Hi sangram,
Post #40: "...at 82dB per sub as per my estimates, eight units will be 124dB/1m, and I might be able to get about 110dB at listening position with 1 watt..."
You might want to simulate this in Hornresp. I'll attach an example SPL comparing 1 (light grey) v. 8 (dark line):
Regards,
Post #40: "...at 82dB per sub as per my estimates, eight units will be 124dB/1m, and I might be able to get about 110dB at listening position with 1 watt..."
You might want to simulate this in Hornresp. I'll attach an example SPL comparing 1 (light grey) v. 8 (dark line):
Regards,
Attachments
double the output (+3dB) over a restricted frequency range by doubling the Sd.
quadrupling the output (+6dB) over an even more restricted frequency range by quadrupling the Sd.
eight ytimes the output (+9dB) by using 8times the Sd over a much reduced frequency range.
The restricted frequency range comes about because the "width" of the sound source is becoming bigger as more drivers are added to the array.
quadrupling the output (+6dB) over an even more restricted frequency range by quadrupling the Sd.
eight ytimes the output (+9dB) by using 8times the Sd over a much reduced frequency range.
The restricted frequency range comes about because the "width" of the sound source is becoming bigger as more drivers are added to the array.
Tb,
are you allowing Hornresp to increase the input power as you add more drive units to the array? Hornresp lets you input drive voltage. It then uses your s/p arrangement to generate the correct driver voltage.
The +17dB with 8units looks like +9dB from 6times the input power and another +8dB from the added Sd of the array.
are you allowing Hornresp to increase the input power as you add more drive units to the array? Hornresp lets you input drive voltage. It then uses your s/p arrangement to generate the correct driver voltage.
The +17dB with 8units looks like +9dB from 6times the input power and another +8dB from the added Sd of the array.
My understanding was that halving the impedance doubles the input power to the array, I was simplifying by adding +6dB for each driver which is incorrect.
I stand corrected. Thanks to tb46 and AndrewT, and for bart-west for pointing out the error. I can only hope that the lower than originally estimated SPL will be enough. I suspect given the casual approach to (and expectations from) the project, I might still be able to get away with it. I'm shooting for reasonable output in a 20x22 room between 30 and 60Hz, so a very narrow-band sub with some usable output down to about 27Hz - mostly for home theater.
I stand corrected. Thanks to tb46 and AndrewT, and for bart-west for pointing out the error. I can only hope that the lower than originally estimated SPL will be enough. I suspect given the casual approach to (and expectations from) the project, I might still be able to get away with it. I'm shooting for reasonable output in a 20x22 room between 30 and 60Hz, so a very narrow-band sub with some usable output down to about 27Hz - mostly for home theater.
Hi AndrewT,
The Hornresp Multiple Speakers function maintaines the input Eg, and handles the resistance according to the series/parallel connection you specify. In this case 8 in parallel (see: Post #40). There was a long discussion on the subject of multiple speakers, and resulting combined SPL (as handled in Hornresp) somewhere here in diyaudio.
Gotta run.
Regards,
The Hornresp Multiple Speakers function maintaines the input Eg, and handles the resistance according to the series/parallel connection you specify. In this case 8 in parallel (see: Post #40). There was a long discussion on the subject of multiple speakers, and resulting combined SPL (as handled in Hornresp) somewhere here in diyaudio.
Gotta run.
Regards,
tb46 and Andrew, thanks for your help. I finished this project today. I'm running the 8 as two groups of 2 ohm arrays, off 8 chipamps (also configured as 4 parallel/channel x 2 channels) with active cooling.
The subs have far more headroom than either my ears or the 90dB/W Wharfedale speakers I'm using them with. This is more than adequate for home theater usage, is able to go far louder than I will ever need them to, low bass is pretty good though being very basic drivers they do not have much below 25Hz. I do have enough headroom to apply EQ so maybe that's next on the cards.
The subs have far more headroom than either my ears or the 90dB/W Wharfedale speakers I'm using them with. This is more than adequate for home theater usage, is able to go far louder than I will ever need them to, low bass is pretty good though being very basic drivers they do not have much below 25Hz. I do have enough headroom to apply EQ so maybe that's next on the cards.
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