Acoustic Elegance AV12-X D2!

[Koon 10+ year member]

I will be running some this year. If I complain about anything you will be the first one notified.

notify me second //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[microhaxo 10+ year member]

update: sub still sounds just as good as the day i got it. Just thought i'd let everyone know..

 

[Electrodynamic 10+ year member]

I'm pretty sure I've read though this entire thread and there are a few things I'd like to clear up:

It's very probably that a single spider more efficient floppy suspension would appear to have 'more output' on the bottom end because it is much easier to move on a per watt basis.

Please explain how Cms factors into efficiency, because efficiency is based on BL, Mms, Re, and Sd. Cms does not factor into the equation.

It has everything to do with size and mass at higher frequencies. If it had nothing to do with it then Why do you even have smaller tweeters? Why do you have midbasses?

Actually, for a speaker moving mass has NOTHING to do with frequency response. It's inductance. Moving mass will affect efficiency. The measurements don't lie; you can see bandwidth not affected by Mms but strongly affected by inductance.

We have smaller tweeters for two reasons:

1. Wider dispersion

2. We have a tiny voice coil for low inductance, and that means not a lot of BL. If we want to keep the efficiency up, the rest of the Mms must be small.

Look at the number of 2", 3", 4" and larger speakers which reproduce right up to 20 kHz and beyond. There are hundreds of such examples, and most have moving masses 10 to 100 times beyond that of a tweeter. It seems that moving mass does not limit your bandwidth.

See the image below. Concerning high frequency extension, 'wanna guess which response has mass added and which one has inductance added? The red line is the stock driver. The blue and green lines are the responses of the modified driver.

I asked the question, How does this impulse delay due to inductance apply in a car, in the real environment, not in a lab?

Take your time alignment adjustment and skew it 2 milliseconds. Can you hear the difference?

Also...can a human actually hear it?

Timing differences down to

10 microseconds can be perceived.

What I am asking is...how does that lab data apply to the scenario that the speakers are actually in?

Quite well if you understand the effects the environment plays on the lab data. If you don't, then you get a lot of "lab data is irrelevant" type statements. Lab data is not irrelevant at all (otherwise why even post T/S parameters?) - rather, a lack of understanding what the lab data tells you and how your application of the data will change the sound makes it difficult for people to understand.

It's tossed out as "does not apply" because people don't understand how to apply it. That is not a failure of the data as much as a failure of the user.

 

[squeak9798 5,000+ posts]

Please explain how Cms factors into efficiency, because efficiency is based on BL, Mms, Re, and Sd. Cms does not factor into the equation.

I didn't go through you're entire post, because this line sort of struck me as funny.

If you look at the sensitivity document hosted on your own website, we find that;

Efficiency (No) = 9.64 * 10^(-10) * Fs^3 * Vas / Qes

Sensitivity (SPL) = 112+10*log(No)

And then if we do a little investigation into the variables in that equation, we find that Fs and Vas are calculated as follows;

Notice anything? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

That said, I don't necessarily agree with Nick's assessment that have you quoted there. I'm merely pointing out how Cms indirectly affects efficiency/sensitivity

 

[Koon 10+ year member]

hows the AV holdin up?

 

[John_E_Janowitz 10+ year member]

That said, I don't necessarily agree with Nick's assessment that have you quoted there. I'm merely pointing out how Cms indirectly affects efficiency/sensitivity

The efficiency formula is the amount of power that is actually transferred to acoustic power. If you notice, it's rare that any "subwoofers" ever get over even 1% efficiency. That means 99%+ is dissipated as heat in the coil. Knowing this, it is important to have drivers that are more efficient in that right so you have more output vs more heat. The 1w/1m efficiency is not affected by Cms.

John

 

[squeak9798 5,000+ posts]

The 1w/1m efficiency is not affected by Cms.

If you look at the above formulas, how does Cms not affect efficiency and sensitivity? Using an excel spreadsheet, I can get sensitivity to bounce all over the place simply by adjusting Cms, which in turn alters Fs and Vas, which in turn alters No and thus SPL.

Or, thinking about this with an extreme example......if I replace the spider of a driver with a dowel rod of the same mass that does not allow the cone to move, how does this not affect the efficiency as you would now have 0db sensitivity and an No of 0% ? The only thing I changed was how compliant the suspension is......changing it from "X" to 0.......

Asking seriously, as there is apparently something I'm not understanding here.

