Is two subs that much better than one?

After a couple of days pratting about with setup and placement I'm getting some promising results with a MJ Ref 1. Should I add another? Other than trying, which I will do when I get the chance, what is the general view: line level or speaker level connection. The Neutrik lead looks like crap - how cheaply can this be upgraded? I was thinking of a DNM mains lead type thing. Does anyone want to sell an MJ 1? PS I know Henry T just flogged a pair, oh well.

Alex

 

Alex,

I evaluated a Ref 1 for a few weeks and thought it was a super little sub. It integrated really well with my main speakers and I really like the variable phase adjustment. I used both high and low level, but couldnt really spot much of a difference between the two connections. I never tried anything other than the stovk leads though.

I have never used two subs, but everyone says that two are better than one, so I guess it would be worth a try sometime.

Cheers, Robbo

 

Speaker level connection...

...is best if you believe what they say, as you inherit the character from the power amps and the 'whole' should therefore be more integrated than if you used a line-level connection.

Two subs are generally better than one - I once had dual REL Stentor subs, one for L and one for R, and together (once setup properly) they helped eliminate low frequency nodes in my room - and of course you also benefit as the gain can be turned down a little which means for a given volume either sub is working a little less hard - but then, the subs were never, ever, anywhere close to their limits when I used them as big RELs are both powerful and use efficient drive units, which means that you back off the power before the structural damage occurs

jtc

 

Thanks both,

Low or high level is a conundrum - Rel make a big play of speaker level for the reasons jtc states. The theory is good. Nonetheless, before I gave it away a Paradigm PDR10, using speaker wire to the HX1.2, actually compromised the amp's performance just by being plugged in.

Martin Moorcroft, who sells Velodynes AFAIK, says line level is much better since the signal doesn't go through an extra level of amplification and makes the perhaps valid point that if low bass is non-directional etc you're hardly likely to spot whether its carrying the main amps signiature or not.

Alex

PS Robbo, I read your review and made my choice (on appro anyway) largely because of it. I know that bass timing and integration are important to you (well everyone I guess) . . .

 

The Neurtrik lead is perfectly adequate for the task of feeding a tiny low frequency signal to the sub. Don't think of it in the same terms as speaker cable. It's function is more akin to that of an interconnect. The voltage is higher but the current is tiny.

 

Two subs are generally better than one i.e. each works less hard so there is less distortion plus it can be helpful to have two sources of bass depending upon the room. Conversely, for the price of two subs you should be able to buy one superior one which might sound better then the two cheaper ones e.g. I think I'd take one Velodyne CHT15 over two CHT10's as one CHT15 will provide deeper bass (one 15†driver has more than double the surface area of two 10†drivers incidentally) but it would be an interesting comparison nonetheless.

As you already have one Ref 1 though then another could be a very good idea but you should definitely get one to try out first to see how a pair work in your room. Regarding placement, depending upon the room, it could be that there is only one optimum place for a sub which would mean stacking them (this practice is not uncommon) which may not be too popular if there are wives/girlfriends to consider.

As for the low vs high question I favour low for the reasons Moorcroft mentions and my (slightly cynical) opinion is that REL sing the praises of high level for music because they know many hifi fans probably only have the high level option available to them anyway (i.e. no pre-outs on the stereo amp). This thing about capturing the “flavour†of the hifi power amp I just don't buy – not down at the frequencies we are talking about i.e. >50Hz. For bass down here you want as clean a signal as possible – you don't want to be amplifying a signal that may well have picked up small distortions from the hifi amp.

That's my take on it anyway.

Matt.

 

Bah

Tiny little pseudo woofers aimed at LL-B's and other light weight yellow bellies

 

Merlin,

Apparently, French riot police have concluded that an angry mob subjected to 6HZ will spontaneously empty bowels and bladder - careful.

 

Hi Alex,

You might be better off getting some (anonymous) larger than mine full-range speakers, rather than trying to integrate subs. But I don't know.

Your room is plenty big enough for some big behemoths.

 

Ah! Forget the depth - feel the width

 

Hi Bub,

I'm sure you're right. Problem is no matter how much I haggle or crawl I'm unlikely to get something full range like MF9s for anything like my budget. Also, my speakers are worthless s/h which makes selling them distressing. RKR thinks that once the 10mm T&E is in I won't need subs at all but in the meantime, its the cheapest option by far (unless he's right of course).

