Okay I found Mackie SRM450 diaphragms on Ebay for less than 15 bucks a piece. Mackie uses pretty much identical HF horns on the SRM450, both also have the multi cell wave guide. They are identical to the originals. I'll get them ordered this Friday if possible and they should be here late June or early July.
I thought I'd take a few pics while I have one apart.
I thought I'd take a few pics while I have one apart.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
That looks a lot like a P Audio designed horn driver. If the voice coil is 1.75", then it's likely a P Audio BMD-440 or equivalent. Most pro audio repair shops should be able to hook you up with a replacement diaphragm for that, no problem.
If it's a 1.4" diameter voice coil, it's likely an SND-34 or something similar...
EDIT: Mackie does use a version of the BMD-440 in the SRM-450. You are right to be wary of the difference between one-piece-back diaphragms, and coils that use a separate back-cup and diaphragm- they do fit slightly differently, and are not inherently interchangeable, without at the very least, some fiddling and modification...
Regards,
Gordon.
If it's a 1.4" diameter voice coil, it's likely an SND-34 or something similar...
EDIT: Mackie does use a version of the BMD-440 in the SRM-450. You are right to be wary of the difference between one-piece-back diaphragms, and coils that use a separate back-cup and diaphragm- they do fit slightly differently, and are not inherently interchangeable, without at the very least, some fiddling and modification...
Regards,
Gordon.
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It's a BMD-440 alright. Found replacement diaphragms on Ebay for 15.50 a piece with free shipping. Will order them this Friday. 🙂
Got the diaphragms ordered, will update when they arrive.
Meanwhile, I have a question about damping.
As you can see in th first picture, the damping wool is folded up behind the woofer and doesn't reach the bottom of the box. Should it fill the whole back or is it supposed to be folded like that?
In the second picture you should be able to see that the plastic mold has these "pockets" for structural strenght. Would filling these with some wool or similar material give any improvements? I think I have some old cotton and foam left over from a bass cabinet build.
I apologize for the blurry pics, my phone's camera lens are seriously scratched up.
Meanwhile, I have a question about damping.
As you can see in th first picture, the damping wool is folded up behind the woofer and doesn't reach the bottom of the box. Should it fill the whole back or is it supposed to be folded like that?
In the second picture you should be able to see that the plastic mold has these "pockets" for structural strenght. Would filling these with some wool or similar material give any improvements? I think I have some old cotton and foam left over from a bass cabinet build.
I apologize for the blurry pics, my phone's camera lens are seriously scratched up.
would losing upper midrange be an an advantage? overstuffing could result in losing spl at the x-over region and make it sound worse, hard to say i guess...
the few phonic 450 i've heard seem reasonably well balanced/voiced so i can't say that your proposed mod would be beneficial
the damping wool shouldn't reach the bottom it would impede the ports
the few phonic 450 i've heard seem reasonably well balanced/voiced so i can't say that your proposed mod would be beneficial
the damping wool shouldn't reach the bottom it would impede the ports
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Eh, I'll bother you guys again. I haven't really used many active PA speakers before, so I don't know if this is right but when I use the EQ, bass boost seems to boost the midbass and lower midrange also. When I keep it at unity, it's nice and balanced. When I turn it down all the way, it sounds kind of cold, seems to cut the midbass but some of the very low freq. is still there. When I boost them, it boosts both the very lows and also mid bass, giving the speakers a very warm sound. Is this correct? As I said, I have not used many active speakers before. I run some bigger stuff through a Sony MXP-290 and there the bass EQ only boosts lows and there is a separate control for mids.
My guess is that the corner frequency for the bass control is at a relatively high frequency. It's probably actually boosting/cutting up to say, 200 Hz or so. That would definitely add "mud" to the midbass and lower mids, if you crank that up.
If you're frequently needing to boost the bass significantly, that, IME, is a warning sign, that you may not have enough speaker for the job. Might be time to start looking for a compact subwoofer of some sort, to augment what you have...
Regards,
Gordon.
If you're frequently needing to boost the bass significantly, that, IME, is a warning sign, that you may not have enough speaker for the job. Might be time to start looking for a compact subwoofer of some sort, to augment what you have...
Regards,
Gordon.
I don't really need to boost the bass, ever. These things have plenty of bass and punch even in a large outdoor setting. They are one of the loudest and heaviest sounding 12" speakers. I only asked about the bass EQ because I was testing if everything works and noticed this when I adjusted the bass. If I would ever have to adjust the bass, I can do it from my mixing console.
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