# What does a tweeter Recommended crossover point mean?



## jgscott (Sep 1, 2013)

I don't totally get crossover points. I know it cuts the frequency.

But, what would be the difference in crossover points, on a tweeter at 2500hz vs 3000hz? 

The tweeter I want to use id spec'd out as this:

Freq Resp: 2500-22,000 hz
Impedance: 4 ohms
Sensitivity: 86 db
Power Rating: 20 watt nominal (40 watt peak)

Recommended Crossover Point: 2.5khz or higher

Also would the ideal crossover point for this tweeter depend a lot on the mid woofer use in conjuntion if running a 2 way combo? Thanks


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## 1fishman (Dec 22, 2012)

What'sthe tweeter?


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## Lycancatt (Apr 11, 2010)

the recommended crossover point is usually a "don't play it lower or you'll break it" point, but also can be a "it doesn't sound so good below this number" point as well. what works for any given tweeter is highly dependent on what mid/woofer is being used. generally playing a tweeter lower sounds better for imaging, but to low and you've got distortion/stresses in the tweeter that make the sound harsh/unlistenable.


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## jgscott (Sep 1, 2013)

1fishman said:


> What'sthe tweeter?


 Tweeter is Nakamichi SP-10

Mid is Dynaudio out of Volvo. Like GT182. 

here is a measure someone on this forum did of the Dynaudio Volvo spec of the mid. Pictures.


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## jgscott (Sep 1, 2013)

Would this crossover work with those 2 speakers good?

_Dynaudio Crossover X 250
The X 250 is designed to accommodate four different woofers: MW 150, MW 160, *MW 160 GT*, and MW 170 in combination with our MD 100 neodymium tweeter. 
No matter which woofer is used the sound is characterized by a linear frequency response and excellent dispersion ensuring outstanding sonic performance in a wide range of cars. 

Technical Specifications for MW 150
Crossover Frequency 2800 Hz
Nominal Impedance 4 Ohm
Power Handling 100W
Dimensions 
(W x H x L in mm) 38x84x145
Net Weight (in kg) 0.35
Technical Specifications for MW 160/GT
Crossover Frequency 2800 Hz
Nominal Impedance 4 Ohm
Power Handling 120W
Dimensions 
(W x H x L in mm) 38x84x145
Net Weight (in kg) 0.35
Technical Specifications for MW 170
Crossover Frequency 2800 Hz
Nominal Impedance 4 Ohm
Power Handling 150W
Dimensions 
(W x H x L in mm) 38x84x145
Net Weight (in kg) 0.35 _


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## MacLeod (Aug 16, 2009)

Thats not telling you a whole lot. Technically the crossover point is the point where the mid and tweet cross at the same level. Say for example you cut the mids at 2K with a 12db slope and the tweeters at 5K at a 12 db slope, the "crossover" would be 3.2K. At that frequency both mid and tweet would be attenuated by 8db (unless I did my math wrong and just embarrassed myself). My old Polk Audio SR components stated a 3100 Hz crossover but the tweeter was actually cut at like 6.3KHz if I remember right. So that "2800 Hz" isnt the actual cutoff point for the tweeter. 

Im a big believer in tweaking with crossover settings. I think in some instances you can do more to change your SQ playing with crossover points and slopes than you can with EQ alone. The "ideal" crossover setting is gonna be something youll have to play with and itll depend on where its mounted, where the mid is mounted and how they interact together. If you have the ability to go active, I suggest spending a lot of time trying several different points and slopes. 

As for where to start, 2.5K is a little low for a tweeter IMO. 3.2 is usually the lowest I would ever take a tweeter. Anything lower than that and I just didnt like the sound of them that much. If you can find the T/S parameters for that tweeter, look for the Fs which is the resonance frequency which means the point where the frequency response drops off by 3db or something to that effect. Generally youll want to cut that particular tweeter off at 1 octave (or twice the number) above that point. Fs of 1000 Hz? Cut at 2 KHz at the lowest.



1fishman said:


> What'sthe tweeter?


Its the little speaker that plays all the high pitched stuff. Youd think people would know this by now. Yeah, I crack myself up.


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## jgscott (Sep 1, 2013)

So would the _Dynaudio Crossover X 250, posted spec above, be in the ballpark with those mids and tweeter I'm going to use?_

_On the crossover cover itself it says:_

_Tweeter Crossover 3.000 Hz/12db Oct._
_Woofer Crossover 3.000 Hz/ 6db Oct._

_With adjustments of +2 db_
_and -2db_

_I cant find the T/S specs anywhere on the teeters. I think they used the same tweeter in the sp-65c coax but cant find the specs of the tweeter on those either._


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## jgscott (Sep 1, 2013)

Can some please answer this question for me with a opinion please.


