Thinking of cobbling together MarkAudio Pluvia 11 (7.1ohm) with a Tannoy 8" Bass woofers (4.5ohm) beneath.
The more I read on crossover design the less certain I become about how to proceed.
The bass woofers were crossed at 400hz in the 611mk2 so planned to build xover at this frequency.
Tried plenty calculators but much advice says that experimentation is more useful than the calcs.
Aside from binning the project, what would you do?
The more I read on crossover design the less certain I become about how to proceed.
The bass woofers were crossed at 400hz in the 611mk2 so planned to build xover at this frequency.
Tried plenty calculators but much advice says that experimentation is more useful than the calcs.
Aside from binning the project, what would you do?
The resistance data that you measured refers to the Re, which is the DC resistance ( of the coil). It goes that the nominal impedance ( resistance at AC...) is 8 Ω for the MA and 6 Ω for the Tannoy.
Yes, you can leave the present part of the crossover that goes to the woofer - lowpass @ 400 Hz- and arrange a matching ( mirroring...) high-pass for the MA.
If the actual filter is 2nd order for the woofer, you can experiment with 1st order for the MA. If excursion is too high, try 2nd order ( also if the steepness of the two curves is no good,i.e. they don't match, like too much overlap or "holes" in between etc. ).
But first, I would analyze the present crossover ( if you have it..!?) and see how it is conceived.
Yes, you can leave the present part of the crossover that goes to the woofer - lowpass @ 400 Hz- and arrange a matching ( mirroring...) high-pass for the MA.
If the actual filter is 2nd order for the woofer, you can experiment with 1st order for the MA. If excursion is too high, try 2nd order ( also if the steepness of the two curves is no good,i.e. they don't match, like too much overlap or "holes" in between etc. ).
But first, I would analyze the present crossover ( if you have it..!?) and see how it is conceived.
Not long ago, I must have had a brain hiccough or something and decided to play with the near-infinite crossover possibilities of my Behringer DSP. Based on that extended examination of slopes and frequencies and theoretical models, I conclude it makes remarkably little difference although I am hesitant about defining "remarkably".
In other words, if you examine the freq plot of your drivers and choose an XO point they are happy with, wiring up (or much, much better, buying a DSP and an extra second-hand stereo amp) a 12 dB/8ave XO, theoretical model be damned, you will be happy. (Hint: buy extra components so you can match-up L and R.)
There are some very elaborate crossovers like the famous BBC mini-speaker with 18 elements. The purpose of the extra elements are to shape the tone, not to make the XO theory more true. And that is done as the last empirical step.
When you are up and running, you can EQ the system in various ways.
B.
In other words, if you examine the freq plot of your drivers and choose an XO point they are happy with, wiring up (or much, much better, buying a DSP and an extra second-hand stereo amp) a 12 dB/8ave XO, theoretical model be damned, you will be happy. (Hint: buy extra components so you can match-up L and R.)
There are some very elaborate crossovers like the famous BBC mini-speaker with 18 elements. The purpose of the extra elements are to shape the tone, not to make the XO theory more true. And that is done as the last empirical step.
When you are up and running, you can EQ the system in various ways.
B.
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Why don't you post the data sheets of the drivers, including impedance plot, so we can help you?
"woofers were crossed at 400hz" - why?, is this the baffle step frequency? If crossing at ~ 400 Hz you are likely to be able to use a simple first order crossover if the drivers are well behaved
"woofers were crossed at 400hz" - why?, is this the baffle step frequency? If crossing at ~ 400 Hz you are likely to be able to use a simple first order crossover if the drivers are well behaved
Re crossover advice
Thanks for the suggestions folks.
Pluvia11 parameters listed below.
Impedance plot attached alongwith
Crossover schematic from 3-way Tannoy 611.
Some online posts suggest 400 hertz too high for woofer xover and suggested lowering to 150.
Can't find any parameters for the Tannoy woofer at all. Would you advise replacement with a driver of known specs?
RE 5.4 Ohms
FS 39.118
SD 109.359 cm²
VAS 24.751 ltr
CMS 1.457m M/N
MMD 10.7 m Kg
MMS 11.358 g
BL 6.556 TM
QMS 1.797
QES .351
QTS .293
LE 68.550 uH
SPL 88.131 dB
X Max 7mm 1 way
POWER (NOMINAL)
45 Watts
POWER (MAXIMUM)
90 Watts
Thanks for the suggestions folks.
Pluvia11 parameters listed below.
Impedance plot attached alongwith
Crossover schematic from 3-way Tannoy 611.
Some online posts suggest 400 hertz too high for woofer xover and suggested lowering to 150.
Can't find any parameters for the Tannoy woofer at all. Would you advise replacement with a driver of known specs?
RE 5.4 Ohms
FS 39.118
SD 109.359 cm²
VAS 24.751 ltr
CMS 1.457m M/N
MMD 10.7 m Kg
MMS 11.358 g
BL 6.556 TM
QMS 1.797
QES .351
QTS .293
LE 68.550 uH
SPL 88.131 dB
X Max 7mm 1 way
POWER (NOMINAL)
45 Watts
POWER (MAXIMUM)
90 Watts
Attachments
I would based solely on this since it's apparently designed to primarily just add some 'fullness'/'warmth' to vocals, higher tuned instruments: http://www.audiocostruzioni.com/r_s/diffusori/diffusori-5/tannoy-611II/tannoy-611-II.htm
ROTFLMAO! Thanks! I needed a good laugh. 😉
GM
ROTFLMAO! Thanks! I needed a good laugh. 😉
GM
" suggest 400 hertz too high for woofer xover " - no it's not, but as I hinted above, I'd base the crossover freq. on your baffle width. So the crossover frequency would be (115/ baffle width in metres). Next, you need to find the impedance of each speaker at that frequency, to use in your parts value calculations. If you look at the graph you posted, you'll see that most drivers in the low hundreds have an impedance slightly above the measured Re, so you can use that for your Tannoy calculations.
For a simple first order crossover, Rod Elliot gives these formulas here: Passive Crossover Network Design :
C = 0.159 / ( Z × fx )
L = ( 0.159 × Z ) / fx
where Z = (actual) impedance of the speaker in ohms
For a simple first order crossover, Rod Elliot gives these formulas here: Passive Crossover Network Design :
C = 0.159 / ( Z × fx )
L = ( 0.159 × Z ) / fx
where Z = (actual) impedance of the speaker in ohms
To take maximum advantage of the P11 i would suggest XO as low as 200-300 Hz, and down that low ir makes a lot of sense to bi-amp and put the XO before the amps.
Trying to do a passive that low is difficult due to teh driver’s resonance peaks.
With this consideration XO should be placed somewhere between (0.707 to 1) times the BS(-3) ~4560/(baffle width in inches) [value from Olson’s experimental data].
dave
Trying to do a passive that low is difficult due to teh driver’s resonance peaks.
s)
With this consideration XO should be placed somewhere between (0.707 to 1) times the BS(-3) ~4560/(baffle width in inches) [value from Olson’s experimental data].
dave