Hi peeps.
right this minute i have just two 2way top speaker cabs running my full range duties in my PA system.
i feel the tweeters are lacking. i have the eq boosting from 10k and up, so that includes, 12k, 14k, and 18k. i have them maxed out to make any sort of crispness to the sound.
im not really sure what the Xover frequency is, (its somewhere around 8-12k) but the cabs also get quite harsh and very suddenly distorted in the upper frequencies when pushed.
running Eminence Delta 12A woofers and cheap "weconic" 2inch compression horn tweeters on the tops.
if needed, i can pull one apart and put up specs of the Xover.
basically, i feel that the tweeter needs to be louder to match the driver, and the only way i know of, thats simple to do, is to put a resistor in line with the woofer to quieten it rather than trying to boost the tweeter.
do you think that i should be making the tweeter do more work? as in, lower the crossover frequency and pass the woofer lower so its not doing such high frequencies?
if it turns out to be the compression driver at fault (and is just cheap crap), id really like to make sure i make a better choice as far as a replacement is concerned. but also dont want to spend a fortune just on tweeters....
TBH, the tweeter itself sounds nice. i like the sound of it when at reasonable/loud volumes, until i push it, and then it sounds harsh. female vocals suffer, electric guitar suffers, and piano. so this is the frequency range thats suffering.
midbass is fine, deep bass is handled by SS15 Jbell subs and works great... just that upper mid/hi frequency band.
please help.
thanks
Brendan.
right this minute i have just two 2way top speaker cabs running my full range duties in my PA system.
i feel the tweeters are lacking. i have the eq boosting from 10k and up, so that includes, 12k, 14k, and 18k. i have them maxed out to make any sort of crispness to the sound.
im not really sure what the Xover frequency is, (its somewhere around 8-12k) but the cabs also get quite harsh and very suddenly distorted in the upper frequencies when pushed.
running Eminence Delta 12A woofers and cheap "weconic" 2inch compression horn tweeters on the tops.
if needed, i can pull one apart and put up specs of the Xover.
basically, i feel that the tweeter needs to be louder to match the driver, and the only way i know of, thats simple to do, is to put a resistor in line with the woofer to quieten it rather than trying to boost the tweeter.
do you think that i should be making the tweeter do more work? as in, lower the crossover frequency and pass the woofer lower so its not doing such high frequencies?
if it turns out to be the compression driver at fault (and is just cheap crap), id really like to make sure i make a better choice as far as a replacement is concerned. but also dont want to spend a fortune just on tweeters....
TBH, the tweeter itself sounds nice. i like the sound of it when at reasonable/loud volumes, until i push it, and then it sounds harsh. female vocals suffer, electric guitar suffers, and piano. so this is the frequency range thats suffering.
midbass is fine, deep bass is handled by SS15 Jbell subs and works great... just that upper mid/hi frequency band.
please help.
thanks
Brendan.
Pull the horn out and check the XO for padding power resistors that are generally there to cut output.
Horns generally are much louder than direct radiating woofers so will have the power resistors to cut their output. You can run a jumper wire across the power resistors to get an idea how much louder they can go.
Another issue is the age of the compression driver--if it is years old and has been in storage or used in bars--if it allows, take the compression driver apart and look for something clogging the phase plug. Spiders love to put a nice little next of eggs in the phase plug which will kill your output quickly.
Give it a shot, can't beat the price of jumper wires and cleaning up the compression tweeter dome.
Horns generally are much louder than direct radiating woofers so will have the power resistors to cut their output. You can run a jumper wire across the power resistors to get an idea how much louder they can go.
Another issue is the age of the compression driver--if it is years old and has been in storage or used in bars--if it allows, take the compression driver apart and look for something clogging the phase plug. Spiders love to put a nice little next of eggs in the phase plug which will kill your output quickly.
