Hello, I have a pair of ATC SCM 20 PSLT and I would like to know if the crossover components can be improved without changing its sound.
??? What sort of improvements are you looking for if the sound is not to be changed?
PS Some ATC speakers have no baffle step correction (for example) and this would be well worth addressing if this is the case with your speaker. I don't know whether this is the case or not with your speaker. Anyone?
PS Some ATC speakers have no baffle step correction (for example) and this would be well worth addressing if this is the case with your speaker. I don't know whether this is the case or not with your speaker. Anyone?
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The components in an ATC speaker tend to be good quality but the technical performance delivered for the price tends to be modest at best compared with better engineered speakers from Genelec, Neumann and the like. If you consider the ATC speaker in the link above it would benefit greatly from some DIY attention to introduce baffle step correction, improve the radiation pattern with a waveguide, active crossover if this available and possibly more. The high quality components mean it is well worth doing if interested in improving technical performance. Of course, improving the performance will substantially reduce the resale value given the strength of the brand so it is not necessarily recommended.
To the op: don't modify them, at 6000€/pair for bookshelf (edit: pslt are 9000€/pair!) if you dislike them sell them and go buy or build something else.
Waveguide on ATC won't do, ATC philosophy is wide radiating pattern over a large part ( most) of the freq range ( +/- 80* so around 160* pattern). Trying to 'solve' this ( even if it makes sense) will have a poor outcome if you like the 'sound' of this brand.
Trying to modify the passive xover won't bring anything. Maybe switch to active filtering ( like in the bigger amplified model SCM110A) but it'll probably be not as easy as it seems and will kill resale value for sure...
Waveguide on ATC won't do, ATC philosophy is wide radiating pattern over a large part ( most) of the freq range ( +/- 80* so around 160* pattern). Trying to 'solve' this ( even if it makes sense) will have a poor outcome if you like the 'sound' of this brand.
Trying to modify the passive xover won't bring anything. Maybe switch to active filtering ( like in the bigger amplified model SCM110A) but it'll probably be not as easy as it seems and will kill resale value for sure...
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About bsc ( baffle step compensation) and ATC: i know the pro range and most of them have a 'bass compensation' potentiometer on the back ( both passive and active).
It makes sense as they can be inwall mounted or used freestanding.
I don't know if they use it on hifi models but for bookshelves i bet they rely on wall bass reinforcement. For a tower i don't know? Anyway it can be implemented before amp, it's a simple high shelf attenuator with freq defined circa 115/ width of cabinet in meter. So around 480hz for scm20pslt should be in ballpark ( 115/0,239= 481hz).
If OP have a computer as source any plug in of hi shelf eq on output should do.
It makes sense as they can be inwall mounted or used freestanding.
I don't know if they use it on hifi models but for bookshelves i bet they rely on wall bass reinforcement. For a tower i don't know? Anyway it can be implemented before amp, it's a simple high shelf attenuator with freq defined circa 115/ width of cabinet in meter. So around 480hz for scm20pslt should be in ballpark ( 115/0,239= 481hz).
If OP have a computer as source any plug in of hi shelf eq on output should do.
It will if there is no baffle step correction like in the ATC speaker in the link above. The linked speaker is an SCM19 rather than an SCM20 so the OP's speaker may be OK but having seen something like this it would seem rather unwise to make assumptions. ATC seems to be a rather different company these days to what they were a few decades back.
A shallow waveguide can smooth the directivity of the tweeter over the lower frequencies while doing little at the high frequency end. The Harman Revel speakers are an example of waveguides on wide beamwidth speakers.
I think we mostly agree Andy and the famous mid driver use a short horn to achieve the 160* pattern but it work way lower than their 2way models ( usually xover circa 2,5khz to softdome, mid is used typically from 400/700hz).
For BSC when missing we usually implemented it by using an eq before the amp on monitors out of desk. Nowadays i would stick a vst plug on output of daw an call it a day.
Iow what i purposed to solve the hypothetical issue.
