Look, each time you use less than the total, the room is excited differently especially in the modal region. Since your modal region trick is to blend mains and subs in a special way, I guess that you have to play them all together to see what you have done. I thought of 3 simple solutions. One is to use a Y cord or Y adapter. Second is to use pink noise from a CD. Third is to use synchro free RTA which burns your special noise CD too. Steady in LF averaging. See here.
Rob, see Post #1
Duh
You have a nice room! Reminds me of mine but I like yours better.
Well I am sure everyone has already been through these. This is what I would try to see if things change for better or worse.
I would double check that your L/R balance is correct. Just do a level check with an SPL meter and a noise source to verify the speaker levels are the same.
Make sure the distance to each speaker is the same.
Move the coffee table
Set-up a temporary seat in front of the couch further away from the wall.
See if any of this helps with your image and peak.
Good Luck
Rob🙂
Duh
You have a nice room! Reminds me of mine but I like yours better. Well I am sure everyone has already been through these. This is what I would try to see if things change for better or worse.
I would double check that your L/R balance is correct. Just do a level check with an SPL meter and a noise source to verify the speaker levels are the same.
Make sure the distance to each speaker is the same.
Move the coffee table
Set-up a temporary seat in front of the couch further away from the wall.
See if any of this helps with your image and peak.
Good Luck
Rob🙂
“the nulls are prominent at +/- 5° here, each generating a 6 - 10 dB, octave-wide hole in the response at crossover; the listener must be precisely on-axis vertically to avoid them.”
Or get outside of them by being more off axis.
“Because of the crossover topology there has to be two nulls, one up one down”
? The nulls will be there by interference w/o XO at all.
“I get too many requests for loaners for reviews.”
Aren’t reviews exactly what you need to get the word out?
Or get outside of them by being more off axis.
“Because of the crossover topology there has to be two nulls, one up one down”
? The nulls will be there by interference w/o XO at all.
“I get too many requests for loaners for reviews.”
Aren’t reviews exactly what you need to get the word out?
I'm wondering if a swept sine signal is appropriate at all to do measurements within the modal region (< 300 Hz). To calibrate the multiple subs there has to be a steady state sound field whereas the swept sine is more transient? Maybe Earl can shed some light on that.
Best, Markus
Best, Markus
Markus
I would tend to agree with you that swept sine is not a good choice for the LFs. I would use noise. Are your results spatially averaged? To do spatial averaging at HFs you cannot sweep the mic by hand as I suggested. You have to do gated measurements at several location and then average the dB number. The hand sweep technique will average down the HF because of the large time window at those frequencies.
But actually for an in-room response what you show is not bad. Its very smooth above 200 Hz, except for that 600 Hz peak. I might want to track down that peak if I were you. Is it localized i.e. just near the listening position, or is it everywhere.
Its impossible for me to say if your LF response is as good as you can get it. Its not as good as I'm used to, but I've never tried to set up a small room in an appartment. everything that I have done has been more custom and bigger. It could well be that what you have is "as good as it gets" in that region. If the peaks and dips are global, i.e. still exist after spatial averaging, then EQ at these frequencies would help.
I would tend to agree with you that swept sine is not a good choice for the LFs. I would use noise. Are your results spatially averaged? To do spatial averaging at HFs you cannot sweep the mic by hand as I suggested. You have to do gated measurements at several location and then average the dB number. The hand sweep technique will average down the HF because of the large time window at those frequencies.
But actually for an in-room response what you show is not bad. Its very smooth above 200 Hz, except for that 600 Hz peak. I might want to track down that peak if I were you. Is it localized i.e. just near the listening position, or is it everywhere.
Its impossible for me to say if your LF response is as good as you can get it. Its not as good as I'm used to, but I've never tried to set up a small room in an appartment. everything that I have done has been more custom and bigger. It could well be that what you have is "as good as it gets" in that region. If the peaks and dips are global, i.e. still exist after spatial averaging, then EQ at these frequencies would help.
noah katz said:
Yes that is correct, but the crossover topology changes their location and spread.
Yes, I would be interested in some reviews, but they need to be serious reviews if I am going to make a custom set for this. I offer a "touring" set now for those who want to review them in their own homes.
One more word on crossover "nulls". These are inevitable consequences of crossovers and multiple non-coincident drivers and exist in ANY system with this type of sources. So the fact that the Nathan has them is NOT the issue, the issue is "are they well controlled" to the point that they don't seriuosly degrade the listening experince and I claim they are. Obviuosly people here HAVE NOT seen other systems vertical responses (or horizontal for that matter) because they are ALWAYs bad. Crossovers are EVIL things that cause serious problems. They should be avoided at all costs. That's a major reason for my doing many of the things that I do - to avoid use these sound degrading devices. I consider the use of any crossover that could be avoided as a serious compromise in performance.
My systems all have only one crossover - the minimum from my point of view - and this appears to yield very possitive reviews. I think that the data supports my position on this.
This is also why I shy away from OB - because I can see no way arround not having another crossover and active filters and multiple amps. These are all negaitive things to me - high cost, high complexity, low performance advantages. Not good "value".
How long and loud can I play White Noise before smoke is coming out of the waveguide?
I measure 94 dBSPL in the nearfield of the speaker and 68 dBSPL at the listening position. To get over the noise floor I would have to add another 30 dB...
I measure 94 dBSPL in the nearfield of the speaker and 68 dBSPL at the listening position. To get over the noise floor I would have to add another 30 dB...
