Flamingo-TBFC Bass Alignment

Flamingo-TBFC Bass Alignment
27 Liters Bass Reflex
TB W6-789E courtesy of Mark Nash

I struggled with this Tang Band W6-789E for many years. While the manufacturer’s specs look decent, my measurements with DATS proved otherwise. I had a Qts of 0.6 instead of 0.46 that’s listed in the datasheet. I am not a fan of high Qts. My favorite Qts is 0.32~0.35. I find the bass sounds about right at these figures.

After 3 attempts loading the 789E with a 13L BR, I decided to try something different. I used a larger 27L box this time round. This brought my System Q down to 0.78 from a high of 0.81. Another change I made is to tune the bass alignment for 48Hz. This reduced the peak in the bass. Below is the simulated bass of the Flamingo-TBFC. 

Fig 1 – Tang Band W6-789E bass reflex alignment in 27L box

As it turned out, this did the trick. Bass is much tighter. Though the attack is not as fast as a Qts of 0.32, it is still very acceptable when I auditioned the Flamingo-TBFC.

Fig 2 – Flamingo-TBFC Frq Response

Fig 2 is the frequency response of the W6-789E in a 27L box tuned in Fig 1. Bass is generally at 85dB. When it hits 50Hz, it is about 5dB less. This is eerily predicted in the simulation in Fig 1.

Sound of Flamingo-TBFC

The Flamingo-TBFC is a very likeable speaker. The tonal balance is close to perfect. The midrange and treble are excellent. No screeching voices, no excessive sibilance, no harshness in the highs.

The bass is as tight as can be for a Qts of 0.6. This is what was haunting me all this while. With this 27L box tuned for a low peak, it solved the flabby bass of woofers with high Qts.

Now that I’ve found a way to work with high Qts woofers, I am compelled to re-visit some of my previous designs. Amongst others, I have four units of HiVi M8a that need the same treatment. It would be nice if manufacturers are more diligent in their quality control. There’s nothing more depressing than woofers are out of specs.

Update: Mar 21, 2023

Placement of Flamingo-TBFC

It is generally accepted that a loudspeaker should be away from boundaries, walls, floor etc, for clearest bass. What happens if I place the Flamingo-TBFC on the floor?

Well, the bass became much louder. The problem is the bass became “fat”. It has lost it’s clarity. 

When I raised the Flamingo-TBFC 12″, the bass sounds just right. Bass clarity is restored. This is what JBL did with their L100 Studio Monitor

With the Flamingo-TBFC raised, the tweeter is 31″ from the floor. It is still not high enough to be at ear level of the listener. When I construct a proper box, I will tilt the front panel so that the tweeter is aiming at the face when one is seated. This again is exactly what JBL did.

Another work around with floor placement is to relocate the front port which is near the floor to the back panel and position it behind the tweeter. If that works, there’s no need to raise the Flamingo-TBFC.

Spring is coming. Hopefully, I can build some speakers. At my age, nearing 70, lifting 25 lbs is a challenge.

Unless otherwise stated, all measurements were made in Full Space (4 pi) with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied.