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Old 12th December 2012, 08:58 PM   #621
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Originally Posted by ikoflexer View Post
My prediction is that the measurement will not look like the simulation, with all due respect for Don's skills. I think the simulation might be oversimplified.
The simulation assumes perfect horns. If you unrolled the horns so they were straight, and used no stuffing, you'd get physical results closer to the simulation. The folds introduce a HF loss, and Cal found stuffing is required to damp the resonances predicted by the model... Note also that I recommended restricting the frequency response display in the simulation to a maximum of 1 KHz, to avoid being distracted by higher-order resonances that would be much smaller in reality.

Making the model more accurate means it gets complex very quickly. It's like predicting the weather - the more accurate you want the prediction, the more factors you have to include in the model.

Last edited by Don Hills; 12th December 2012 at 09:06 PM.
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Old 12th December 2012, 09:32 PM   #622
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Originally Posted by xrk971 View Post
Don Hills,
I like your reverse spiral horn clock radio. I think the old Bose gen 1 had only a serpentine path on 1 driver and they went to 2 on later generations exiting a single common port like Klampy's. Are you thinking 2 in drivers or 3 inchers? The TB W3 881si for $10 ea comes to mind.... The led's with auto mosfet is a really good idea too. Do you have a schematic for that? I just had a thought, if the spirals are relatively thin, stack two one fires up and the other down, or they could both fire to common down port?
Xrk971
I've only seen the Gen 1 internals. Driver choice would depend on how big you wanted to make it - small drivers with low Vas / Qts would allow making it smaller.

No, I don't have a schematic, but it's not hard - all I need is to get a round tuit.

An enclosure with two spirals would be twice the volume of that with a single spiral, and would be complex to build. It needs some thought...
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Old 12th December 2012, 11:19 PM   #623
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Quote:
Originally Posted by adason View Post
maybe it would sound the same in the box of the same size
Nope.
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Originally Posted by xrk971 View Post
(Cal - do you have means to do a measurement?)
Nope.
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The spiral definitely has a PROFOUND effect
Yup.
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When I place my ears next to the output horns on the edges...
...A surprising amount of horn output is noted.
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I got bunch of really good sounding 4" fullrange speakers
hehe, looks like we have another in the fold.

Adason, there's no hiding my speaker addiction as you guys are all aware but this has offered a number of things that I have not had before in speaker building. You will realize this when yours are done.

Cheers.
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Old 12th December 2012, 11:23 PM   #624
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Quote:
Originally Posted by Don Hills View Post
The folds introduce a HF loss, and Cal found stuffing is required to damp the resonances predicted by the model...
Without stuffing, it sounds bloody awful. With too much, it sounds like a regular FR in a box. Get it just right and something begins to get all fuzzy in your insides.
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Old 12th December 2012, 11:35 PM   #625
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Quote:
Originally Posted by Don Hills View Post
I've only seen the Gen 1 internals. Driver choice would depend on how big you wanted to make it - small drivers with low Vas / Qts would allow making it smaller.

No, I don't have a schematic, but it's not hard - all I need is to get a round tuit.

An enclosure with two spirals would be twice the volume of that with a single spiral, and would be complex to build. It needs some thought...
Two spirals would just double the thickness or add about 2.5 in in height.
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Old 12th December 2012, 11:41 PM   #626
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Originally Posted by Cal Weldon View Post
Without stuffing, it sounds bloody awful. With too much, it sounds like a regular FR in a box. Get it just right and something begins to get all fuzzy in your insides.
It's a fine line between not enough and too much stuffing. I got lucky but wonder if it would be worth playing around with. You are right describing it as getting fuzzy inside. I actually have found a renewed interest in listening to music because some songs sound so much better than I knew they could sound. Almost a rediscovery of certain songs for me which did not grab me and make me feel fuzzy inside before. I hope you are enjoying yours properly hung up on the wall now. Or is it stands?
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Old 13th December 2012, 12:41 AM   #627
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In case I didn't make myself clear about the advantages:

1. Fast
2. Cheap
3. Easy
4. Highly gratifying
5. Done two at a time

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Originally Posted by xrk971 View Post
properly hung
That doesn't hurt.

Any questions?
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Old 13th December 2012, 12:44 AM   #628
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You forgot number 6: high WAF if properly hung, on wall that is....

Last edited by xrk971; 13th December 2012 at 12:48 AM.
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Old 13th December 2012, 12:47 AM   #629
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Wow, I just noticed that thread broke 20k views!
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Old 13th December 2012, 12:48 AM   #630
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So what you are saying is that they are fast, cheap, and easy, but it helps if somebody is well hung? LOL.
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