# AudioFrog GB15 1.5" Tweeter (Objective Review)



## ErinH (Feb 14, 2007)

Link can be found here:
http://medleysmusings.com/audiofrog-gb15-1-5-dome-tweeter/











PS: If you would like to help me keep up funds for testing, there’s a little ‘contribute’ button that goes through Paypal all the way at the bottom of every page. Any little bit helps.


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## Elgrosso (Jun 15, 2013)

Yeah good reading for the morning! 
15/30° look pretty good, and super low distortion 
Interesting how the grill smooth it a bit.


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## quietfly (Mar 23, 2011)

nice job as always!!!


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## Huckleberry Sound (Jan 17, 2009)

Nice Work!!!


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## gregerst22 (Dec 18, 2012)

Good review. Testing with the colander er.. i mean grille on and off was a nice touch.


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## WhiteL02 (Jul 25, 2014)

Enjoyed reading your reviews


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## sirbOOm (Jan 24, 2013)

I think the big question is: when are you selling the test subjects for a phat discount?


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## ErinH (Feb 14, 2007)

I won't be selling them.


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## Huckleberry Sound (Jan 17, 2009)

Thank you!


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## kaigoss69 (Apr 2, 2008)

Thanks Erin, tweeter looks good. Little disappointed in the midrange, seems the manufacturer's recommended minimum HP of 110Hz 12dB/oct seems a bit too low, no?


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## ErinH (Feb 14, 2007)

kaigoss69 said:


> ... midrange, seems the manufacturer's recommended minimum HP of 110Hz 12dB/oct seems a bit too low, no?


Just so others know, the spec says ">110hz, >12dB/octave".

But to answer your question, it's really a matter of perspective. I recommended a 200hz crossover on the GB40 based on what I see in the test data. The Fs is 106hz. The THD at 96dB and 100hz is just above 3%; which seems to be the point where distortion is gaining on audibility. Going up an octave to 200hz cuts that THD in less than _half_ to 1.25%. Besides, really, why do you need to cross a 4" driver below 200hz?... To keep the sound above the dash? You can do this at 200hz (and higher) with a proper tune while keeping a good polar (the half-wavelength of 200hz is 2.8ft) and increasing output potential overall. If you're told otherwise then you should reconsider that notion. I haven't crossed any of my mids (4" or 5") below 300hz in _years_ and they are in the pillars. Limit excursion, limit distortion, increase clean output potential.

So that's why I suggested the crossover I did. Obviously everyone is welcome to do what they want and if they feel the mfg suggested crossover is right for their situation then go with that. I know us car audio guys often like to get a bit loud, so I make my recommendations on that.


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## reclermo (Feb 18, 2015)

The build quality on the AudioFrog pieces looks to be top notch. I had a look through your site, and really liked the selection of drivers you've been testing. That Satori mid looks like a real beauty! Keep up the great work!!!


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## 14642 (May 19, 2008)

Thanks Erin.

As you've made pretty clear in your testing, we designed the tweeter to be used WITH the grille. It makes a small difference for high frequencies and tweeters, but grilles make no difference for midrange drivers, so long as there's more than about 50% open area. 

I'll respond to Kaigoss' suggestion about the mids in the thread about the mids.


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## 14642 (May 19, 2008)

Oh, there's one more thing I shoudl explain with regard to tweeter design:

There is ALWAYS a dip in the response of a dome tweeter that corresponds to the height of the dome above the baffle. This is probably why B&W puts their tweeter in a little pod above the box in their home speakers. The frequency of the dip corresponds to the path from the dome to the tweeter and back--it's the result of destructive interference. 

If you look carefully at the pictures, you'll see that the tweeter is recessed in the cup and there's a small ring that directs the sound through the grille. All of those dimensions have been designed to best compromise between the two kinds of mounting in a car--in a relatively flat baffle like the top of a door panel or a KP or without a baffle like a sail panel or an A-Pillar. 

A taller dome increases the rigidity of the tweeter to help reduce modal issues. A shorter dome shifts the peak to a higher frequency. An inverted dome decreases this condition significantly, but makes the off axis response at really high frequencies pretty irregular. We opted for a tall dome and to manage the compromises with the housing, the little ring and a tall dome.


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## Elgrosso (Jun 15, 2013)

ErinH said:


> Besides, really, why do you need to cross a 4" driver below 200hz?... To keep the sound above the dash? You can do this at 200hz (and higher) with a proper tune while keeping a good polar (the half-wavelength of 200hz is 2.8ft) and increasing output potential overall. If you're told otherwise then you should reconsider that notion. I haven't crossed any of my mids (4" or 5") below 300hz in _years_ and they are in the pillars. Limit excursion, limit distortion, increase clean output potential.
> 
> So that's why I suggested the crossover I did. Obviously everyone is welcome to do what they want and if they feel the mfg suggested crossover is right for their situation then go with that. I know us car audio guys often like to get a bit loud, so I make my recommendations on that.


Yep that was my idea (for gb25). It was not as nice around 500hz, and I tried to fix a dip below (succeed in a way).
But i still have a lot to do and wanted to try higher again so your comment drives me even more for this.
Just about distortion, at 200/24db i can't hear any, but maybe I don't listen loud enough .
A side point, in fact I'm not even sure ms-8 really uses the precise crossover I set, I sometime have the feeling it does what it want, it adapt or moves the point a bit. Could this be right?


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## Victor_inox (Apr 27, 2012)

good work on those tweets,measured good, sounds good, looks good as well.
I`m not a big fan of grill like that, octagonal holes would give it more opening like 76-78%
but that doesn`t look to be critical.


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## rton20s (Feb 14, 2011)

Thanks Erin for your efforts on this!


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