Acoustic Elegance AV12-X D2!

[loud-n-low 10+ year member]

which is better on the lowest notes?

 

[Xprime4 10+ year member]

I wonder if that ht sub could survive our cold canadian winter xtrem temperature. if so, it really got me interested

 

[bass_lover1 10+ year member]

A driver like that really shines on the upper end, try a 100hz crossover and see if you like it.

 

[microhaxo 10+ year member]

It wont shine at 100 with my box, its 2.75 cuft at 30hz.. Its crossed at 80hz right now and it sounds rather nice //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

John lives in WI and i live in MN, it gets -8f in the winter and with the windchill -30f i think they will hold up but i dont play subs in the winter any more, they are basically frozen blocks..

Also the sub hits the lows really WELL, but at the same time it hits higher frequencies that my previous subs have put aside.

 

[bass_lover1 10+ year member]

Why wouldn't it? Just because the extra output down low masks the relatively normal behavior of it in the upper end?

That far above tuning your box has similar characteristics to a sealed enclosure. It's worth a shot for such a simple test. My DIYMA sounds best running 100hz @12b down to 25hz@ 12db.

 

[microhaxo 10+ year member]

Ill give it a try tomorrow and see how she sounds //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Xprime4 10+ year member]

Quebec winter temperature goes down to -30 CELCIUS in january/feb and got up to 30 Celcius in summer. The sub would see a lot of temperature variance. would the surround eventually break from that.

I'm usually warming it a little in winter before getting it going. Never had any problem with car audio subs

 

[kendogg 10+ year member]

A driver like that really shines on the upper end, try a 100hz crossover and see if you like it.

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You sure about that?? I turned the xover up on mine as far as it would go and it made no difference. Mine had little to no output in the upper frequency range. Compared to another driver in the same vehicle, my little Orion XTR 12 off 1/3 the power has more output above 50 Hz.

 

[G.W.Kush]

65 n down 65+ should be midbass //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[John_E_Janowitz 10+ year member]

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You sure about that?? I turned the xover up on mine as far as it would go and it made no difference. Mine had little to no output in the upper frequency range. Compared to another driver in the same vehicle, my little Orion XTR 12 off 1/3 the power has more output above 50 Hz.

I think we have covered this MANY times now but you clearly still do not understand. If you didn't have any upper bass it is from not setting it up properly. I spent literally HOURS trying to explain this to you in the past, but if you continually ignore everything I say there is nothing I can do to help you.

A big dip in response at the top end of the bass is due to positioning and/or cancellation between the sub and front stage playing the same frequency range. When two drivers are playing the same frequency range but are out of phase, they will cancel each other over a certain narrow band. The way to correct this is to have proper time alignment between the drivers. Also positioning the sub appropriately so it is in phase with the front stage at the upper bass region or adjusting the phase knob if you have one will correct the issue.

Keep in mind that phase will be different from woofer to woofer. Phase is directly derived from the frequency response which is affected by the driver's impedance curve. Quite simply if drivers do not have the same inductance, they will react differently. You may get lucky and throw a driver in where everything works just great and as a shot in the dark everything just happens to line up perfectly where you put the box with no adjustment. This doesn't happen too often though. If you stick a different woofer with drastically higher or lower inductance in that same position the phase will not be the same and it will be out of alignment. There are reasons there are 0-180degree phase adjustments on many subwoofer amps. This is the most simple adjustment to get the drivers in phase and remove this cancellation. You don't have to worry about moving the position of the enclosure or having processing with time alignment, although time alignment is the ideal way to go.

The AV woofers extremely flat impedance and response up to over 1KHz, so there are absolutely no issues with playing to 100Hz. This is well documented in many places. We pulled 129.3dB on the TermLab at 72hz where there is virtually no cabin gain in BumpinBuick's 4Runner. The majority of all front stage components out there will never come anywhere near this kind of level to keep up. Below are response and impedance curves from the AV12X. You can clearly see how high they play and how flat the impedance curve is.