This is why I suggested 'The Audio Critic', Peter Aczel, specifically, for a review pair, even though I have no idea if he would interested. I do know that I would be interested in reading his review, because it seems that he is thoroughly in the Linkwitz camp regarding active filters and multiple amps, and if he thought highly of your approach and product, well, that would mean something to me, because I respect him, from reading him.
I also respect you, from reading you.
Mr. Aczel is in his 80's, and again, I'd have no idea if he'd be interested in traveling to hear speakers, but, I tend to doubt it.
Mr. Linkwitz does offer a kit version of his Pluto active speakers that compares with the cost of your kits, as far as the cost argument goes, and the inclusion of amps for a similar price to a passive kit would seem to be a good value.
But, I have an amp, and I, as an audio gear consumer, do tend to track your way because your way fits with how I already am. I want to use what I have in electronics, and get new speakers.
I also respect you, from reading you.
Mr. Aczel is in his 80's, and again, I'd have no idea if he'd be interested in traveling to hear speakers, but, I tend to doubt it.
Mr. Linkwitz does offer a kit version of his Pluto active speakers that compares with the cost of your kits, as far as the cost argument goes, and the inclusion of amps for a similar price to a passive kit would seem to be a good value.
But, I have an amp, and I, as an audio gear consumer, do tend to track your way because your way fits with how I already am. I want to use what I have in electronics, and get new speakers.
gedlee said:
I don't want to be disrespectful but critical listening is something you just can't do anymore when you're over 80...
Best, Markus
An externally hosted image should be here but it was not working when we last tested it.
Best, Markus
I would tend to agree with Markus. Hearing does tend to change dramatically above 60 years old.
I would be very interested in the "right" reviews, but these are hard to come by. Everyone has their agenda. There basically isn't a good source of reviews that I know of.
I would be very interested in the "right" reviews, but these are hard to come by. Everyone has their agenda. There basically isn't a good source of reviews that I know of.
That's an opinion; another is, and I don't have the link from the Linkwitz Labs website handy, is, that even deaf people can tell the difference in the sense of sound 'reality' a speaker can project.
markus76 said:
Of course our hearing adapts to new situations but to what extend? Why do we use glasses or hearing aids to compensate for lost abilities if we just need to "adapt"?
Best, Markus
Best, Markus
Markus
I think that you would have to play those speakers at unrealistic levels before you could damage them.
If you are having trouble with signal to noise then you are doing something wrong. I have no problems at all in this regard, but I do have a quiet situation. But as I described to you we had no problems in Thailand and there was an airport across the street. With cross-correlation the signal to noise can be almost 0 dB and you should still be able to get a decent response curve with enough averages. Sounds to me like your measurement system does not use cross-correlation, but a tracking filter, which can be a real problem in a noisey situation (which is why its not used too much anymore).
But if its the subs that you are trying to set up then you should be band limiting the noise to the LFs and this should get you above the noise floor even with real-time measurements. The actual dBA numbers will be quite low in this case because of the LF rejection of the A-weighted filter and there is no risk to the tweeter.
Can you supply a "noise floor" measurement from your location? How bad is it?
I think that you would have to play those speakers at unrealistic levels before you could damage them.
If you are having trouble with signal to noise then you are doing something wrong. I have no problems at all in this regard, but I do have a quiet situation. But as I described to you we had no problems in Thailand and there was an airport across the street. With cross-correlation the signal to noise can be almost 0 dB and you should still be able to get a decent response curve with enough averages. Sounds to me like your measurement system does not use cross-correlation, but a tracking filter, which can be a real problem in a noisey situation (which is why its not used too much anymore).
But if its the subs that you are trying to set up then you should be band limiting the noise to the LFs and this should get you above the noise floor even with real-time measurements. The actual dBA numbers will be quite low in this case because of the LF rejection of the A-weighted filter and there is no risk to the tweeter.
Can you supply a "noise floor" measurement from your location? How bad is it?
Have you tried high slopes with digital crossovers?
When using FIR with really high slopes there is almost no overlap between drivers, and comb filtering effect tend to disapear.
This is back to the practicality situation. High slope passive crossovers are not practical and active just adds too much cost. The errors solved by high-slope active do not appear to justify the high cost.
So much of these discussions are "apples" to "oranges" because we are talking about "cost effective" versus "ideal". I find the outrageous sums often spent on audio systems to be a real problem. The goal to me is "cost effective supurb quality". Thats what I believe that I have achieved and what I claim to produce. I am not in the "cost is no object" camp of audio design and I never will be, because that is all just an academic exercize of no real interest to me.
So much of these discussions are "apples" to "oranges" because we are talking about "cost effective" versus "ideal". I find the outrageous sums often spent on audio systems to be a real problem. The goal to me is "cost effective supurb quality". Thats what I believe that I have achieved and what I claim to produce. I am not in the "cost is no object" camp of audio design and I never will be, because that is all just an academic exercize of no real interest to me.
Markus, try SynRTA. It will work. I have posted the link. Post #221. Its free to download and use. Has an internal menu that burns the needed signal for each resolution you wanna use on CD, so you can drive the whole system simultaneously, no pain.
The noise floor reaches sometimes 60 dbSPL. It's only low frequency noise that you can't hear at that level - actually one has the feeling that it's very quiet here:
Uncalibrated Spectrogram:
Uncalibrated FFT:
Has someone band limited White Noise? I guess 20 Hz to 300 Hz is enough?
Best, Markus
Uncalibrated Spectrogram:
An externally hosted image should be here but it was not working when we last tested it.
Uncalibrated FFT:
An externally hosted image should be here but it was not working when we last tested it.
Has someone band limited White Noise? I guess 20 Hz to 300 Hz is enough?
Best, Markus
- Status
- Not open for further replies.