The Subwoofer Battle :

                                                  

"”When you want more bass, you miss it; when you have it, it disturbs you.“ 

Franco Serblin, Founder Sonus Faber

                                                                SVS PB 2000 Pro

 I was a pure stereo guy, no subs needed, was my thought process

I have used Towers with 5.5 & 6" ( Yamaha, Q acoustics, B&W). 8" ( Klipsch RP 8000), 10" ( JBL E100)

I remember listening to antique  towers with their 15" woofers and being impressed with their bass

Was happy enough with them before I got exposed to subs

A grand piano, would not sound grand enough,Drums would not have that weighty kick etc

A dedicated amplifier for the power hungry bass frequencies, makes sense

The bottom octave is important & getting the subs right was important to me 

 

Having too many components, does not sit well with me

So I started of with a single sub, Yamaha 10" ( SW 700),  it was a ported down firing sub

Stuck it in a corner, did not sound right.

Tried a sub crawl, found the best position in the room, slightly better but not happy

The sub crawl is when you place the sub in your listening position, play back some bass heavy music and get down on your  hands and knees, crawl around the room and find where you get the best bass, now place the sub in that position and you should get the same bass in your listening position.

Next came a Velodyne ( CHT-12 QR) a 12" Front ported design, which was very good ,came with a remote & a few DSP modes.This gave me much more satisfactory results but was boomy in parts of the room.

                      Velodyne CHT 12 QR

I also tried a single 15" Klipsch sub-woofer in my stereo set up & found it overpowering the room & making the sound unbalanced

Sealed dual subs were highly recommended, widely on the webHence I picked up a pair of SVS SB 1000's found them under powered and my single ported velodyne was outperforming the pair, so I gave them up

Along the line, I started noticing that the boom & rattle from the sub were irritating me and spoiling my appreciation of music. On reading about it and discussing with friends, there was no consensus on this.

One school of thought was, subs bring in unwanted sounds & rattles, keep your stereo simple, go the no subs route

The other option was to measure the room.

I also needed to measure & DSP my home theater (HT) subs 

So I decided to bite the bullet & solve both sub issues in my home theater & stereo

This involved getting a calibrated mike, I went with a umik 1

Downloaded Room equalization wizard, mini dsp software and got a mini dsp 2x4 HD

There are some really good tutorials available on youtube, which helped me tremendously

After some trial & error, I managed to dsp my home theater dual 15 " Klipsch Subs

The subs became much more controlled & accurate in their response, a real revelation for me.

I had disposed of the dual SVS SB 1000 and picked up my first SVS SB 2000 Pro 

Paired it with my velodyne 12" sub.

I already knew the best position for the dual subs, so I put them there

The subwoofer crawl, is not useful for dual sub placement.

Objective measurement is the way to go for dual subs & above but positioning them correctly is very important. 

I had noticed this on measuring the room, for placing my dual 15" in the HT

You may have to try a combination of different positions, like diagonally opposite corners, front corners & front 1/3 of the wall facing each other. Another neat trick, I cam across is to slightly raise the subs to avoid room modes, I used a 12" table to raise my velodyne sub, it helped improve the response in the room

You have to start the measuring process by making sure that both subs are volume matched

I measured the stereo room and noticed that some frequencies were boosted due to room acoustics to 95 db, at nominal volume levels , where my target was around 81 db.

I played around with SVS DSP and brought down that range by 6 db and also tried the dsp modes on the Velodyne, to see which would give me the best response curve.

I had a few dips in the response curve, which I was able to correct with slight dsp correction on the SVS and the final response was an almost flat curve with the full stereo system playing back.

On my HT & stereo, an 80 Hz cut off gave me the best response

Please note that, I did not use a mini dsp in my stereo, just the velodyne & SVS dsp.

Getting dsp'ed calibrated bass changed my enjoyment of the stereo system, no more unnecessary boom or rattle, the lowest octave started to sound right.

I was so impressed with this , I decided to complete the package and got a matching second SVS sub.

The SVS Pro series subs have a blue tooth app, which makes doing settings from the listening position, very easy.

The calibration, which took me 6 hours on my earlier sub system , took me an hour on dual SVS Pro subs.

     Green is Subs without DSP, Blue is after partial DSP

 

Useful links:

- Room Equalisation Wizard 

-minidsp