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Re: SPC designs

Posted by seancuster71@gmail.com (P) on December 26, 2024 at 23:12:27

In Reply to: Re: SPC designs posted by Inmate51 on December 17, 2024 at 20:31:43:

Sorry if you assume I am defensive. And yes, I am passionate about the sound reproduction of all speakers from the 1930's to present including full-range drivers. As far as my measurements, how could they help you know anything other than they have a flat response and what frequency range they have. Measurements as important as they are can't tell you how a speaker sounds. You can have two 2-way speakers both using different 8" drivers with different 1" silk dome tweeters both can play flat from 45 HZ to 20,000 KHZ but one could sound better than the other so how would you know from measurements.

As far as all my measurements go they are all taken with the driver in the cabinet that was designed for it. So, If you want to compare my measurements with the manufactures it wont work because the manufacturer measures drivers in free air not in cabinets. So If you measure a speaker's frequency response in free air then in a ported cabinet then a sealed cabinet you would see the all are slightly different including the impedance. For example a woofer in a sealed cabinet will only have one impedance spike while the same woofer in a ported cabinet will have two impedance spikes.

If I had a Visaton bg-20 8" full-range and I measured it in a 1 cubic ft sealed cabinet, it would have a F3 of 73 HZ put that same driver in a 1.5 cubic ft ported cabinet you now have a F3 of 45 HZ HUGE difference!!!! So, my measurements are taken from different ways the drivers are used in the designs I have used them in so I am having a hard time understanding how this would help you in any way.

And as far as measurements go do you know how measuring drivers work? It is not a picture of a frequency response and a picture of an impedance response. When you measure a driver you are getting a file its called either a FRD file that is for frequency response or a ZMA file that is impedance response you then have to upload these files into simulation software then you will see their response on a graph which is what your thinking of when some one like a designer or manufacturer takes a screenshot of a driver's FRD or ZMA while those files are open in simulation. All my measurements are in the form of FRD & ZMA files not pictures. I have plenty of FRD & ZMA files of various drivers measured in the cabinets they were designed for. If you wanted to see them, you would need to upload them into simulation software to view them and their response will not match the manufacturers who measure in free air.

And would you also like waterfall graphs and polar plots for drivers? These are important if you want to look at drivers decay or dispersion. Do you want to see the filter response and group delay along with current and voltage measurements? How about the impulse and step response.
What measurements are you interested in because all play a factor in the design of a speaker, not just frequency response like people think. Makes no sense to look at speaker measurements and look just at frequency and impedance. That's like buying a car based only on its 0 to 60 times. It makes no sense what if it goes 0 to 60 faster than any car but takes twice as long to stop? Would you still buy it?


You said it yourself you like to learn so If I was you i would start with Vance Dickson loudspeaker cookbook I would also check into buying Clio pocket 3.0 or Dayton Omni Mic & DATS V3

And to stop you from bugging me about my speaker designs & measurements I will design and build a speaker and post the process here in this forum. I have a couple designs in mind. One is a transmission line using small drivers like 8" so maybe a 8" full range with a tweeter. Or I do have some empty cabinets 14" wide 14" deep 26" tall, maybe a 12" with a 8" full-range and a small format compression driver on a small waveguide, a modern version of an electro voice Leyton, a speaker made between 1950 to 1960. Or I could do a 10" woofer in my 14 x 14 x 26 cabinets with a 4" to 6" full-range and a nice dome tweeter. I will sit down after new year's and figure out what design, then I will order the components and start the build. This should be pretty fun. Maybe I could even video the process of how to design the crossover, post videos on you tube and share those videos here in the forum.

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