Dave, just to make sure this is the one you are talking about...
http://www.creativesound.ca/pdf/RT1.pdf
Regards, Rade
http://www.creativesound.ca/pdf/RT1.pdf
Regards, Rade
Does Jim Griffin XO design will work with this tweeter (CSS RT1) too or it will need modification?
Padding? ok, with padding I will experiment anyway to find right amount however I asked if crossover can stay untouched or needs modification.
Sorry, as you see I do not have clue about XO.... I was thinking you are talking about something else.
RAART,
The Jordan driver and the G2si have an appreciable difference in sensitivity so we have to attenuate (or pad) the tweeter so that we have a balanced amount of sound coming from each driver.
In the crossover diagram (see the Jordan with a Ribbon MLTL reference in my first message in this thread) you will see a serial 8 ohms resistor and a parallel 4 ohms resistor in front of the tweeter. This resistor pair form a voltage divider which places less voltage across the tweeter and more voltage across the 8 ohms resistor. This assures a balanced frequency response across the band.
Now the CSS ribbon is about 5 dB less sensitive than the G2si version, so we want to increase the voltage across the CSS ribbon. We can start by reducing the 8 ohms resistor to 4 ohms if you choose to use the CSS ribbon. This would increase the voltage across the CSS ribbon. We can then listen to the speaker and ascertain the balance in the sound from the woofer (below 3 kHz) and tweeter (above 3 kHz). If you have measurement capability, then you can verify if the frequency response graphically is flatten across the band. Otherwise we may have to adjust the resistor value to best response.
Does that sound like something you could do? Once you like the response (checked by either measuring or listening), you can place the crossover in the enclosure and you are done.
Jim
The Jordan driver and the G2si have an appreciable difference in sensitivity so we have to attenuate (or pad) the tweeter so that we have a balanced amount of sound coming from each driver.
In the crossover diagram (see the Jordan with a Ribbon MLTL reference in my first message in this thread) you will see a serial 8 ohms resistor and a parallel 4 ohms resistor in front of the tweeter. This resistor pair form a voltage divider which places less voltage across the tweeter and more voltage across the 8 ohms resistor. This assures a balanced frequency response across the band.
Now the CSS ribbon is about 5 dB less sensitive than the G2si version, so we want to increase the voltage across the CSS ribbon. We can start by reducing the 8 ohms resistor to 4 ohms if you choose to use the CSS ribbon. This would increase the voltage across the CSS ribbon. We can then listen to the speaker and ascertain the balance in the sound from the woofer (below 3 kHz) and tweeter (above 3 kHz). If you have measurement capability, then you can verify if the frequency response graphically is flatten across the band. Otherwise we may have to adjust the resistor value to best response.
Does that sound like something you could do? Once you like the response (checked by either measuring or listening), you can place the crossover in the enclosure and you are done.
Jim
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Thank you Jim,
I can do this definitely... Thank you for explaining this the way I can understand this. About measuring... What I need to have to measure freq. spectrum? Some kind of software and a calibrated mic or I need to purchase aes/ebu interface for a balanced input and extra hardware for microphones. In terms of PC technology I am very good at it if is something in that direction.
Jim, what do you think about CSS RT1? I just want to hear your opinion on this too. Why did you choose G2si...
Thx. Rade
I can do this definitely... Thank you for explaining this the way I can understand this. About measuring... What I need to have to measure freq. spectrum? Some kind of software and a calibrated mic or I need to purchase aes/ebu interface for a balanced input and extra hardware for microphones. In terms of PC technology I am very good at it if is something in that direction.
Jim, what do you think about CSS RT1? I just want to hear your opinion on this too. Why did you choose G2si...
Thx. Rade
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RAART,
I've never used the RT1 but it looks similar enough to the G2si that it should work. The RT1 has a thicker ribbon element and should be a bit more robust than the older G2si design. Notice that the faceplate of the RT1 has a slightly larger diameter than the G2si so the rebate cutout will need to be enlarged. If you use the rectangular faceplate, then you will have to adapt to those dimensions.
Concerning measurement you can use one of several free software programs but you will need a microphone (calibrated would be nice) and likely a preamp that can supply bias voltage to the mike. But setup, compatibility with your computer, and similar issues would need to be conquered. I would just verify the sound by ear unless you plan future speaker building projects. Of the store brought measurement systems, I prefer the Dayton Audio OmniMic (available from Parts Express) for its easy setup.
Jim
I've never used the RT1 but it looks similar enough to the G2si that it should work. The RT1 has a thicker ribbon element and should be a bit more robust than the older G2si design. Notice that the faceplate of the RT1 has a slightly larger diameter than the G2si so the rebate cutout will need to be enlarged. If you use the rectangular faceplate, then you will have to adapt to those dimensions.
