ATC speakers help

[julesd68]

Does anyone out there have experience of the latest ATC standmount range?

I am wondering what characteristics they have and whether they suit a wide range of music.

And since they are sealed boxes, does that offer improved bass definition than a rear-ported speaker when positioned near a back wall?

cheers.

[YNWaN]

I've heard the 11's a couple of times and really liked them.

[theabbot]

You could try asking on the ATC forum

http://www.atcforums.co.uk/index.php

Mike

[hoopsontoast]

Does anyone out there have experience of the latest ATC standmount range?

I am wondering what characteristics they have and whether they suit a wide range of music.

And since they are sealed boxes, does that offer improved bass definition than a rear-ported speaker when positioned near a back wall?

cheers.

I have owned the SCM7's and heard the 11's and 19's a lot.
I actually think the SCM7 is the best of the lot, but also worth looking out for the SCM10, same bass driver as the 7 but in a larger cabinet and a smoother tweeter.
They can be a little rough on the treble occasionally (the SCM10 does better in this regard) but they are very open well integrated between the mid/treble, the SCM7 especially.
THey have very fast and tight bass, but do respond to a lot of power if you really want to get the very best out of them but they do supprisingly well on small amps in normal nearfield situations.
They will do better than most when positioned up against a rear wall, but they do like to be a foot away from the rear walls to help with the soundstage IME. (opens up a lot)

I found that the SCM7 is quite senstive to stands, and found the Target R1 an almost perfect match, size wise and really helps with the bass definition and depth.

The 11's I found a bit 'middle child' as I would prefer to save some money and go for the 7, or save up more and go for the 19.

The SCM19 when given a BIG amp, will rock with the best of them, really supprising bass depth can be got from them, considering the mid bass size and the sealed box. Excelent dynamics and slam! That may be down to the SL-spec bass driver, and IME they sound better to the SCM40 (integration, bass control and dynamics)
I would advise that they are not against rear walls though, need again, at least a foot from the rear walls.

The main thing, is that the presentation is the same for all 3 in the range I found, if you dont need the extra SPL/bass depth that the 19's provide, go for the 7's IMO and IME.
The 19's only really come into their own I found at high levels or a big room.

I have not heard the SCM-20SL though, its on my to-hear list someday.

[julesd68]

The SCM19 when given a BIG amp, will rock with the best of them, really supprising bass depth can be got from them, considering the mid bass size and the sealed box. Excelent dynamics and slam! That may be down to the SL-spec bass driver, and IME they sound better to the SCM40 (integration, bass control and dynamics) I would advise that they are not against rear walls though, need again, at least a foot from the rear walls.

Many thanks Rob for such an informative reply! :)

A couple of questions if I may ...

Do you think my 100W 405-2 will handle the SCM19's?

Would you say that the presentation of the speakers is neutral? They would need to handle hard rock and classical by equal measure - I need slam and delicacy too! I don't have a huge living room but I tend to listen to my rock records at around 90db and also tend to play my classical music on the loud side. My current speakers are 23cm from the rear wall.

[julesd68]

You could try asking on the ATC forum

http://www.atcforums.co.uk/index.php

Mike

Thanks Mike, I didn't know there was one ...

[DSJR]

A stock 405-2 drove my original 20's with little trouble apart from getting very hot indeed :lol: The hotter it got, the sweeter it sounded, although the power output may well have been very low by this point and the amp most probably soft clipping? Make sure the Quad supply caps are intact and not bulging or leaking and, if the preamp allows this, use the Quad with chunky speaker leads and site it close to the speakers (I must dig my pics from this period out...)

Modern ATC's all seem to have a slightly bumped-up upper mid, as usual for small stand-mounts with monitor connotations. Unlike some, ATC's do seem to retain some bass extension, where some others of this type allow the bass to follow the downtilt from the upper mid. I don't know the exact issues, but I have seen tests on one or two of the current crop and they're all balanced the same, as are the 20SL's.

[julesd68]

A stock 405-2 drove my original 20's with little trouble apart from getting very hot indeed :lol: The hotter it got, the sweeter it sounded, although the power output may well have been very low by this point and the amp most probably soft clipping? Make sure the Quad supply caps are intact and not bulging or leaking and, if the preamp allows this, use the Quad with chunky speaker leads and site it close to the speakers (I must dig my pics from this period out...)

Dave, that's really interesting - I have just got my 405-2 back from repair and service. Yesterday I did my first listening session with it. When I switched it on, I left it for 30 mins to warm up, stuck on a record and was shocked - all I got was a thin midband with no bass to speak of. Five hours later it was very hot but was absolutely singing! Such a great amp.

[DSJR]

I never got that kind of difference and weedy it aint usually (mine weren't) :) But the thing that often took eight hours of light use and an hour of thrashing to clear was a very slight sparkly sting in high frequencies not there in the 303 or 606 models, let alone the AVI mono's I replaced the last one with (using the ATC 20's at the time).

