Hi,
That was then. Now there are no other budget options.
Easy to work with, with minimal x/o components.
rgds, sreten.
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What about a tweeter makes it easy to work with, just curious? I've been reading that a lot around the web and I never really fully understood what about a tweeter made it difficult to work with (and vice versa) other than poor response or harmonic distortion (in which case it simply shouldn't be worked with at all).
It was in post #1 12 x 24 x 8
I use this (easy to use) box calculator:
http://www.rockfordfosgate.com/Support/BoxWizard.aspx
So vented boxes right?
I use this (easy to use) box calculator:
http://www.rockfordfosgate.com/Support/BoxWizard.aspx
So vented boxes right?
I don't remember saying this. Actually though, I was shooting for around a 1.2 cf box tuned to around 40hz which yields an f3 of around 41hz. I'm actually planning on using these as front replacements for my current towers in my home theater, which I coincidentally also use for music a lot hence why I'm looking for better stereo sound. Honestly I only need these things to go down to 60hz, but a little extra extension, when I don't want the subwoofer waking up the dorm above us, doesn't hurt
P.S. I use the modeling software called WinISD to design my boxes and SketchUp to plan my cuts and model what the box will look like.
Lost? No. You say you're in dorm. Will you be putting these anywhere near a wall?
Baffle compensation is a kludge that on average results in a better listening experience. There is more than one thing going on at a time and it's difficult to predict.
It is simpler than some of the options.
Sorry, I had forgotten I put that in the original post; it was really late at night. Anyways yeah, ported. I actually gave the dimensions wrong. The actual dimensions are 24 x 9 x 12" and one of the edges sits on the outside of the box, not taking up any of the internal airspace. So, the woofer is seeing 23 x 8 x 11.5" of internal airspace, 1.22 cubic feet. After brace and woofer displacement, we're probably looking at like 1.15 cubic feet or something along those lines.
Yes, the speakers will be near walls, and several feet from any corners. Yeah I forgot all about room gain and reflections; the sound waves are in the room still, they're not gone. I'll still probably stick with a -3db pad on the tweeter and go from there. Resistors are cheap anyways, so not much of an issue if I need more or less attenuation.
I was reading some more and I read that zobel networks aren't always necessary if the impedance rise isn't that severe. However, I don't know what is considered severe enough to call for a zobel network. Do I need one or no? I have the parts chosen for one if need be because I first thought it was a necessity, but now I'm not so sure.
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Could someone please explain notch filters to me. There seems to be two very distinct sides to this debate and the majority seems to be against notch filters, arguing that they do more harm than good if not properly implemented. Also there are series and parallel notch filters. What are the differences between them and which should I be using on the peerless woofer? Finally, do you need a combination of a zobel network and notch filter for it to work properly or can I get by with just a notch filter, because, from what I read, notch filters are designed to spike the impedance in that area to decrease SPL for those specific frequencies; would the two be fighting each other basically?
SB Acoustics 2-Way Title Page
I built these in vented form with a truncated, elliptical box, and they are loved by the recipient.
I built these in vented form with a truncated, elliptical box, and they are loved by the recipient.
Capt.
As mentioned by others, is this a good driver for a two way?
It's been around for a long time and I can't find any completed projects using them. And again the description recommends sub-woofer use.
Some folks use cardboard boxes for testing, might want to try that.
I did sim it in WinIsd, 1.8ft3 for a f3 @39 (huge box)
Example here of a good mid bass for DIY-ing:
https://www.madisoundspeakerstore.c...-6-7/silver-flute-w17rc38-08-6-1/2-wool-cone/
As mentioned by others, is this a good driver for a two way?
It's been around for a long time and I can't find any completed projects using them. And again the description recommends sub-woofer use.
Some folks use cardboard boxes for testing, might want to try that.
I did sim it in WinIsd, 1.8ft3 for a f3 @39 (huge box)
Example here of a good mid bass for DIY-ing:
https://www.madisoundspeakerstore.c...-6-7/silver-flute-w17rc38-08-6-1/2-wool-cone/
Hi,
Its a fine budget driver for a two way, it just needs some care in x/o design.
However anyone reading this thread looking for a budget 2 way see : X-LS Classic kit
rgds, sreten.
Its a fine budget driver for a two way, it just needs some care in x/o design.
However anyone reading this thread looking for a budget 2 way see : X-LS Classic kit
rgds, sreten.
Maybe I should just change the tweeter I'm using. I was back on Zaph's website and the Vifa DX25 looked intriguing. Although owned by Tymphany now, I found them on PartsExpress for only a few dollars more than the SBAcoustics.
Tymphany DX25TG59-04 1" Fabric Dome Tweeter
This tweeter has a significantly lower fs which should allow for a lower crossover along with it being a 1" tweeter to begin with. Harmonic Distortion doesn't really seem to be a problem until around 800hz a still isn't terrible (only the Fundamental 2 showing any issues at all according to Zaph). Now the question is, where should I cross it over? 2000hz maybe? Lower? Any Suggestions?
Tymphany DX25TG59-04 1" Fabric Dome Tweeter
This tweeter has a significantly lower fs which should allow for a lower crossover along with it being a 1" tweeter to begin with. Harmonic Distortion doesn't really seem to be a problem until around 800hz a still isn't terrible (only the Fundamental 2 showing any issues at all according to Zaph). Now the question is, where should I cross it over? 2000hz maybe? Lower? Any Suggestions?