I had big worries about integrating subs until I actually tried it - it can be done, here at least, where I can plonk it/them just about anywhere.

Alex

 

The best connection is low level with external active xover, if you have a stereo setup without it, stick to high-level, and save some money in cables, splitters, etc... The standard cable that comes with RELs is good enough...

I have two subs, it is very simple to test, just switch one off and bass will imediatelly sound more like coming from a point source, rather than filling the room, also more ressonances, as two will cancel odd room nodes... :MILD:

 

Budget

Not even s/h? I was thinking, as if you didn't guess, about active ATC 150s or even 200s. They would be a riot. They go for about half-price or even slightly less s/h. See if you like my little 'uns.

You could always keep the pods as ornaments.

 

Depends what you're after, but IMO, two is better than one for a more seemless integration. Despite what some of the theorists say, I've almost always been able to hear where a sub is and believe that we can locate the location of *musical* low frequencies down to quite a low number of Hz - much lower than 50 I'd say - but certainly no lower than 30 at a guess.

Unless a sub and its main speakers are purpose designed to work with each other as a combo from the first off, you'll going to have some fun integrating them. Having high order crossover slopes helps a great deal if trying to match non purpose made bed fellows.

Try both high and low level connections if you can (I'm a believer in having a signal where colourations/distortions are common to both main and sub ), but the supplied cables are usually very shoddy and even a DIY effort made out of say braided mains cable should be worth a go as a cheap experiment - not that I'd conclusively advocating cable differences of course .

 

Henry – regarding localisation of bass – I did a bit of investigation into this a while ago and was surprised by the results. These figures are off the top of my head but are in the right ball park.

Something in the region of 40-50% of people cannot locate bass below 150Hz! This astonished me but it was based on reasonable research. Very few people can locate bass below 80Hz – we're talking the odd few here – you could be one of them though! When you get lower i.e. 50-60Hz then forget it. THX use an 80Hz crossover for a good reason.

It's worth remembering though that subs can produce a fair amount of harmonic distortion, especially at the lower frequencies and this distortion (which is at a higher frequency of course) can give the location of the sub away.

I also wonder if the visual side of things plays a big part too i.e. we can see the sub and hear the deep bass i.e. we know where it's coming from so it's hard then to be objective about directionality. I honestly think that , back when I had the HGS Velodyne, if you'd walked into my room blindfolded, sat down and listened to some music there's no way you would have been able to locate the sub (and that was with an 80Hz crossover).

Matt.

 

The xover is "only" 24db per octave, so there is much info, plus the said harmonic distortion above 80db, or whatever...

Still, my main problem is that I find reasonable speakers, not small satelites of course, do play better the frequencies between 50 and 80 than subs, in every system I tested, somehow it integrates better with 60 or 50, rather then 80hz...

With one sub, the bass appears to come from only one point, with two, it spreads and fills the room better, IMHO...

 

I guess the direction spotters aren't going to like 'em stacked. If I close my eyes the cellos on this Shostakovich are firmly rooted back left, including the bass; the sub is back right.

 

Alex,

If you want to hear some serious subs, try to get a listen to Merlins fricking awesomes. They are not about ultimate depth (dont go much lower than 20hz) but rather bring an effortless quality to the music. They are for sale too

 

Two subs definitely help with integration. It's much easier to get a good room response curve below 200Hz with two subs than with one.

Michael.

 

Thanks Robbo, and they are currently in the process of getting me evicted!

It's interesting, but if you take a typical Pro THX setup, as found in the better multiplex's, you will find that even the biggest subs are rated down to about 22hz (-3db). you will also find that the crossover from the low frequency transducers (typically 15" or 18" paper cones) is between 500hz and 1khz.

IMO there is a special sensation you get when bass frequencies from say 100hz down are produced by big low distortion cones. As in the cinema, it's an effortlessness and seemlessness that I have not heard from any small cone subs regardless of design.

I crossover at 100hz. I only get down to about 25 hz in room, but what's there is damned special. Mighty weight and scale, reminds me of a real cinema I have to say. I just don't understand the specmanship regarding how far your subs will go into infrasonics.

I'd have to agree with most subs Antonio. But for movies, with bloody good subs, 80-100hz really does seem right. It's just most domestic subwoofers are not up to the job IMO.