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Old 22nd March 2009, 11:18 PM   #1051
noah katz is offline noah katz  United States
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"I don't suppose you subtracted the volume of the port from the box volume."

No, but here it is with a 4" ID/4.5"OD x 8.3" L port (subtracts .1 cu ft from Vb), giving max velocity of 19 m/s.
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Old 22nd March 2009, 11:21 PM   #1052
454Casull is offline 454Casull  Canada
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Quote:
Originally posted by gedlee

Power handling would be a conservative 100 watts with about a 94 dB sensitivity. This would give it about 104 dB MAX_SPL, which I also think is likely to be quite conservative.
Wouldn't that be 114 dB?
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Old 23rd March 2009, 12:13 AM   #1053
300Z is offline 300Z  Brazil
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Quote:
Originally posted by gedlee

I don't usually look at the electrical aspects of the crossover, only the total acoustic response. The crossover point is at about 1500 Hz. The LP would be 2nd order and the HP would be (electrically) first order, but acoustically this ends up being more like third order. The waveguide "specs" are a 90 degree OS waveguide with foam plug, and a 1" throat. While I'm sure these details might interest some, its really the end result, i.e. the Polar FR that really matters no matter how you get there.
Thank you for your response.
But I got one more question regarding the crossover... have you addressed the twin impedance peaks in the tweeter in the crossover?

Quote:
Originally posted by gedlee

Power handling would be a conservative 100 watts with about a 94 dB sensitivity. This would give it about 104 dB MAX_SPL, which I also think is likely to be quite conservative.
Why is the power handling rated at 100watts?
A while back when I ran some calculations on these drivers (altho in a ported box) when high passed around 75hz these drivers could handle over 200w without exceeding x-max and is capable of 117dB continuous.
With a sensitivity of 94dB I assume there's no BSC?

Leo
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Old 23rd March 2009, 12:29 AM   #1054
gedlee is offline gedlee  United States
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Quote:
Originally posted by 454Casull

Wouldn't that be 114 dB?
Opps - yes thats correct.
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Old 23rd March 2009, 12:32 AM   #1055
gedlee is offline gedlee  United States
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Quote:
Originally posted by 300Z

Thank you for your response.
But I got one more question regarding the crossover... have you addressed the twin impedance peaks in the tweeter in the crossover?
Of course - thats obvious from the frequemcy plots isn't it?

Quote:
Originally posted by 300Z

Why is the power handling rated at 100watts?
A while back when I ran some calculations on these drivers (altho in a ported box) when high passed around 75hz these drivers could handle over 200w without exceeding x-max and is capable of 117dB continuous.
With a sensitivity of 94dB I assume there's no BSC?

Leo
Its the tweeter that limits the power handling not the woofer.

BSC is taken care of since the crossover is designed based on data measured in the actual box thats used so any BSC would automatically be accounted for.
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Old 23rd March 2009, 02:09 AM   #1056
sba is offline sba
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goskers,

If I had my druthers, I'd have the same setup that you have.

I'm glad to hear that you think the system is awesome....seems like everyone really likes it.
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Old 23rd March 2009, 02:10 AM   #1057
sba is offline sba
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gedlee,

Thanks, I'd really enjoy having that porting option. And later on, when things change, I could plug the ports and incorporate the multiple subs.

I'm still saving up....and hope to place an order in late spring or this summer.

Thanks again
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Old 23rd March 2009, 02:15 AM   #1058
sba is offline sba
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noah,

Thanks for posting the plots.
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Old 25th March 2009, 02:12 PM   #1059
uhoh is offline uhoh  United States
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Quote:
Originally posted by gedlee
[B]
I guess if you don't use subs that would be a significant improvement. I didn't really know since I have never done it. I don't suppose you subtracted the volume of the port from the box volume. There is certainly no reason why ports couldn't be added to the enclosure. I might try this for those who don't want to opt for subs.
I listened to the Nathans with and without a sub. (A single small 8" "sub" that probably only really goes down to 50-60 Hz.)

The Nathans sounded good by themselves, but they were kind of "thin." Adding in just enough sub to fill in was very beneficial.

Ideally, people would use multiple subs as you have recommended. If they can't do that, one inexpensive sub is better than none IMO.

I'm just thinking that, as you mentioned, your speakers work very well as designed, so why mess with them? Adding a sub or two or even three is not very expensive and complicated for anyone who has built a pair of Nathans or Abbeys.
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Old 25th March 2009, 02:28 PM   #1060
gedlee is offline gedlee  United States
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Quote:
Originally posted by uhoh

I'm just thinking that, as you mentioned, your speakers work very well as designed, so why mess with them? Adding a sub or two or even three is not very expensive and complicated for anyone who has built a pair of Nathans or Abbeys.
Agreed. I find that some people just want to change something so that they can take ownership in a purchase - they had a part in the design. As you say, this seems to me to be ill advisable to me as well.
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