It shouldn't be necessary to use one but this is easy to say when a person has experience. There are reasons to go ahead with it in the design process, and it's something I typically do up until I'm satisfied with a crossover.
Some say that they affect the sound. This argument is of a secondary nature and is debatable. It will simplify any changes you make and that's important because when you make a change, you want as few factors to be involved as possible so that you can get to the root of what is happening.
It's true that any filter done wrong isn't completely helpful. A person needs to know that a speaker is a filter itself, and that a crossover is intended to continue the filtering until you have the response that you want.
Notch filters cover a narrow band and that makes them more sensitive to tuning. They may be used to produce a deep notch and this also makes them sensitive.
Sometimes you can find other ways to deal with a peak, but a peak may need to be dealt with all the same.
This is a tricky topic. When a peak is out of band as this one is you might attempt a series notch filter (the series string is put in parallel with the driver).
Since the band is usually narrow, these can be less sensitive to impedance variations.
IMO, 6" paper bass is a difficult speaker. Always seems to lead to a crossover at 2kHz which is hard on tweeters.
I can think of much easier polycones which have a natural rolloff:
Peerless 830874 HDS 164 PPB MidWoofer Speaker
Vifa P17WJ-00-08 Woofer
Why, well they work with a higher 3-3.5 kHz crossover. OK, you have bought this useless peaky midbass, but it's never too late to revise your ideas.
I can think of much easier polycones which have a natural rolloff:
Peerless 830874 HDS 164 PPB MidWoofer Speaker
Vifa P17WJ-00-08 Woofer
Why, well they work with a higher 3-3.5 kHz crossover. OK, you have bought this useless peaky midbass, but it's never too late to revise your ideas.
From Zaphaudio site:
Vifa DX25 ($31) - Smooth and extended response at both ends with mild 3dB depression in the whole top octave. Low Fs for a tweeter with no rear chamber. Good CSD. Excellent 2nd order HD above 1.8kHz, very bad 2nd order HD below 1Khz. Cross over 1.8kHz LR4 or 2.5kHz LR2. Very efficient with high power handling. Tested August 2005.
Your Peerless woofer has been mated to a Vifa tweeter in this design: http://www.hellsound.de/contents/de/BVSAK2S.pdf
Note that the name of the tweeter is the German equivalent to the BC25TG15. The Vifa DX25 should be something better.
Ralf
Ralf, interesting find, looks like a Amiga build with different drivers.
BC25TGG15 here: Vifa, BC25TG15-04
BC25TGG15 here: Vifa, BC25TG15-04
I've looked into that one too. What concerns me though is that it probably needs a significantly higher crossover point due to its fs being north of 1khz. The other vifa has a really low fs of 650hz and a lower sensitivity, both of which benefit my situation. Maybe a 2nd order crossover simply isn't a possibility for this build, due to the woofer. Maybe a 4th or 3rd order is what I should be using; I feel like it would solve so many issues.
Another thing, when designing a crossover, do you use nominal impedance provided by the manufacturer, or measured impedance at the given frequency which is likely to be different? Would a zobel network make the impedance flat at a lower or higher value than the nominal measurement? Thanks!
Hi,
I wish people would read some of the answers they have already got better.
You want a dumb answer, there isn't one for slightly tricky budget drivers.
YMMV but you need to design the x/o using tools as discussed earlier.
The bass mid needs a third order BSC elliptical x/o like Zaphs L18 design.
I still recommend using the budget TB tweeter with a 2nd order x/o. *
As previously stated your goal is cabinet BSC and assymetrical 4th order
L/R acoustic to control the vertical dispersion. If you follow the advice
given you will learn a hell of a lot more than waffling about zobels.
rgds, sreten.
http://zaphaudio.com/ : Read through his thorough designs.
* No real impedance peak and a response easy to massage to
4th order L/R acoustic with second order electrical around 2KHz.
I wish people would read some of the answers they have already got better.
You want a dumb answer, there isn't one for slightly tricky budget drivers.
YMMV but you need to design the x/o using tools as discussed earlier.
The bass mid needs a third order BSC elliptical x/o like Zaphs L18 design.
I still recommend using the budget TB tweeter with a 2nd order x/o. *
As previously stated your goal is cabinet BSC and assymetrical 4th order
L/R acoustic to control the vertical dispersion. If you follow the advice
given you will learn a hell of a lot more than waffling about zobels.
rgds, sreten.
http://zaphaudio.com/ : Read through his thorough designs.
* No real impedance peak and a response easy to massage to
4th order L/R acoustic with second order electrical around 2KHz.
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Hi,
Simulation is the next best thing, and nearly all who measure
also simulate to work out what the hell is going on. Any
decent simulation is far better than simply guessing.
Measurements only change the data, not the process.
Decent data is available for good simulation.
rgds, sreten.
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Well I finally decided to get some software:
Tolvan Data
and...
(Speaker Workshop) Claudio Negro's home page, how to project and test a loudspeaker using Speaker Workshop
Now it's time to figure out how to use it; time to watch/read some tutorials
I'll get back to you guys when I actually have some data, might be a while.
Tolvan Data
and...
(Speaker Workshop) Claudio Negro's home page, how to project and test a loudspeaker using Speaker Workshop
Now it's time to figure out how to use it; time to watch/read some tutorials
I'll get back to you guys when I actually have some data, might be a while.
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