Hey there! I'm kinda new to this site.. or at least active, have been reading a lot in here and it seems to be the right place to ask about speakers 
½ a year ago i finaly finished my very first homebuild speakers. Now after ½ a year of listening i have encountered a peak at a ceartain frequence range, and i have absolutely no idea where it comes from.
The peak is hurting my ears at higher volumes and it is realy clear in one of my favorite songs "Addicted to you" by Avicii at 0:32 - 0:35 when she sings words like "my", "eye" and so on.
This is not the only song, but the song thats worst. Most songs i hear nothing to it.
I suspect the tweeter, crossover, amp or my room.
The room is approximately 30 m^2 it has 3 drywalls(walls of gypsum) whereof two has an angle og 50 degrees. The last wall is a brick wall which the speakers are faceing.
The amp is a "cheap" DENON 2113 AVR.
First of all.. I know my room aint excelent audio conditions but after all there is a huge blanket on the floor. I also know that the amp is not the best out there.
But can one of these two be the cause of the peak or is there a fault in the crossover/tweeter?
Thx for reading this looong thing xD
The speakers will be described shortly!
½ a year ago i finaly finished my very first homebuild speakers. Now after ½ a year of listening i have encountered a peak at a ceartain frequence range, and i have absolutely no idea where it comes from.
The peak is hurting my ears at higher volumes and it is realy clear in one of my favorite songs "Addicted to you" by Avicii at 0:32 - 0:35 when she sings words like "my", "eye" and so on.
This is not the only song, but the song thats worst. Most songs i hear nothing to it.
I suspect the tweeter, crossover, amp or my room.
The room is approximately 30 m^2 it has 3 drywalls(walls of gypsum) whereof two has an angle og 50 degrees. The last wall is a brick wall which the speakers are faceing.
The amp is a "cheap" DENON 2113 AVR.
First of all.. I know my room aint excelent audio conditions but after all there is a huge blanket on the floor. I also know that the amp is not the best out there.
But can one of these two be the cause of the peak or is there a fault in the crossover/tweeter?
Thx for reading this looong thing xD
The speakers will be described shortly!
The drivers are: http://www.scan-speak.dk/datasheet/pdf/r2604-833000.pdf
and: http://www.scan-speak.dk/datasheet/pdf/18w-8531g00.pdf
The crossover is a 2. order passive and looks like this:
The crossover where created while testing with a MusicHall stereo amp and in another room but the curve looked like this:
The speakers looks like this:
and: http://www.scan-speak.dk/datasheet/pdf/18w-8531g00.pdf
The crossover is a 2. order passive and looks like this:
The crossover where created while testing with a MusicHall stereo amp and in another room but the curve looked like this:
The speakers looks like this:
Scanspeak 18W/8531G00
Vifa XT25TG30-04
Looking at the crossover and specs is not obvious and I don't know.
When we go through the design we can't find a thing (simulation?) but read what said Mario Pankov here. And others, more here.
Vifa XT25TG30-04
Looking at the crossover and specs is not obvious and I don't know.
When we go through the design we can't find a thing (simulation?) but read what said Mario Pankov here. And others, more here.
What Inductor is saying, is you are overdriving the Fs peak in all probability.
This is a big rise to about 25R around 600Hz, IIRC. The XT25 is notorious for it.
Anyway, the simple fix is to shunt a 10R resistor across the XT25 tweeter. It should avoid the horrible resonance on certain notes.
Like below.
I've added a 3R, or thereabouts, to the bass shunt too, because it sounds better IMO. I'm like that.
This is a big rise to about 25R around 600Hz, IIRC. The XT25 is notorious for it.
Anyway, the simple fix is to shunt a 10R resistor across the XT25 tweeter. It should avoid the horrible resonance on certain notes.
Like below.
I've added a 3R, or thereabouts, to the bass shunt too, because it sounds better IMO. I'm like that.
Attachments
#system7:
Now you say the FS is the problem, but the tweeter isn't even playing near it's own FS, can the FS then still cause problems?
The frequence i hear is def. also a lot higher than 450 Hz.
But seriuosly thankyou for taking the time of making af crossover xD
Is it done by some kind of simulation program or just by gut feeling ??
#Lojzek:
The response of the speakers where meassured multible times while building the crossover. The curve i attatched above was the final result of the attatched XO and those drivers yes.
