Bass Reflex Modified (Tannoy Reveal Active)
The first time setting up my studio, i became crazy to fine tuning the speakers position, every distance from every walls was taken, just to find the best tune (off course small rooms are hard enough).
After 12 days spent moving everything in the room i found the correct position (ok, ok, the best one!).
Now was the time to connect everything and play music!! Mmmmmmm, good enough but not the best; so i played every kind of music from classical to jazz and off coarse trance for the most time. Something was wrong but not usual room node; tipical mechanics distortion.
The massive air flow in the bass reflex system, sometimes produce internal turbolence that generate small vortex inside the reflex tube. NOISE and DISTORTION!
Frequency analysis
The searching start with a basic setup: Frequency Generator or sweep tone (download 1,9 Mb) and silence:
- Play the 290-300 Hz.mp3 file at -20db
- Adjust the level before speakers distortion
- Start to play the lowest frequencies file (10-19 Hz.mp3) and listen the sound
- Repeat with every file and pay attention at some sound like FRRRRRRR
If you don’t hear the FRRRRRRR sound, ok your speakers are pretty good, or maybe you played a sweep tones at level too low.
For people who found the problem; ok we've found the noise and are ready to remove it!
Tools and material
Complete list:
1 rule
1 scissors
1 adhesive tape and
100 strows (FLUO are the best).
You've to choose then thinest strows possible, it's very important for best result; every strow reduce more or less the tube size, altering the FB of bass reflex system.
Measure the tube length
Ok now that you have the tube lenght it's time to take something to drink (the work now became long), like chai or green tea.
Coffee you say? It's a not good idea, you've to cut a lot of strows now, very accurate!!
Cut all the strows at the same tube lenght.
Fix the strows
Take 50 strows in your hand and put all into the bass reflex tube; check to fill all the tube without strow crush
Take your strow and fix them with scotch; one on top, one on bottom and one in the middle.
Apply the custom reflex tube
Now we're ready!
Put your rolled strows into the bass reflex tube, be sure to fix that.
Before made the second one: re-play the same sweep tone and listen the result; switch to the modified reflex and the original one many times.
Ok now it's time for a good black coffee!!
Check your custom reflex many time, sound feels good? Controlled bass? more precision and less distortion?
If so, good listen and good music!
Good for children
Many cutted strows, what i must make with theese strows?
If you have children, you know the answer! If not, ask at someone with children; they'll are happy to take your cutted strows
09/07/2006