Give it a shot, can't beat the price of jumper wires and cleaning up the compression tweeter dome.
im gonna correct myself here, pulled apart the tweeter today, its only 1inch. dont know where i got 2inch from... but anyway..
so i did what you said 18hurts, opened the cabs. and fair enough, a big fat resistor on the XO board. i bypassed it and holy cow, talk about loud tweeter! so, thats a big plus.
second, i decided to see what the woofer would sound like unfiltered. and yep. livened it up tenfold.
so what im thinking is that the Xover is way wrong for my cabs. on to the next step, i better check out the upper frequency response from Eminence and decide on a Xover frequency and probably redesign the XO.
so this is what was in the cabs.
and this is what i have as parts right here, now.
and my tweeter driver.
so i did what you said 18hurts, opened the cabs. and fair enough, a big fat resistor on the XO board. i bypassed it and holy cow, talk about loud tweeter! so, thats a big plus.
second, i decided to see what the woofer would sound like unfiltered. and yep. livened it up tenfold.
so what im thinking is that the Xover is way wrong for my cabs. on to the next step, i better check out the upper frequency response from Eminence and decide on a Xover frequency and probably redesign the XO.
so this is what was in the cabs.
and this is what i have as parts right here, now.
and my tweeter driver.
ok, so heres my speakers. Delta 12A
Speaker Detail | Eminence Speaker
according to that response graph, i should be putting a 6db/oct filter at about 1500hz to get a reasonably smooth response.
but if im right, that means that the tweeter should be 6db/oct at about 6khz, so as to not spike between its cutoff and the woofers cutoff.
does this sound acceptable to everyone?
edit: of course without seeing the tweeters response. which i have no way of finding as i have zero idea as to what they are... but, theyre from the Weconic speakers i first bought.
http://www.graysonline.com/retail/W...0-watt-max-15-2-way-carpet-covered-dj-speaker
Speaker Detail | Eminence Speaker
according to that response graph, i should be putting a 6db/oct filter at about 1500hz to get a reasonably smooth response.
but if im right, that means that the tweeter should be 6db/oct at about 6khz, so as to not spike between its cutoff and the woofers cutoff.
does this sound acceptable to everyone?
edit: of course without seeing the tweeters response. which i have no way of finding as i have zero idea as to what they are... but, theyre from the Weconic speakers i first bought.
http://www.graysonline.com/retail/W...0-watt-max-15-2-way-carpet-covered-dj-speaker
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Right about not designing XOs with minimum data, but why not try one set in between, 3k should obviate most of the woofers peak and the tweeter may be able to handle 3k if you use second order to remove most of the deep bass.
Only one way to find out.
A coil meant for a first order at 1500 should do 2nd at 3k if you Zobel the woofer to keep the impedance flat.
Experiment will prove or disprove that assumption, I am sometimes right and often wrong.
9uF is a first at 2k if the impedance is 8R
Only one way to find out.
A coil meant for a first order at 1500 should do 2nd at 3k if you Zobel the woofer to keep the impedance flat.
Experiment will prove or disprove that assumption, I am sometimes right and often wrong.
9uF is a first at 2k if the impedance is 8R
too much from the tweeter you mean? youre probably right.. lol the woofer just isnt really a good match for "full" range. its a great punchy solid driver, but yea, its a bit flat when filtered.
at the moment, if i worked it out properly, its a 1500hz 2way XO. so wouldnt that already be more harmful than what im talking about in regards to the tweeter?
at the moment, if i worked it out properly, its a 1500hz 2way XO. so wouldnt that already be more harmful than what im talking about in regards to the tweeter?
ok, i think ive come to a conclusion with my crossover requirements.
gonna do a 1st order hi-pass starting at about 1.5khz. -6db@3k -12db@ 6k and -24db@ 12k (which will be inaudible anyway coz the woofer doesnt reproduce that high anyway) and the tweeter, i will low pass at 6k, but ill do it as 2nd order, so will be -12db@ 3k and -24db @1.5k
if anyone can add to this im all ears, as i know im making semi-educated guesses here. especially with not knowing the tweeter specs.
gonna do a 1st order hi-pass starting at about 1.5khz. -6db@3k -12db@ 6k and -24db@ 12k (which will be inaudible anyway coz the woofer doesnt reproduce that high anyway) and the tweeter, i will low pass at 6k, but ill do it as 2nd order, so will be -12db@ 3k and -24db @1.5k
if anyone can add to this im all ears, as i know im making semi-educated guesses here. especially with not knowing the tweeter specs.
id have to defer to anothers expertise. To be honest, depending on the CDs Fs, 1.5k may be too low even with 2nd or higher orders, and i think its likely that the CD resonance is being excited much of the time. At low levels youd get away with it, but at loud levels im sure it would be grossly distorted. The Fs could be anywhere between 500hz and 1.5k, as a guess. Crossing at 2-3khz would seem a safer bet, if you ask me. Problem is then the woofers sound at 2k and up. If you went active you could push the limits a bit more using very steep filters. Besides, no offense meant, im not keen on the eminence driver at all. Whatever you end doing to these cabs i really feel that its going to be a big compromise.
