Then you will really need to add coupling and extra bits to the panels------ did you keep the cut-outs?? Do you have any 2*1 to run side to side and front to back??
If you have any MDF left it may be able to be used to make a small box for the mid.
Just a point too, I try and make all of my speakers in mirror imaged with mid and tweeter offset from the centreline; some people think it helps, I agree.
Not trying to rain on your laundry here, just trying to help
If you have any MDF left it may be able to be used to make a small box for the mid.
Just a point too, I try and make all of my speakers in mirror imaged with mid and tweeter offset from the centreline; some people think it helps, I agree.
Not trying to rain on your laundry here, just trying to help
I didnt keep the cut outs. When you say coupling are you talking about bracing the panels or are you talking about something else. And I can use all the help I can get I dont care if you tell me something I am doing is wrong. This is my first speaker so I was expecting to have a lot of problems. I have a lot of MDF left over and using it for the Mid enclosure is what I was thinking to.
Coupling as in tying opposite sides of the box together, also little blocks placed at the junction of each side ( corner blocks ) bracing would be a strip placed along the long dimension of the panel, often I use them together when I don't use a holey brace.
makes a sort of "Capital H " hard to describe in words.
I can't say that the box is put together badly, it looks like most commercial boxes I bought when I was younger ( in the 70's ) so long as there are no air leaks and don't fall apart.
As you say it is your first box, you should have seen mine!!!
makes a sort of "Capital H " hard to describe in words.
I can't say that the box is put together badly, it looks like most commercial boxes I bought when I was younger ( in the 70's ) so long as there are no air leaks and don't fall apart.
As you say it is your first box, you should have seen mine!!!
dustruss said:
Its ok, maybe not perfect, but who would expect that first time, it should do fine
You can make "small" 90 degree triangulars, and glue them into all joint corners...use a flexible chalk
Would also help your crossover if box could be tilted a bit
And as moondog mentions, offcourse mid needs a seperate chamber
Moondog55 said:As you say it is your first box, you should have seen mine!!!
LOL
Me too. This design has a lot of potential to make a pretty good noise. The first box I built turned itself into kindling quick!
There are several points of agreement from me thus far. Getting the mid and tweet closer together could help a lot.
Other than that, I would say keep tinkering with it. The journey can be more fun than the destination in cases like this.
take care,
Robert
Ok I have been playing with the crossover I went to a First order because I dont have enough inductors for anything else right now. I went with 8.5 mH coil in series with the woofer, then a 100 mf cap and .45 mH coil in series with the mid, then a 6.7 mF cap in series with the tweeter. I also had a 20 ohm 20 watt resistor in parallel and 8 ohm 20 watt resistor in series with the tweeter. Overall the tweeter and mid were very loud. I have a equalizer on the stereo I use, so I turned up the bass and turned down the trebble and mid. The woofer sounded good but I still couldnt turn it up to much because the mid and trebble were still getting more power than the woofer. I dont know if you are suppose to do this but I put some resistors on the mid like I did the tweeter. It made the woofer seem a little louder. Im not sure why my tweeter and mid are so loud and Woofer so low? Should I use different values for the resistors to tone them down more?
OK. it may be that the inductor you used had a high resistance.
Was it air core or steel laminate??
Do you have a multi meter?
If you do have one check the DC resistance of the coil.
Just want to check the value of those caps ( uF = micro Farad ) is what I usually use ( mF meaning milli Farad is big).
That woofer has a big spike at 1500 Hz, you may be hearing the mid plus a lot of that spike right where we hear the best ( where our ears are most sensitive ) Aren't crossovers fun!!
Was it air core or steel laminate??
Do you have a multi meter?
If you do have one check the DC resistance of the coil.
Just want to check the value of those caps ( uF = micro Farad ) is what I usually use ( mF meaning milli Farad is big).
That woofer has a big spike at 1500 Hz, you may be hearing the mid plus a lot of that spike right where we hear the best ( where our ears are most sensitive ) Aren't crossovers fun!!
I think it's time for some-one else ( preferably some-one better than I am or experienced with these drivers ) to jump in and offer some help.
What do you have in the cupboard to use?? You could try the strange network in parallel to the woofer
Reading the impedance from the website graph; the impedance at 1500 is 40 Ohms, first order 1.5k is 13 uF, the peak in response is 12dB.
