I'm so fed up with the whole Acoustic Elegance experience I'm just going to sell them if/when they get here. I want to finish my system this month and the only response is I will get them one day. They can go to hell as far as I'm concerned.

So onto another semi-affordable IB capable 15" sub. I've read good things about the Flatlynes after reading about them for a few hours. The big problem is I can't find a complete list of specs anywhere. Diymobileaudio is down more than it's up and of course it's been down most of the day today so I can't search over there. I can find most of the specs for the 12" but not the 15". 12" has an xmax of 18mm. 15 is unknown but some are estimating it to be around 25mm. Looking at the surround (I know you can't judge just based on the surround) I suspect it has a lot more left in it to xsus. I mostly want to know so I can decide if one will be enough or if I need to get two. I'm not sure why these specs seem to be so top secret.

Most of the time I doubt I would use 20% of what it has to offer but I want it to be able to go loud once in a while.

 

Nearly every review of an IB sub that I have read says that it is the best thing since sliced bread. I don't know anything about the Flatlyne, but it is probably the same. Such good reviews scares - either they are all good subs (and you cannot go wrong with any), or the people reviewing them are easy to please and/or work for the companies in which case the review is worthless.

Personally, I would not get anything where I could not get specs or other "top secret" stuff with ease. One day, it is specs, the next day you have to wait 9 months for your subs. Sound familiar? If no win:win up front, then it never will be.

I would go with a brand/company that has a good rep and hope that they are as good with IB as they were with their other stuff... since a review would probably be near stellar anyway.

 

Can't you call the company up and just ask the tech guys?

 

BTW - I am not saying that IA is a bad company or anything, just no specs, then no buy for me. If you are not 100%, then move on.

 

I finally got to the bottom of it. Found a huge flamewar with the owner and a bunch of the diy guys. Buried in that thread were the specs of the 15". I just wanted xmax which is 18mm to see if I should use one or two. Xsus is 26mm+ from what he said. I can understand those guys wanted specs but I don't agree with the majority of them that think specs are more important than listening to the sub. Once those guys or I should say once one of them decides to flame a manufacturer, they all jump in and there's just no hope. Pretty sad, I felt bad for the owner.

 

IA makes some good stuff but them hiding specs is a deal breaker for many..including me.

Have you considered the IDQ ?

 

I could understand the frustration, I was getting pretty frustrated until I found them after a couple hours of searching.

However, there's an entire group of people that think you can find out everything you need to know about a speaker by the specs alone. While you can get an idea of how it will perform, some get so carried away that it seems like they put more emphasis on the specs than how it actually sounds to your ears. Hopefully there's a happy medium.

I got the specs on the 15 and while I was hoping for a little more xmax so I could run only one, I think I'm going to try it. My thought is that with an xsus around 26mm, would I even hear a little extra distortion once it goes past the 18mm xsus at that sound level?

It doesn't have to be perfect, but I really want to try it based solely on the reviews of people that have run it. I've seen a lot of trash talk from people that have never run one but I've never seen anything less than a glowing review from the people that have run them especially in IB form. Worst case scenario I don't like and and install the AE IB15s if/when they get here.

I guess most of this is aimed at the Diymobileaudio crowd. I really liked that place at first but as I read more and more posts I realized that there's a whole bunch of people that seem to know just enough about this stuff to make very annoying arguments but not understand the big picture. I'm one of the former but I realize I don't know that much unlike many over there. I'll stick with the bikinpunks and nieburs over there for my info.

For what it's worth, here's the specs on the 15" Flatlyne since it's not on their site.
Fs: 25.9 Hz
Re: 3 Ohms series
Qms: 4.38
Qes: .60
Qts: .53
Mms: 269g
Cms: 0.14mm/N
Sd: 810cm^2
Vas: 104.9
Spl: 86.7dB 1W/1m
Bl: 14.6 N/A
Xmax: 18mm

 

IA is made in Rogersville, AL. A pair of the 12's were just installed in a car going down the big SBN show in Daytona, FL this weekend. AudioX did the install on this car and IA's booth car.(Same place that works on my car) If the 15's I have do not work well I will be approaching them. Owner is a cool guy to hang out with after a show. Search Steve Cook on facebook. Pics of all the cars and mine are there. Good thing is if IA starts slacking you can let me know. I can take care of it. Or atleast try.

