Don't shoot... don't shoot... I'm just the messenger...
You're very quick into disagreeing with someone. Did you try to look for the thread I mentionned?
Kelvin
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Don't shoot... don't shoot... I'm just the messenger...
You're very quick into disagreeing with someone. Did you try to look for the thread I mentionned?
Kelvin
I'm not quick i just know from experience what my preference is. Doesn't invalidate your preferences at all, both can be true.
Your experience taught you your preference - it's all good. We all need experience in order to learn.
What I said earlier, isn't my preference at all - just stated what I read on a forum. Let me post the thread on here and see what we can learn from it:
http://www.soundsolutionsaudio.com/f...aw-discussion/
Hoffman's iron law is a bitch... You can only choose 2. The only way to bend the law is by going IB (great if you have the right car)
Kelvin
Agree, Idon't mess with hoffman, just do ib
For what it's worth, I've been studying on this subject for the past year. I built a tool that predicts power efficiency vs frequency and what the burp-sub-salesman mentions is not wrong. Power efficiency and voltage sensitivity are very different above resonance vs below resonance. A higher reference sensitivity 2.38v/1m on a woofer data sheet is not going to mean more low-bass output per volt, and a higher reference efficiency 1w/1m does not mean more low-bass output per watt.
I've been able to replicate the results of Don Keele's paper on the subject, and the results of Vanderkooy's paper whom Keele based his paper on. Don Keele's paper is linked below, and he does a good job making the concepts easy to understand even if you skip all the math stuff.
https://www.xlrtechs.com/dbkeele.com/PDF/Keele%20(2003-10%20AES%20Preprint)%20-%20Nom%20vs%20True%20Eff%20High%20BL.pdf
You also might have a point though. There might be some quality that is relate to having a high reference sensitivity/efficiency that sounds better to you and there is nothing wrong with that :)
no $hit... you don't say?
That post first post was a cracker, and I thoroughly enjoyed that.
You Sir...
have a refreshing clarity of thought, command of language, and appreciation of the physics that is refreshing to read.
I think electro-acoustical efficiency and voltage sensitivity are once again being inter-twined into a discussion with out either of them being explicitly stated. They are not always the same, in fact in car audio, hardly ever. The statement quoted from Jacob @ sundown, well it's not that it's true nor false, it just doesn't paint the complete picture. Unless you have the equations for both reference efficiency and 2.83V sensitivity burned into your brain cells, it can be quite easy to get convoluted into the subject. Honestly, the key is to model about 10,000 subwoofer simulations and to vary certain parameters to see how it all un-folds.
Decided to model the AF GB12 (orange) vs CSS SDX12 (red) vs Adire Audio Brahma (yellow) in the most ideal ported boxes that I could figure out. The Brahma really wants a huge Ported box so I went with a 2 cu ft which is the biggest I would use in a car for a 12. The Brahma is not really ideal for use in a ported box according to my simulations and is better suited for a sealed box but a DSP would be able to smooth things out.
Loving the commentary and great information that has been posted in this thread!
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