REL's and active Naim

If you insist on adding the sub, then hook it into the high-level speaker outputs for the low frequency speakers.

-=> Mike Hanson <=-

Forget about it, unless you like to waste a lot of your time.

Arthur Bye

As for the Rel, as per Mike and Arthur.

Good listening; the music's still groovin'.

Philip

naimniac for life

Anyone who doubts the PRaT should hear my system - using twin Stentors. Basswise, they are considerably deeper than the SBL, and if setup properly, they should compliment the rolloff of the SBL not reinforce its lowest frequencies.
When setup perfectly, bass should transition from the main speakers to the REL completely seamlessly, and there is a point at which the two speaker systems begin to work as one.

Siting isn't that difficult, so long as you realise that 15Hz waves are big and therefore they may bounce off things and cancel themselves out - that's why two subs are easier to site than one.

PRaT? The low frequencies which the SBL misses are not really susceptible to PRaT to any real degree - likewise, they aren't directional, so they should be setup to be subtle within the context of the music. If the rolloff is set properly, they should not affect PRaT or musicality. The cheaper RELs may not be as good in this regard, but the Stentor and Studio subs add a certain something to the music that leaves non-sub'd systems sounding very flat and lifeless.

My advice would be to hear a properly setup sub system and make your own mind up - there are too many variables to make a snap decision, but at the same point don't be put off by people who obviously haven't heard these subs setup properly.

A Stentor can be had secondhand for well under £1000, a Studio is around £1600 secondhand or more. These are seriously good subs, and IMHO essential for those deepest frequencies.

If you want to know more, please email me.

John

quote:

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..works very well, if you play around with location a bit, and turn the subs way down so that
they're not overemphasising things.

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John:

Can't say I agree with you here. I've got a Stadium II on my AV system and have tried innumerable times to get it going right with a Naim system. I managed to get it sounding ok with a set of Sonus Faber Concertos, but they were too slow for my taste. Anything faster I could not get to work. I've tried Epos 22's, Epos 30's, Vienna Acoustic Beethoven's, Totem Mani-2's, and Soliloquy 5.0 Monitors. Actually the Soliloquy's worked ok too.

The timing just gets too screwed up. Yes it helps to keep the high cut off as low as possible, but invariably there is overlap at around 50 hz. This is where the trouble is and stays. I've spent a good bit of time with Sumiko (US importer) trying to sort this out to no avail.

The funny thing is, on my Sony AV system I haven't had any of these problems. Fairly easy to set up and timing seems ok.

To be fair to you I haven't tried the double sub set up but I'm unconvinced that a downward firing sub can solve the problem.

Arthur Bye

quote:

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invariably there is overlap at around 50 hz

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...that is *way* too high. Try 30Hz for floor standers, 40Hz for standmounts. Ensure that the gain on the sub is around 3/10 for a single sub MAXIMUM, 2/10 in a stereo pair.

Thing is, they work best doing the really low stuff - 50Hz is getting into directional territory, and you don't want your sub doing much in that region. 30Hz and below? Well, admittedly the Stentor is a more sophisticated beastie than the Stadium, but at really low frequencies you'll find that the very acoustical nature of the sound (i.e. long wavelengths) are not by their nature that quick in any case, so the point is moot.

I've had the subs keep up well with Audio Physic Virgos, which were fast (albeit perhaps not quite as fast as Kans) but in my experience the perception of speed is a mid-range and above phenomenon, and speed of deep bass is extremely difficult to detect. In my system, when a bass drum is hit, the Stentors can keep up with the speed and PRaT of my LP12/Lingo/Aro, and that's a fast source.

I guess a lot of this is room dependent, but I suspect that the perceived 'slowing down' effect of a subwoofer would be due to too much overlap in the roll-off region, and perhaps too much gain on the active sub's amp.

HTH,

John

You still have overlap at 50 hz as the sub is still producing sound even when set at the lowest cutoff setting( I think Rel's have a 1st order rolloff). If your main speaker go down that low they start to fight with the sub, unless you can get it timed right.

It's also very room dependent. My room has always been +10db around 50 hz which compounded the problem.

Arthur Bye

John

I've heard Paul Murray's system, and the sub is an unequivocal success. It's tuned very low (around 22Hz turnover point and set to almost inaudability).

That extra extension really changes the sound of the (active 250) SBLs for the better - the sound muddies up dramatically without it.

Connection to the power amp outputs is almost mandatory - connect to the L & R positive outputs & one of the negatives.

Note that the supplied cable is of quite a high capacitance (considered very bad for Naim amps). Paul uses a very low capacitance speaker cable instead. Also, he connects at the speaker ends of the A5 since the cable run will further isolate the amp from the sub.

Arthur - suggest you get hold of another Neutrik or XLR connector & some cable (maybe A5?) and have another go.

cheers, Martin

P.S. playing Devil's Advocate here, some rooms just don't play deep bass well (very slow) and a sub will just make it worse, but it's just showing up a problem that is probably already affecting you main speakers - and one that will get worse as your source & amps get better.

sorry, just re-read your post - gosh you have a problem there. I struggle with something similar in my room, but hadn't realised it might be as much as a 10db lift.

No wonder your sub didn't work.

cheers, Martin

I don't think it impossible to set up a Rel sub with most speakers. I just think it's way too difficult to do. I spent a lot of time trying to get the location of the sub right. At times I thought that I had found it. Invariably though I would find some recording where the timing would be off. Once again, I would try to relocate the sub, but it was an endless process.

The Rel sub when properly set up always seem to help out the upper regions of the main speakers in frequency ranges where the sub doesn't even venture. Don't quite know why this happens, but it does.

It's quite possible that my problems could be ameliorated by moving my system to another room, but that's not an option.

My solution for now it to have main speakers that go fairly low. I still get the +10db jump at 50hz, but at least it's in time.

The Rel Stadium II has been relegated to my AV system for now, which seems a sad fate for such a musical speaker.

I would also add that I have a Rel Strata II combined with a set of Sonus Faber Concertinos in my home office that work quite well in the fabric of Carver amplification. My feeling is that this works ok as the Concertino's don't go very low and the speed of the sub is better matched, probably by coincidence.

Arthur By

Regards

Henry