Gated measurements on 100-ish Hz frequencies require almost free field conditions, that's no option here. I agree on the ground bounce or any other first reflection that screwed up that measurement. In a normal living room, measure in box or close to the cone and port. When a large hall is available, use ground plane technique.
it was measured proper way and results were not screwed up. there was no ground or any other first reflection messing up these results. sad fact is that driver is cheap, hard to tame.
I bought pair of these from an guy who tried to play them in his construction of ported box and failed. I tried to use them too AND in sealed box and I failed in that too.
So looking forward to see what will come out. My sincere guess was to use really big BIG coils but money went in other direction
namely this but that is another story off topic here
I bought pair of these from an guy who tried to play them in his construction of ported box and failed. I tried to use them too AND in sealed box and I failed in that too.
So looking forward to see what will come out. My sincere guess was to use really big BIG coils but money went in other direction
namely this but that is another story off topic here
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There is nothing bad about the Peerless 830 668.
It is misleading to draw the wrong conclusion blaming
it on the manufacturer.
The room boundary reinforcement, axial response:
3 ft above floor
4 ft from rear wall
4 ft from side wall
Response varies very much depending on the speaker placement
in respect to boundaries.
Courtesy of Jeff Bagby, Diffraction and boundary simulator.
Regarding Lampizator's thought, if you like it...you will ...does
not sound like a scientific statement. That would mean if you don't
like metal cone drivers without XO filter, you won't with a proper
one too, which is not true in reality.
It is misleading to draw the wrong conclusion blaming
it on the manufacturer.
The room boundary reinforcement, axial response:
3 ft above floor
4 ft from rear wall
4 ft from side wall
Response varies very much depending on the speaker placement
in respect to boundaries.
Courtesy of Jeff Bagby, Diffraction and boundary simulator.
Regarding Lampizator's thought, if you like it...you will ...does
not sound like a scientific statement. That would mean if you don't
like metal cone drivers without XO filter, you won't with a proper
one too, which is not true in reality.
Attachments
You may call it bad or wrong or good or excellent. I don't advocate expensive parts, gear or whatever. Yet this one falls in the cheapest offer of the Peerless. I don't blame manufacturer but our way to choose things and to expect what cannot be expected from specific part. The fact is what I am saying all the time: This one is extremely difficult driver to tame.
I believe that assumption to let it play till 400Hz is wrong. The problem is that this driver has its own tendency to play long toward midfrequencies and plays them in a crappy way. Yet, whatever I have tried to harness this driver in the box of approx 70litres, ported, then sealed, simply failed.
Measurement was performed in realistic space, in the middle of the 30sqm room, far far away from walls and certainly elevated enough and far far away from any simulator even Jeff Bagby's.
I thought conclusion was obvious but maybe my previous posts were not:
Driver was measured in the box first without Xover then with several attempts of different combinations of the Xover.
Conclusion: There isn't really difference in the graph presenting problems of this driver WITHOUT and WITH Xover. Sincerely measured, shared in good will.
Again, I didn't test it with bigger coils.
And Lampizator, the newest Bill Gates of Audio world, has some points right regardless of what we are thinking of him. It certainly does not sound like scientific statement bit he is right. Loudspeaker building is not only science. Science could be only the basis and good start, later we come to empirical results, tests and tweaks.
I had chance to listen 'ultralinear' speakers which sound was clinically precise, yet boring, choking, dull and those which graphs were 'dirty' sounded beautiful.
BTW: (our language) Sad tek vidim, Bok Lojzek, Branko iz Bg je ovde
I believe that assumption to let it play till 400Hz is wrong. The problem is that this driver has its own tendency to play long toward midfrequencies and plays them in a crappy way. Yet, whatever I have tried to harness this driver in the box of approx 70litres, ported, then sealed, simply failed.
Measurement was performed in realistic space, in the middle of the 30sqm room, far far away from walls and certainly elevated enough and far far away from any simulator even Jeff Bagby's.
I thought conclusion was obvious but maybe my previous posts were not:
Driver was measured in the box first without Xover then with several attempts of different combinations of the Xover.
Conclusion: There isn't really difference in the graph presenting problems of this driver WITHOUT and WITH Xover. Sincerely measured, shared in good will.
Again, I didn't test it with bigger coils.
And Lampizator, the newest Bill Gates of Audio world, has some points right regardless of what we are thinking of him. It certainly does not sound like scientific statement bit he is right. Loudspeaker building is not only science. Science could be only the basis and good start, later we come to empirical results, tests and tweaks.
I had chance to listen 'ultralinear' speakers which sound was clinically precise, yet boring, choking, dull and those which graphs were 'dirty' sounded beautiful.
BTW: (our language) Sad tek vidim, Bok Lojzek, Branko iz Bg je ovde
I wouldn't expect this or any other woofer with this kind of Sd and Xm to even approach wideband or "pleasing" sound. sorry if youre expecting something different.
certainly Peerless sells this in the subwoofer category,
most times a huge peak followed by a sharp dip usually points to some measurement errors, and / or room effects at LF. it's silly playing with a passive low-pass filter to try and correct this. measure it outside pointing at the sky.
It's difficult to make a larger woofer in any 2 way sound good, let alone a subwoofer. yes you must cross them low as in any subwoofer, using passive filters to do this costs lots of copper and iron. so in the end I think you were fighting easily two or three problems, none related to each other, and simply blamed the "cheap sub" and threw in the towel.
edit> crossover points, diffraction, and baffle step work hand in hand best. so you cannot choose parts, drivers, Xover and cabinet dimensions irregardless of the whole and have a easy time!