Kirk

 

IA's Booth car for tthe Daytona show this weekend.

http://www.facebook.com/#!/photo.php...135263&theater

IA 12" IB

http://www.facebook.com/#!/photo.php...135263&theater

My tweets

http://www.facebook.com/#!/photo.php...135263&theater

My mids

http://www.facebook.com/#!/photo.php...135263&theater

Tweets are with an under $5 mount.

 

PS Yes that is a CL with the 12".

 

Looks like that's 6hrs north of Mobile. Too bad, if it were a little less I would make the drive to check out their shop when I'm down there.

Just to clarify, which 15s are you looking to use and are you going IB?

 

Did you look at these?

Finalized the coils and specs for the 18 IB model.
Re 1.5 Ohms (single 2 Ohm)
Le .87mH
Fs 22.9 hz
Qms 3.25
Qes .79
Qts .63
Vas 381 l
Mms 258 g
Sd 1210 cm^2
Spl 89.4 1W/1m

 

30mm of max on an 18.... wow. One should do lol. The way John at AE explained it is you don't want a QTS too high ib since a car is not a true IB and the Q will go higher once instated and depending on trunk volume and number of drivers. I'll link to it once I get to a computer. I think using two of the AE 15 subs in the Tl's 15 cubic foot trunk gives a Q around .63 or something like that. I know that was the main change he made..... lowering the QTS when he modified the IB15 for car use. This stuff hurts my head....

What brand is that 18? I would actually prefer a single 18 assuming it will play nicely up to 70 Hz.

 

My bad. FI 18 IB.

 

The rest it true. It ends up being a mostly sealed sub in a box that is like 20 (or whatever) cubic feet. This is likely why your W6 had no output when you opened the trunk... it was outputting as a sealed sub, but not as true IB.

Just wait, once you get this figured out and are happy, you will likely get the urge to tinker again and want figure out a way to vent your trunk for true IB for even better SQ in the cabin. Then, you will want the higher QTS sub.

 

That makes sense. So if the W6 was closer to. 707 maybe opening the trunk would not have killed all of the output???

I've thought about venting if it ever became necessary. It would be easy to run a solenoid to a vent so that everyone around me does not have to hear the bass at redlights but I can open it when alone or showing it. Maybe it would be a tuning nightmare to have it vented only part time too.

It was interesting to watch the flappers on the factory vents. With the trunk wide open and the sub at a moderate volume, they were opening with the bass. Kind of surprised me.

 

Not sure an 18 would fit the profile of the back seat causing the baffle to be tilted making the sealing difficult and no trunk space savings.

 

30 mm is nice

 

Could you guys help me out with something... I saw a post where a guy was thinking of "upgrading" his two AE IB15s to a pair of the Flatlyne 15s for more output. Both have about the same excursion, how can one get significantly louder than the other at very low frequencies when both are mechanically limited in that range?

 

Motor force and power handling i would assume.

 

Velocity and acceleration.

I just took a 18" paper plate and moved it 12 inches. No sound though. I didn't move it fast enough.

 

The part where I get lost is I thought it was as simple as dcone area and excursion. This is the part I might be wrong but if each sub is playing the same frequency, has the same cone area, and the same excursion, how can one be louder. Or put another way, if they're both playing a 20 hz test tone and moving 15mm, how can average acceleration be different between the two? I can understand motor strength in a ported enclosure but where I get lost is how it affects output in IB.

 

Sensitivity?

 

I have a great explanation for this in one of my engineering books from 15 years ago. I will see if I can find it when I get home. In a nutshell, the acceleration and deceleration is important - the more powerful motor can stop the assembly faster and get it moving faster in the other direction faster. More speed makes the sine wave travel faster even though it has the same frequency. I am sure that I jacked some of this up - it has been a long time.

The diaphragm efficiency can also make a big difference. Usually the higher the db at 1W/1M, the more efficient/louder the driver can be. Just looking at the 2 subs in this thread, the FI is at 89.4 and the flatlyne is at 86.7. The FI can make more sound with less effort becuase it is more efficient (if the specs are correct). Chances are that it will be a lot louder, even above the tested 1 watt.

