With those costs you kind of need a crystal ball to figure what you will need well in advance and ship everything all at once !!
tax
with our government seemingly putting there hand in our back pokets at the drop of a hat
is if the total invoice amount goes over $1000 AUD then we get slugged another 10% duty so it is a balance inbetween amount, duty and freight
my last emotiva order cost me an extra $500 odd dollars in duty
hay and now we world enviromentally worried aussies are getting a carbon tax
if you please!
cheers speedie
With those costs you kind of need a crystal ball to figure what you will need well in advance and ship everything all at once !!
with our government seemingly putting there hand in our back pokets at the drop of a hat
is if the total invoice amount goes over $1000 AUD then we get slugged another 10% duty so it is a balance inbetween amount, duty and freight
my last emotiva order cost me an extra $500 odd dollars in duty
hay and now we world enviromentally worried aussies are getting a carbon tax
if you please!
cheers speedie
tax
blossom
maybe you should order parts through bondi and get a hoilday on your duty savings
only joking
bloody anzac governments tax tax tax !
cheers speedie
blossom
maybe you should order parts through bondi and get a hoilday on your duty savings
only joking
bloody anzac governments tax tax tax !
cheers speedie
gizzmos arrive
tony, allen and all other helpfull posters
the parts express stuff arrived today which i am thankful that it didnt get caught up in the xmas rush stuff
i have loaded both programs into my laptop which was relitively simple
the woofer tester looks like a pretty good program for all of the measurements that are required for crossover input
i had a little play with it this afternoon tested some speakers, capacitors and inductors that i have instock and the program measurements are damn close to the meter readings that i have so it looks like i could have saved on the LCR meter costs in the first instance
it is going to take some time to get my head around its use
the other bit of kit (daytons omnimic measurement system) is a god box it does some really cool stuff
i think that it will convert its files to the CLIO format which i am sure that bassbox will read
it looks like it will tie in with Jeff Bagbys crossover sim software
so now i can get some readings and hopefully get my learning curve on to the upward trend
once i get some readings logged i will post them on the two way system that this post was created for
cheers speedie
tony, allen and all other helpfull posters
the parts express stuff arrived today which i am thankful that it didnt get caught up in the xmas rush stuff
i have loaded both programs into my laptop which was relitively simple
the woofer tester looks like a pretty good program for all of the measurements that are required for crossover input
i had a little play with it this afternoon tested some speakers, capacitors and inductors that i have instock and the program measurements are damn close to the meter readings that i have so it looks like i could have saved on the LCR meter costs in the first instance
it is going to take some time to get my head around its use
the other bit of kit (daytons omnimic measurement system) is a god box it does some really cool stuff
i think that it will convert its files to the CLIO format which i am sure that bassbox will read
it looks like it will tie in with Jeff Bagbys crossover sim software
so now i can get some readings and hopefully get my learning curve on to the upward trend
once i get some readings logged i will post them on the two way system that this post was created for
cheers speedie
Hi Speedie, good to hear the goodies have arrived It will probably take a while to get the hang of using the software, and setting up for the best measurements. Experimentation is the key. Take notes so that you know what you did.
The way I tested how good my measurements were was to do the following (I ended up using these measurements to design the final crossover):
Take a measurement of each driver running on its own (but without moving anything)
I took the measurements on axis with the tweeter (rather than on axis with each driver) though I have an MTM and ran both M's when doing the test. You might want to take mid way between the bass and tweeter.
Then take a measurement (again without moving anything) with the crossover in place and both drivers running.
Take impedance measurements of each driver in the box (preferably again without moving anything from the above).
Put your measurements into the crossover simulation program and simulate the actual crossover you used in the last measurement. If possible use put the DCR for the coils in as well.
Compare the simulation result to the actual measured result. If your measurements are good (and the simulation software is too) then you should see a good correlation.
With respect to setting up for the measurements a bigger space is best. I try to set up so that the speaker isn't paralell to any walls if I am inside and try to keep a minimum of 1.5M in any direction to any surfaces. Floor and ceiling usually are limiting factors.
