I designed the hardware and wrote the software for that measurement. That was a long time ago.
This board has quite a few threads on speaker measurement equipment.
Ed
This board has quite a few threads on speaker measurement equipment.
Ed
Just measure. The tweeter is less efficient than the woofer. The electrical dip at the crossover shows up acoustically as part of the bass boost.
Ed
Ed
Am I mis understanding something? With the tweeter at -9db, isn't the tweeter more efficient? Or should the bass panels be at -9db?
You need to set your active crossover to match the electrical response of the stock crossover that I posted in #8.
The low-pass section is 12dB/octave with a -3dB frequency of 230Hz. The high-pass section is 6dB/octave with a -3dB frequency of 1.6KHz.
Make sure that the polarity is reversed on the tweeter.
I suspect that the active crossover has not been set up properly because the stock MG1.6 has strong mid-bass.
Ed
The low-pass section is 12dB/octave with a -3dB frequency of 230Hz. The high-pass section is 6dB/octave with a -3dB frequency of 1.6KHz.
Make sure that the polarity is reversed on the tweeter.
I suspect that the active crossover has not been set up properly because the stock MG1.6 has strong mid-bass.
Ed
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The crossover between drivers is exactly per your post. However, I did not mention that the bass panels also has a high pass at 60hz, 24db slope, with the lower signal mixed into my sub...
This probably eliminates the hump for my speakers.
This probably eliminates the hump for my speakers.
Okay, the high-pass at 60Hz would counteract the bass panel's lowest resonance.
I am probably not going to be of further help since you are charting new territory. 🙂
Ed
I am probably not going to be of further help since you are charting new territory. 🙂
Ed
Not too different from what you are doing. I recently completed work on a pair of 3.7i speakers. They have active crossovers now and we added these slender woofer boxes with two 12" Eminence woofers in each to take over the bass at 100 Hz. So they handle 27Hz up to 100 Hz. The results are really great. If you plan to have the woofers close to the panels it's good to place them at right angle to the Magnepans so they don't push the membranes around with the bass.
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Old memories of hearing the Martin Logan E2 Statements. Anyone know which mid bass driver they used as the clarity was in matched IMHO.
Hi,
while a digital LMS is a powerful tool it can't solve the problem of differing distribution character between dipole and monopole.
With the system I've shown above, as well as the ML Statement2, the problem is tackled in a way that with falling frequencies the transitions from dipolar cylindrical to dipolar lobed to monopolar are smooth.
The hard break in distribution character between a too high xovered monopolar sub and a dipole leads to the often experienced slow and lagging bass sound.
jauu
Calvin
while a digital LMS is a powerful tool it can't solve the problem of differing distribution character between dipole and monopole.
With the system I've shown above, as well as the ML Statement2, the problem is tackled in a way that with falling frequencies the transitions from dipolar cylindrical to dipolar lobed to monopolar are smooth.
The hard break in distribution character between a too high xovered monopolar sub and a dipole leads to the often experienced slow and lagging bass sound.
jauu
Calvin
The behavior depends on the wavelength of sound (1KHz is ~1 foot wavelength).
A dipole has a figure-eight radiation pattern. At high frequencies, the wavelength is short compared to the dimensions of the speaker and so the front and rear waves act independently. At low frequencies, the wavelength is long and so cancellation occurs. Dipole speakers are designed to compensate by boosting low frequencies.
A monopole has a spherical radiation pattern. Due to the baffle, box speakers are omnidirectional at low frequencies but become front-firing at high frequencies. This produces the characteristic box speaker sound. For your purpose, the woofer will be omnidirectional.
I think Calvin has stated the key to success - the transitions have to be gradual.
Ed
A dipole has a figure-eight radiation pattern. At high frequencies, the wavelength is short compared to the dimensions of the speaker and so the front and rear waves act independently. At low frequencies, the wavelength is long and so cancellation occurs. Dipole speakers are designed to compensate by boosting low frequencies.
A monopole has a spherical radiation pattern. Due to the baffle, box speakers are omnidirectional at low frequencies but become front-firing at high frequencies. This produces the characteristic box speaker sound. For your purpose, the woofer will be omnidirectional.
I think Calvin has stated the key to success - the transitions have to be gradual.
Ed
I believe that Martin-Logan claims their woofer module transitions smoothly from dipole to monopole. I don't know how they do that.
Ed
Ed
You should do the best setup you can get without (!!!) Dirac, then, when things are working well, run it.