This is all fine and dandy in academia, but it is totally possible that we get bullshitted on the specs... even more of a good reason to trust a company with a good rep. After all, they are in business to make money and it is not like we have never been lied to, or misled, before.

 

on paper, the fi should be 4x louder since it has more efficiency and more cone area

 

Specs from the stock version of the 15 I am using. These are slightly different but this will give you an idea. Much higher sensitivity, much lower LINEAR excursion. Stronger motor/lighter cone. Different topolgy.

Resonance frequency - fs: 18 HzEquivalent volume - Vas:600 literQms1,5 Qes0,26 Qts0,22 Nominal resistance - Zn8 OhmDC resistance - re:6 OhmEffective cone area - Sd:835 cm2Compliance – Cms:0,615 mm/NMechanical resistance – Rms:9,59 kg/sMoving mass – mms:127 gInductance 1 KHz – Le:0,98 mHForce factor – Bl:18,22 N/AWinding height – Hc:25 mmAir gap height – Hg:10 mmNominal power – Pn:400 WAcceleration factor:143 Efficiency – SPL:93 dBLinear excursion (x-max) 8.6 mmMax. excursion (P-P)46mm

I know in a four cube sealed box one makes my SUV flex pretty much uncontrolably with very little wattage. I could barely see the sub moving on the very lowest notes. Was going over 140db as my meter was reading 'over'. Not an SPL World Record by any means. But for a SQ sub I was impressed.

If IHC was closer I could tune his up and he could service the tranny in mine.

 

Here is what I read (summarizing):

First off, materials can be huge, but I won't go into that. Better magnets and conductors can make a huge difference, which I am sure that we all know.

What I referred to as acceleration and deceleration is what they call control - the ability for the device to make a nice sine wave in the desired frequency. As devices speed up, it takes more power to control the device or else the sine wave get too long (underpowered) as the device struggles to reverse it's movement - sounds terrible.

Moving air gets exponentially harder with more power. This includes air in the coil area, surround, basket, etc. as well as the air in front of the device. They call this overhead. This can slow the device down and elongate the sine wave - unless, overhead is overpowered. There are some sweet calculations that change with air pressure and humidity - oh college, nostalgia...

They called excursion "movement." How far the device can move is not an issue, rather how far the motor can drive the device is at point. The movement is only important if it can be controlled and make a good sine wave. They say that total movement can make good pressure, but mostly academic since nobody would want to listen to it. Effective movement still makes a good sine wave. More effective movement needs more power. A well designed speaker should have both total and effective movement near the same.

The product of effective movement and area minus overhead should equal effective pressure. Keep in mind that effective means a good sine wave is being generated. Also remember that overhead is exponential and not linear, so the more power, the more that is lost to moving air... so power needs power.

Back to the question at hand, here is what I think is happening if 2 drivers with the same excursion are producing different outputs.
0). Materials.
1). Efficiency - overhead is higher with one than the other.
2). Excursion is measured as total and not effective. One is not hitting the total excursion because it is not powerful enough to do so - distortion starts so it never gets played any louder, or it just won't go any more (we have all been there). The other one can reach full excursion because it is under control due to the increased power. I think that some might be physically measuring how far the cone can go and calling that excursion while others measure it with how far the motor will drive it under good playing conditions. Big potential difference in results.
3). Any/all three.

I hope that I made sense of what I read.

Your thinking was right, but your forgot overhead (which can be huge). I think that the issue at hand is that there are no CEA-2006 specs to measure speakers against. I need to see RMS and Total specs on these babies just like an amp. I guess that you could write/call the companies and see if the motor drove the xmax figure, or if they measured how far they moved it with their hands. Then ask them for the CFM of the air that is allowed in/out of the vent to see if there is any concern for more overhead.

 

You can also look into the Focal Polyglass 40v2. This is a 16" sub and works excellent free-air. They can be had pretty cheap, relatively speaking. I ran one for a while, and it is quite impressive. Two would be ridiculous.