This is where it gets tricky and I get out of my depth, if it was I doing this XO, I'd play until it sounded OK, I don't want to give you advice that may very well be wrong with these drivers.
You could try the values I gave earlier and listen to see if there is an improvement in overall balance.
However I think you should fix the midrange into its own box first, even if it is just bluetac and a coffee can to start with.
If you plan it right the box for the mid could even incorporate the front to back coupling needed.
What do you have in the cupboard to use?? You could try the strange network in parallel to the woofer
Reading the impedance from the website graph; the impedance at 1500 is 40 Ohms, first order 1.5k is 13 uF, the peak in response is 12dB.
This is where it gets tricky and I get out of my depth, if it was I doing this XO, I'd play until it sounded OK, I don't want to give you advice that may very well be wrong with these drivers.
You could try the values I gave earlier and listen to see if there is an improvement in overall balance.
However I think you should fix the midrange into its own box first, even if it is just bluetac and a coffee can to start with.
If you plan it right the box for the mid could even incorporate the front to back coupling needed.
What you may be hearing could be some peaking on mid driver
Also maybe wrong/shallow tweeter roll off, you may need a small paralel coil, maybe with a series resistor
Maybe too much overlapping of mid and tweeter, mid series inductor could be too small, or you may simply need an RC(paralel cap/resistor)
Also mid series cap fore highpass, 100uf may be too big
8ohm in series with tweeter sounds like a lot, experiment more, but after the above points have been adressed
Your bass may be playing too much midrange, or there may be a peak still audible
In short, first of all you seem to need a number of paralel componets
Also maybe wrong/shallow tweeter roll off, you may need a small paralel coil, maybe with a series resistor
Maybe too much overlapping of mid and tweeter, mid series inductor could be too small, or you may simply need an RC(paralel cap/resistor)
Also mid series cap fore highpass, 100uf may be too big
8ohm in series with tweeter sounds like a lot, experiment more, but after the above points have been adressed
Your bass may be playing too much midrange, or there may be a peak still audible
In short, first of all you seem to need a number of paralel componets
I have just been playing with the crossover it sounds a little better. I want to put the xover point on the woofer lower. Right now its at 300. I ordered more inductors they should be coming in on thursday. I have made a box for the mid. I decided to go with a smaller box for now. I want to experiment to see what will sound better, to vent the box or to leave it unvented. Where can I purchase damping material?
Thank you Dustin
Thank you Dustin
You can use the stuffing from a pillow to start with. I am in a minority as I tend prefer fiberglass.
You may want to delay the experiment with venting until after you have fixed the XO and put the mid into its own box tho, just because sealed boxes are easier, personally I think they sound better too.
If you mid-range has a second order or steeper XO then a small box won't matter,
Make the XO second order electrical as low as you can afford, if using the rule of thumb (ROT ) that the mid needs to be crossed over 2 octave above resonance use that as the XO frequency to start with.
You may want to delay the experiment with venting until after you have fixed the XO and put the mid into its own box tho, just because sealed boxes are easier, personally I think they sound better too.
If you mid-range has a second order or steeper XO then a small box won't matter,
Make the XO second order electrical as low as you can afford, if using the rule of thumb (ROT ) that the mid needs to be crossed over 2 octave above resonance use that as the XO frequency to start with.
Im not sure what you mean that the small box wont matter, do you mean it is not needed at all? I think I had my terminology mixed up I just meant the crossover point for the woofer. I think I have a problem with the second crossover point. You said it should be somewhere around 2800 but I dont think my tweeter can have that low of a frequency. Here is a pdf of the tweeter. http://www.parts-express.com/pdf/264-360.pdf
When you say XO do you mean crossvoer poing or are you talking about something else?
Thank you
Dustin
When you say XO do you mean crossvoer poing or are you talking about something else?
Thank you
Dustin
Sorry ! I need to remember that you can't see inside my head
XO = Crossover.
Regarding box size for mid-range, it is a relatively high "Q" driver, if you are using a first order XO the driver will be working in its piston range ( that is ;; it will be moving in and out a large distance ) so you would need to calculate the correct box size for that driver using a program or a calculator and the formula; I put it in a program by Jeff Bagby
http://audio.claub.net/software/jbagby.html#WBC
but it needs Windows Excel to work.
