Large 4 way using Active Crossovers

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#101
LewinskiH01 said:
Right. I also use active. Nevertheless the physics aren't affected and if your xo frequency is such that the corresponding half of a wavelength is larger than the MTM center to center distance, generally lobbying becomes an issue. Hence all the questions. But you don't seem very interested in hearing that.
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You better write to Wilson and tell him he has it wrong too. 😱😀

Dunlavy used or invented the Vertical Symmetrical Array(VSA) which people constantly think is D’Apolito, but it’s a different mindset. D’Apolito is a concept for near field monitors, and can work fine. Dunlavy was an antenna designer & VSA was big in that field for focusing energy based on optimisation of signal delivery. Speaker design is similar but at dramatically lower frequencies. I don’t know of another antenna engineer who designs speakers, but Dunlavy’s were the flattest ever tested, pass a Square wave, deliver thunderous bass & are efficient, and low distortion due to multiple drivers sharing the load. so that’s why we copy his.
 

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#102
phase_accurate said:
It is the inverse actually. If the center to center distance is getting larger than half the wavelength the lobing issues begin. If it were the other way around it would be quite easy to fulfil.
While lobbying can be an issue in politics it is defilitely lobing that is an issue with loudspeakers ! 😉

I run a large MTM that doesn't fulfil D'Appolito's distance requirement either. But it does still profit from the increased vertical directivity at lower frequncies and the fact the lobing is symmetrical (I am experimenting with crossover topologies having improved transient response that are otherwise problematic with TM topologies).

Regards

Charles
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In active system the midrange can be to "hard in the face" i have noticed.

My 2" soft dome is a little nasty at 3kHz. Do you recommend to lean it upwards to avoid the center radiation or any other trix?

(it was a no baffle half horn test)

Cheers!
 

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#103
phase_accurate said:
While lobbying can be an issue in politics it is defilitely lobing that is an issue with loudspeakers ! 😉

I run a large MTM that doesn't fulfil D'Appolito's distance requirement either. But it does still profit from the increased vertical directivity at lower frequncies and the fact the lobing is symmetrical (I am experimenting with crossover topologies having improved transient response that are otherwise problematic with TM topologies).

Regards

Charles
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Hehe. Can I take cover saying I'm not a native English speaker? 😁

I'm interested in learning more about your experience with MTM with large M-to-M relative to xo frequency. How perceivable was lobing? (unlike lobbying, which is designed to be unperceivable, or loving, which is kind of evident).

FWIW I'm working with linear phase xo, time aligned. Experimentig with 6" midranges and a 9" AMT tweeter, at 2kHz. And reaching low with the midrange is not particularly valuable as it's a 4-way.
 
#104
Just take into account that you don't listen to your speakers at 1 or 2 metres. Usually you sit at least 3 to 4 metres away. Any design you do should take into consideration the listening distance. No one sits 1 metre from the speakers. There is one sweet spot. The Sovereigns were designed for listening to at a distance of 3.3 metres/11 feet and the distance centre to centre of the mid ranges is 310mm.
 
#105
Great post! I built an SCIV clone with Dunlavy inspiration. The SCV used a Vifa M30 12”. The SCVI used custom made Emminence 15” subs. Someone posted the specs here long ago but it was an infinite baffle design. Years back, Andrew Rigby replied with a list of the drivers they were using. Rigby represented DAL. Thanks again and post more!
 
#106
mickiboi007 said:
Dunlavy used or invented the Vertical Symmetrical Array(VSA) which people constantly think is D’Apolito, but it’s a different mindset. D’Apolito is a concept for near field monitors, and can work fine. Dunlavy was an antenna designer & VSA was big in that field for focusing energy based on optimisation of signal delivery. Speaker design is similar but at dramatically lower frequencies. I don’t know of another antenna engineer who designs speakers, but Dunlavy’s were the flattest ever tested, pass a Square wave, deliver thunderous bass & are efficient, and low distortion due to multiple drivers sharing the load. so that’s why we copy his.
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Where can I learn more about Dunlavy's design approach? I searched online and hit reviews from 2001/05 suggesting Dunlavy's website had a lot of technical info, but that website is probably down now. I've been exploring MTM but coming from D'Appolito point of view. Dunlavy might be what I'm searching for.
 
#108
speedygg1 said:
Great post! I built an SCIV clone with Dunlavy inspiration. The SCV used a Vifa M30 12”. The SCVI used custom made Emminence 15” subs. Someone posted the specs here long ago but it was an infinite baffle design. Years back, Andrew Rigby replied with a list of the drivers they were using. Rigby represented DAL. Thanks again and post more!
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Any pictures speedy? I would love to see them.
 
#111
So its been 5 months since I have finished my speakers.

They continue to amaze me every day. They are without a doubt one of the best speakers I have ever heard at any price. The sonic clarity, dynamic presence, sound stage and pinpoint vocals that sit on the tip of your nose are simply stunning.

There is no doubt what so ever that active speaker systems are definitely the way to go. The mid range is spectacular. Those tiny little 3 1/2" ScanSpeak drivers are superb.

The Ultimate Preamp is one hell of a product.
 
#112
mickiboi007 said:
So its been 5 months since I have finished my speakers.

They continue to amaze me every day. They are without a doubt one of the best speakers I have ever heard at any price. The sonic clarity, dynamic presence, sound stage and pinpoint vocals that sit on the tip of your nose are simply stunning.

There is no doubt what so ever that active speaker systems are definitely the way to go. The mid range is spectacular. Those tiny little 3 1/2" ScanSpeak drivers are superb.

The Ultimate Preamp is one hell of a product.
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Don't remember the case. Can you send some present photos of the build?
 
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