My best measurements have actually been taken on my balcony on still quiet days.
Anyway take some measurements, if you aren't sure what to make of them, post them and ask for any acoustic measurements try to include the impulse response as well, and a description of the measuring environment.
Tony.
It will probably take a while to get the hang of using the software, and setting up for the best measurements. Experimentation is the key. Take notes so that you know what you did. The way I tested how good my measurements were was to do the following (I ended up using these measurements to design the final crossover):
Take a measurement of each driver running on its own (but without moving anything)
I took the measurements on axis with the tweeter (rather than on axis with each driver) though I have an MTM and ran both M's when doing the test. You might want to take mid way between the bass and tweeter.
Then take a measurement (again without moving anything) with the crossover in place and both drivers running.
Take impedance measurements of each driver in the box (preferably again without moving anything from the above).
Put your measurements into the crossover simulation program and simulate the actual crossover you used in the last measurement. If possible use put the DCR for the coils in as well.
Compare the simulation result to the actual measured result. If your measurements are good (and the simulation software is too) then you should see a good correlation.
With respect to setting up for the measurements a bigger space is best. I try to set up so that the speaker isn't paralell to any walls if I am inside and try to keep a minimum of 1.5M in any direction to any surfaces. Floor and ceiling usually are limiting factors.
My best measurements have actually been taken on my balcony on still quiet days.
Anyway take some measurements, if you aren't sure what to make of them, post them and ask
for any acoustic measurements try to include the impulse response as well, and a description of the measuring environment. Tony.
measurements
thanks tony for your reply
my workshop is a tilt panel design and is 200 sq/meters in floor space with a roof hight of 4.5 metres
i should be able to get some good readings in there
on a good day you can here a pin drop so it has relitive low ambient backround noise
i was reading through WT3 help section tonight and they incicated that it is possible to get a good zobel network by just doing freqency sweeps of the driver in question then adding a resistor and cap accross the driver and keep doing sweeps and watch the raising impedance curve reduce by the increasing R/C values
no maths required and visual proof of components doing there job
if you can afford this little gizzmo it would be an asset to your hobby also
cheers speedie
thanks tony for your reply
my workshop is a tilt panel design and is 200 sq/meters in floor space with a roof hight of 4.5 metres
i should be able to get some good readings in there
on a good day you can here a pin drop so it has relitive low ambient backround noise
i was reading through WT3 help section tonight and they incicated that it is possible to get a good zobel network by just doing freqency sweeps of the driver in question then adding a resistor and cap accross the driver and keep doing sweeps and watch the raising impedance curve reduce by the increasing R/C values
no maths required and visual proof of components doing there job
if you can afford this little gizzmo it would be an asset to your hobby also
cheers speedie
photos
we must have similar hobbies
i use a sony alpha 700 plus quite a few lens
my southeast asia holidays have yeild some great photos
i havent put a hand on my old olympus analouge cameras for ages
om 1,2,10 motorwinders flashunits darkroom gear and more lenes than i care to remember
arh the good old days
still have boxes full of how to camera mags from the seventies and eighties
now it is speakers stuff
do you homebrew by chance! surely not another common habit
see ya speedie
we must have similar hobbies
i use a sony alpha 700 plus quite a few lens
my southeast asia holidays have yeild some great photos
i havent put a hand on my old olympus analouge cameras for ages
om 1,2,10 motorwinders flashunits darkroom gear and more lenes than i care to remember
arh the good old days
still have boxes full of how to camera mags from the seventies and eighties
now it is speakers stuff
do you homebrew by chance! surely not another common habit
see ya speedie
yes good point Allen, speedie your crossover modelling software may be able to take off axis measurements into consideration as well.
I made myself a swivelling speaker stand for easily taking off axis measurements which can be seen here --> http://www.diyaudio.com/forums/equipment-tools/200198-low-cost-speaker-testing-stand.html It might give you some ideas
Speedie, I haven't tried home brewing, but I've always wanted to I had a mate who used to do it and every time he did a batch he gave me a few bottles to stash in the cupboard beside the hot water heater. I do like a good home brew!