Concerning measurement you can use one of several free software programs but you will need a microphone (calibrated would be nice) and likely a preamp that can supply bias voltage to the mike. But setup, compatibility with your computer, and similar issues would need to be conquered. I would just verify the sound by ear unless you plan future speaker building projects. Of the store brought measurement systems, I prefer the Dayton Audio OmniMic (available from Parts Express) for its easy setup.
Jim
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About computer set-up I am not worried at all. I just need to get a mic.
Which free software is good? I can find one however while many of you tried those ones and I do not want to waist my time on experimenting, please let me know (free and commercial) which is very good one...
Jim, in regards of faceplate... While I will build my own faceplate (aluminum, probably brushed or polished) for the tweeter, do I need to keep same thickness of the faceplate?
Which free software is good? I can find one however while many of you tried those ones and I do not want to waist my time on experimenting, please let me know (free and commercial) which is very good one...
Jim, in regards of faceplate... While I will build my own faceplate (aluminum, probably brushed or polished) for the tweeter, do I need to keep same thickness of the faceplate?
RAART,
On the faceplate I don't know what you have in mind but based on the thickness of the faceplate, you will need to route the surface of the baffle so that you have a flush mounting.
You can google 'free loudspeaker measurement software' and read links about various software that can be used. Free means you will need a microphone, preamplifier with bias capability, a compatible sound card or USB capture module, time to work issues with computer set-up, a support forum for answers to questions, etc. Long threads abound about REW, HOLM, ARTA, Speaker Workshop, AUDMES, etc. on various loudspeaker forums.
Free is worth what you pay for it. That is why I use OmniMic.
Jim
On the faceplate I don't know what you have in mind but based on the thickness of the faceplate, you will need to route the surface of the baffle so that you have a flush mounting.
You can google 'free loudspeaker measurement software' and read links about various software that can be used. Free means you will need a microphone, preamplifier with bias capability, a compatible sound card or USB capture module, time to work issues with computer set-up, a support forum for answers to questions, etc. Long threads abound about REW, HOLM, ARTA, Speaker Workshop, AUDMES, etc. on various loudspeaker forums.
Free is worth what you pay for it. That is why I use OmniMic.
Jim
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What about this... $150 less then OmniMic but uses the same EMM-6 (PE)
True Audio: Audio Spectrum Analyzer and Loudspeaker Design Software
True Audio: Audio Spectrum Analyzer and Loudspeaker Design Software
Note that you are dealing with 1/3 octave measurements at that level with the True Audio RTA software. Notice that they do not suggest loudspeaker measurements at that level. It is more for room with speaker measurements or car audio and not for specific loudspeaker evaluation.
The TA 1/24 octave software ($60 more) would work for speaker development but you would likely need a USB capture interface (TA's suggestion is $97) so you are pushing into the near $300 class and you still don't know that your computer would be compatibile.
With the OmniMic you are making measurements within 10 minutes after you receive it. It is a real speaker measurement system. The OmniMic is a self contained microphone and USB capture system in one device so you don't need a EMM-6.
The TA 1/24 octave software ($60 more) would work for speaker development but you would likely need a USB capture interface (TA's suggestion is $97) so you are pushing into the near $300 class and you still don't know that your computer would be compatibile.
With the OmniMic you are making measurements within 10 minutes after you receive it. It is a real speaker measurement system. The OmniMic is a self contained microphone and USB capture system in one device so you don't need a EMM-6.
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I understood, just was looking for cheaper options. I called trew audio and they have something similar but it is very expensive around $1000+tax...
In terms of removable bezel I am just working on design that I want to have. Desirable thickness of the bezel will be the same as Jordan's need for the flush mount however front baffle will be not routed while the bezel will surround them and making it flush.
In terms of removable bezel I am just working on design that I want to have. Desirable thickness of the bezel will be the same as Jordan's need for the flush mount however front baffle will be not routed while the bezel will surround them and making it flush.
A good friend of mine recommends Earthworks measurement series while he has been working with those ones for long time, however they are out of my budget... He will take look around if he can find me something for reasonable price and if not then OmniMic.
Measurement Series | Earthworks Audio
Measurement Series | Earthworks Audio
Anyone have experience running one of these on a Mac with Parallels/WinXP (at home there is only 1 "heritage" application for which I need Windows at all, so I'm hardly interested in upgrading to Win7) - or would one be better off buying a cheap used or refurbished laptop dedicated for measures only?
Chris, I'm a PC guy so no experience with either True Audio or OmniMic functionality with a Mac running Parallels/WinXP. You might check with John Murphy (True Audio) or Bill Waslo (designer of the OmniMic software) for compatiblity. TA has a website but both Murphy and Waslo follow the Parts Express Tech Talk forums.
Jim
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