It was meassured by a guy whom has a lot more knowledge of this subject then I. He used a Clio system for the meassurements.
Puuuh it's hard to describe how loud, but my guess would be around 90 dB...
Thats approximately 70-80% of the amps cpability
Now you say the FS is the problem, but the tweeter isn't even playing near it's own FS, can the FS then still cause problems?
The frequence i hear is def. also a lot higher than 450 Hz.
But seriuosly thankyou for taking the time of making af crossover xD
Is it done by some kind of simulation program or just by gut feeling ??
#Lojzek:
The response of the speakers where meassured multible times while building the crossover. The curve i attatched above was the final result of the attatched XO and those drivers yes.
It was meassured by a guy whom has a lot more knowledge of this subject then I. He used a Clio system for the meassurements.
Puuuh it's hard to describe how loud, but my guess would be around 90 dB...
Thats approximately 70-80% of the amps cpability
You have to be sure where the problem really is. Can you play music disconnecting the woofer or the tweeter and report back? Second aspect is the room, the problem is there even if you move the speakers in other positions (or you move in the room)? Last aspect worth investigating is resonance from the panels.
Ralf
Ralf
Danner,
If I were to guess, I'd blame the receiver before speakers.
The measurements look normal in the XO area, but it is not
specified where the mic was placed while measuring and the
filter isn't addressing baffle step.
When you are saying 90dB or 70-80%, this still is not helping
much. If the volume knob was set at 10 o'clock, I would call it
overdriven and by looking at transformer size built in, not very
promising. Still, I could be very well wrong about it.
Have you got any other amp to try ? Any impedance measurements
of the finished box ?
If I were to guess, I'd blame the receiver before speakers.
The measurements look normal in the XO area, but it is not
specified where the mic was placed while measuring and the
filter isn't addressing baffle step.
When you are saying 90dB or 70-80%, this still is not helping
much. If the volume knob was set at 10 o'clock, I would call it
overdriven and by looking at transformer size built in, not very
promising. Still, I could be very well wrong about it.
Have you got any other amp to try ? Any impedance measurements
of the finished box ?
We are guessing, of course, but that filter is simplistic to the max. It's not enough to use shiny looking components for a good result.
I would expect the bass to be prone to breakup without any shunt arm resistance. I'd also reckon a steeper third order on the XT25 tweeter with some resistance thrown in would help. See, purely reactive components just reflect energy from the drivers, they don't absorb it. So it can get out of hand. You can end up with a woofer, tweeter and cabinet resonance all going haywire together if you're really unlucky.
I'd reckon this speaker tends to harshness at the best of times. It might go into a catastrophic breakup at high level too. If you look at some Troels designs with low inductance scanspeak 18W drivers and the similar R2604 ring-radiator tweeter, he does a lot more work. Those resistors do more than you think and, make for a smooth sounding speaker. This applies particularly where driver materials aren't lossy.
DIY Loudspeakers
I didn't think the impedance of this speaker was bad at all. Looks like it stays above a benign 6 ohms at all times, so amplifier is probably not the problem.
I would expect the bass to be prone to breakup without any shunt arm resistance. I'd also reckon a steeper third order on the XT25 tweeter with some resistance thrown in would help. See, purely reactive components just reflect energy from the drivers, they don't absorb it. So it can get out of hand. You can end up with a woofer, tweeter and cabinet resonance all going haywire together if you're really unlucky.
I'd reckon this speaker tends to harshness at the best of times. It might go into a catastrophic breakup at high level too. If you look at some Troels designs with low inductance scanspeak 18W drivers and the similar R2604 ring-radiator tweeter, he does a lot more work. Those resistors do more than you think and, make for a smooth sounding speaker. This applies particularly where driver materials aren't lossy.
DIY Loudspeakers
I didn't think the impedance of this speaker was bad at all. Looks like it stays above a benign 6 ohms at all times, so amplifier is probably not the problem.
#giralfino
I'm really bussy in school, but i'll make a test the next week and I'll return with the answer so we can narrow the guessing a bit
#inductor
I don't have other speakers in the house xD
#Lojzek
The fun thing is, that when we build the crossover with his amp and in his livingroom the speakers generally sounded a lot warmer and softer than they ever had with my amp and room..
The mic was placed right in front of the speaker, approx 50 cm form the speaker.
Srry.. the baffle step?
Well the amp is digital and the volume knob is turning more than 1 full revolution from 0-100%...