Anyway after living with 110A for some years as main at work i know I dislike this kind of loudspeakers and truly prefer narrower radiating pattern despite the ATC strength ( the mids are really transparent and revealing but i find them boring overall / including other biggers monitors in the range like 200 or 300 ).
They require a lot of treatment in room to sound at their best which is not the best choice for domestic use imho ( the downside to wide radiating pattern).
Each one it's own i suppose.
For BSC when missing we usually implemented it by using an eq before the amp on monitors out of desk. Nowadays i would stick a vst plug on output of daw an call it a day.
Iow what i purposed to solve the hypothetical issue.
Anyway after living with 110A for some years as main at work i know I dislike this kind of loudspeakers and truly prefer narrower radiating pattern despite the ATC strength ( the mids are really transparent and revealing but i find them boring overall / including other biggers monitors in the range like 200 or 300 ).
They require a lot of treatment in room to sound at their best which is not the best choice for domestic use imho ( the downside to wide radiating pattern).
Each one it's own i suppose.
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The highs could be improved by changing the capacitors to something like Jantzen Superior/Alumen/Amber-Z
I have modified my SCM11 and highly recommend at least to change the tweeter cap and tweeter resistors. It's likely the same 6.8uf. I used Auricap XO 200V for their nice price/performance.
.Thank you for answering, I do not want to modify but rather improve the components of the higher quality claryticap capacitors by Mundorf as well as the resistors
You want them to sound the same but with audiophile capacitors and resistors in the crossovers? Not sure I can see the point but it seems fairly straightforward so long as someone reasonably competent swaps the components. Modifying the crossovers will reduce resale value and the number of people interested in purchasing. If you do swap some components I would suggest keeping the originals so that they could be returned to standard if you sell them in the future.
No he dicho que vayan a sonar igual, seguro que con mejores componentes respetando sus valores seguro que habrá una mejora
Boutique crossover components is just snake oil. Changing the actual crossoer topology is what will make for changes, not putting more expensive "audio grade" caps in. Don't waste your money.
Your opening post says without changing the sound. If you want to change the sound and improve it reliably then you will need to measure what is deficient, work out what changes will address this deficiencies and introduce them.
The components in a passive crossover are not particularly linear which is why high performance speakers use active crossovers in order to remove this source of degradation. The component tolerance can also be wider than one might like. Unfortunately the full non-lineariy in passive crossover components is generally not provided in their published specifications and so DIYers are rather limited in the engineering approach they can take to the design of a passive crossover. The larger engineering-orientated speaker manufacturers are less limited because their relationship with manufacturers means they will often be able to obtain more detailed commercially confidential information plus the speaker manufacturer will often invest time measuring in detail the performance of the various components available to them and opting for the ones that are the best fit in terms of performance, price, availability, reliability, etc... This information is valuable given it's limited availability in the public domain and so tends to be kept within the company. I recall (but cannot find - anyone?) a KEF engineer (I think) posting that performance generally did not follow price in their tests but detailed information was not included.
The vacuum created by the incomplete information about the performance of passive crossover components along with their becoming obsolete for high technical performance speakers decades ago has lead to them becoming a source of income for companies seeking to add value in the eyes of a few non-technical people via marketing. Usually these expensive audiophile components do have physical features/difference on which to hang the marketing stories and their nonlinearities may well be different to components constructed differently. So it is not unreasonable to expect to hear very small audible differences with a swap of nominally the same components but whether it will be judged better, worse or just different is going to be largely unknown. What is known is that even if the result is an improvement it almost certainly won't be a cost effective one or else the manufacturer would have done it in the first place.
If you want to reliably introduce a small technical improvement then look to swap the passive crossover for a competent active one. The size of the improvement is likely to be small if your SCM20 crossover is well designed but if it is as badly designed as the SCM19 I linked to above then the improvement may be more substantial. If you already have the hardware to hand for an active setup then the only cost is a bit of time setting it up making it well worth doing but if you don't then purchasing it just to mod your current speakers is very unlikely to be cost effective. But if you intend to use the hardware for future speakers then it might be worth considering.