As a measured example of how placement affects phase and then response, here are the measurments from Bose301's Magv4 in his blazer. The light blue curve was the original placement. There is a huge peak at just under 50hz followed by a large dip at about 88hz. The difference in magnitude between these two points is 45dB! This will make it sound like the woofer is not even playing at all as many people experience. The dark blue curve is the flattest placement. This is simply changing the same woofer in the same box to firing upwards. A lot of the bump below 70hz was decreased and the bump at 88hz came up significantly.

There is still a large amount of extra low end, but the apparent difference is now only 18dB vs 45dB. All that was done was to change the position of the box in the vehicle.

If an amplifier has a 0-180 phase adjustment knob you can play test tones to hear if you are getting any of this cancellation or null. If you hear a point where there is a big null, you can then turn the phase adjustment until you get to the point where the level comes back up in this region. In some cases you won't get perfectly in alignment anywhere in this 0-180degree range. You can then flip the polarity on your woofer. This would then allow you to be going from 180-360degrees. A simple 0/180 switch only gives you 2 options. One way may be better than the other.

John

 

[bass_lover1 10+ year member]

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You sure about that?? I turned the xover up on mine as far as it would go and it made no difference. Mine had little to no output in the upper frequency range. Compared to another driver in the same vehicle, my little Orion XTR 12 off 1/3 the power has more output above 50 Hz.

Could be wrong, but with an inductance that low (it rivals some 6" drivers) it should be able to play cleanly way above that. If you don't like it, then you don't like it no biggy.

 

[kendogg 10+ year member]

John, you have yet to come up with any explaination of why such a 'lesser' driver with 1/3 the power can do what yours wasn't doing. In the same position, in the same vehicle.

:edit:

As usual, I skimmed past most of your post, because reading the same thing and seeing the same graphs over and over again with no other explaination gets boring. My woofer is ancient, I have no idea what the impedance curve of it looks like. If I can ever get an enclosure built for the 11Ov2's, we'll see if they exhibit the same problem as your driver did. FWIW, yours, and the DIYMA12, are the only drivers I've ever owned that experienced this phenominon.

 

[bass_lover1 10+ year member]

Dang, John beat me to it //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[John_E_Janowitz 10+ year member]

Quebec winter temperature goes down to -30 CELCIUS in january/feb and got up to 30 Celcius in summer. The sub would see a lot of temperature variance. would the surround eventually break from that.
I'm usually warming it a little in winter before getting it going. Never had any problem with car audio subs

We can occasionally get that cold here in Wisconsin also, although not too often. I remember one year when I was at Michigan Tech up in Houghton when Lake Superior completely froze over. We'd have temps in that range for several days at a time.

The colder the temperature, the better most electronics work. Heat is the big thing that affects amps. Likewise in a woofer, heat raises the resistance of the VC wire so the warmer it is, the less power you can deliver. The colder the better as far as getting power to the woofer. The only thing typically to worry about in a woofer is that the surround will stiffen up in the cold. We specifically picked santoprene for the surround. It has the lowest brittle point of any rubbers out there. It was designed for use in gromets and rubber boots in vehicles that would be subjected to these kind of extreme temperatures. It's brittle point is -65F or about -54 Celsius. It should have no issues with cracking or breaking, although these extreme temperatures will raise the Q of the driver significantly. It should work with no issues, but in any very cold weather situation I would play any woofer at moderate levels until the inside of the cabin warms up.

As far as the top end of the heat spectrum, santoprene is good to nearly 280F before it begins to drastically soften. It is thermoformed at about 320F. In any woofer the thermal power handling will go down in extreme heat situations. Amps will heat up easier and clip easier as well. Anytime the ambient temperature of the vehicle is higher, a woofer or amp can't dissipate heat as easily as if it were colder.

John

 

[NDMstang65 10+ year member]

Could be wrong, but with an inductance that low (it rivals some 6" drivers) it should be able to play cleanly way above that. If you don't like it, then you don't like it no biggy.

What about cone breakup and nodes of the cone deflecting at resonance //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif..inductance is cool and all...

Just because a Mercury 2.5 EFI drag boat engine will turn 14,000rpm during a 1/4 mile pass doesn't mean it should do that all the time right?