The Secret to Great Bass in Your Space (1 Viewer)

I have had subwoofers for years, but have never been completely satisfied with their sound. I read a post by Brian Ding, founder of Rythmik and a PhD in electrical engineering some time ago that said the most impactful bass is not in the lowest registers, but in the 60-70 HZ zone. I decided to put this to the test. I bought 2 Rythmik FBM 8's, dual 8" paper woofers (for speed, response, nuance). I placed them in front of my mains ( Ascend Sierra 2's,) and still wasn't satisfied. I contacted Dave Fabrikant, owner of Ascend, who recommended I do the sub crawl to better locate them. And VOILA! Awesome bass! Finally!! for those who may be interested, I will describe how I set this up:
1. I have 2 Rythmik 15's (in my case, lt front and rt rear corner worked the best, and they are crossed over at 50hz.
2. The 2 MB 8's are on the front right and left sidewalls (where they got the best extension and volume). The 8's are crossed over with the high pass filter at 50hz, so they are reproducing from 80hz (where all the fronts are crossed) to down to 50hz, the perfect range for them and where they excel. All subs use the line in input.
3. I spent time phase aligning all the subs, using an SPL meter and a SoundDr test CD AT 50 HZ, adjusting phase (distance) switch until I found the maximum output at the 50 HZ range. What this did was made all the bass sound like it was coming from the front. It's as though I have one massive driver in the center front of the room, awesome!!
I have never been completely satisfied with my system until now. If you really want to experience what real, visceral, vibrate-in-your-chest-bass, this is how to do it! Rythmik FMB 8's, highly recommended!!

Sub Crawl was "introduced" by Miller & Kreisel when they invented David and Goliath...

Decades ago.

You could have accomplished the same boost in the 60-70hz range with a parametric EQ between your receiver and subs.

Robert_J said:

You could have accomplished the same boost in the 60-70hz range with a parametric EQ between your receiver and subs.

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True, but my 15" can now be dedicated to the lowest registers and the FMB 8's can now handle the mid bass from an optimal position. I have tried the boost you describe in the past, but it didn't give me he results I'm experiencing now.

Do you have any pre and post FMB frequency response graphs?

Robert_J said:

Do you have any pre and post FMB frequency response graphs?

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I do not, I'm positive they would show a significant improvement, my ears are pretty reliable barometers.

Improvement in what way?


I was able to get my in-room response to + or - 3db from 120hz to 17hz using 6 or 7 filters in a Behringer Feedback Destroyer. It is level matched to the rest of the system when only one of the two 15's is playing. When I want to show off with an action movie, I'll turn on the 2nd 15. Since they are co-located, that gives me about a 6db increase.


And don't take my questions the wrong way. I'm just trying to make sure that all the visitors to this thread know there is more than one way to get to almost perfect bass. And that what may be perfect for you may not be perfect for me.

Not sure I'm seeing the "secret" since sub crawl is something I read about repeatedly while doing a learning expedition on all things sub. O_o

ChromeJob said:

Not sure I'm seeing the "secret" since sub crawl is something I read about repeatedly while doing a learning expedition on all things sub. O_o

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Thanks for reading, but I did not intend to suggest that the sub crawl is any type of secret. just one of the steps I took to arrive at a good place ( using miniDSP is likely a better way to do this). The main ingredient for me was the addition and proper setup of the mid bass speakers. I was excited at the huge improvement in my system and wanted to share it with those who might be interested.