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i appreciate your worries dawg
but i will check once its done how it sounds. i can not let myself get put off from one negative comment.
just a thought;
have you tried to fix it with a constant Q graphic equalizer? to boost/attenuate frequency ranges that close to each other you will need a high Q factor. a 31 band equalizer is a good option for testing to smooth that out (Q factor 4,3 or so).
but i will check once its done how it sounds. i can not let myself get put off from one negative comment.
just a thought;
have you tried to fix it with a constant Q graphic equalizer? to boost/attenuate frequency ranges that close to each other you will need a high Q factor. a 31 band equalizer is a good option for testing to smooth that out (Q factor 4,3 or so).
i will give that measuring a try once im done with the build. can be fun.
hey guys - if i was after a ultra linear response i would simply buy myself one more pair of active studio monitors. it would even be somewhat cheaper than building this project! - BUT i already have a pair in my studio. i really do not need one pair more
using more expensive drivers the builds get very expensive - each one has to adopt to their budget.
anyway - im sure these sound better than my old jamo satelite system from the 90's i use now for the tv... they dont even reproduce the range from about 300 to 80 hz properly
I do believe in "voicing" midranges to a small extent, but I too mostly find the resonant ones more "pleasing" and cannot hope to get any meaningful off axis info. from these feelings either. I think "exiting" colorized speakers are best left to full range aficionados, really I think those "systems" can be a fun time, given the right "vibe" and music choices.
Hi Branko,
Can't agree with that, measurements show potential beyond
400 Hz. I would expect TS parameters to be off directed to
higher Qt, based on my former experience in general.
I would suggest anyone to measure them before ordering timber.
Ok, let's assume you room was 5,5*5,5 m.
You were complaining about the 70Hz something range hump
and dip that follows it. Now, see if this has anything to do with
the point in room you were taking the measurement.
1st graph: 3ft from the floor,18 ft (5,5m)from side and rear wall.
2nd graph: 10" from the floor, 18 ft from side and rear wall.
Loudspeaker building is applied science at things we like
to keep in our homes. People will always have issues building
stuff. That's where diyAudio comes in to straighten it out.
Can't agree with that, measurements show potential beyond
400 Hz. I would expect TS parameters to be off directed to
higher Qt, based on my former experience in general.
I would suggest anyone to measure them before ordering timber.
Ok, let's assume you room was 5,5*5,5 m.
You were complaining about the 70Hz something range hump
and dip that follows it. Now, see if this has anything to do with
the point in room you were taking the measurement.
1st graph: 3ft from the floor,18 ft (5,5m)from side and rear wall.
2nd graph: 10" from the floor, 18 ft from side and rear wall.
Loudspeaker building is applied science at things we like
to keep in our homes. People will always have issues building
stuff. That's where diyAudio comes in to straighten it out.
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a few changes to the design.
tuneable vent - the outlet of the vent and also the inlet (inside) are designed to have 1 additional piece with interlocking metal plates that fits into a groove
if i decide to have access to the inside i will leave an air proof maintenance entrance in the back.
if not i will do the tuning with the addition in the outlet.
at first i will use duct-tape to air-proof the addition, and once down to to final size i'll most likely glue it into place. if needed i can easilly make several pieces of varying lengths etc. the final endpiece will be done most likelly in hardwood.
tuneable vent - the outlet of the vent and also the inlet (inside) are designed to have 1 additional piece with interlocking metal plates that fits into a groove
if i decide to have access to the inside i will leave an air proof maintenance entrance in the back.
if not i will do the tuning with the addition in the outlet.
at first i will use duct-tape to air-proof the addition, and once down to to final size i'll most likely glue it into place. if needed i can easilly make several pieces of varying lengths etc. the final endpiece will be done most likelly in hardwood.
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What is the motivation for tilting the cabinets?
The mid/tweeter cabinet appears to be tilted forward rather than the more usual vertical or backwards to help align the tweeter and midrange acoustical centres. Is the tilting accounted for in the crossover or is it small enough not to matter?
yes, u got it
most likelly both inside and on the outside. after plotting the volume of the cab tuned at different differences i see the interval of increments in cm is about 2,80 for 29hz an aditional 3.2 and so on. i will later have a closer look when it is time.flared ports - i read i should measure about the first 1/3rd of the rounded part as part of the vent...
i dont know your experience with studio monitors, but they are usually tilted slightly forwards standing ontop of foam decoupling pads. this is since if they are higher up the sweet spot for the mixing also moves up so the tilting brings the focus back to the listener position.
same idea is aplied here. the inclinatin of the tweeter is only 3 degrees from vertical, but the tilt of the woofer section makes it look more severe. its fooling the eye a bit since the woofer is leaning back 6º and the TM is tilted 9 degrees in relation to the woofer but in reality as stated before it is only 3º. both the woofer and the TM are sill in same line. in depth the Mid is about 4mm behind the line of the tweeter woofer. but ONLY if i would be standing up to listen to them, if i sit down they are aligned.
the woofer is aimed at the listener position more or less, the focal point is at 3,5-4 meters at about 90cm heigth - perfect for leaning back on the sofa.
i will make the top part tilt adjustable. i want to be able to to put it to vertical position, or even lean it forward a few more degrees - if i need to.
also adding wheels to the base will add a few more cm of heigth.
also if the design turns out be a flaw it has an easy solution. i can tilt the woofer cabinet forward to vertical position using 2 rubber pads in the back of the stand and just put the tm box back in vertidal.
I am still not clear why you are tilting the woofer cabinet. I would not expect it to have any adverse affect but I cannot see any benefit either unless you consider it to be more attractive?
reason nr1;
its mostly to have fun building it. also ive made several designs during the last months, and my dear wife seems to prefeer tilted. after i showed her this pic of a pair of speakers made by i think a russian firm, she got her ideas set.
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yes, u got it
flared ports - i read i should measure about the first 1/3rd of the rounded part as part of the vent...
oops ^^ i mean frequencies
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