[DSK]

i would rather have a pair of original subs than a single larger sub, unless future upgrade to two subs is planned - two subs is mandatory for best results, imo.  good results *can* be had w/only one sub, if it's directly centered between the monitors, but two is still better ...

Doug,
Perhaps you can help me understand this a bit better. If I understand correctly, it is the upper bass that provides the directionality cues and imaging. A sub that is -24db by 150hz can not be located by ear (probably not if placed away from main speakers and certainly not if placed between the main speakers).

So, when a single sub is used to add bottom end weight to floor standing main speakers (that are flat to say about 40 or 50hz), and is placed between the main speakers, and the sub has a 24db/octave LP filter that is set around 40 to 50hz, .... in what ways are 2 subs better than 1 (aside from more headroom in a big room where music is played at ear bleed levels)?

Many thanks for your advice.

[ooheadsoo]

Sometimes you can feel the pressure of the sound coming from the subwoofer.

[Rory B.]

As for the Lowboy styling, I used to think that the whole Larger sub design was just weird, but it has kind of grown on me. I didn't know that the 15" Megawoofers were not WCF.

Get two New Original Subwoofers and drive them each with a side of the QSC RMX850. Or, get the VMPS Passive Crossovers if you already have a really powerful amp and don't want to buy another one. I can personally attest to the performance gain from having a separate, more powerful amplifier for the low frequencies, though. Passive crossovers can have the effect of decoupling the speaker from the amplifier at low frequencies. With an active crossover before the sub's amp, the amplifier is more directly coupled to the woofer, without having to go through inductors and all that stuff. (I would expect that overall "musicality" is enhanced.)

[doug s.]

Doug,
Perhaps you can help me understand this a bit better. If I understand correctly, it is the upper bass that provides the directionality cues and imaging. A sub that is -24db by 150hz can not be located by ear (probably not if placed away from main speakers and certainly not if placed between the main speakers).

So, when a single sub is used to add bottom end weight to floor standing main speakers (that are flat to say about 40 or 50hz), and is placed between the main speakers, and the sub has a 24 ...

"...A sub that is -24db by 150hz can not be located by ear (probably not if placed away from main speakers and certainly not if placed between the main speakers). ..."

this is where yure wrong.  i have always been able to locate an off-center sub, even when crossed over as low as 50hz w/24db/octave slope.  having a single sub *exactly* between the monitors will not degrade the soundstage when crossed over low enuff, imo, but having a pair of subs adjacent to the monitors will actually *enhance* the soundstaging.  

also, i prefer two subs because it will usually load a room better, (different drivers from different locations), and it will provide reduced distortion at any given spl.  this is a main component of "musical" bass, imo...

doug s.

[DSK]

"...i have always been able to locate an off-center sub, even when crossed over as low as 50hz w/24db/octave slope.  having a single sub *exactly* between the monitors will not degrade the soundstage when crossed over low enuff, imo, but having a pair of subs adjacent to the monitors will actually *enhance* the sound ...

Doug, thanks for your response. I'm certainly not disputing anything you said (I don't have sufficient experience with subs in 2-channel systems to do so), I'm just thinking out loud...

I agree that low distortion is a key element of a 'musical' sub. However, ignoring VERY loud volume levels (that I don't often listen at anyway), this should not be a factor in a 'quality' sub .... and I don't mean 'big name' sub here, I mean true 'quality' sub.

I also have trouble accepting that bass down in the omnidirectional range will effect left/right imaging .... tonality, musical weight, image body... yes, but not left/right imaging. I realise that despite a 24db/octave LP filter the sub will play up into the directional range, but it is so far down (relative to the main floor standers) that it shouldn't effect left/right imaging.

Gotta run for now. Cheers!

[doug s.]

Doug, thanks for your response. I'm certainly not disputing anything you said (I don't have sufficient experience with subs in 2-channel systems to do so), I'm just thinking out loud...

hey, no problem!

I agree that low distortion is a key element of a 'musical' sub. However, ignoring VERY loud volume levels (that I don't often listen at anyway), this should not be a factor in a 'quality' sub .... and I don't mean 'big name' sub here, I mean true 'quality' sub.

since clean low bass is really difficult to produce, even extremely hi-quality subs' distortion levels are relatively high, compared to most other links in the audio chain.  my vmps' are rated at ~5%, at 120db, which is outstanding, imo.  reducing distortion w/subs *is* quite worthwhile, imo - 5% is still getting up there...

I also have trouble accepting that bass down in the omnidirectional range will effect left/right imaging .... tonality, musical weight, image body... yes, but not left/right imaging. I realise that despite a 24db/octave LP filter the sub will play up into the directional range, but it is so far down (relative to the main floor standers) that it shouldn't effect left/right imaging.

you yust have to hear recordings w/directional low bass, to be conwinced...  ;~)  

a friend of mine has a set-up w/a pair of subs & a marchand x-over.  he related this story to me:  after fiddling w/his system once, he couldn't figure out what had happened to his soundstaging.  nothing dramatic, but a slight reduction.  then he realised he'd accidentally turned on the marchand's "sum" switch, which converts the bass to mono.  even w/a pair of subs flanking his monitors, he noticed the difference in soundstaging between mono & stereo...

regards,

doug s.

[Dean]

Try and get an audition on some REL subs (or B&W as well), they are probably the highest regarded subs here in the UK.