Hi,
There are online reports of this tweeter (MCM 53-5165, http://www.farnell.com/datasheets/2329960.pdf) sounding very good above 2000Hz.
I plan to use it in a conical waveguide of 8" size and cross at ~1400Hz, 2nd order HP. Since the waveguide will give a bit of gain on the lower side of its range, is the xover too low or ok?
Thanks and Regards,
WonderfulAudio
There are online reports of this tweeter (MCM 53-5165, http://www.farnell.com/datasheets/2329960.pdf) sounding very good above 2000Hz.
I plan to use it in a conical waveguide of 8" size and cross at ~1400Hz, 2nd order HP. Since the waveguide will give a bit of gain on the lower side of its range, is the xover too low or ok?
Thanks and Regards,
WonderfulAudio
I do not have the math in front of me, bit , regardless of the tweeter, 1400 seems to be too low for an 8" wg. Best way to create a crossover is to take measurements and run a sim. Xsim is a more basic soft, but Vituixcad cad is probably the way to go. Just as reference revel crosses their two way with 6.5" about 2300Hz,
AllenB,
This is the waveguide profile
Practical DIY Waveguides - Part 3
to match as per Rod's design it can be crossed at 1.5Khz to an 8" midbass.
I dont want to go lower than 8" in order to have directivity control to a higher frequency than 6.5".
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Greets!
Don't know, the math is beyond me, so all I can say is that the most common R-O-Ts puts the effective mouth area at ~625 Hz which meets close enough the R-O-T Fc = 1/2 octave below Fs = 890*0.707 = ~629 Hz.
Don't have enough dimensional info about the tweeter to determine the theoretical optimal throat, hence depth, wall angle and if it is set at 90 deg. for a 1" and it needs to be smaller or larger, then this will of course change the mouth size, depth.
That said, a 90 deg wall angle with an effective 6.9" dia. mouth only loads down to ~10^6/[90*6.9] = ~1610 Hz, so doesn't quite meet Rod's 1500 Hz XO point, ergo less so at 1400 Hz, though whether it matters enough to be audible depends on the chosen woofer's polar response........and before there's any more confusion; lacking any tweeter power testing, by 700 Hz WG I mean it ideally needs to be a full 1/2 WL long = 350 Hz Fc since a conical expansion is very 'fast', the price one pays for reduced throat distortion.
Don't know, the math is beyond me, so all I can say is that the most common R-O-Ts puts the effective mouth area at ~625 Hz which meets close enough the R-O-T Fc = 1/2 octave below Fs = 890*0.707 = ~629 Hz.
Don't have enough dimensional info about the tweeter to determine the theoretical optimal throat, hence depth, wall angle and if it is set at 90 deg. for a 1" and it needs to be smaller or larger, then this will of course change the mouth size, depth.
That said, a 90 deg wall angle with an effective 6.9" dia. mouth only loads down to ~10^6/[90*6.9] = ~1610 Hz, so doesn't quite meet Rod's 1500 Hz XO point, ergo less so at 1400 Hz, though whether it matters enough to be audible depends on the chosen woofer's polar response........and before there's any more confusion; lacking any tweeter power testing, by 700 Hz WG I mean it ideally needs to be a full 1/2 WL long = 350 Hz Fc since a conical expansion is very 'fast', the price one pays for reduced throat distortion.
The data sheet does not contain much information, so there is no way to answer your question. I think 1400 Hz is fine for an 8" waveguide, as the Dutch & Dutch 8c is crossed at 1250 Hz. 8c - Dutch & Dutch
Forget about the reviews about the sound of the MCM, a waveguide will drastically alter any description of the sound. The dispersion, frequency response and distortion all will differ. Furthermore, if the waveguide throat does not match the tweeter, it could result in harsh peaks around 10 kHz that depend on how far you move off-axis, so they cannot be equalized.
Forget about the reviews about the sound of the MCM, a waveguide will drastically alter any description of the sound. The dispersion, frequency response and distortion all will differ. Furthermore, if the waveguide throat does not match the tweeter, it could result in harsh peaks around 10 kHz that depend on how far you move off-axis, so they cannot be equalized.
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