Hi
I have a pair of Mission M33i floorstanders here that need replacement mid/bass drivers (amp malfunctioned and died).
The speakers didn't cost me anything and I don't want to spend much on a solution. The usage will be playing loud rock music and EDM in my workshop whilst me and the wife workout in our gym.
I can find the right size (hole spacing & cutout) easily enough.
My question is, the frequency response. The original drivers are 48Hz to 20,000Hz.
The replacements are likely to be ~35Hz to 8,000Hz.
My understanding (from a mate who may or may not know) is that for my intended use, I don't need frequency response much above 8,000Hz, recognising this is not an audiophile kind of setup at all. It just needs to be clear and loud. Overtones, harmonics, headroom etc, not so important (I think).
The specs of the originals can be found here: Mission M33i
The likely replacement can be found here: Possible replacement
I know nothing at all about crossovers and so on... just considering taking a punt.
Any advice gratefully received.
Thanks.
I have a pair of Mission M33i floorstanders here that need replacement mid/bass drivers (amp malfunctioned and died).
The speakers didn't cost me anything and I don't want to spend much on a solution. The usage will be playing loud rock music and EDM in my workshop whilst me and the wife workout in our gym.
I can find the right size (hole spacing & cutout) easily enough.
My question is, the frequency response. The original drivers are 48Hz to 20,000Hz.
The replacements are likely to be ~35Hz to 8,000Hz.
My understanding (from a mate who may or may not know) is that for my intended use, I don't need frequency response much above 8,000Hz, recognising this is not an audiophile kind of setup at all. It just needs to be clear and loud. Overtones, harmonics, headroom etc, not so important (I think).
The specs of the originals can be found here: Mission M33i
The likely replacement can be found here: Possible replacement
I know nothing at all about crossovers and so on... just considering taking a punt.
Any advice gratefully received.
Thanks.
That is the frequency response of the entire 2-way speaker combination, not to be confused with the frequency range of the bare mid/bass drivers.
The tweeters handle the upper range of frequencies as determined by the crossover, typically from 3,000 Hz upwards.
https://www.hifidatabase.com/Mission_m33i_971.php
The Thiele/Small parameters for the possible Kevlar cone mid/bass replacements state a Qts of 0.35.
All I can say is that this value indicates suitability for a vented enclosure like that of the Mission M33i.
If the driver physically fits the opening then you would wire it along with the existing crossover and tweeter and keep your fingers crossed that this will produce a satisfactory result for your intended workshop usage.
Unfortunately, an optimal approach would require the use of measuring equipment and a thorough knowledge of loudspeaker design.
P.S. If the tweeters don't work then don't wire up the crossovers, but connect the mid/bass replacements directly to the speaker input terminals. The upper frequency extension of 8,000 Hz provided by the replacements alone should be sufficient for your purposes - I know that I can't hear pure tones above that frequency!
Good luck.
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If the tweeters have also been damaged and are no longer 'tweeting', remember to completely disconnect the crossover circuit from the loudspeaker input terminals and connect only the mid/bass driver to the terminals. Failure to do so could result in amplifier damage with certain crossover designs.
If the tweeters 'tweet', then by all means keep the original crossover wiring arrangement.
Do let us know how the rescued speakers end up sounding to you.
If the tweeters 'tweet', then by all means keep the original crossover wiring arrangement.
Do let us know how the rescued speakers end up sounding to you.
Well blimey that was successful.
I tested the tweeters - fine.
The replacement drivers slotted straight in, fixing holes didn't quite line up so carefully drilled some new ones.
Hooked up an old mid-90s JBL subwoofer to the 1992 Cyrus 2 amp, and the speakers to the sub outputs. Played some gentle dub for half and hour then turned it up a bit. The wife comes out and says "that sounds better than they did before".
And it does. Heaps more bass from the new drivers that the M33s managed. The sub hasn't been used for a while but still sounds great. For a shed gym setup, it's a 10/10.
Cost me NZD92 to repair. Stoked!
Thanks for the help fellas.
I tested the tweeters - fine.
The replacement drivers slotted straight in, fixing holes didn't quite line up so carefully drilled some new ones.
Hooked up an old mid-90s JBL subwoofer to the 1992 Cyrus 2 amp, and the speakers to the sub outputs. Played some gentle dub for half and hour then turned it up a bit. The wife comes out and says "that sounds better than they did before".
And it does. Heaps more bass from the new drivers that the M33s managed. The sub hasn't been used for a while but still sounds great. For a shed gym setup, it's a 10/10.
Cost me NZD92 to repair. Stoked!
Thanks for the help fellas.
Thanks for the eagerly awaited report.
It just goes to show:
I wish you many happy workouts!
Thought I'd add an update...
I replaced the Cyrus 2 with a cheap 4 way amp from a wholesale audio shop I know in Auckland. A mate runs the same unit and it's great for the purpose.
Bought two more of the replacement 6.5" drivers linked in post #1 and changed out the old damaged drivers in a pair of M64i Mission floorstanders. Got some new banana plugs while I was at it.
Went up into the loft and dug out the original 1993 speaker cable, Esoteric PA101 AWG 12-4. I know guys get a bit cranky about flash cables, but this stuff makes an incredible difference. I bought it when I bought my original set up - Cyrus 2, PSX, Mission 753, Phillips CD850 Mk2. All those units are still in use.
Re-did everything, tested each speaker individually and then together with the old JBL sub. So four floorstanders, one sub, the original Phillips CD.
Blast off!
I replaced the Cyrus 2 with a cheap 4 way amp from a wholesale audio shop I know in Auckland. A mate runs the same unit and it's great for the purpose.
Bought two more of the replacement 6.5" drivers linked in post #1 and changed out the old damaged drivers in a pair of M64i Mission floorstanders. Got some new banana plugs while I was at it.
Went up into the loft and dug out the original 1993 speaker cable, Esoteric PA101 AWG 12-4. I know guys get a bit cranky about flash cables, but this stuff makes an incredible difference. I bought it when I bought my original set up - Cyrus 2, PSX, Mission 753, Phillips CD850 Mk2. All those units are still in use.
Re-did everything, tested each speaker individually and then together with the old JBL sub. So four floorstanders, one sub, the original Phillips CD.
Blast off!
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