Peak/Distortion on a specifik tweeter frequence on homebuild - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th April 2014, 07:46 PM   #1
diyAudio Member
 
Join Date: Jun 2013
Location: Denmark
Default Peak/Distortion on a specifik tweeter frequence on homebuild

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

a year ago i finaly finished my very first homebuild speakers. Now after 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!
  Reply With Quote
Old 7th April 2014, 08:08 PM   #2
diyAudio Member
 
Join Date: Jun 2013
Location: Denmark
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:
Click the image to open in full size.
Click the image to open in full size.

The crossover where created while testing with a MusicHall stereo amp and in another room but the curve looked like this:
Click the image to open in full size.

The speakers looks like this:
Click the image to open in full size.
  Reply With Quote
Old 7th April 2014, 08:12 PM   #3
diyAudio Member
 
Inductor's Avatar
 
Join Date: Feb 2006
Location: Cascais
I "suspect" the tweeter. The tweeter Fs going through the crossover... and showing up.
  Reply With Quote
Old 7th April 2014, 08:14 PM   #4
diyAudio Member
 
Join Date: Jun 2013
Location: Denmark
#Inductor can you elaborate?
  Reply With Quote
Old 7th April 2014, 08:44 PM   #5
diyAudio Member
 
Inductor's Avatar
 
Join Date: Feb 2006
Location: Cascais
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.
  Reply With Quote
Old 7th April 2014, 08:57 PM   #6
diyAudio Member
 
Join Date: Jun 2013
Location: Denmark
Hmmm bugger xD

Simulation?
Thx read it tomorrow
  Reply With Quote
Old 7th April 2014, 09:27 PM   #7
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
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.
Attached Images
File Type: png XT25_Attenuator.PNG (7.7 KB, 156 views)
__________________
Well, there it is! Best regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 7th April 2014, 10:08 PM   #8
Lojzek is offline Lojzek  Croatia
diyAudio Member
 
Lojzek's Avatar
 
Join Date: Feb 2012
Danner,

you 've said "the curve looked like this". Does that mean you
measured the response of these drivers and XO filter and the
graph is the one you have here ? How loud did you play the
the Avicii song or where did the volume knob point while
hearing distortion?
  Reply With Quote
Old 8th April 2014, 06:53 AM   #9
diyAudio Member
 
Join Date: Jun 2013
Location: Denmark
#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
  Reply With Quote
Old 8th April 2014, 10:06 AM   #10
diyAudio Member
 
Join Date: Feb 2009
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
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tracking down source of distortion peak in my MTM wintermute Multi-Way 45 20th August 2013 04:34 AM
Crossover frequence and sidemounted woofer heinz1964 Full Range 12 17th February 2012 03:49 PM
Spect output peak to peak for 807 SE ul walter807 Tubes / Valves 2 1st December 2010 11:24 AM
200V peak to peak @25MHz ketan Parts 1 8th June 2008 03:21 AM
Pre Outs and peak-to-peak ? CheekyMonkeyVZi Car Audio 7 12th December 2006 08:30 AM


New To Site? Need Help?

All times are GMT. The time now is 12:16 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2