I've been using pink noise and trueRTA to set up my systems for a few years, and have always been unhappy with a flat response. Reading up on this kind of thing suggests that the harsh mid / treble I get is due to the bass freq's reflections being added to the direct sound, causing me to up the (more direct) treble to match the bass.. ie: the bass is measured with reflections, the treble is direct leading to a boost in higher freq's.
Some books suggest target curves, such as the 'Handbook for sound Engineers', but I'm assuming this is for larger spaces than mine. (have tried the suggested curves)
At the moment I'm using a 1dB / oct drop from 20Hz to 20kHz. This gives a pretty good balance, but still harsh with films at reference levels.
I'm using right now:
mono subs:
2 sealed tempests 10Hz - 30Hz crossed 24dB/oct to:
2 Labhorns 30 - 80 crossed 24dB/oct to
stereo mains (per side)
1 beyma lx60 15" (sealed) 80 - 330Hz crossed 24dB/oct to
1 Precision devices PD107 10" (sealed) 330 - 1200Hz crossed 24dB/oct to
1 Beyma 380 1" cd on a TD250 (90 x 40) horn 1200 - 20k
What I thought would be cool is if people could post a response at listening position with a few words about what their system comprises of and what they feel it sounds like with music / dvd's etc. I'm gonna do a plot tomorrow, as it's past my bedtime right now😀
I think this could be quite a useful 'real world' thread if enough people post..
Cheers!
Rob.
Some books suggest target curves, such as the 'Handbook for sound Engineers', but I'm assuming this is for larger spaces than mine. (have tried the suggested curves)
At the moment I'm using a 1dB / oct drop from 20Hz to 20kHz. This gives a pretty good balance, but still harsh with films at reference levels.
I'm using right now:
mono subs:
2 sealed tempests 10Hz - 30Hz crossed 24dB/oct to:
2 Labhorns 30 - 80 crossed 24dB/oct to
stereo mains (per side)
1 beyma lx60 15" (sealed) 80 - 330Hz crossed 24dB/oct to
1 Precision devices PD107 10" (sealed) 330 - 1200Hz crossed 24dB/oct to
1 Beyma 380 1" cd on a TD250 (90 x 40) horn 1200 - 20k
What I thought would be cool is if people could post a response at listening position with a few words about what their system comprises of and what they feel it sounds like with music / dvd's etc. I'm gonna do a plot tomorrow, as it's past my bedtime right now😀
I think this could be quite a useful 'real world' thread if enough people post..
Cheers!
Rob.
Considered using a fft program live Smaart Live? Or a SIM 3 if you've got 10 large laying around.
Systems which sound harsh in the treble when equalized flat usually have power response that drops with frequency (the norm for speakers) or when the environment they are in is very absorptive at high frequencies.
Equalize your speakers so they are flat anechoically (outside) and then work from there. Usually you will want to bring down the 3-4k range a dB or so... Small changes are better than large ones at the fine tuning stage. Move a slider a small amount and listen to a few songs, etc...
If you can't bring them outside: Before I had measurement gear I used to have decent luck making it flat in-room or in-car with band limited noise up to 1-2Khz and then make minor adjustments by ear above that.
Equalize your speakers so they are flat anechoically (outside) and then work from there. Usually you will want to bring down the 3-4k range a dB or so... Small changes are better than large ones at the fine tuning stage. Move a slider a small amount and listen to a few songs, etc...
If you can't bring them outside: Before I had measurement gear I used to have decent luck making it flat in-room or in-car with band limited noise up to 1-2Khz and then make minor adjustments by ear above that.
Hi,
in 1974 Moller showed the ideal 1/3 octave pink noise curve, for audio listening: obtaining such a curve means you have a well sounding system, no matter the music genre. I don't hear many people talking about Moller's response, unfortunately. Be aware that you need 2 pink noise generator, to compare your system with Moller's curve.
Henning Møller, “Hi-Fi Tests-with 1/3 Octave Pink Weighted Random Noise”, AES convention 47 (February 1974), Preprint Number A-5.