 

[Papermaker85 5,000+ posts]

1w1m is calculated, and its NOT directly related to output.. the spec is nearly usless, unless you run it around 1k.. CMS DOES efficiency.. as in it enables the use of more efficient system designs... we all know larger boxes and more port area mean greater efficency.. lack of cms cause more excursion for a given input/alignment.. what many programs don't account for is the corrspondance between the ports Q and cms/mms/actual motor strenght(BL^2/Re+electrial input in wattage)...

 

[Electrodynamic 10+ year member]

I didn't go through you're entire post, because this line sort of struck me as funny.
If you look at the sensitivity document hosted on your own website, we find that;

Efficiency (No) = 9.64 * 10^(-10) * Fs^3 * Vas / Qes

Sensitivity (SPL) = 112+10*log(No)

And then if we do a little investigation into the variables in that equation, we find that Fs and Vas are calculated as follows;

Notice anything? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

That said, I don't necessarily agree with Nick's assessment that have you quoted there. I'm merely pointing out how Cms indirectly affects efficiency/sensitivity

When you work the entire equation you'll find that Cms cancels out. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Cms is only in there to make things easier to plug in and calculate.

 

[squeak9798 5,000+ posts]

When you work the entire equation you'll find that Cms cancels out. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Cms is only in there to make things easier to plug in and calculate.

I found the flaw in my original simulation //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

I was failing to recalculate Qes.

Garbage In - Garbage Out.

Heh.

//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

 

[microhaxo 10+ year member]

I hear a real quality song to listen to with SQ bass is Roses by outkast, is this true? When i listen to it on the AE it sounds way different than the Q or Polks. It sounds really clean but Is there some reference or specific notes i should listen for. I guess its hard to tell when i have no reference.

 

[John_E_Janowitz 10+ year member]

A few good tracks with detailed bass that isn't heavily compressed.

Duende by Black Light Syndrome. Beginning has a short bass solo with some quick notes. Good subwoofer will produce each note clearly and differentially. A poor subwoofer it sounds like a rumble that only changes tone.

Are You In by Incubus.

Good SQ demo song in general. Lots of left/right imaging. Drums are recorded well. Toms roll from side to side. Nice punchy kick drum

Fever by Ray Charles on Genius Loves Company.

Another good SQ demo song. Very tight upright bass. Good female and male vocals.

Flirt and It Just Happens That Way by Mindi Abair on the CD It Just Happens That Way

Two other good SQ songs with good imaging, saxaphone, and tight punchy bass.

John

 

[bose301s 5,000+ posts]

I also like to use some Pink Floyd for demos. Anoth Brick In The Wall Pt. 2 is a great all around demo with tight punchy bass and will also give your mids and tweeters a good workout. Mother, the track after, starts out slow with no bass but once it does come in it is a good test, it should be forcefull but tight and crisp. From that same album Comfortable Numb follows the same format, tigt punchy bass aith bass guitar. All excellent demo songs.

 

[kendogg 10+ year member]

For those interested, I just got my ED 11Ov2's installed yesterday. They do not seem to exhibit the lack of upper frequency extension that the AV15 did. This is now 3 separate drivers that have not exhibited this problem in my vehicle. Perhaps it's time to stop blaming the user or the vehicle and start (rightfully) blaming the poorly performing drivers???

A comment from a friend who's not much of an audio person was simple 'wow, these things have WAY more range than that 15 you had did" >_>

 

[microhaxo 10+ year member]

I wouldn't buy anything Ed. Also you are comparing 4 10" drivers to a single 15??

I think its been shown over and over that the AE series drivers have LOTS of upper range output.

 

[Koon 10+ year member]

you are comparing the upper end output of 1 15" compared to 4 10"s? 4 10"s have 314 inces^2 of cone area and 1 15 has 177 inches^2 of cone area. which one did you think was gonna have more upper end output?

EDIT: microhaxo, how's the AV holdin up?

 

[microhaxo 10+ year member]

AV is doing great.

 

[Koon 10+ year member]

anyway you could get ur 12 on a TL (termlab)?

 

[bumpin buick 5,000+ posts]

if you ever want to jump the boarder to Wisconsin I can meet up with you and throw it on my Termlab.

 

[microhaxo 10+ year member]

I will be buying a mic soon to test, it wont be with termlab software but it will be with Room EQ and TrueRTA (things i can afford lol)

I would jump over to WIS but it would take me ~6 hrs to get anywhere close to you buick.

If anyone in Minnesota close to twin cities has a TL let me know.