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New build Help

cleonjr

cleonjr

Super Member
Ok here goes,
Fountek FE83 3" Full Range Driver 8 Ohm http://www.parts-express.com/fountek-fe83-3-full-range-driver-8-ohm--299-020
GRS 6PR-8 6-1/2" Poly Cone Rubber Surround Woofer https://www.parts-express.com/grs-6pr-8-6-1-2-poly-cone-rubber-surround-woofer--292-426

Stuck on crossover 2000 =10uf https://www.parts-express.com/dayton-audio-dmpc-10-10uf-250v-polypropylene-capacitor--027-428 or 3500=5.6uf https://www.parts-express.com/dayton-audio-dmpc-56-56uf-250v-polypropylene-capacitor--027-425 or what?

the cabinents are gonna be 14" h 12"w and 10"d and I have lots of cotten fibre fill. bout the decision I am having trouble is finding a suitable crossover point.maybe you all can help me with sugestions.thank's everyone!!!

edit; the founteks are enroute the woof's and caps are on hold.
 
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I would think the lower the better, but higher increases power handling. I would try for 500 hZ - or less but that's more based on reading rather than actual experience. Limits are costs of inductors and resistors for low crossover frequencies. I'm presuming the Fountek is better in the midrange. At least the sensitivities are close, which helps make it simple.
I would also do some research on baffle step correction, if not being used near field. .
My 2 cents. Good luck.
 
sregor said:
I would think the lower the better, but higher increases power handling. I would try for 500 hZ - or less but that's more based on reading rather than actual experience. Limits are costs of inductors and resistors for low crossover frequencies. I'm presuming the Fountek is better in the midrange. At least the sensitivities are close, which helps make it simple.
I would also do some research on baffle step correction, if not being used near field. .
My 2 cents. Good luck.
Click to expand...

Actrualy they will be nearfield,yes I want to get as much out of the fountek's as comfortably possible,kinda leaning to the 1500-2000 range. the cabinents will be sealed.lows will still be there in a nearfield setting.i chose the 2 drivers cause i thought they would play well together with just a simple 1st order crossover.I might consider adding a inductor on the low side?
 
Inductor consideration..

Might want to consider adding the inductor.. they are relatively inexpensive and will ensure the woofer remains "woofing" :yes:.

I have found them to be a "stabilizing" component in the crossover designs used thus far.

You can get them at Parts Express: www.partsexpress.com

By the way, they also sell mounting boards and the like to compliment your assembly.
 
One thing I just thought of ,will the fountek need to be sealed to cope with the woofer backwave.think i worded it right?
 
:headscrat Speaking from inexperience here, so my word is far from gospel: if a speaker needs double the wattage for each octave down than it's half for each octave up to remain at the same level. So let's start at 60 hz, the woofers lowest octave would be up to 120 hz, at 60 watts (max RMS rating) 120 to 240 at 30 watts, 240 to 480 at 15 watts, so at the Fountek's 12 watt rating it seems it would be pretty safe to go down to 500 hz. per sregor's suggestion, keeping more of the mid-range on the speaker designed to handle it best.
...yes:yes:, no:no:, maybe:scratch2:?
 
Seal or not to seal?

cleonjr said:
One thing I just thought of ,will the fountek need to be sealed to cope with the woofer backwave.think i worded it right?
Click to expand...

I plan on using the Fountek for a book shelf design.. not planning on "sealing" it as I assume the specs are based on an open back (if this is your seal point):scratch2:.

However, I do "gasket" my speaker mounts because I figure any compression loss or physical movement will offset performance.... but then again I prefer vented designs that rely on dynamic pressure :scratch2:.

So... not sure if I any help there:scratch2:
 
50nstillhifi said:
I plan on using the Fountek for a book shelf design.. not planning on "sealing" it as I assume the specs are based on an open back (if this is your seal point):scratch2:.

However, I do "gasket" my speaker mounts because I figure any compression loss or physical movement will offset performance.... but then again I prefer vented designs that rely on dynamic pressure :scratch2:.

So... not sure if I any help there:scratch2:
Click to expand...

I will try it both way's they have those isolation cups,the mid/high range to my understanding are not so much dependant on open air,or is this wrong thinking on my part.
 
cleonjr said:
I will try it both way's they have those isolation cups,the mid/high range to my understanding are not so much dependant on open air,or is this wrong thinking on my part.
Click to expand...

Not sure myself.... :scratch2:?

I would think anything restricting or interfering with any speaker diaphram movement will change something... also consider the damping material which absorbs most of the "back wave sonics". At least in theory this is what it should do.. besides keeping the enclosure from "resonance".

Typically, I add material until I get the suppression desired. Also there is a material called "polyfill", great for damping the open chambers of the enclosure. I use it as a "tuning material" :yes:..

So.... I would like to know the result of your "both ways' test. You could be on to something and if it sounds good to you... There you go:music:!
 
Ok, how does this look,
1st Order Butterworth
800 Hertz crossover point
6.5 Ohm Tweeter / 7.55 Ohm Woofer
Capacitors
C1 = 30.58 uF
Inductors
L1 = 1.5 mH
 
new dilema?

looking at 6.5 woofers I came across these that are under $20 in my price range can I get a nod on what will work best on the low/mid low end,since the founteks are gonna handle most tof the mids crossed at 800.here is what I found
http://www.parts-express.com/peerless-sds-160f25pr01-08-6-1-2-paper-cone-woofer-speaker--264-1146
http://www.parts-express.com/philips-ad7066w8-6-1-2-paper-cone-woofer-with-rubber-surround--299-361
http://www.parts-express.com/bs28-6p-6-aluminum-cone-woofer-8-ohm-shielded--299-349
and my original choice https://www.parts-express.com/grs-6...m1010X497171X45121f5b1d9a23df924446709a8d5a3e
I am leaning towards the peerles.
 
valvenator said:
I notice you're leaning toward the 6 1/2" under $20 speakers. Have you considered any of the Goldwood drivers?
http://www.parts-express.com/cat/hi...earchable","1")]&PortalID=1&showMoreIds=10014
Click to expand...

yea I did,I am gonna go with 6.5 cause I think I can get the best low end and keep the cabinet size manageable for a near field listening space.I am a tempting a get it right the first time build so I want the best components for a low budget Project,the peerless and the monitor audio replacement seem to be on par with what I need and I know that they are reputable speakers.I am trying to get the low's as deep as I can without using a passive radiator or porting.and also have it handle a small bit of the mid/low duty.

I will look at the specs on all the woofers when I get time but I am strongly considering the peerless or the BS28-6P 6" and at quick glance these seem to have the desirable specs I need.
 
:headscrat I just noticed even though the Goldwoods are rated at a higher wattage their cone excursion is less than half of the Peerless.
 
Not "boxed in"..

cleonjr said:
I have been using this to calculate my project ,are there any others or is this A good choice? http://www.diyaudioandvideo.com/Calculator/Box/
Click to expand...

Yes... that's the science behind it but you can alter the dimensions for shape and form as long as you maintain a close "spatial volume".

For example, I used an 18" calculated size .. but my speakers are geometrically triangular. The altered "box" shape I compensated by choosing a more powerful driver... specifically the woofer.

So... you can be creative ... and not be "boxed in", pardon the pun :D
 
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