You already have a 1st @1500 on the woofer and 2000 on the tweeter and you want to cross it higher, this will leave a huge hole in the response.
There is a difference in the tweeters power handling going from 1st at 2k to a 2nd at 3k and there should be less distortion in the high range with a second order XO, passive crossovers at the higher frequencies are not all that expensive
Welcome to the world of wild guesses...
Good to hear the tweeter is loud enough--most likely waaaaay too loud now. As others have mentioned, the issue is the correct XO frequency to protect the tweeter and mesh well with the woofer.
You can also remove the coil from the woofer and run some test tones through it to hear if it makes it higher than 1,500Hz with a decent enough response. If so, then you can cross it higher properly.
Get a program to model what happens when playing around with crossover filters, different slopes and that sort of thing. Don't get too anal about it, the main point of a PA speaker is to not fail--compromise to sacrifice a little sound quality for durability.
Good to hear the tweeter is loud enough--most likely waaaaay too loud now. As others have mentioned, the issue is the correct XO frequency to protect the tweeter and mesh well with the woofer.
You can also remove the coil from the woofer and run some test tones through it to hear if it makes it higher than 1,500Hz with a decent enough response. If so, then you can cross it higher properly.
Get a program to model what happens when playing around with crossover filters, different slopes and that sort of thing. Don't get too anal about it, the main point of a PA speaker is to not fail--compromise to sacrifice a little sound quality for durability.
ok, so as i said before, i know what ive physically done, but as far as what its electrically done, ive got no idea! so heres where im at.
starting point. stock 2way 6db/oct (remembering now, this crossover is the stock one for this tweeter, it used to be paired with a 15inch driver.)
i unsoldered the caps, stock they're 4.75uf so the two in parallel would equal somewhere in the vicinity of 9.5uf which is equal to approx 1500-1800hz @6db/oct @8ohm.
they're now in series, so should equal very roughly 2uf which gives me approx 11000hz @6db/oct
next up is this, im not sure why it works, but the coil pretty severely cuts the woofers hi range. but with the cap in parallel with the coil (1.0uf) it sounds like it bypasses the dirty lump in the deltas response and smooths it out and actually sounds quite crisp and fresh, rather than just muddy and filtered.
and then i added a resistor in parallel to the existing one, as when i bypassed it with wire, it was WAY too loud. so the 39R resistor seems to be near perfect volume when run alongside the woofer.
and one last shot of the underside of the XO
all in all, right now without being able to pump it up to hear it properly, it sounds alot more fresh and lively, clean and clear. and ive been able to turn the EQ right off and it sounds like it used to with the EQ maxed out. so im very much looking forward to turning it up a little and making a few EQ adjustments if needed.
starting point. stock 2way 6db/oct (remembering now, this crossover is the stock one for this tweeter, it used to be paired with a 15inch driver.)
i unsoldered the caps, stock they're 4.75uf so the two in parallel would equal somewhere in the vicinity of 9.5uf which is equal to approx 1500-1800hz @6db/oct @8ohm.
they're now in series, so should equal very roughly 2uf which gives me approx 11000hz @6db/oct
next up is this, im not sure why it works, but the coil pretty severely cuts the woofers hi range. but with the cap in parallel with the coil (1.0uf) it sounds like it bypasses the dirty lump in the deltas response and smooths it out and actually sounds quite crisp and fresh, rather than just muddy and filtered.
and then i added a resistor in parallel to the existing one, as when i bypassed it with wire, it was WAY too loud. so the 39R resistor seems to be near perfect volume when run alongside the woofer.
and one last shot of the underside of the XO
all in all, right now without being able to pump it up to hear it properly, it sounds alot more fresh and lively, clean and clear. and ive been able to turn the EQ right off and it sounds like it used to with the EQ maxed out. so im very much looking forward to turning it up a little and making a few EQ adjustments if needed.
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