and that Ricci was mean and didn't sell me his NSWs he had for sale several years back. The nerve of that guy

[Lab_Experiment]

On 6/18/2023 at 6:12 AM, peniku8 said:

Since you describe the opposite effect, if I undersood you correctly, this doesn't apply, since you're seemingly describing expansion.
There is only one cause of expansion in subwoofers that I am aware of and it is minute.

Just to be clear, what I negatively experienced with the commercial sub was this:

 

0-74% (VERY QUIET)

75-100% (VERY LOUD)

What I was missing was all the fun that happens at 0-74%.

 

I had to compress the life out of my music to hear it without nulls in the sounds. It definatly performed when I compressed my sound and gave that "rave" feeling but thats not what im going for.

 

Another interesting way to describe it is to say that the sub sounded like it only had 4th gear. It really performed in 4th gear but I don't just drive on the highway all the time.

 

I think it was either a cheap amp or this is where the ht/pa design philosophy divide exists. Id be suprised you havent experienced what im talking about I've heared this behavior from a few different PA systems.

 

I certainly want earth shaking SPL dont get me wrong. I have 8000 watts that I want to give to the 20hz-60hz region.

 

Will the SKhorn give me the intimacy I need, or should I make another type of box? The tradeoff in efficency between horn and sealed boxes seems tragic but for my application, I rather build more inefficient boxes and lose SPL than sacrifice the quiet parts of the signal. 

[peniku8]

Sealed subs are not suited for live sound applications. They won't have enough headroom down low

[Lab_Experiment]

I think I will attempt an SKHorn build or two othorn builds unless someone says not to. Will probably be a few months before construction begins.

 

After it's all built I will report my opinion here on how the box performs with respect to what I am trying to achieve.

[peniku8]

I'm probably going to sell mine; you don't happen to be in Germany? lol

[Lab_Experiment]

On 6/19/2023 at 11:37 AM, peniku8 said:

I'm probably going to sell mine; you don't happen to be in Germany? lol

Canada, otherwise i'd go check those out in a hurry. Probly cost a few organs on the black market to ship those beasts over here lol

[dbstedt]

On 6/19/2023 at 11:09 AM, Lab_Experiment said:

Just to be clear, what I negatively experienced with the commercial sub was this:

0-74% (VERY QUIET)

75-100% (VERY LOUD)

What I was missing was all the fun that happens at 0-74%.

It definitely sounds like something was defective OR maybe you were driving the cab(s) into heavy distortion at "75%" and up.

Any details on the hardware you were using?  Box, amp, etc.

[Lab_Experiment]

On 6/28/2023 at 2:47 PM, dbstedt said:

It definitely sounds like something was defective OR maybe you were driving the cab(s) into heavy distortion at "75%" and up.

Any details on the hardware you were using?  Box, amp, etc.

I had sound coming from PC(ABLETON) -> FOCUSRITE 6i6 -> *ACTIVE SPEAKER*

I don't want to say the brand of the speaker, the thing was a rental so it could have been damaged but it was probably one of those speakers that cost under 1000$ for the entire speaker + amp.

I spent 3x that on each of my new QSC amps alone so that's probably why I'm much more satisfied.

I doubt the box itself was built so poorly that it actually ruined the rental speaker. Right now I'm convinced my bad experience was caused by the cheap amplifier in the speaker.