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 Post subject: My kinda speaker
PostPosted: July 14th, 2018, 7:11 pm 
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Joined: July 17th, 2016, 6:24 am
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 Post subject: Re: My kinda speaker
PostPosted: July 14th, 2018, 8:02 pm 
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Joined: July 8th, 2016, 4:34 pm
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What's the cut off frequency of the big horn?


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 Post subject: Re: My kinda speaker
PostPosted: July 14th, 2018, 8:10 pm 
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brombo wrote:
What's the cut off frequency of the big horn?


Good question. I was wondering about disconnect between horns.
I would assume the bass horn goes up to 100Hz and black horn goes down to about 400 Hz.


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 8:51 am 
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Joined: January 15th, 2015, 7:19 am
Posts: 1697
Location: Baltimore MD
I always been curious to why it's considered that the launching point is at the VC and not the opening.
Maybe I can see that with horns but what about conventional drivers


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 10:14 am 
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Joined: July 24th, 2015, 4:17 pm
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Location: Parkville, Maryland
Pelliott321 wrote:
I always been curious to why it's considered that the launching point is at the VC and not the opening.
Maybe I can see that with horns but what about conventional drivers



The launching point would be at the voice coil. I recall when the late David Wilson was dialing in a pair of WAMMs here in Baltimore he used a dual-trace scope and pulses to line up the multiple drivers. When all was said and done they were all neatly aligned voice-coil-to-voice-coil. Since he was going for drivers' output to arrive at a point (the prime seating position) they were arranged in a way (kind of an arc) so that they were all aimed at that seated position.

The thing was that with all of those drivers including the electrostatic tweeters, as big as that system was, it sounded as one. Most manufacturers do not try to do that but Vandersteen and Dahlquist -- as but two examples -- made the effort in production speakers.

Of course Magnepans and electrostatic speakers are time-aligned by default. My horn-based system has an add-on ring tweeter that once time-aligned with the 800-Hz horn it joined the party and sounds as one driver not two.

I've sat in front of a big system a while back that had a tweeter tower, mid-range tower, and sub-woofers. It was not time aligned and that was immediately evident because of disjointed reproduction. It felt as though I was listening to three systems that could not synchronize and work together. It simply was not "speaking" with one voice.

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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 11:08 am 
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Pelliott321 wrote:
I always been curious to why it's considered that the launching point is at the VC and not the opening.
Maybe I can see that with horns but what about conventional drivers


I see your point. Time aligning sub bass horn is impossible but Mid and HF horns should be time aligned.

For compression drivers diaphragm is the launching point and for cone drivers, cone is the launching point.


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 11:24 am 
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Alignment possible with dsp crossover.


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 11:35 am 
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Joined: February 28th, 2013, 3:31 pm
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Actually time alignment of any speaker is relatively simple if you do it electronically. Doing it multi amped is better but you can also do it with a single amp by doing the alignment in frequency bands that correspond to the ranges in which the drivers are operating. With passive crossovers the result is not as good as there is some overlap of the drivers but it is much better than nothing.

Now that I have moved the eggs up to my living room I will be doing some work with my DEQX on among other things time alignment. Since the eggs also have a passive crossover I will be able to do threee major things that should be interesting. The first is to run the eggs with the DEQX in essentially bypass mode where it basically acts as a high quality DAC feeding a single amp. In this scenario, the passive crossover does all the work. The next condition will be to also use the DEQX as the DAC with a single amp through the passive crossover but use the DEQX to do time alignment within the frequency bands for each driver and also speaker and room EQ as needed. The third condition will be to do a full blown triamped system with all the whistles and bells in the DEQX. The DEQX will be able to store the settings of the three scenarios so we can reproduce the tests anytime at will. It should make for a good meeting at some later date but we would have to do the listening in shifts as my living room is not very large.


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 12:10 pm 
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Joined: July 8th, 2016, 4:34 pm
Posts: 570
For those of you who prefer linux over windows take a look at the following -

https://github.com/bmc0/dsp/wiki/System-Wide-DSP-Guide

I am going to eventually implement my dsp crossover with this software and a xonar essence stx ii 7.1 card. Three way crossover for a stereo pair. Two cbt36k's with associated 18 inch subwoofers. All speakers are parts express kits.


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 Post subject: Re: My kinda speaker
PostPosted: July 15th, 2018, 12:19 pm 
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Joined: January 15th, 2015, 7:19 am
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Location: Baltimore MD
just as a thinking exercise, time alignment can only be done at specific frequencies.
Using the voice coil as the measuring point, what about all the other launching points at different frequencies along the cone.


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