18 replies to this topic

[coll]

Something seems slightly wrong on the AA website regarding the dual 2 ohm AA Chaos 10 inch.
Using the T&S figures given on site the box size for a sealed enclosure seems wrong, when I calculated it out if the box is 0.6 cu ft (min. size) the system QTC is 0.55 which is of course very low and for 1.0 cu ft (max. size) the QTC is 0.49.
So what is wrong the T&S figures or min and max box sizes.

[Impious]

I haven't looked at the website, but a Qtc of .55 is not "very low". A Qtc of .577 is a standard Bessel alignment, Qtc of .5 is critically damped and has optimal transient performance. Meaning, many people throughout the world aim for a Qtc around those values. Given we are in an automobile, we don't need a Qtc of .7 as we don't need the lowest possible F3 since we have cabin gain to help fill in the bottom end. So, just from your post it doesn't appear there is anything wrong with either the TSP or the suggested enclosure volumes.

The suggested enclosure volumes from any manufacturer are exactly that: suggestions. It doesn't mean you can't use the driver in a different alignment if you so choose.

[coll]

I take you point but I have never seen a manufacturer suggest a minimum box size this big before giving such a low starting QTC and I mean never, just look at Fi and Re so I say again there is something not right somewhere.

[Impious]

I take you point but I have never seen a manufacturer suggest a minimum box size this big before giving such a low starting QTC and I mean never, just look at Fi and Re so I say again there is something not right somewhere.

Many manufacturers "recommend" small enclosure volumes simply because they have a higher peak output which makes the average consumer think the product is "better". That doesn't mean the recommended enclosures are optimal for the driver. Hell, I never even look at manufacturer suggested enclosure volumes. They don't know what I look for from a performance aspect, and I don't know what they were aiming for from a performance aspect when they suggested those enclosure volumes. I take the time to design my own enclosure, or lack there-of since I generally run my drivers IB (even when they might not be specifically "suggested" for IB use by the manufacturer). It's the only sensible way to go about it.

As far as I know, Scott for the most part doesn't really use enclosure modeling, target curves or target Qtc's to recommend enclosure volumes for his drivers. He uses his experience with the driver to suggest the range of enclosure volumes that most consumers would prefer. So the results will all vary slightly when plugged into enclosure modeling software.

You apparently know how to use enclosure modeling software....if you're not happy with the recommended enclosure volumes, model something else that you would prefer more.

I fail to see why you are having such problems or making an issue out of something that really isn't an issue? Again I say it seems like you're trying to make a big deal out of nothing.

[coll]

Just find it strange that Fi and AA seem to have the same designer and Fi quote small enclosure sizes and AA large for the 10 inch sizes it makes it seem that the figures are not correct or there is a mistake with the enclosure sizes with AA.
Just look at others and you will see what I mean.
I am actually thinking of using a Fi or AA for home music use not HT and am having difficulty getting information from either. I would like to know what the high QTS is on the Fi SSD and Q models but cant get an answer and enclosure sizes vary all the time so its difficult to model without exact figures.

[Julian]

Scott was the owner of RE and is now the owner of Fi and AA.

[BILTD]

Just find it strange that Fi and AA seem to have the same designer and Fi quote small enclosure sizes and AA large for the 10 inch sizes it makes it seem that the figures are not correct or there is a mistake with the enclosure sizes with AA.
Just look at others and you will see what I mean.
I am actually thinking of using a Fi or AA for home music use not HT and am having difficulty getting information from either. I would like to know what the high QTS is on the Fi SSD and Q models but cant get an answer and enclosure sizes vary all the time so its difficult to model without exact figures.

I gave you the answer on AVFourms with regards to H-Qts. The info you seek on the enclosure parameters are on the Fi/AA sites. All the threads you have started on various forums have been answered correctly and accurately by proffessionals who know what they are talking about. The only answer Fi/AA will give you is the answers you've already read and seen, so I'm not sure why its so important to be hearing it from the horses mouth?

Anyway, I trully hope you find the answers your looking for

[coll]

Hi BILTD
Sorry just finding hard to make a decision, also trying to see now if I can fit a 12 inch into my space.
I assume that if I go for a 12inch Fi the high QTS versions are also plus 0.08 above the normal QTS figures.

[BILTD]

Hi Coll,

Yes thats correct. Also if its any interest to yo I have a semi-used Q15 D2 H-QTS with cooling and Intl. Lead options for sale, its in superb condition!

Edited by BILTD, 18 June 2012 - 07:09 AM.

[coll]

Hi BILTD sorry but 15 inch is out of the question still trying to figure if a 12 inch can be utilised.
What is the best size of cabinet for a 12 inch SSD for home music use.

[BILTD]

I would go for around 1.5cf net with heavy fill. 100dB @ 20Hz is achievable with this alignment with your 500w plate amp.

[coll]

Hi BILTD have spent sometime looking at this, I can fit in a 12inch SSD with H-Qts but max size I can make sealed cabinet is 1.1 cu ft. I can of course fill it with BAF which will help a bit.
I am assuming H-Qts for driver is 0.44 and I have modelled it in Win ISD and its not bad and of course I have 6db boost at 25 hz. My crossover is 70 hz and so I am only 4db down at 25 hz. As I said I only use the sub for music at home and there is not much below 30 hz anyway.
Overall I think it will give me a better performance than the RE SR10 if you agree will place order soon

[BILTD]

Hi Coll,

Correct Qts is 0.44. f3 I get is 36Hz in 1.1cf with all walls lined. Not sure how you are getting it @ 25Hz. I use Bass Box pro for modelling.

[coll]

Hi BILTD

Using WinISD with 1 watt input I get about 85db at 70 hz my crossover point and 75 db at 25 hz.
My amp is set to give 6db boost at 25 hz so I will actually get 81 db at 25 hz when playing hence only 4 db down.
This is pretty much what I get now with the RE SR10 but I am looking for a cleaner sound.

[coll]

Hi BILTD
One other sub I have been looking at is AA Havoc 12 inch, how would this be for home use in a sealed cabinet of say 1.0 cu ft with my amplifier