Oops, should I have bought the 300

I don't hear it that way, but that also depends on the source and preamp used, and of course the all important speakers !!!

as for 250 sounding mechanical, maybe it was only telling you that your source had that quality.

Sloop John B posted:

It seems you upgraded without posting here and asking first which sadly shows a very poor lack of judgement.

Buyer's remorse (after a Naim purchase) is very much frowned upon. 

After a purchase it's best to start a thread with at least one of the following  in the title

1. 3 exclamation marks
2. Wow
3. Wow with 3 exclamation marks

 

Using of any of the following is now frowned upon 

1. jaw dropping or any general open mouthed reference 
2. in the house
3. in da house
4. wow with 4 or more exclamation marks

 

in the thread itself it is obligatory that

1. You are smiling ear to ear
2. the noise floor is lowered
3. you're rediscovering your collection 
4. your wife  heared the difference from the kitchen and rushed in to ask what had changed. 

 

Good to have but but not essential 

1. inky blackness
2. veil removed (always a good idea to give some measurements of the thickness of the veil that was removed).

 

If you keep to these simple rules you will have many long  years of Naim happiness and loads of friends here on the forum. 

 

.sjb

You have forgotten either 'Foot tapping' or 'Boogie factor' 

analogmusic posted:

as for 250 sounding mechanical, maybe it was only telling you that your source had that quality.

 

A possibility that was ruled out, because I've used the same source (and speakers) with 250, 250DR, 300 and 500. So it wasn't difficult to isolate the 250 effect.

What I find curious is the almost complete absence of speaker interaction observations in threads like this. According to my dealer, both ProAc and Naim are well aware of issues, particularly in less than cavernous listening rooms, with over bearing bass from the D300 (both versions) when paired with the Response and K ranges (don't know about the 500 - it's so far out of my reach I didn't bother to enquire). It was on receipt of recommendations from both companies that the 250DR was substituted to such great effect. 

Whilst I can understand that in terms of price and quality the 300 is a division above the 250, I don't quite understand what is an almost slavish obsession amongst some forum members with 'upgrading' to the exclusion of synergy with the rest of the system, particularly loud speakers. Having demo'd a fair few speaker brands over the last 2 or 3 years I knew, with absolute certainty, that I wanted to a) keep the ProAc 'sound' and b) maximise the quality of that speaker sound. Having listened to D30s and D48s I knew that only the K6 would deliver both for me, so the rest of the system had to make that work. Fortunately that's what has happened, because of good advice and help from the dealer. 

Spending more on moving up the Naim amplification ladder doesn't always work, contrary to the views expressed on this thread (and affordability was not a factor in my decision making).

The room is always the final arbiter. A fact  which if embraced and acted upon can be the gateway to a very happy and cost effective future. 

It is possible to upgrade with synergy but it can be a luxurious/unobtainable option if you can't get to a good dealer, listen to things at length in various combinations and get a home demo. I have been in such situations down the years and it probably goes some way to explaining why I didn't touch my system for 18 years until something broke.

In our room and system we found a 250 seemed to provide the least synergy. We would have needed to build a new system around a power amp. Not what we were looking for.The 300, with a 252 was perfect. But this upgrade should not be confused with the situation laid out by the OP. I don't expect many people find themselves in a position where they can have either a 250 or a 300.  It doesn't have to be Naim, although they usually get first shot when we decide to treat ourselves. 

Our 282/250 try our was years before we decided to have a little sniff at a 252/300. A Graaff GM50 wiped the floor with a 282/250 in our room/ears. Just like an Audio Innovations 500 saw off 202/200 by a big margin. And both for less money. It seemed that for whatever reason, Naim amps didn't sit right with us. It later transpired that we were wrong both further down and further up the range.

To us the 300, with a 252, was the epitome of synergy and completely different approach to listening to music. compared to  the 250 (with a 202, 282 and 252). Which is why I contributed to this thread. We've had a 250.2 at home twice and a 250DR once. As well as 282, 252, 300, 500, 500DR, 152 and 155.  Out of all of these the 250 .2, 250DR and 282 are the ones  which seemed unable to justify themselves to us. The 202/200 didn't make it beyond the dealer's demonstration room so it is impossible to predict how it would have sounded at home. 

In a different room the results would likely be different. Although I doubt the Naim pecking order would have differed.

Is the increased bass of the 300 over the 250 an increase in sustained bass notes as from bass instruments such as bass guitar, double bass, organ, synth, contrabassoon etc., or is it primarily on bass drum? If the latter then unless the amp is emphasising it, it may be just that the correct relative volume of the drum is being reproduced by tge 300 and not by the 250. If it is all bass, then I am puzzled as to what is going on.

If the amps going up the range all have a flat frequency response across the full audio spectrum, I struggle to understand how some may boost the bass other than on transients.  I note the specifications only give the -3dB points at the extremities of the soectrum - I've always assumed no peaks in response in between, but is that true? Assuming it is, I would expect the better amp to possibly seem louder with percussive sounds like bass drum, but not with more prolonged notes such as those from the normal bass instruments. (Reasoning below).

I am aware of three effects at play:

1. Control of the speaker (i.e keeping the bass 'taut'): here the lesser power amp might be expected to yield a more wallowy sound than the better one - however that would if anything make the lesser amp sound overblown.
2. Speed of reacting to transients, providing adequate current as quickly as demanded: here the better amp would sound 'faster', and that might mean It could sound louder because the full peak is not missed, though that would apply only in the microseconds of the pulse rise of a percussive sound and not in the slower rise of, say, a bass instrument, nor in the sustained length of a note.
3. Maximum available intantaneous power: in this regard the normally expected result would be for lesser amp to run into distortion on transients that the better amp can handle, or possibly reduce their amplitude if a limiter is incorporated. Leaving aside the subjective effect of any distortion, the ability to deliver more intantaneous power means the better amp could produce louder peaks - however in most music that would only affect the transient peaks such as percussive sounds, rather than the longer notes from bass instruments.

is there something I've missed?

TID (Transient Intermodulation Distortion)

Driver latchup

RF immunity (radiated, present at input, via PSU)

PSRR

Load effects (e.g. phase effects such as imaginary currents)

Yes, I missed load effects, which can differ with different amp output design, maybe particularly with the 500 compared to others being a bridged amp, though I'm unclear what difference there might be between 250 and 300 in this respect

How any of those would the others affect the amount of bass output? (I ask because I don't know)

Part of what one perceives as bass is the way that the fundamentals (30Hz - 200Hz) interact with the harmonics (60Hz - ~1kHz); these all affect that.