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 for the reply. So lacking mid-bass is the nature of the IB setup or this particular driver? Or is thereanything 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.
So lacking mid-bass is the nature of the IB setup or this particular driver?
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
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.
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.
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.
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.