Regards,
Claudio
in 1974 Moller showed the ideal 1/3 octave pink noise curve, for audio listening: obtaining such a curve means you have a well sounding system, no matter the music genre. I don't hear many people talking about Moller's response, unfortunately. Be aware that you need 2 pink noise generator, to compare your system with Moller's curve.
Henning Møller, “Hi-Fi Tests-with 1/3 Octave Pink Weighted Random Noise”, AES convention 47 (February 1974), Preprint Number A-5.
Regards,
Claudio
Hi Rob,
What Ron said...
Smith, Keele & Eargle in their paper 'Improvements in monitor loudspeaker design' were the first that I know of to explore the realtionship between house curves and the power response of speakers. It's well worth reading.
Cheers, Ralph.
What Ron said...
Smith, Keele & Eargle in their paper 'Improvements in monitor loudspeaker design' were the first that I know of to explore the realtionship between house curves and the power response of speakers. It's well worth reading.
Cheers, Ralph.
It's not just the power response of the speaker but the absorptive characteristics of the room. Most rooms absorb the highs more than the lows. So, even a speaker with flat on-axis anechoic response and perfect power response will still show rolled-off in-room highs with pink noise and an RTA. EQ'ing that speaker flat with an RTA will make it sound too bright.
hi rob
catapult say it all...
i had the same problem whit in room measurement,the solution i use now is measuring driver by driver in very nearfield whit the "rel" fonction in truerta before each measurement.
i place the mic at about 10 cm ,apply "relative" to get a "reference" ,make measurement and save it
apply the same method for the other driver,and adjust level of driver to get the same spl for each,but very important use "rel" before each measurement.
at listening position it don't give a flat response but very clean sounding
excuse my poor english....
greets
catapult say it all...
i had the same problem whit in room measurement,the solution i use now is measuring driver by driver in very nearfield whit the "rel" fonction in truerta before each measurement.
i place the mic at about 10 cm ,apply "relative" to get a "reference" ,make measurement and save it
apply the same method for the other driver,and adjust level of driver to get the same spl for each,but very important use "rel" before each measurement.
at listening position it don't give a flat response but very clean sounding
excuse my poor english....
greets
Thanks for the responses, though most just confirm what I said in the initial post:
ie: the bass is measured with reflections, the treble is direct leading to a boost in higher freq's.
I was hoping to get some in room measurements that could prove useful for me and many others..
Looks like I'll tread the journey alone😀 Will post curves as I get time to do so...
Rob.
ie: the bass is measured with reflections, the treble is direct leading to a boost in higher freq's.
I was hoping to get some in room measurements that could prove useful for me and many others..
Looks like I'll tread the journey alone😀 Will post curves as I get time to do so...
Rob.
Hi Rob,
How well is everything time aligned?
Just yesterday i noticed again how fat or thin the low end can sound by adjusting the delay.
CO
How well is everything time aligned?
Just yesterday i noticed again how fat or thin the low end can sound by adjusting the delay.
CO
I use the dcx2496 for xo, so the delays are pretty close.
I think I'll drag them outside over Christmas and have a measure.
Cheers,
Rob..
I think I'll drag them outside over Christmas and have a measure.
Cheers,
Rob..
If 10cm nearfield measurements are used to quantify the response curve of the speaker, does it include baffle effects?
I need to decide whether to add baffle step correction to an active crossover that is crossed over at about the baffle wavelength frequency.
I need to decide whether to add baffle step correction to an active crossover that is crossed over at about the baffle wavelength frequency.
Why didn't anyone tell us RTA is now free? (for whole octave resolution).
This is the result with my radioshack meter and laptop microphone and headphone sockets.
This is a pair of fr125s crossed (mono) at 200Hz to a pair of 10" sealed subs.
I am about to build my crossover with BSC and LT for the bass. Then the bass output on my AVamp can be used to drive my ported tempest for movies only.
Robwells, wow .. 2 different sets fo subs below 80Hz seems quite extravagant.
