Optical or RCA ?

[Reid Malenfant]

Ah, they are kind of tiny then, in fact about the same size as the original Wharfedale Diamond You definately need a sub & it'll have to be a very musical one as well as it looks like it needs to extend up to 80 or possibly 90Hz

There was me thinking you might have something that would get down to 40 or 50Hz

[colinB]

The REL t series i was looking at crossover is 30-120 hz with a 10" driver.
Sound allright?

[Reid Malenfant]

Possibly yes, if they are using the Tymphany (Peerless) XLS drive units it should be quite good

[colinB]

The BK one does for sure but im struggling understanding the specs as usual.
It just states -6db at 17hz

[Reid Malenfant]

So it'll go below 20Hz... It'll probably do -3Db at 20Hz itself which is pretty good though it all depends at what level it can actually reproduce it. There is little point in being able to go down to 20Hz if it can only manage 90Db as that is only 15Db above audibility at that frequency

equal-loudness-contour.jpg

In case you aren't quite understanding what -3Db means, it is a slight difference in volume, it's a bit lower. In the midrange we can detect a difference of 1Db or sometimes a tad less.

[Jac Hawk]

Watching kef eggs on e bay and various subs. Hope its all worth it.
Ive never heard a good system before, the ones i have heard have been all in one cinema in a box type and they have never impressed me, but im up for giving it a go.

Choosing the easy path only leads to the dark side young skywalker

[colinB]

LOL. Ok Obi-Wan i will take my time and avoid buying tat and do it properly.

[Jac Hawk]

Seriously though mate, you will find that the smaller your front pair are the more difficult it is to get a sub that can do that sort of range, be good at home cinema and music too.

I have a pair of Mordaunt Short MS45Ti's on 14 inch stands and my sub a yammy YST-SW80 (which is crap at home cinema by the way) is set at 50hz the lowest it can go and 180deg out of phase it was a doddle to set up realy but that's because i have large front speakers which do a lot of the low Hz donky work, (tell me if i'm wrong here mark) but the lower down the Hz scale the sub goes the more out of phase it will become, so if you're needing a sub to kick in at 80 or 90Hz say, but extend down to 20Hz it's going to be a tricky job to get a good compromise with regards to a phase setting so choose a sub which has a variable phase setting between 0 and 180 and you'll be covered and much happier with the results

[Jac Hawk]

LOL. Ok Obi-Wan i will take my time and avoid buying tat and do it properly.

Been on a Star Wars bender these last few days, can you tell?

[Reid Malenfant]

<snip> (tell me if i'm wrong here mark) but the lower down the Hz scale the sub goes the more out of phase it will become, so if you're needing a sub to kick in at 80 or 90Hz say, but extend down to 20Hz it's going to be a tricky job to get a good compromise with regards to a phase setting so choose a sub which has a variable phase setting between 0 and 180 and you'll be covered and much happier with the results

The higher up the sub has to reach the more problematic things become due to phase shift. Not quite the same thing but nearly. If you think about it 50Hz is a much longer wavelength & as it's pretty long it's relatively easy to get a sub in phase no matter what it's position (as long as there is a continuous shift control & a 180 degree switch). But at 100Hz the wavelength is shorter & the sub might need to be physically closer to the main speakers to get it in phase.

Phase will shift over a subs passband depending on the enclosure design, but as long as it's in phase at the point where the main speakers roll off it's not a problem.

As well as that it becomes more obvious where the sub is. I know people say that below 150Hz it all becomes omnidirectional, but i can often detect where a single sub is down to about 80Hz