3 way using ATC midrange

[tech.knockout]

There are little/none established designs on the net regarding a 3 way using the S version of the ATC mid. (model SM75-150S).

The wilmslow kits are close, but all of the kits use the non S version of the unit. From what I searched Non-S versions are hard to find second hand. (Yes I must buy second hand, the difference in price is staggering). And something with decent sensitivity and higher spl would be nice.


Its best choose driver units that integrate well with this ATC dome, to keep crossover design as easy as possible. I will leave the crossover designing to an audio consultant if I cant find an appropriate established 3 way design. Maybe someone here can find it or someone who has done something similar themselves.


For now, can somebody suggest some good driver combinations and some design tips? The ATCs would take a large chunk of the budget, so no point suggesting things that are exotic and expensive like Raven tweeters.

This is what I come up with:

seas millenium tweeter
ATC
lambda TD12H

[thylantyr]

seas millenium tweeter
ATC
lambda TD12H

If you have the Lambda faraday motor I think you can get
good integration between the Lambda and ATC. These drivers
are 'premium drivers' costing $270 US for the Lambda and
~$450? US for ATC. Since you made it this far, you also
use premium tweeters (not that Seas are not).

[tech.knockout]

more like around $300US for ATC. I reckon the seas is good enough.


Is it wise to let a speaker consultant design the crossovers for me? From what I seen crossover design can be alot of guesswork and long hours

[gary f]

Call it pride but i would NEVER let any consultant toutch my speakers...

Seriously, all the fun of DIY is to end up with your own design. It may be long but it will be OK.

By the way, if you don't fell confident to get a crossover right, don't spend 1000$ on drivers. But i guess even a bad Xover would sound good with state of the art units.

F

[5th element]

Yes an excellent xover with low-medium quality components can makes the drivers really sing.

A not so good xover although implemented with a good dose of commonsense and fab drivers will also yield a pleasing result.

As the ATC unit has the ability to go quite high the hiquophon drivers are supposed to sound fabulous but require higher freq xovers. The higher you can push the xover the better with regards to leaving the region around 2k which the ears are sensitive to. Looking at a freq graph I would say you can use the ATC up to 7 or 8k. If you cant access software to help with design pushing higher would help.

[tech.knockout]

Nar I will leave it to an audio consultant and if it is too expensive this way , then I have to give up and go for an established design.

I cannot possibly design crossovers. The average person like me doesnt have speaker measurement equipment, advanced design software, and other capital etc etc.

[5th element]

Hmmm you can get measure speakers for free using loudspeaker workshop and building the wallin jig, mic preamp and a cheapo electrec condenser mic. The panasonic WM61A capsule is great for this.

The SWshop measuring doesnt hold a candle to Just MLS IMO but its is free after all.

[tech.knockout]

thylantyr, are u really sure the lambda will integrate well with the ATC---->designing a crossover for them wouldnt be that difficult? Have you used/using this woofer?

5th element, I dont have the expereince nor enthusiasm in building electronic stuff.

[SimontY]

Others will disagree, probably strongly, but I don't think you strictly need software, or measuring equipment to design a good, simple crossover.

Guesswork, and lots of experimentation over a long period of time can certainly get you there.

My experience of this is with kit speakers with which I never was really happy. The x-over was 2-way 2nd order with an impedance filter, just the run of the mill computer design no doubt. XO fr. was about 2-3khz I guess.

I am now using the bass driver full range and the tweeter 2nd order from about 5khz I guess, the sound is beguiling, immersive, satisfying, and non-fatiguing, with decent enough imaging.

I believe the numbers mean very little without knowledge to go with them, as we all like different sound, and in my case the standard design sounded harsh, fatiguing, thin, lacking in body, weight, detail, and realism.

I think part of the problem is having a x-over in the 'presence' region (2-6khz or thereabouts) where the ear is most sensitive.

4khz or higher gets you out of the fundamental range of all traditional musical instruments, leaving the tweeter to reproduce cymbals and harmonics, stress-free In this regard, using a super-duper midrange driver from ATC will probably make your speakers sound incredible.

[spd]

Hi

I don't see why you need the S version of the ATC unit. The standard unit is very loud and normally needs some attenuation anyway. Especially when considering baffle step.
I would recommend with the Seas tweeter that you crossover at 3.5kHz. The ATC unit is easy to crossover at this frequency as you can use the natural roll off with a simple 2nd order filter, assuming a 3rd order HF filter. The most difficult thing to design with the ATC is the lower crossover. I have found the best results using a 3rd order filter for the ATC. When combined with the natural roll off of the ATC at 380Hz you end up with 24dB/oct.
The bass driver will require a 4th order filter. (24dB/oclt) - this is very important to get right. alot of experimenting required here.
Also, the high order filters will help with power handling. I have had no problems driving my speakers with 300watts RMS.
The ATC is not easy to integrate with the Bass driver but once you do then the sound is amazing.