I did that and it needs a biggish box, but you are using it as a mid-range and you are using the XO to restrict the amount of the musical signal going to the driver ( that's what Crossovers do ) in old text books i have seen XOs called dividing networks which is a better description of what they do.
With a first order network more of the bass signal gets through to the mid-range, so to stop a peaking response the box needs to be bigger.
Using a second order XO less of the bass signal gets through to the mid so box size become less critical.
Using that 5inch with a second order XO at around 300hz, a box of around 5 to 8litres will do, but don't forget to use some damping material such as polyfil
XO = Crossover.
Regarding box size for mid-range, it is a relatively high "Q" driver, if you are using a first order XO the driver will be working in its piston range ( that is ;; it will be moving in and out a large distance ) so you would need to calculate the correct box size for that driver using a program or a calculator and the formula; I put it in a program by Jeff Bagby
http://audio.claub.net/software/jbagby.html#WBC
but it needs Windows Excel to work.
I did that and it needs a biggish box, but you are using it as a mid-range and you are using the XO to restrict the amount of the musical signal going to the driver ( that's what Crossovers do ) in old text books i have seen XOs called dividing networks which is a better description of what they do.
With a first order network more of the bass signal gets through to the mid-range, so to stop a peaking response the box needs to be bigger.
Using a second order XO less of the bass signal gets through to the mid so box size become less critical.
Using that 5inch with a second order XO at around 300hz, a box of around 5 to 8litres will do, but don't forget to use some damping material such as polyfil
Thanx for the link to the tweeter, it was gone when I looked for it earlier.
Very efficient tweeter; much louder than the mid-range, it will need to be padded down using resistors or buy an adjustable L-pad.
I think you are right when you say it needs a higher XO point.
When I see super tweeter I tend to think 7000/8000Hzbut if you can accept more components in the tweeter XO it may be able to be used lower.
I confess I was thinking of another tweeter entirely.
Are you determined to use that particular tweeter?/ it may be easier to pick another tweeter with a much lower resonant frequency that is also less efficient
Very efficient tweeter; much louder than the mid-range, it will need to be padded down using resistors or buy an adjustable L-pad.
I think you are right when you say it needs a higher XO point.
When I see super tweeter I tend to think 7000/8000Hzbut if you can accept more components in the tweeter XO it may be able to be used lower.
I confess I was thinking of another tweeter entirely.
Are you determined to use that particular tweeter?/ it may be easier to pick another tweeter with a much lower resonant frequency that is also less efficient
I am in the same boat moondog. I am happily following the thread and progress, but I am pretty sure I have run close to the limit of my experience. You are doing a terrific job as far as I am concerned. If I were to reply, I would only be repeating your advice so far so I have just been reading along.
I wonder if some of our more seasoned builders have a specific reason for not posting to this thread? I don't see anything that should be keeping them out. I know some have pretty strong opinions about driver choices etc, but I am always willing to work with what someone has if I can.
I like that tweeter, but now that I am looking at the graphs, you might be right. There is likely to be some gap between the useable limits of the mid and high driver where the crossover could cause some audible problems. That's as much as I could say though. I don't know what those problems will be or how they will look on a graph. I just know that stretching those limits and then using electronic components to compensate may cause issues.
I hope we get some more traffic here soon. Anyone want to pick some people to send PM's to and see if they want to chime in? I don't know most of these guys well enough for that.
take care,
Robert
I wonder if some of our more seasoned builders have a specific reason for not posting to this thread? I don't see anything that should be keeping them out. I know some have pretty strong opinions about driver choices etc, but I am always willing to work with what someone has if I can.
I like that tweeter, but now that I am looking at the graphs, you might be right. There is likely to be some gap between the useable limits of the mid and high driver where the crossover could cause some audible problems. That's as much as I could say though. I don't know what those problems will be or how they will look on a graph. I just know that stretching those limits and then using electronic components to compensate may cause issues.
I hope we get some more traffic here soon. Anyone want to pick some people to send PM's to and see if they want to chime in? I don't know most of these guys well enough for that.
take care,
Robert
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