looking for 6.5inch woofers suitable for a 30 - 35Hz horn... and a small horn too :P

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two peerless 850122s in a horn.... best I could come up with.. :p
 

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Any drawings of how you are going to make this horn? I was also thinking of a horn with dual 6.5" or 8" woofers, though not for car, so it can be a tad larger. I wanted it to be useful down to about 25-30Hz... but I have not done anything with horns before, so a picture could be useful to see how you are going to do this.
 
needtubes said:
Any drawings of how you are going to make this horn? I was also thinking of a horn with dual 6.5" or 8" woofers, though not for car, so it can be a tad larger. I wanted it to be useful down to about 25-30Hz... but I have not done anything with horns before, so a picture could be useful to see how you are going to do this.


I haven't designed the horn yet, as I haven't decided what the best drivers to use are.. :p
 
SkinnyBoy said:
umm... there are some here.....
http://www.d-s-t.com/peerless/data/850122.htm

but I'm not sure if they are the ones I used.. lol


why do you ask? :)


The response curve looks a little peaky and has an odd low end hump....Just wanted to see the specs of the driver. At first I though it looked like a too high q driver, but at .4 its hardly out of useable range for a horn.

Certainly looks like the horn could benefit from being a little larger...
 
>I also discovered that if you put multiple drivers in the one horn, the horn length gets shorter... why is that?

====

View the single driver horn along its length, now cut off whatever portion of the initial expansion is required to get to the larger throat area dictated by the multiple drivers........ ;) Note that if the shorter length is <1/4WL of the effective mouth's Fc then it will perform like a high Q sealed cab below its effective 1/4WL.

GM
 
JeremyD said:



The response curve looks a little peaky and has an odd low end hump....Just wanted to see the specs of the driver. At first I though it looked like a too high q driver, but at .4 its hardly out of useable range for a horn.

Certainly looks like the horn could benefit from being a little larger...

yes.. the horn could benifit from being bigger, but I am unsure if the drivers will do 30Hz like the graph suggests anway... :p theit fs is too high... the peaky response is the only way I could get a good 30Hz response is such a small horn, and its only like 2dB of fluctuation anyway... besides the gradual rise as the frequency increases....


GM said:
>I also discovered that if you put multiple drivers in the one horn, the horn length gets shorter... why is that?

====

View the single driver horn along its length, now cut off whatever portion of the initial expansion is required to get to the larger throat area dictated by the multiple drivers........ ;) Note that if the shorter length is <1/4WL of the effective mouth's Fc then it will perform like a high Q sealed cab below its effective 1/4WL.

GM

*looks around* I kinda got lost after "View".. :p :) ahh well... I don't think these drivers will do all that will in a 30Hz horn anyway :p
 
>*looks around* I kinda got lost after "View".. ahh well... I don't think these drivers will do all that will in a 30Hz horn anyway :p

====

Oh well...... sounds like you're not ready to design a horn project if you can't visualize it, but I'm a firm believer of trying something even if it doesn't work well just so long as you learn something from the experience.

Anyway, ideally you want a driver with an Fs somewhat higher than the horn's Fc otherwise you have to squeeze it too much to artificially raise it, increasing the probability of causing stress cracks, non-linear performance due to suspension warping, or burning it up from overheating.

Using someone else's measured specs, two of these yields a hair over 1:1 compression and four chops it in half for an Fl-Fh of 30Hz-229Hz, so I recommend at least two, and preferably four to ensure good performance and to shorten the horn considerably.

Note though that cabin gain in a car typically begins around 80Hz, so building a horn with a 30Hz Fc might be a bit too much of a 'good thing'. You need to measure its gain to get a better idea what Fl/Fh to use.

GM
 
I don't know if this is any help, I know it's not 30hz but they're only 6.5's after all and if your intending car use with all that cabin gain it might get you somewhere near.
s1-240
s2-301.6
s3-417.6
s4-696
s5-788.8

then 4 CON boxes from top
40
41.8
40.9
58.6

By my reckoning it's 3db down at 39hz.
 
REDSKIN said:
I don't know if this is any help, I know it's not 30hz but they're only 6.5's after all and if your intending car use with all that cabin gain it might get you somewhere near.
s1-240
s2-301.6
s3-417.6
s4-696
s5-788.8

then 4 CON boxes from top
40
41.8
40.9
58.6

By my reckoning it's 3db down at 39hz.


yeah.. I guess... and thats a pretty small horn.. except that you were still working with a 25 litre compression chamber.. lol

and btw.. its the same as a 180cm long exp horn 240 - 800 cm^2 :p lol which is alot easier and quicker to type in.. :p
 
REDSKIN said:
Doh! in my haste to post I forgot to mention....
vrc-16
lrc-16
vtc-2000
atc-600
Sorry!

"and btw.. its the same as a 180cm long exp horn 240 - 800 cm^2 lol which is alot easier and quicker to type in.. "

If I actually knew how to work speakers sims I'd be dangerous!


that creates a peak... thought we didn't want a peak.. :p lol
 
:bawling: Sorry!:bawling:

It was the talk of car use that led me to believe that this was more of a subwoofer project, so I thought a nice flat response from 100-40hz would be ok and with the hpf set at 80 hz the peak after 100 would have been tamed.

I think I'll keep just keep quiet now, to stop my ignorance showing!:rolleyes:
 
REDSKIN said:
:bawling: Sorry!:bawling:

It was the talk of car use that led me to believe that this was more of a subwoofer project, so I thought a nice flat response from 100-40hz would be ok and with the hpf set at 80 hz the peak after 100 would have been tamed.

I think I'll keep just keep quiet now, to stop my ignorance showing!:rolleyes:


nah.... just that someone commented on a peak before.. :p if you leave the vrc as it was.. 25 litres... then its fine... the 40Hz peak I'm talking about...
 
DOH! again!!!!!

Like I said if I could actually work a speaker sim I would be dangerous. I'm looking at my Hornresponse curve and it's flat as a pancake and thinking what 40hz peak?????????......................... then as I stare at the screen Doh! I realise that it helps if I entered the cms correctly(00 instead of-04).

So after a bit of tweaking try.
s1-160
s2-394.4
s3-464
s4-696
s5-1400
then the 4 CON boxes
40
41.8
45.9
58.6
 
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