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Good Idea, Bad Idea?

BKr0n

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For a speaker enclosure I'm working on, the main driver's min requirement by the manufacturer is 50W. I had planned for 20. Because of speaker sensitivity, if I wanted to make it 40 (being closer to recommended) I would probably need to add another woofer. Then... well my brain did its brain thing and I thought this up... Two subs iso with the main driver in front. Either do a wave guide and a port, or two sets of 3 PRs. Good idea, or bad idea?
 

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voodooless

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No idea.. this really needs much more details… we don’t even have dimensions…

And why care about the Watts so much?
 
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BKr0n

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No idea.. this really needs much more details… we don’t even have dimensions…

And why care about the Watts so much?
Ngl laughed a little too hard when I read that.

Bookshelf speakers. Main driver is 5", subs are 5 and 1/2", so i would say about at least a foot tall. Height is really going to depend on the solution I pick. The radiators match the woofer so that would make it at least about 2 ft tall (including feet). Depth about 10".

Also thank you magical moderator who moved the post lol
 

voodooless

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I still have no idea what the colored areas are supposed to be? I still have no idea what the concept is supposed to be?

Waveguide? For the tweeter? Or do you mean a reflex port for the woofer?
 
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BKr0n

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Reflex port... it keeps getting called different things in the stuff I read :rolleyes:
 

voodooless

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Reflex or PR is mostly a budget trade-off for something like a 5” woofer. Obviously a port is much cheaper than two or three PR’s. Both can work well is designed properly.

Oh, and with “iso” you probably mean isobaric? That’s quite a waste of resources. It’s probably better to find a single woofer that suits the enclosure better.
 
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BKr0n

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Actually if I go with this design... I wanted to do some sort of MFB before, but I wasn't sure about removing the dust cap. With this, there's a possibility I could do it optically. I would need to figure out a test rig...
 

voodooless

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For MFB, you don’t need to remove the dust cap in all cases. See here for instance for various options:


Also remember that MFB with reflex or PR is a no-go!
 
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BKr0n

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That was one of the first things I went to. The cone itself is too convex for something to lay flat on it. Why I was thinking optical is because it will take mechanical energy out of the equation, but would still include cone movement. Rather than use an accelerometer to measure excursion, use a laser diode, and measure the modulation of the waveform.
 

voodooless

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Rather than use an accelerometer to measure excursion, use a laser diode, and measure the modulation of the waveform.
Yeah, why not make it even more complex… But hey, it’s not as if that’s stopping you at all.
 

AdamG

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Also thank you magical moderator who moved the post lol
The way things work around here. Lots of helpful members. @Jim Taylor recommended moving your post here to the DIY area to get you more engagement. @BDWoody agreed with Jim’s suggestion and presto change-o. Teamwork and @voodooless shows up to help answer your questions. I can see myself out..:p
 
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BKr0n

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Yeah, why not make it even more complex… But hey, it’s not as if that’s stopping you at all.
So funny story... still can't figure out if I wanna do full analog or do digital lol. Couldn't decide so I just kinda shifted my focus for a bit. I actually may have a design for the subs. Just need to finish the math, then build and test.

I think optical wouldn't be too difficult. For one it means I don't have to remove the dust cap which is a risky proposition in and of itself. For another, it's just simple addition and subtraction, then plugging it back into the system. I may even already have a place for it in my current design. May just need to tweak a bit.
The way things work around here. Lots of helpful members.
I've definitely noticed :) I've actually had a really good experience here so far! Voodoo just helps keep me grounded :p
 

Killingbeans

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For a speaker enclosure I'm working on, the main driver's min requirement by the manufacturer is 50W. I had planned for 20. Because of speaker sensitivity, if I wanted to make it 40 (being closer to recommended) I would probably need to add another woofer. Then... well my brain did its brain thing and I thought this up... Two subs iso with the main driver in front. Either do a wave guide and a port, or two sets of 3 PRs. Good idea, or bad idea?

That wattage thing makes no sense. Does the manufacturer give a reason for the 50W min. requirement?
 

MAB

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For MFB, you don’t need to remove the dust cap in all cases. See here for instance for various options:


Also remember that MFB with reflex or PR is a no-go!
Are there refences and measurements of drivers and these motion-feedback mods? I see on PirateLogic's homepage some very nice modified units, but I couldn't find much more.
I am embarrassed to say, I haven't ever seen compelling data, and too often find non-physical nonsense. I am pretty sure I am just not looking in the right places.
 
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BKr0n

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That wattage thing makes no sense. Does the manufacturer give a reason for the 50W min. requirement?
...seems I was mistaken. It was 15 to 180w. Still, I kinda like the idea. I was just going to do a Set of PRs, but then I had this idea and I figured "eh, why not?"
Are there refences and measurements of drivers and these motion-feedback mods? I see on PirateLogic's homepage some very nice modified units, but I couldn't find much more.
I am embarrassed to say, I haven't ever seen compelling data, and too often find non-physical nonsense. I am pretty sure I am just not looking in the right places.
https://en.wikipedia.org/wiki/Laser_rangefinder but much simpler
 

voodooless

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Are there refences and measurements of drivers and these motion-feedback mods? I see on PirateLogic's homepage some very nice modified units, but I couldn't find much more.
I am embarrassed to say, I haven't ever seen compelling data, and too often find non-physical nonsense. I am pretty sure I am just not looking in the right places.
Yes, it’s out there, just not very easy to find. I don’t have the links on recall either ;)

Next to the bass distortion reduction, the other advantage is that it automatically EQs the driver for the most part. and your limited to closed box designs.

On the other side, a reflex enclosure may yield lower distortion as well for way less effort.
 
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Salt

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If You are not about only BlaBla, contribute facts:
- what tweeter?
- what mid and /or midwoofer?
- size of enclosure
- design of enclosure (closed/vented: BR/TML/....)
 
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BKr0n

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If You are not about only BlaBla
BLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLABLA
- what tweeter?
- what mid and /or midwoofer?
- size of enclosure
- design of enclosure (closed/vented: BR/TML/....)
Sorry about that. This has been something I've been working on for a minute so a few people here already know a little bit about it. So the driver in question is the SP1632 from KEF. It's typically found in the R series, and I got a good deal on a set so i figured pull the trigger on a project. It's a coaxial driver so the mid and tweeter are together. Pretty much trying to get really big sound in a tiny package, so about bookshelf size speakers (although if I go with the two subs it will be taller). The subs are Dayton Audio E150HE-44 5 1/2". As far as enclosure design, I honestly don't know yet. I just got the "two sub" idea today. That and lately I've just been working on circuitry so haven't really touched on that yet.
 

MAB

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Yes, it’s out there, just not very easy to find. I don’t have the links on recall either ;)

Next to the bass distortion reduction, the other advantage is that it automatically EQs the driver for the most part. and your limited to closed box designs.

On the other side, a reflex enclosure may yield lower distortion as well for way less effort.
Thanks. I at least don't feel uniquely challenged that I can't find.:D
I always felt there be amazing advantages - after all, feedback is good...
But like you say, reflex is a good way to extend the low end and reduce distortion for cheap. Then I start thinking of issues like port noise. Which leads me to passive radiators, the expensive solution to port noise with new issues and non-linearities.
 
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BKr0n

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But like you say, reflex is a good way to extend the low end and reduce distortion for cheap. Then I start thinking of issues like port noise. Which leads me to passive radiators, the expensive solution to port noise with new issues and non-linearities.
What kinds of issues?
 
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