As I said, modern ATC's will sound a bit thin toned if pulled away from rear walls too much, but desktop use, or stands around 300mm tops from a back wall should balance them up better I think.

[hoopsontoast]

I have not heard any of the quad amps so I cant really comment.
The 19's really do need an amp with plenty of current as they are quite heavy cones, despite being a relatively easy load for the amp (impedance).

If you are looking at the 19's I would search out some 20SL's. Will have the much better tweeter, like the SCM10's.
If you are playing at that kind of level, the 7's may do it, but to get the full effect, the 19's/20's would be perfect.

Not heard them, but there are the SCM10a and SCM16a that go for a lot less than the 20ASL's and would help with the amp matching,

Oh and bear in mind, that the ATC forum is the Musicraft Shop forum, but called ATC Forums. ;) Similar to HDD being AVI....

[julesd68]

A pair of ATC 19's arriving tomorrow - just couldn't resist giving them a go ...

[Reid Malenfant]

Dave, that's really interesting - I have just got my 405-2 back from repair and service. Yesterday I did my first listening session with it. When I switched it on, I left it for 30 mins to warm up, stuck on a record and was shocked - all I got was a thin midband with no bass to speak of. Five hours later it was very hot but was absolutely singing! Such a great amp.
Hi Julian, you could switch on a Quad 405 & leave it for ten years & it'll never "warm up" :eyebrows: The only thing that gets them hot is playing music ;)

The output transistors are never on when it's just idling, but when you play music they start to turn on & warm up. At this point the output transistor base - emitter voltage starts to drop & eventually when they become hot enough they sound superb.

The problem is in the amp design, Quad deliberately made them as they are so the output transistors are safe. They'd have done far better to track the base - emitter voltage with the diodes that bias the thing, it'd then sing like a Canary from the off ;)

Unfortunately they didn't :rolleyes:

[DSJR]

it'd then sing like a Canary from the off ;)

Unfortunately they didn't :rolleyes:

Get the input sensitivity modernised and a modern op-amp on the input and they sing very well as-is i think.

The 405 series inverts the phase, so try wiring red speaker leads to black terminals at either the amp OR the speakers, not both. That should give more push in the bass.

[julesd68]

try wiring red speaker leads to black terminals at either the amp OR the speakers, not both. That should give more push in the bass.

Interesting - the only thing I can really criticise my system for is being a tad light in the bass. I will try your suggestion tomorrow with both sets of speakers and see what happens ...

[julesd68]

The only thing that gets them hot is playing music ;)

:lol: Right, I get it now ...

Excuse my ignorance but can you get the output transistors to warm up by having the volume turned up on the pre-amp but music switched off?? :scratch:

[Reid Malenfant]

No :)

I could explain how it all works Julian, but right now I have had one or two drinks & I don't think it'd make much sense, worse, sense to me :eyebrows:

Too damn complicated to those that don't understand electronics.


All I can say is I think they could have done it better, as I might have said earlier :scratch:

[julesd68]

:glug::glug::glug:

I've just poured myself a nice little cognac ...

[Reid Malenfant]

That'll be nice & warming... Keep the Quad hot & it'll sing, there are quite simple ways that are cheap, to improve them so they sound good nearly all the time.

Enjoy :)

[DSJR]

My favourite D series Crown amps used a similar (I believe) but far earlier sort of feed-forward? way of doing things - a high quality and very tightly specified driver amp with output followers (Quad's Dumpers) to deliver the muscle. These days, transistors are FAR better and Quad have shown from their 77 series amps onwards that a properly designed modern Class B circuit can be made to sound at least as good IMO.

Back to topic - no need to "warm up" a typical 405-2 since thrashing it into some ATC's will do that for you in minutes :lol: Fifteen minutes tops I think and eight hours for maximum sweetness (soft clipping?) I got from both mine.. The series two 606 onwards were pretty well there from cold I remember.

[Reid Malenfant]

The thing is Dave, there is a way to damn near do it from cold & Quad didn't :rolleyes:

All it needs is the right diodes & number of them in the bias network & then thermally linking them to the output transistors & the problem is solved.

Quad kept them seperate, so it needed the output transistors to get hot before it'd come on song :rolleyes:

We are talking 50p of diodes & a thermal linkage & they'd be great from just about go...

[DSJR]

Thanks Mark - we'll chat later when you're not so chilled :)

[julesd68]

I've only just got the bloody amp back from repair and you geezers is telling me to get it modded already :doh:

It's a lark this hi-fi game innit ...

[DSJR]

The Quad Blogspot is great fun. Thing is, these old amps are worth the trouble IMO, from rebuilding II's carefully, to a thoughtful update on the 303, to the 405 and re-capping and even re-wiring a 606..

[julesd68]

Someone pass the Courvoisier ...