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## gijoe (Mar 25, 2008)

You are taking a risk if you are trying to use the Dynaudio crossover for those tweeters. The crossover was designed and built with specific tweeters in mind, they are generally not universal. You'd need to know the impedance of the tweeter that Dynaudio used in that setup, at a minimum. 

Now that I look again, you're also trying to use a mid that those crossovers weren't designed for. What else does your system consist of? Does your head unit have any crossovers? I'm not sure your plan to use those crossovers with those drivers is going to work well at all. Best case scenario it'll sound ok, worst case scenario those tweeters will let out the smoke.


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## MacLeod (Aug 16, 2009)

Yeah it aint gonna sound its best but itll work. 3K is a little on the low side for a cutoff frequency on a tweeter IMO. But if its all youve got it wont hurt anything.


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## gijoe (Mar 25, 2008)

MacLeod said:


> Yeah it aint gonna sound its best but itll work. 3K is a little on the low side for a cutoff frequency on a tweeter IMO. But if its all youve got it wont hurt anything.


It MIGHT work.


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## jgscott (Sep 1, 2013)

MacLeod said:


> Yeah it aint gonna sound its best but itll work. 3K is a little on the low side for a cutoff frequency on a tweeter IMO. But if its all youve got it wont hurt anything.


 Thanks. I know its just a guess, but what cut off do you think would be more ideal?

The Sp10 Nak tweeter is known s a very layed back tweeter.


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## Hanatsu (Nov 9, 2010)

"Recommended crossover point" 

Could mean:

1. The highpass freq / slope that the manufacturer thinks is adequate enough to avoid damage to the driver, i.e power handling.

2. The frequency / slope where the manufacturer thinks it performs best at distortion-wise.

3. The above 2 ^^

4. They just got lazy and went with the rule of thumb: resonance frequency (Fs) *2


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## Hanatsu (Nov 9, 2010)

gijoe said:


> You are taking a risk if you are trying to use the Dynaudio crossover for those tweeters. The crossover was designed and built with specific tweeters in mind, they are generally not universal. You'd need to know the impedance of the tweeter that Dynaudio used in that setup, at a minimum.
> 
> Now that I look again, you're also trying to use a mid that those crossovers weren't designed for. What else does your system consist of? Does your head unit have any crossovers? I'm not sure your plan to use those crossovers with those drivers is going to work well at all. Best case scenario it'll sound ok, worst case scenario those tweeters will let out the smoke.


Yeah... passive crossovers are designed to a specific driver. Using other drivers with some random passive crossover might yield unpredictable results at best. 

I'd go for active crossovers if possible, or simply build a pair of passives intended for the tweeter in question.


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## jgscott (Sep 1, 2013)

He said: "_3K is a little on the low side for a cutoff frequency on a tweeter". _What I'm asking is what would be a better guess of a cutoff frequency? I'm not good with this. 2.5K? 3.5K? 

I could not find the spec on the Nak tweeter other than listed above. Thanks


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## Hanatsu (Nov 9, 2010)

jgscott said:


> He said: "_3K is a little on the low side for a cutoff frequency on a tweeter". _What I'm asking is what would be a better guess of a cutoff frequency? I'm not good with this. 2.5K? 3.5K?
> 
> I could not find the spec on the Nak tweeter other than listed above. Thanks


Neither could I. Impossible to say. Slope matters alot too, I've run some exceptional tweeters below 2kHz with steep slopes, some tweeters like the Vifa XT25 got Fs in the 500-600Hz range but doesn't sound good until you use a 3-4kHz HPF. 

The better question would be, how high is it acceptable to run your mids? I would start off with a 3kHz, 24dB slope and go from there (if you got active filters that is).


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## jgscott (Sep 1, 2013)

I read a few post that the Nak tweeter could be the Vifa D26 tweeter.


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## MacLeod (Aug 16, 2009)

jgscott said:


> Thanks. I know its just a guess, but what cut off do you think would be more ideal?
> 
> The Sp10 Nak tweeter is known s a very layed back tweeter.


Can't say. It'll not only depend on the tweeters abilities but also how it's set up in the car. It might play 2.5 KHz just fine but sound like total ass doing so. You need to play with and try different points and slopes.


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## sqnut (Dec 24, 2009)

Hanatsu said:


> Neither could I. Impossible to say. Slope matters alot too, I've run some exceptional tweeters below 2kHz with steep slopes, some tweeters like the Vifa XT25 got Fs in the 500-600Hz range but doesn't sound good until you use a 3-4kHz HPF.
> 
> The better question would be, how high is it acceptable to run your mids? I would start off with a 3kHz, 24dB slope and go from there (if you got active filters that is).


Lokk who's back!!!! Welcome bro.....missed you.


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