Active 250 or passive 135 to go with 82?

Posted by: Martin C on 28 August 2001

I know that this topic had come across a few times on this forum, I just want to ask Ken C,
I found a thread from him that he was decided to get either one or the others, then found another one for updating on his active 250, so obviously he went for the active option.

Ken C, what made you gone for active 250, not 135's, as my dealer do not have a pair of 135's
for demo, I know what active 250 can do, much much better than passive 250, can you give me more details or comparison of these two? I am running an active 90 with SBL at the moment, IMO, the bass for active 90/92 is better than passive 250/82, may be not other department though, actually the cost of active 90 (90X2, Snaxo 2-4+flat) is slightly more expensive than a single 250.

Will place the order this weekend for 82/250X2, just want to know more about 135's, need your advice on this.

cheers
Martin

Posted on: 28 August 2001 by ken c

my initial intent was to upgrade 1*250 to 2*135 passive. my interest in 135's was sparked by a demo for a cdsii when this player didnt sound at all that good compared to a cdx with a 250 driving a pair of b&w's. however when we changed the 250 to 135's, the penny dropped, or may be jaws dropped.

at the same time, i was also curious about going active and wondered what 2*250 active would be compared to 2*135 passive. i believe there was a very live discussion on the old forum where some folk preferred the passive duo. i decided to find out for myself. i had a slight leaning towards the passive combo as this was cheaper and entailed fewer black boxes.

the demo was to be a real ear openner. to me, the active system emphasized more intimacy. the passive 2*135 emphasized more power and control. i got more power, drive, slam and control when i added supercap to drive the snaxo -- so i now have both sides of the world.

but please note, this is with a 52/supercap driving sbl's, and at that time -- cd2 (very good cd player this is). ireally do not know whether i would have reached the same conclusions with an 82 - a very fine preamp.

i suspect either route will give you some additional insights into your music. if you ever get a chance to compare, do let us know what you decide and why.

i hope this helps. if not, shout...

enjoy

ken

Posted on: 30 August 2001 by Martin C

Hi Ken C & RichardN,

Thanks for your advice, I will go to my dealer this Sat, I think I am more likely to go for 82/active 250 option, although is tempted just to get 82/250 and CDSII (but under the current development of other new formats, I'd better wait and see, as it is a big investment). I will keep my 3.5+Hi for a while, I don't want to go thru the stage of CDX, I demo it before (not particularly impressed with a bare CDX), with XPS (it's different story, besides the price difference between CDSII & CDX/XPS is only GBP 1.6K and come with the flash remote.)

I will try Gyrodec though, it looks good and sounds good (according to various reviews), it will improve my source.

will keep you update, I don't think I can try a pair of 135's unless I book an appointment with Hi-Fi experience or the Cornflake shop.

Cheers
Martin

Posted on: 30 August 2001 by Martin Payne

One question you need to answer which miaght affect your choice of passive or active is how old your current amp is.

Since the (S)NAXO-2 feeds the left speaker from one amp and the right speaker from the other, these need to be reasonably matched.

If buying a new amp and your existing one is more than a few (4-5?) years old it might need at least a service. If the amp is an old one (chrome bumpers) then it will probably sound quite different due to different transformers now used.

This is a bit less of a problem with 4x135s, since you can put pairs of amps on bass or treble, and at least get a consistent sound from L-R.

When I took my system active (with all s/h amps) I sent them all back to Naim & they 'matched' them by replacing some circuit boards internally. This could get a lot more expensive if you need to replace transformers also.

Still, I would expect active to be better, and well worth it.

Martin

P.S. the same situation could also exist with 82 driven by 2x HiCaps, since one is used for each channel.

Posted on: 30 August 2001 by Mike Hanson

The other option is to rewire the SNAXO, so that one 250 runs the tweeters, while the other drives the woofers.

I'm not exactly sure why the normal method is to have each 250 deal with a single L/R speaker, rather than splitting it up by frequency range. Perhaps it's load balancing, since woofers take more power than tweeters.

However, it would seem that having each amp deal with the full spectrum (albeit separated by the two channels) might affect the power supply's ability to maintain a constant voltage for both channels.

This might be similar to having a power amp supply a pre-amp with power (i.e. with no Hi-Cap). Because the power amp needs lots of power, it can't provide consistent, low-level power to the pre-amp. Wouldn't the draw for the LF channel affect the HF channel in a similar fashion?

I'm only theorizing, though. Could someone be so kind as to enlighten me?

-=> Mike Hanson <=-

Posted on: 30 August 2001 by Martin Payne

Mike,

yes the load on the bass channel will have some impact on the treble channel, but at least it is only 'crosstalk' within the same channel.

Driving both bass channels would place a heavy load on that amp.

Also, if using one 250 and two 135s in a mixed setup, Naim recommend the 135s on the treble, I think partly because it gives better separation of the treble. This will be maintained in the standard 2x250 configuration.

I don't know if anyone can tell me whether the draw on the PS in the 250 is dependent on frequency, and thus the bass would affect the treble to a lesser extent than might be expected? Just a guess.

cheers, Martin