What is Your Definition of a SQ Sub?

[rc10mike 10+ year member]

Umm, what? Looking at one parameter of a driver can basically tell you nothing of what the driver can do. That's like looking at a Lotus Exige and telling me that because it has sub 300 horsepower that it won't be able to handle corners and straight line roads like you want it too... that makes no sense at all.
My current sub has a rated Fs of 24hz and in it's current enclosure, the new Fs is around 16hz or so and plays measurably flat from 18hz to ~70hz with a 4dB peak at 22hz and everything else is flat within about .1 dB. Tonality is great, punch and aggression is there, group delay is very low, and phasing with my front speakers is great.

What are you running just curious?

 

[shimmyz 10+ year member]

What sub is it

 

[Immacomputer 10+ year member]

Acoustic Elegance AV12 in a transmission line enclosure in a '99 Integra hatch.

 

[shimmyz 10+ year member]

ah yes, a tline. I've been putting alot of thought into building one.

 

[Lizardking 10+ year member]

Umm, what? Looking at one parameter of a driver can basically tell you nothing of what the driver can do. That's like looking at a Lotus Exige and telling me that because it has sub 300 horsepower that it won't be able to handle corners and straight line roads like you want it too... that makes no sense at all.
My current sub has a rated Fs of 24hz and in it's current enclosure, the new Fs is around 16hz or so and plays measurably flat from 18hz to ~70hz with a 4dB peak at 22hz and everything else is flat within about .1 dB. Tonality is great, punch and aggression is there, group delay is very low, and phasing with my front speakers is great.

You're confusing "sound quality" with "sound preference" or "listening preference" when these terms are not the same thing. A sound quality speaker is not one that sounds good to everybody as that's never going to happen.

I don't disagree with you but to answer what he was after concerning sound quality and subs....it's going to vary on individual tastes. I don't disagree that SQ can be measured...but measurements don't mean anything when your own tastes come into play....thats all I was merely trying to point out.

 

[rc10mike 10+ year member]

Acoustic Elegance AV12 in a transmission line enclosure in a '99 Integra hatch.

Pics?

 

[Immacomputer 10+ year member]

No, the sound quality won't vary by individual tastes, the sound preference will vary.

Sound quality =/= sound preference.

If a driver had 0 BL distortion and 0 mechanical distortion and virtually 0 inductance, that would be a near perfect sound quality driver. That doesn't mean that everybody will like it but it will and will always be an SQ driver. Individual tastes have NOTHING to do with sound quality. NOTHING AT ALL.

Pics?

Only of the design -- my camera wasn't working when I built it.

Here is a picture of the design and *** end of the sub as I don't have any of the cone.

 

[Lizardking 10+ year member]

No, the sound quality won't vary by individual tastes, the sound preference will vary.
Sound quality =/= sound preference.

If a driver had 0 BL distortion and 0 mechanical distortion and virtually 0 inductance, that would be a near perfect sound quality driver. That doesn't mean that everybody will like it but it will and will always be an SQ driver. Individual tastes have NOTHING to do with sound quality. NOTHING AT ALL.

I don't disagree at all...but at the end of the day individual tastes trump everytime no matter how perfect something is. You nor I may not like perfect.

 

[BringDaBoom 10+ year member]

I don't disagree at all...but at the end of the day individual tastes trump everytime no matter how perfect something is. You nor I may not like perfect.

Correct, and therefore you are describing sound preference, not sound quality.

 

[Lizardking 10+ year member]

When people think sound quality it's assumed you can hear sound quality....in such way that it is perfect.....when in fact it boils down to perception of what is perfect to you.

 

[BringDaBoom 10+ year member]

When people think sound quality it's assumed you can hear sound quality....in such way that it is perfect.....when in fact it boils down to perception of what is perfect to you.

Negative. Here's where you can see how perfection is not based on what perfect is to you:

1.) 2+2=4. It doesn't matter what you or anyone thinks, 2+2 will always equal 4. It's numbers. It's quantitative fact.

