With different impedances, different Fs, different frequency response, different power handling, short vs long coil, I suspect different levels of distortion, etc... it is likely to be a pretty rough rough equivalence. The lack of data, support and the very high price is a strong indication that neither company considers the DIY market worth bothering with.
The ATC site states the SL version is not available externally but gives (non-)specifications for the S and non-S versions in 4, 8 and 16 ohm versions. This looks to me as if 6 versions of the ATC driver could be available to DIYers if a shop arranged to do so with ATC. Falcon recently started to carry the Volt range and depending on what happens to the up for sale Wilmslow this may happen. Of course another fairly likely option is that if Wilmslow closes there will be no outlet for DIYers to purchase ATC drivers.
It's quite likely that ATC don't supply the S version to 3rd parties to stop other manufacturers undermining their complete speaker business - as PMC were probably doing. I suspect that the withdrawal of supplies of this driver was the reason PMC made their own very similar version.
I think you can add Quested and Neumann (formerly Klein&Hummel) to that.
Not 100% sure about Quested but K&H used ATC mids until they became popular outside of Germany.
The ATC SL versions are for the their bass drivers. These have never been available for DIY as far as I am aware. The SM75-150 and SM75-150S are the same unit and use the same voice coils in 8 or 16ohms. The S version has a much bigger magnet and is more sensitive. 94db instead of 91dB for the non-S version. The response plot for both versions is almost identical so you can use the same crossover.
For systems with a single bass driver the standard version should be fine as the bass driver is far more likely to start distorting at high volume levels before the mid. (Assuming crossover is good)
For systems with a single bass driver the standard version should be fine as the bass driver is far more likely to start distorting at high volume levels before the mid. (Assuming crossover is good)
Further to this, after letting the drivers run in, and some listening comparisons with my own designed three way sealed speakers, I am not so impressed with the prestige as is.
I am assuming/hoping the problem is with the basic analogue active crossover, so I am dropping the passive crossovers off with WA, and hope that the new versions will deliver more satisfaction.
Compared to my home brew speakers, these have poor tonality, a collapsed sound-stage and are less revealing.
So, if the passive crossovers when sorted by WA, don't improve the situation, I will start with my DSP solution.
I am still researching options from firewire sound cards, pro speaker processors, and the likes of DEQX/minidsp....
I am assuming/hoping the problem is with the basic analogue active crossover, so I am dropping the passive crossovers off with WA, and hope that the new versions will deliver more satisfaction.
Compared to my home brew speakers, these have poor tonality, a collapsed sound-stage and are less revealing.
So, if the passive crossovers when sorted by WA, don't improve the situation, I will start with my DSP solution.
I am still researching options from firewire sound cards, pro speaker processors, and the likes of DEQX/minidsp....
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So dropped off the crossovers. I am reassured that this is likely to be a simple error in construction after all.
They had a set of prestige speakers there - they had adequate damping and two internal ring braces - so the cabinets sounded similar to mine - no ringing, good solid construction.
Secondly they seemed very surprised by the issues and said they would 'get to the bottom of it' but likely it was something easy to fix.
I am now much more hopeful that they will deliver a more than satisfactory crossover that will work well passively. I will keep you all updated.
They had a set of prestige speakers there - they had adequate damping and two internal ring braces - so the cabinets sounded similar to mine - no ringing, good solid construction.
Secondly they seemed very surprised by the issues and said they would 'get to the bottom of it' but likely it was something easy to fix.
I am now much more hopeful that they will deliver a more than satisfactory crossover that will work well passively. I will keep you all updated.
That is interesting as WA told me that The Prestiges do not have any internal bracing even tho one of my cabinets had rebates for bracing while the other didn't!
Here's what they said about my crossovers for the ATCs:
'Dear David
I can confirm that the wiring diagram is correct and that the midrange is out of phase. This produces a much smoother response from the ATC midrange and is our standard detail when designing crossovers using this unit.
Regards
Neil
Subject: Re: Speaker kit delivery.
Neil,
The wiring diagram I have been sent for the crossovers looks incorrect. It looks to me as if the mid + and - connections are reversed. As shown, the mid and tweeter will be in opposite phase. Please can you check and confirm.
Thanks
. Here goes
Sent from my iPad using Tapatalk
For sure this is NOT the Prestige crossover. It refers to a Monacor ( not Volt)
12 " woofer and a Vifa Tweeter ( not Scan Revelator 9900) And the values are utterly different from those supplied by WA in their kit. IMHO we should first agree on what we are talking about ,or this thread is taking us nowhere.
The point is whilst the bass and treble drivers are different it was sold as a 'prestige' crossover supposedly crossing over at 380 and 3800hz. Sensitivity on the tweeter is very close: level matching on the bass may differ but not much else
So I have been playing around with my active crossover, and tried just for interest inverting the volt mid dome on the crossover - after WA's comments above about inverting the dome to smooth the freq response. Much better freq response...
Not sure why this is, given I am using standard 24db LR electronic slopes actively, would have thought all the drivers would be best in phase. Anyway, sounds much better now:
I am guessing this is to do with acoustic centre offsets?
Not sure why this is, given I am using standard 24db LR electronic slopes actively, would have thought all the drivers would be best in phase. Anyway, sounds much better now:
An externally hosted image should be here but it was not working when we last tested it.
I am guessing this is to do with acoustic centre offsets?
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So would this point to there being some truth in what WA are saying?
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
The shallow nulls are telling you that the drivers are not summing/cancelling well in the crossover region. Does your box of tricks allow you to add delays?
I wish. I figured it was driver timing. I will wait and see what the new passive crossovers are like, then if needed a digital crossover will allow me to time align it all.
It looks a huge amount better. Is this using your dbx (?) crossover? I'll try the same on my system and see if it has the same result.
When you can't compensate the difference of acoustic centers
by physical movement or baffle slanting and you are not using
asymmetric passive filters, then your option is to add amount of
electronic delay to the driver whose acoustic center is nearer
to the listening position. You will know your job is done once
the summation is 6 db above the XO point with the right null
reverse dip when poles are reversed.
by physical movement or baffle slanting and you are not using
asymmetric passive filters, then your option is to add amount of
electronic delay to the driver whose acoustic center is nearer
to the listening position. You will know your job is done once
the summation is 6 db above the XO point with the right null
reverse dip when poles are reversed.
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