Improved Bass Through Multi Subs

[tesseract]

I'll post this here for reference, and for members to read and discuss if they wish.


My personal goal is to utilize two CS-18.T Duo systems in the Romeyn scenario. I've discussed the view in other threads that room treatments and EQ are not as effective as randomly placed multi subs.

http://jamesromeyn.com/home-audio-gear/dsa-1-0-distributed-subwoofer-array-5-pieces-4k-usd/

A summary of the approach similar to the one above, with graphs. Only three subs are used, individual EQ is optional, but the method and end result are basically the same.

http://mehlau.net/audio/multisub_geddes/

The mathematical simulations of Welti/Devantier. The first method assumes a sealed room of given proportions which is unlikely to be your room or mine. All methods described here encourage the use of global EQ.

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/multsubs.pdf

http://blog.acousticfrontiers.com/storage/low-frequency_optimization_using_multiple_subwoofers.pdf

While not bass specific, here is an interesting article that may help those using room equalization to utilize it for best effect.

http://blog.acousticfrontiers.com/whats-new/2010/7/1/room-correction-a-primer.html

[tesseract]

The method I am using now is the "flanking sub" approach. I have stand mounted monitors that exhibit floor bounce notch, as most do, and found this and use of the Dayton phase (delay) control an effective way to deal with it.

"Multisubs obviously don't help the midrange above 200Hz or so. That's where the improved midwoofers in the mains help you. But they can be used to help the lower midrange between 100Hz and 200Hz, if needed. When you put matched-directivity two-way speakers on stands to get them up to ear level, the vertical height creates a floor reflection that introduces a self-interference notch around ~150Hz. So if you put your two-ways on stands, I recommend placing a sub on the ground beside and slightly behind each one. Low-pass the sub around 90Hz to 120Hz so there is still some output in the lower midrange, blending with the mains. These flanking subs will smooth the floor bounce notch as well as other room modes." - Wayne Parham

[tesseract]

Subwoofer alignment with full range speakers.

http://www.excelsior-audio.com/Publications/Subwoofer_Alignment.pdf

[tesseract]

Boundary Cancellation and Room Modes Chart

Help eliminate room response nulls.

Boundary Cancellation and Room Modes Chart:

http://www.padrick.net/LiveSound/CancellationMode.htm

Harman calculator using Excel:

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Pages/Calculators.aspx

[tesseract]

An important discussion describing the positive effects of flanking and multiple subs. I flank my mains with the duals I have now, have measured the results and the improvement made in the midbass is significant.

http://www.diyaudio.com/forums/subwoofers/202641-setting-up-multiple-subwoofers.html

[ejames78]

Nice info as expected from tesseract

What would you recommend for a 15 x 18 apartment room for optimal bass. Thanks.

[tesseract]

What would you recommend for a 15 x 18 apartment room for optimal bass. Thanks.

Hey, ejames78. Welcome to the Chane discussion board.

Does your receiver have a bass management system with subwoofer out, allowing you to make crossover, level and distance settings, or is this for a 2 channel system? I'll recommend a few of various price, one or so that will be able to work either way. As this is a multiple subwoofer thread, for optimal bass I'd recommend at least two subs used in one of the manners described above.


The NXG Technology NX-BAS-500 looks to be one of the better budget subs. Jim Wilson's review can be found here.

The Klipsch Sub-12HG isn't on sale right now, but may come up on sites like Newegg at a discount..

The Rythmik LV12R would be the top choice in this price range, review here.


Those first two are the bare minimum and might leave you wanting more, but they can get you by. The Rythmik is in the price range ($500) where things start to get really good. If you need more subwoofer than that, let us know, we'll hook you up.

[ejames78]

Thanks for the good advice......as usual ;).

[ejames78]

So if I'm understanding correctly, you would still prefer 2 subs even in a small room such as the one previously mentioned? :salute: Just trying to make sure I understand correctly.

[tesseract]

When buying subs, I almost always recommend multiples, it smooths room modes for more accurate bass response throughout the room. This is beneficial for multiple listeners or for moving around the room. It matters less with one static listening position, EQ can help compensate. But EQ is only good for THAT spot, other areas will suffer.

Buy one sub now, with an eye toward getting a second identical sub later. This means that some bargain closeouts are not the best course of action, as acquiring a second identical sub at a later date becomes difficult.

[tesseract]

Also, one of the Rythmiks will be better than two of the others i mentioned, as far as quality in one listening position goes. Get the best sub you can afford, save up for a second one, if you foresee the need.