No to both of those, i just know as i said that they sounded way diffrent at his place.
I have tried them once with another musichall amp in my room, that didn't really chance much. Thats why i suspect the room the most.
#system 7
Well i thought that generally you would want as simple a filter as possible?
But i might be wrong, either way the speakers sounded very fine at his place.
I have read a lot at his page, but i gotta admit, his filter designs are beyond what i can figure out xD
I'm really bussy in school, but i'll make a test the next week and I'll return with the answer so we can narrow the guessing a bit
#inductor
I don't have other speakers in the house xD
#Lojzek
The fun thing is, that when we build the crossover with his amp and in his livingroom the speakers generally sounded a lot warmer and softer than they ever had with my amp and room..
The mic was placed right in front of the speaker, approx 50 cm form the speaker.
Srry.. the baffle step?
Well the amp is digital and the volume knob is turning more than 1 full revolution from 0-100%...
No to both of those, i just know as i said that they sounded way diffrent at his place.
I have tried them once with another musichall amp in my room, that didn't really chance much. Thats why i suspect the room the most.
#system 7
Well i thought that generally you would want as simple a filter as possible?
But i might be wrong, either way the speakers sounded very fine at his place.
I have read a lot at his page, but i gotta admit, his filter designs are beyond what i can figure out xD
First, for the purposes of the discussion, it may help to correctly identify the tweeter. Is it the Vifa XT25TG30 or the Scan R2604 833000? Very similar but not the same animals.
I'm with giralfino - try to identify if it's a tweeter or a woofer problem.
My immediate thought though was that you've crossed the woofer too high at about 3.2kHz. Troels has only used that driver once in a 2-way crossed at 2.5kHz and he didn't like it that much. Look here, especially the conclusion down at the bottom of the page.
And Zaph chose to cross at 1.7kHz in his 2-way Zaph|Audio - ZRT - Revelator Tower.
The other possibility, albeit perhaps remote, is that you are experiencing the downside of drivers of that high quality - poor recordings are not faring well.
I'm with giralfino - try to identify if it's a tweeter or a woofer problem.
My immediate thought though was that you've crossed the woofer too high at about 3.2kHz. Troels has only used that driver once in a 2-way crossed at 2.5kHz and he didn't like it that much. Look here, especially the conclusion down at the bottom of the page.
And Zaph chose to cross at 1.7kHz in his 2-way Zaph|Audio - ZRT - Revelator Tower.
The other possibility, albeit perhaps remote, is that you are experiencing the downside of drivers of that high quality - poor recordings are not faring well.
FRD and ZMA files
Scanspeak 18W/8531G00
Scan-Speak 18W/8531G Frd & Zma Files.
Vifa XT25TG30-04
https://app.box.com/s/qa3g6ukzxp6410dwmcrv/1/566224876/2983113757/1
Scanspeak 18W/8531G00
Scan-Speak 18W/8531G Frd & Zma Files.
Vifa XT25TG30-04
https://app.box.com/s/qa3g6ukzxp6410dwmcrv/1/566224876/2983113757/1
#jReave
This is the driver i use:
I will during next week
Hmm, as said my knowledge is weak so i just did what i was recommended so please keep the bets comming I'll have a look
That would truely bee downer as i mainly use Spotify
#Inductor
What exactly is that ?
#Lojzek
Looks interesting.. The modified filter, is that the filter proposed by system7 ?
This is the driver i use:
I will during next week
Hmm, as said my knowledge is weak so i just did what i was recommended so please keep the bets comming I'll have a look
That would truely bee downer as i mainly use Spotify
#Inductor
What exactly is that ?
#Lojzek
Looks interesting.. The modified filter, is that the filter proposed by system7 ?
Drivers pdfs
Scanspeak 18W/8531G00 - 7" Midwoofer
Vifa XT25BG60-04 - 1" (Ring Radiator) Tweeter
- Sometimes it takes 18 posts...
- I will come back in... ................. nine 1/2 weeks, see ya!
Scanspeak 18W/8531G00 - 7" Midwoofer
Vifa XT25BG60-04 - 1" (Ring Radiator) Tweeter
- Sometimes it takes 18 posts...
- I will come back in... ................. nine 1/2 weeks, see ya!
#jReave
This is the driver i use:
I will during next week
The modified filter, is that the filter proposed by system7 ?
Any resemblance is purely coincidental.
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