@DrewsBrews said:
If ya squint hard enough, both are a leaky enclosure spilling into another space. Technically yes-different, since one space shares the same space as the front of the cone while the other does not.
So, I am thinking something between the two. Ported or sealed. This is what I was talking about. Is there software to sim this?
@a4eaudio said:
A couple of comments on "aperiodic" which was mentioned a few times above.
When Ben has talked about his ice-cream sandwich method, he is using a multichambered aperiodic sealed box - it is actually two sealed boxes with the divider causing an aperiodic effect between the two sealed boxes. But it is not leaking to the outside world. He does this to reduce the impedance peak.
A normal aperiodic box for the woofer brings down the "hump" in a "too-small-box", something like the Q=1.2 above. It is a resistant port between the sealed box and the outside world. You can model it in the Advanced Box Settings of WinISD by setting Ql to 3.
I am not getting these posts in order. I have to go back and read them. They pop up at random. I refresh and I still have to go way back and posts that I didn't see before. Anyway, carry on...
@DrewsBrews said:
...Both would seem to achieve a similar effect of taming an otherwise excitable bottom end for the driver. Maybe I'm just oversimplifiying
I'm not disagreeing with you. I'm not sure how to model the multichamber sealed version, but the typical reason for a normal aperiodic box is to reduce the Q in a too-small box. This seems particularly relevant to your WinISD image above. Analogkid may already know all of this anyways, but looking at your box model above I thought this might be a good candidate for a normal aperiodic box.
Completely different driver but here is a Q=1 sealed and Q=0.90 in the same box aperiodic. Of course if you saved your model above, just change Ql to 3 and we can see what it does to the actual drivers under discussion.
Seeing what Infinity had to do to the crossover tells me a ton. Crazy they would spend that much on crossover parts to fix sh!t drivers. Although They didn't use very good crossover parts. I think these drivers could have been good with a bigger magnet to lower total Q and a bit better Bl. The Mms is super low which is good. These things have tiny magnets on them.
Not that I want to start off this sort of argument... but maginets aren't all created equally. alot of the MCM drivers have pretty big maginets, but were reportedly weakly magnitized. The small size magnet may indicate a small diameter voice coil. Which likely helped reduce the moving mass that you noted.
I mean even the Ferrari f40 is probably objectively overall pretty crap compared to modern cars. But when you view the experience through the right rose colored lense..
Single woofer might be the way to go. Pretty big box and these things seem pretty weak. I don't think they will play very loud. Even Infinity realized it in 89 and used two.
It's cool everyone is trying to make it work. I dig it.
I think they will work fine the way Infinity did it but damn, they did crazy things in the crossover. It works, and I could do that. Still wanna try to do something with them. But, I still want the " Infinty and Beyond" theme, lol!
@DrewsBrews said:
Not that I want to start off this sort of argument... but maginets aren't all created equally. alot of the MCM drivers have pretty big maginets, but were reportedly weakly magnitized. The small size magnet may indicate a small diameter voice coil. Which likely helped reduce the moving mass that you noted.
I mean even the Ferrari f40 is probably objectively pretty crap compared to modern cars. But when you view it through the right rose colored lense..
I am with you on that. Don't get me started on engines and cars. But, certainly, I think a bigger magnet would help this driver or possibly, as you say, better magnitized. To me, the material is the quality of the magmatism, so who can say what is right without knowing tje quality of the magnet.
@kenrhodes said:
Could use them in an isobaric if the load doesn't go too low.
I thought about that, and it would work very well I think, but the goal is to recreate/ re- imagine Infinity speakers from the 80s. Yeah, futile, I guess, but just a fun kind of thing to try.
@DrewsBrews said:
Not that I want to start off this sort of argument... but maginets aren't all created equally. alot of the MCM drivers have pretty big maginets, but were reportedly weakly magnitized. The small size magnet may indicate a small diameter voice coil. Which likely helped reduce the moving mass that you noted.
I mean even the Ferrari f40 is probably objectively overall pretty crap compared to modern cars. But when you view the experience through the right rose colored lense..
I forgot to add, I measured the voice coil and can say, it is 19 mm or 3/4 ".
@4thtry said:
Have you considered gluing another big magnet onto the existing magnet to lower the Qts. I have done this a few times and it seems to work well.
I did actually think of that. Wasn't sure how to do it.
Ok, stupid me.. the above technical manual was for the exact model pictured. RS-6001
By those dimensions (minus pedistal height).. If .75" material, empty/unbraced, calculates to 1.55cf internal.
Sounds like they are sealed alignment. Based on the talk here, and I see no port in rear photos.
Dang thats a hefty change. Using a bunch of neodymium? I tried it myself one time, but got much smaller changes. Maybe due to a subwoofer having heavier cone with more influence on Q.
If I were to try to mimic this Infinity design myself with the MCMs.. I'd have to make em deeper for ~2cf ported to get satisfactory bass extension.