This is the result with my radioshack meter and laptop microphone and headphone sockets.
This is a pair of fr125s crossed (mono) at 200Hz to a pair of 10" sealed subs.
I am about to build my crossover with BSC and LT for the bass. Then the bass output on my AVamp can be used to drive my ported tempest for movies only.
Robwells, wow .. 2 different sets fo subs below 80Hz seems quite extravagant.
Attachments
RobWells said:
Hi Rob,
Ive got the same unit. Could you check something for me?
I just found out that when summing the bass to a mono subwoofer it sounds worse than just using mono.
I'm running mono at the moment (sub amp is no good) so its not a question of imaging.
So when i listen to the right channel with L+R summed to ths sub its worse than just right to the sub (3db higher settings)
So i'm wondering if you notice the same. This could also be done in stereo but it would surely be audible because your throwing away some "stereo image"
Thanks, if you can find the time for it...
Collin
jimbo1968 said:
Jimbo,
I honestly think the 1 octave resolution is way too low to do any serious measuring with. Many people seem to think 1/12th oct is the minimum for 'ok' measurements.
Beware of eq'ing a pair of 10's per side if you like good volumes. My last speakers had 2 x scanspeak 8565-01's per side (2 x sealed 10" per side) and they ran out of steam with movies at good levels. Fine with normal music at 'normal to loud' listening, but not with d&b / electronica / jungle at 'loud' levels.
The best compromise was crossing them at 40Hz to the subs.. Sounded great with all music, movies still a bit too much for them.
""wow .. 2 different sets fo subs below 80Hz seems quite extravagant.""
😀 "DIYaudio.com - projects by the fanatics, for the fanatics"
Rob.
Coolin said:
Hi Collin,
I have 2 dcx's - 1 is used for my 3 way stereo pair, the other is used for my 2 way subs (fed from the sub out from my av processor) My processor does the mains / sub xo at 80 Hz. The mains are designed to roll off at 80Hz so as to add to the processors 12dB high pass giving 24dB/oct slope, to match the processors 24dB/oct low pass on the subs.
I did it this way so I have the spare dcx channel for my centre speaker when I buy the drivers for it....
I think I'd have to make up some custom cables to split the mains to both dcx's to be able to check this out, and tbh I've got a fair bit to do in the next few weeks. If you've got an idea of a simple way for me to check it then I'll have a go..
Cheers!
Rob.
actually it's only one 10" per side. but winisd says I should be able to manage 100db without pushing the FR125S past 1/2xmax and using all of the 10mm xmax of the 10" it will go down to an f3 of 32Hz
Seeing as 80db is quite loud for me it should be fine.
1 octave RTA is better than nothing though, it has confirmed the response of the 10" boxes. I downloaded speaker workshop in case that had better resolution but it wasn't obvious how to fire up the RTA.
I'm not sure how far I'm going to take the diy speaker making. Once i've got these crossed and equalised and i've built my amps I might be happy.
Seeing as 80db is quite loud for me it should be fine.
1 octave RTA is better than nothing though, it has confirmed the response of the 10" boxes. I downloaded speaker workshop in case that had better resolution but it wasn't obvious how to fire up the RTA.
I'm not sure how far I'm going to take the diy speaker making. Once i've got these crossed and equalised and i've built my amps I might be happy.
""1 octave RTA is better than nothing though""
You'd get better results using test warbles and your spl meter than the 1 oct RTA. Just would take a lot more time.
Cheers,
Rob.
You'd get better results using test warbles and your spl meter than the 1 oct RTA. Just would take a lot more time.
Cheers,
Rob.
RobWells said:
Hi Rob,
Does your av processor have stereo sub outs then?
Your not listening to mono bass are you ?
What i'm proposing is if you could;
- Mute L channels including L bass subs on both of your DCX's
- Listen to R channel including R subs and on your bass DCX switch between A(or B or C) input and summed input (A+B)
Using the compare button you can swich this quickly to check the difference.
You might have to -3 dB the summed input because its combining two channels.
See if you hear a difference !
Regards, Collin
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