# Polyfill, horns and you



## nubz69 (Aug 27, 2005)

So I have now had horns in my car for about 8 months. I initially just gave them a basic tuning and I didn't really do much critical listening. Now that winter is over I have started to put some work into getting them to sound great. The first problem I had to overcome was the loss of my old RTA. Up till recently I had been using audiotools on my iphone, it was better then nothing but not as accurate as I wanted to get. I still had my measurement mic, so I bought a preamp and started using ARTA. With that I started tuning my system. 

After a few attempts at getting the car to sound the way I wanted, I decided to start over from square one and just get the horns perfect. Now I have been playing with crossovers at 1khz-1.5khz and 12db-48db slopes. Until last night the best sound I got was from [email protected] slopes. If I went lower, I would get harshness in the 1-4khz range. Last night I decided to try an acoustical filter made of polyfill. Although there are many schools of thought on what causes harshness in horns (IMD, HOM, etc.), I don't know if I subscribe to any one of the groups. I figured it was worth a try though as it is reversible and cheap. I loosely filled the horn body with polyfill and gave it a listen. I have one thing to tell you, if you have horns, go buy some polyfill today and try it out. I am now able crossover a [email protected] and it sounds a whole lot smoother. Another added benefit, which I didn't expect, is that my horns now mate better with my relatively inefficient midbasses. I think this may be due to the fact that the polyfill is padding the sensitivity a bit, which is helping them mate better. My next step is to play with looser and tighter packing of the polyfill to see if I can make it sound even better. After that I will EQ them again.

I am not saying that this will work for everybody but it is such a cheap and easy thing to try, it's almost a waste not to try it. The only drawback I have found so far is that their might be a very very minor masking of detail. My horns are very detailed and a small loss, for such a big gain is worth it for me. What I am hearing may also be attributed to the change in frequency response due to the stuffing. Once I eq the system again I will reevaluate what I think.


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## asawendo (Nov 22, 2009)

I did my HLCD with some different absorbing material in their mouth and so far have been crossing over my horn as tweeter at 5K 24db. I've got smooth and relax sounding with enough detail. So it works for me.

Best regards

Wendo


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## nubz69 (Aug 27, 2005)

Can I ask why you are crossing over your horns so high?


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## asawendo (Nov 22, 2009)

nubz69 said:


> Can I ask why you are crossing over your horns so high?


I have 3way setup like this:

Midbass: Faital Pro 75-800Hz 24 db butterworth
Midrange: Accuton C50 800-5000Hz 24 db butterworth
Tweeter: Steven Audio HLCD 5000-20000Hz butterworth

Sub: JL Audio W6

Best regards

Wendo


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## subwoofery (Nov 9, 2008)

asawendo said:


> I have 3way setup like this:
> 
> Midbass: Faital Pro 75-800Hz 24 db butterworth
> Midrange: Accuton C50 800-5000Hz 24 db butterworth
> ...


Strange way to use your drivers. 
The meat of a dynamic system lies in the 1kHz-4kHz range and the horn is not playing much of that range... The smallest driver does 

Kelvin


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## mattyjman (Aug 6, 2009)

seems like a waste of a horn implementation to be running them so high


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## mattyjman (Aug 6, 2009)

subwoofery said:


> Strange way to use your drivers.
> The meat of a dynamic system lies in the 1kHz-4kHz range and the horn is not playing much of that range... The smallest driver does
> 
> Kelvin


we posted at the same time  great minds think alike!


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## subwoofery (Nov 9, 2008)

mattyjman said:


> seems like a waste of a horn implementation to be running them so high


Just my opinion but I feel that 5kHz and up would be better suited for an AMT or a ribbon. Sweet azz RAAL 

Kelvin


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## subwoofery (Nov 9, 2008)

mattyjman said:


> we posted at the same time  great minds think alike!


Of course  

Kelvin


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## asawendo (Nov 22, 2009)

Maybe its strange he he he. But it works for me! a lot of my friends asking similar question like yours. 

PS: I do own Raven Ribon.


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## asawendo (Nov 22, 2009)

I forgot to mention that I use three pair of midrange in series above the dash.


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