|
|
Post by tamiya on Dec 7, 2018 18:36:26 GMT -7
Hi, I'm just finish installed my IB sub setup. Room is 10x16(front baffle wall to rear wall)x8ft ceiling, sub drivers mount on the baffle wall in the front. The drivers are four Fi audio IB318v2, power by NX3000D bridge mode. Problem is the frequency response roll off about 13db from 35 to 80Hz. EQ them back up is no problem, I got pretty flat FR from 12-80Hz after EQ but I don't get the chest punch I want. Is this the natural response of the IB318 driver or I did something wrong? Thank you.   |
|
|
|
Post by ThomasW on Dec 7, 2018 21:15:03 GMT -7
You have it really flat down low but chest compression is higher in frequency. Generally speaking from 60Hz to 120Hz. So use your EQ and raise the output in those higher frequencies
|
|
|
|
Post by tamiya on Dec 8, 2018 6:56:47 GMT -7
Thank you for the reply. So lacking mid-bass is the nature of the IB setup or this particular driver? Or is there anything I can do to improve? I prefer less the EQ the better because raising the output level as you suggest via EQ helps a little but didn't get the punch I want. How about AE IB18HT? Are they design the driver to be a flat response? Here is additional info about my setup. My VAS is about 5x, I wire the driver as follows, there is some air leak through the front¢er cutout but it's minimum.  |
|
|
|
Post by ThomasW on Dec 8, 2018 8:30:25 GMT -7
Neither it's a function of higher output of certain frequencies, specifically 60Hz to 120Hz. And that's only a part of the IB subs passband
Most subs are tuned to or have boost in that frequency range because a lot people mistakenly believe that's bass. It's not of course it's mid-bass. It's output from both the sub and your main speakers that creates chest compression.
So if you want chest compression you need to boost the frequencies that create it.
The other thing to consider is are you sitting in a null? Let's see a measurement of the frequencies up to 120Hz
|
|
|
|
Post by tamiya on Dec 8, 2018 11:38:22 GMT -7
Well, all I need is a flat response curve. At least in my case, the response doesn't look flat.
The driver begins to lose the energy above 35Hz.
Don't get me wrong, I got plenty of tactile feeling from the bass, shaking the sofa without breaking a sweat(my wattage meter showing only 800w at 116db during intensive scene like Interstaller black hole/rocket launch) but the roll off from 35Hz is bothering me.
My REW graph is all the way up to 200Hz, I couldn't find any nulls.
I did some heavy bass absorption treatment too, as you can see my native response before EQ is spike or valley free.
I wish Fi audio IB3 is in the data-bass.com so I can have an idea of the native response of the drive.
I emailed Fi audio regarding the response curve they never reply.
|
|
|
|
Post by ThomasW on Dec 8, 2018 16:33:17 GMT -7
I've never seen a driver with 'flat response'. If one were designed that way (flat anechoic) it certainly wouldn't be flat when put in a room.
Fi drivers have a high Le and as a result will display a hump in the middle of the frequency response as is shown in your plot.
The idea with the Fi drivers is to have more that enough power handling so that the FR can be EQ'ed to taste without straining the drivers.
|
|
|
|
Post by tamiya on Dec 8, 2018 22:19:53 GMT -7
I understand the room mode is the factor but knowing native response of a driver is important too.
At least I know what to expect and what caused by the room mode and what is not.
According to you, Fi audio driver is not designed for a flat response from the get-go.
So it's not something I did wrong, it's the design spec. It's a relief for me.
|
|
|
|
Post by ThomasW on Dec 10, 2018 7:54:35 GMT -7
OK now I understand your concern.
Nope nothing wrong with your driver that's the curve it's supposed to have. Looks just like you'd run a closed box sim in WinISD
|
|
|
|
Post by moonfly on Dec 10, 2018 10:06:58 GMT -7
Have you tried it with only the bottom subs in?
|
|
|
|
Post by tamiya on Dec 11, 2018 9:47:13 GMT -7
It's all behind AT screen, it's gonna be a pain to take it down and get inside the baffle wall to do the rewiring since my room is fairly small.
What are you trying to achieve by only connecting bottom 2 sub drivers?
|
|
|
|
Post by tamiya on Dec 29, 2018 13:30:32 GMT -7
OK now I understand your concern. Nope nothing wrong with your driver that's the curve it's supposed to have. Looks just like you'd run a closed box sim in WinISD Hi, I'm happy to report back that I got the chest punch I want after retweeting the FR curve. I watched The Hurricane Heist today it's punching my chest through the whole movie, my wife couldn't take it and asked me to turn down the volume from 0 to -10, LOL I think I didn't get it the first time cause I didn't use the right content source and I set my LFE too low at 120Hz, now is 150Hz. This is what I'm at right now and I'm very happy with the bass performance     I disabled the Audyssey subwoofer EQ and I was able to make the flat FR from 80 all the way to 130Hz using manual EQ with NX3000D. ![]() My 11Hz THD is 7% at 105db, and due to the EQ my 80Hz is 4.6% at 110db which is a little higher than I expected but totally ok I guess. I don't think I can hear the difference between a few percentages of THD. Highly recommend IB sub to anyone wants to try it. |
|
jonfo
New Member
Posts: 34 
|
Post by jonfo on Mar 2, 2019 10:17:04 GMT -7
|
|
|
|
Post by jagman96 on Mar 4, 2020 9:28:21 GMT -7
Just to add to the this, your in-room sub response is a natural house curve. If you run your subs hotter than the rest of your gear and have them cross over such that the output of both your mains and your subs are equal in the 80 hz range, and set your LFE to cross over higher like you have, you'll have killer bass without hardly any EQ.
|
|