2.) A sound wave has a physical form. The wave length has concrete measurable numbers from crest to crest and trough to trough. There is no denying it. It's the sound wave's "DNA" if you will. To alter the wavelength there by makes the sound wave no longer "x" frequency. It's distorted. Just like if you modify 2+2 to 2.1+2 it no longer equals 4. it's 4.1. It's darn close, but it's not the same.

3.) When a speaker produces sound, any movement from the cone that is not linear alters the sound wave. Therefore, you have not accurately reproduced sound. Therefore it is not perfect. No matter what you may think....the fact remains that the soundwave coming out is not 100% perfect. The subwoofer that emits the least ammount of non-linear movement, therefore is producing the most accurate soundwave.

DISCLAIMER: I've used one simple aspect of speaker mechanics in point 3 to illustrate this. There are several. i kept it short and simple to further illustrate that perfection is not what one thinks it is. It's mathematical and quantitative. A true sphere is perfect. It is completely and mathematicaly 100% symetrical in all aspects. If you don't think so, that's your opinion, but it's still perfect.

We're going around in circles. We are all basically agreeing on everything, save for the terms. We agree on what SQ means, I.E. accurate sound reproduction. Where we don't agree and where you refuse to either believe or do not understand, is what you refer to as SQ is NOT...it is sound preference. What sounds good to you may not sound good to others. You PREFER a sound over others. You LIKE and therefore THINK a certain sound sounds better. That does not MAKE it better. Numbers tel you that. That is how true SQ is judged at competitions. They don't stick their head in and go "sounds good." There are mics and computers reading the performance of your stuff.

 

[Lizardking 10+ year member]

I think we all basically agree as well. Doors of preception.....lol Some good science in your explanation.

 

[BringDaBoom 10+ year member]

Why thank ya //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[rc10mike 10+ year member]

Id like to hear some of these "exotic" enclosures!

 

[newusername 10+ year member]

I want to apologize for adding to some of the confusion around this topic, based on previous posts I've made. An article in the most recent article of VoiceCoil magazine had an interview with Earl Geddes and his use of some of these terms has led me to re-evaluate the semantics of exactly what we're saying.

First, we must use the terms correctly to understand exactly what we are inferring when we say that. This is what has led to the confusion, at least on my part.

So, when we say "sound quality", what do we really mean? According to many, sound quality means accurately reproducing the source. When we look at the term "sound quality", there is no possible way it can mean this. Reason? For starters, how accurately we can reproduce the source is a completely quantitative practice, meaning we can use science and numbers to determine how close to the source the material is. This is COMPLETELY different from a "qualitative" approach, where we wish to describe the behaviour with adjectives. The term "sound quality" or "SQ" is intended to describe a certain "quality" of the speaker (or system), and not any qualitative analysis. In this sense, SQ is completely up to whomever the listener is.

Where's the problem? Well, the problem is with organizations who hold SQ competitions, pretend that they are checking accuracy to the source, all the while not realizing that they are attempting to use qualitative analysis to describe behaviour that is more easily described using quantitative measurements.

Simply put: SQ is personal preference, as it is the "quality" of sound. Being accurate to the source (which many claim SQ is, but in actuality is not) is not about personal preference, and is completely quantitative.

Further thinking:

1. Yes, I still stand pat in saying that the goal of a speaker system is to reproduce, not to impress. As such, quantitative analysis (ie. with reliable measurement) is a better approach to system design, particularly during R&D.

2. Using a large selection of qualitative data (enough to fairly represent the Earth's population), we can develop a model which will show a correlation between the quantitative data (the measurements) and the qualitative data (the perception). GedLee has been working on this, and it really shakes the core of a lot of audio engineering. The use of the THD and IMD metrics is completely inappropriate for describing the perceived behaviour, but passing the same physical data that creates THD and IMD measurements through a model similar to the GedLee one will make prediction of perception accurate for the number of humans who fall within the reasonable curve of that model.

Regardless, the purpose of a speaker system is to reproduce the signal (btw, for whomever said that there are speakers with low distortion, I submit that this is completely false within any reasonable bandwidth, although obviously we must define what "low" is). Those who choose to remain ignorant of science, at any level, will continue to do so at their own peril.