Comments
My brief looking at a couple of old Infinity XO's was that they were sealed in too small a box and woofers loaded with a large series cap.
So, I am thinking something between the two. Ported or sealed. This is what I was talking about. Is there software to sim this?
Here is an XO I saved...
I am not getting these posts in order. I have to go back and read them. They pop up at random. I refresh and I still have to go way back and posts that I didn't see before. Anyway, carry on...
This is very cool. Thanks for posting this. Gives some insite to what they did.
Yeah, 600 uF. Whoa!
And 45 mH!!!!?
I'm not disagreeing with you. I'm not sure how to model the multichamber sealed version, but the typical reason for a normal aperiodic box is to reduce the Q in a too-small box. This seems particularly relevant to your WinISD image above. Analogkid may already know all of this anyways, but looking at your box model above I thought this might be a good candidate for a normal aperiodic box.
Completely different driver but here is a Q=1 sealed and Q=0.90 in the same box aperiodic. Of course if you saved your model above, just change Ql to 3 and we can see what it does to the actual drivers under discussion.
@a4eaudio
Ok here's what I get for the same enclosure just with your Ql=3 leak. (still single woofer in 2cf no stuffing or lining, compared to no leak)
Seeing what Infinity had to do to the crossover tells me a ton. Crazy they would spend that much on crossover parts to fix sh!t drivers. Although They didn't use very good crossover parts. I think these drivers could have been good with a bigger magnet to lower total Q and a bit better Bl. The Mms is super low which is good. These things have tiny magnets on them.
Not that I want to start off this sort of argument... but maginets aren't all created equally. alot of the MCM drivers have pretty big maginets, but were reportedly weakly magnitized. The small size magnet may indicate a small diameter voice coil. Which likely helped reduce the moving mass that you noted.
I mean even the Ferrari f40 is probably objectively overall pretty crap compared to modern cars. But when you view the experience through the right rose colored lense..
Single woofer might be the way to go. Pretty big box and these things seem pretty weak. I don't think they will play very loud. Even Infinity realized it in 89 and used two.
It's cool everyone is trying to make it work. I dig it.
I think they will work fine the way Infinity did it but damn, they did crazy things in the crossover. It works, and I could do that. Still wanna try to do something with them. But, I still want the " Infinty and Beyond" theme, lol!
I am with you on that. Don't get me started on engines and cars. But, certainly, I think a bigger magnet would help this driver or possibly, as you say, better magnitized. To me, the material is the quality of the magmatism, so who can say what is right without knowing tje quality of the magnet.
Could use them in an isobaric if the load doesn't go too low.
I thought about that, and it would work very well I think, but the goal is to recreate/ re- imagine Infinity speakers from the 80s. Yeah, futile, I guess, but just a fun kind of thing to try.
I forgot to add, I measured the voice coil and can say, it is 19 mm or 3/4 ".
You must have accidentally measured a tweeter!
Yeah, well, the 80s, dude, lol!
Yes,a woofer back then was much like that. The 90s it got better. Now we are in 2024. That is a long time. I feel really old...
Have you considered gluing another big magnet onto the existing magnet to lower the Qts. I have done this a few times and it seems to work well.
Could also do a "Clone a Famous Maker", wouldn't have to be just Infinity...
InDIYana Event Website
I did actually think of that. Wasn't sure how to do it.
Read up on how with my Opaz thread. I had to do it to make the drivers match Qts.
https://diy.midwestaudio.club/discussion/2154/my-indiyana-2023-tweeter-yoga-theme-build/p1
InDIYana Event Website
What model is this anyway? I can't seem to find it.
Are they ^ ported or sealed and what volume are the cabinets?
What about those mid-domes? Size?
I like the look of that alignment . . .
Ok, stupid me.. the above technical manual was for the exact model pictured. RS-6001
By those dimensions (minus pedistal height).. If .75" material, empty/unbraced, calculates to 1.55cf internal.
Sounds like they are sealed alignment. Based on the talk here, and I see no port in rear photos.
Yes, yes! They are closed box. The original boxes were about 1.65 cubic ft.
I tried added magnets. It dropped Qts from .8 to .57. But modeling it, it's maybe better without the added magnets.
Dang thats a hefty change. Using a bunch of neodymium? I tried it myself one time, but got much smaller changes. Maybe due to a subwoofer having heavier cone with more influence on Q.
If I were to try to mimic this Infinity design myself with the MCMs.. I'd have to make em deeper for ~2cf ported to get satisfactory bass extension.
Any woofer suggestions for fitting 2 8" woofers into a 1 cu ft box sealed and able to reach 40 Hz f3 ???
w/o eq these will get you close -
https://www.parts-express.com/Dayton-Audio-RSS210HO-4-8-Reference-Series-HO-Subwoofer-4-Ohm-295-458?quantity=1
sorry, you’ll probably want the 8ohm version
with a bit of eq 30s