I'm new around here. I've been reading your posts relating to DIY speakers. Based on those, I think my questions should be cake for you guys. I am using Bassbox 6 Pro to design speakers for my new HT. I've built 3 or 4 speaker systems in the past. The first pair, in 1980 or so using drivers from a surplus store and no knowledge whatever resulted in a crappy end product, no surprise there. The pair of 6" 3-way mains and sub I'm using now was done with the help of the Advanced Speaker Design book and drivers from Radio Shack. The system sounds pretty good although the main cabinets don't provide enough bass to make a low enough transition to the sub for true "nondirectionality" of low freqs. And the sub is muddy and boomy with cabinet resonance (too little bracing and wrong port tune).
With the advent of Dolby PL IIx too "expand" my music, my new focus is on imaging and openess with low distortion. After much reading and talking with the guys at PE (I live not too far from Dayton) I've decided on mains and center using 2 or 3 5-6 1/2" midbasses and a dome tweeter with 3 sats and a sub based on the 15" Titanic III. A year ago I would have scoffed at 2-way mains but now I'm sold (I think).
Anyway to my ?'s.
Can quality midbass drivers (stiff-coned 5-7" woofers) paired with a good tweeter actually provide the range of a 3-way system?
My vented enclosure design shows a good rolloff with the 3dB drop at about 35 Hz and a flat response to about 500 Hz. But no matter what midbass/woofer I choose, Bassbox shows a sharp (12 dB @ 2kHz !) rise after 500 k. At this high frequency I wouldn't think box design would effect level. And, if I alter the box/port dimensions it indeed shows no real difference. This seems somewhat natural to me since I've always had to adjust my EQ in a V pattern with the dip at 500Hz or 1 kHz to get natural sound out of any system. But, shouldn't I see a flat response closer to the 3-6 kHz upper limit of these drivers? The manufacturer's published graphs show a much flatter response to far above 500 Hz. My lower limit in Bassbox shows roll off and frequency closely matching published graphs. I foresee a x-over point somewhere around 2.5 k so the spike above 500 Hz will remain in the finished system.
I just can't imagine why Bassbox shows this same result for 6 different approx. 6" drivers ranging from $15 Dayton's to $80 Vifa's.
Any help is gratefully appreciated.
With the advent of Dolby PL IIx too "expand" my music, my new focus is on imaging and openess with low distortion. After much reading and talking with the guys at PE (I live not too far from Dayton) I've decided on mains and center using 2 or 3 5-6 1/2" midbasses and a dome tweeter with 3 sats and a sub based on the 15" Titanic III. A year ago I would have scoffed at 2-way mains but now I'm sold (I think).
Anyway to my ?'s.
Can quality midbass drivers (stiff-coned 5-7" woofers) paired with a good tweeter actually provide the range of a 3-way system?
My vented enclosure design shows a good rolloff with the 3dB drop at about 35 Hz and a flat response to about 500 Hz. But no matter what midbass/woofer I choose, Bassbox shows a sharp (12 dB @ 2kHz !) rise after 500 k. At this high frequency I wouldn't think box design would effect level. And, if I alter the box/port dimensions it indeed shows no real difference. This seems somewhat natural to me since I've always had to adjust my EQ in a V pattern with the dip at 500Hz or 1 kHz to get natural sound out of any system. But, shouldn't I see a flat response closer to the 3-6 kHz upper limit of these drivers? The manufacturer's published graphs show a much flatter response to far above 500 Hz. My lower limit in Bassbox shows roll off and frequency closely matching published graphs. I foresee a x-over point somewhere around 2.5 k so the spike above 500 Hz will remain in the finished system.
I just can't imagine why Bassbox shows this same result for 6 different approx. 6" drivers ranging from $15 Dayton's to $80 Vifa's.
Any help is gratefully appreciated.
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