Although I used to shoot film, I've never done any dark room work, though my sister used to, and it was another thing I would have liked to try (only B&W though as I am colour blind).
Tony.
I made myself a swivelling speaker stand for easily taking off axis measurements which can be seen here --> http://www.diyaudio.com/forums/equipment-tools/200198-low-cost-speaker-testing-stand.html It might give you some ideas
Speedie, I haven't tried home brewing, but I've always wanted to
I had a mate who used to do it and every time he did a batch he gave me a few bottles to stash in the cupboard beside the hot water heater. I do like a good home brew! Although I used to shoot film, I've never done any dark room work, though my sister used to, and it was another thing I would have liked to try (only B&W though as I am colour blind).
Tony.
Yes, those sovereigns were certainly imposing. Of course I wanted them. I wondered whether I'd be disappointed in myself if I went into hock and bought the 'perfect' speaker and then lost interest in doing them myself.
I used to find the foam intriguing and the in-laid baffle off-putting. I couldn't see it not getting in the way. Now so many of us invert our baffles (as in concave) but we call them waveguides and so forth. Duntech were just approaching it from another direction (sorry about the pun)
By the way, I'm certainly not disappointed.
I used to find the foam intriguing and the in-laid baffle off-putting. I couldn't see it not getting in the way. Now so many of us invert our baffles (as in concave) but we call them waveguides and so forth. Duntech were just approaching it from another direction (sorry about the pun
)By the way, I'm certainly not disappointed.
measurements!!
when one takes speaker readings
1 do you have to set the amp at a certain output
2 do you set by Db meter
3 do you set by volt meter accross speaker output lines
4 do you ignore above
positioning mic
1 is it set at driver centre about 1 metre from on axis from said driver
2 is it then moved from left to right speaker as above, in said position
3 do you play only the one speaker at one time
4 is then placed central to both speakers and both played
5 are these Pertinent questions
when first doing these readings for crossover assumptions do you play test sweeps through the speaker in cabinet less passive crossover?
some many questions
cheers speedie
when one takes speaker readings
1 do you have to set the amp at a certain output
2 do you set by Db meter
3 do you set by volt meter accross speaker output lines
4 do you ignore above
positioning mic
1 is it set at driver centre about 1 metre from on axis from said driver
2 is it then moved from left to right speaker as above, in said position
3 do you play only the one speaker at one time
4 is then placed central to both speakers and both played
5 are these Pertinent questions
when first doing these readings for crossover assumptions do you play test sweeps through the speaker in cabinet less passive crossover?
some many questions
cheers speedie
Hi Speedie
Before anything else, wear hearing protection!
1. yes not too loud! for tweeters (especially not high powered ones) you should limit the bandwidth sent to them (hp filter should be in the software, I used 200Hz but you may wish to go higher, as my tweeters are high powered units).
2. if you have one not a bad idea!
3. yes I have done this. DMM set to AC play mls signal and adjust for 2.8V (alternatively you might want to play a 100Hz sine wave and adjust for 2.8V) typical DMM's are most accurate at around 100Hz.
4. N/A
positioning:
1. that's a good starting point. With your workshop you may be able to get good measurements at 2M. The further away the closer to farfield response (where the drives combine seamlessly) you will get.
2. not sure what you mean here? the two of a Stereo pair? ah I see the next questions the answer is yes... depends on what you are trying to do.
5. skipped 3,4 If you are measuring for crossover design then not relevant IMO. you might want to measure each of your two speakers and average the results (I didn't) If you are doing in room response, then put the mic at your listening position. Take measurements of left only, right only, and combined. check the impulse repsonses of the left and right measurements you will be able to see how well set up you have your speakers. Note that even a few cm off dead centre will vary the results quite dramatically.
For the crpssover design, yes you play each speaker individually without the crossover (see above about bandwidth limiting for the tweeter). The software will probably have options for swept sine or MLS. I used to use MLS, but have changed over to swept sine.
Tony.
Before anything else, wear hearing protection!
1. yes not too loud!
for tweeters (especially not high powered ones) you should limit the bandwidth sent to them (hp filter should be in the software, I used 200Hz but you may wish to go higher, as my tweeters are high powered units). 2. if you have one not a bad idea!
3. yes I have done this. DMM set to AC play mls signal and adjust for 2.8V (alternatively you might want to play a 100Hz sine wave and adjust for 2.8V) typical DMM's are most accurate at around 100Hz.
4. N/A
positioning:
1. that's a good starting point. With your workshop you may be able to get good measurements at 2M. The further away the closer to farfield response (where the drives combine seamlessly) you will get.
2. not sure what you mean here? the two of a Stereo pair? ah I see the next questions the answer is yes... depends on what you are trying to do.
5. skipped 3,4 If you are measuring for crossover design then not relevant IMO. you might want to measure each of your two speakers and average the results (I didn't) If you are doing in room response, then put the mic at your listening position. Take measurements of left only, right only, and combined. check the impulse repsonses of the left and right measurements you will be able to see how well set up you have your speakers. Note that even a few cm off dead centre will vary the results quite dramatically.
For the crpssover design, yes you play each speaker individually without the crossover (see above about bandwidth limiting for the tweeter). The software will probably have options for swept sine or MLS. I used to use MLS, but have changed over to swept sine.
Tony.
If a part of your measurement is too close to the noise floor, it may be compromised. As a rule of thumb you should stay 24dB above the noise floor for any measurement, and more for the most critical ones. You can sometimes get away with lower, especially if you ask your software to take the measurement a few times over and to average them.
If you go too loud you risk overloading your card or your mic. If your mic is good, set up your card properly in software turning the volume up on the input, and run the test routine or take a measurement and watch the level meter if there is one. You want it to go high within the green region.
Setting the measurement level accurately to some setting (eg to find the actual sensitivity etc) is not strictly necessary. You'll have to be able to maintain the level between certain measurements within a session, and try to finish all related measurements within that session.
If you go too loud you risk overloading your card or your mic. If your mic is good, set up your card properly in software turning the volume up on the input, and run the test routine or take a measurement and watch the level meter if there is one. You want it to go high within the green region.
Setting the measurement level accurately to some setting (eg to find the actual sensitivity etc) is not strictly necessary. You'll have to be able to maintain the level between certain measurements within a session, and try to finish all related measurements within that session.
The distance to set your mic back from the driver should be at least three times the baffle width, and more is better. The problem is finding the largest reflection free region. If you take measurements within a typical room, the floor and ceiling will probably be the larger concern, and the further the mic is back, the shorter the region. You'll find that if you put both the driver and mic at mid room height you'll get the longest distance before one of these reflections. Make sure there is no other surface that will reflect sooner than that either around the speaker, and similarly around the mic.
I put my speaker together as if I'm going to use it, minus the crossover. Jack the speaker up so each driver in turn is at mid room height. Then I take a series of measurements, rotating the speaker to various angles. While I'm there I'll make sure I have a shot of the listening axis phase (at least the axis I am presuming I'll choose to listen on, I may retake it later if I'm dissatisfied). Don't move the mic between drivers, don't touch the levels, don't leave it overnight.
Working on just one speaker for this may be satisfactory. These measurements I'm describing are the fundamental ones that need to be done right. At later points I'll probably take many more measurements in establishing how it comes together, works with the room and many other things but none of these needs to be as carefully taken or trusted down the line as these fundamental measurements.
I put my speaker together as if I'm going to use it, minus the crossover. Jack the speaker up so each driver in turn is at mid room height. Then I take a series of measurements, rotating the speaker to various angles. While I'm there I'll make sure I have a shot of the listening axis phase (at least the axis I am presuming I'll choose to listen on, I may retake it later if I'm dissatisfied). Don't move the mic between drivers, don't touch the levels, don't leave it overnight.
Working on just one speaker for this may be satisfactory. These measurements I'm describing are the fundamental ones that need to be done right. At later points I'll probably take many more measurements in establishing how it comes together, works with the room and many other things but none of these needs to be as carefully taken or trusted down the line as these fundamental measurements.
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