Hello, I am having problems with the speaker I tried to make. It is a 3-way speaker. The speakers I am using are the Dayton 15" series II
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-130
, Alesis 5 1/4 woofer for the mid
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-160
, and selenium tweeter
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-360.
I used a 2nd order crossover with low pass at 600 HZ and high pass at 4800 HZ.
I hooked everything up and my tweeter was very loud so I put a resistor across and in series with it sounded a little better.
The speaker still didnt sound that well the 15 inch woofer got distorted at too low of a level. I think it might be because the low pass should be set lower than 600 HZ. I was wondering if anyone had any ideas on what I should do or tell me what I am doing wrong. Maybe these speakers are not a good match I dont know.
Dustin
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-130
, Alesis 5 1/4 woofer for the mid
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-160
, and selenium tweeter
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-360.
I used a 2nd order crossover with low pass at 600 HZ and high pass at 4800 HZ.
I hooked everything up and my tweeter was very loud so I put a resistor across and in series with it sounded a little better.
The speaker still didnt sound that well the 15 inch woofer got distorted at too low of a level. I think it might be because the low pass should be set lower than 600 HZ. I was wondering if anyone had any ideas on what I should do or tell me what I am doing wrong. Maybe these speakers are not a good match I dont know.
Dustin
I just had a look at the performance graph at PE, and I would be crossing that woofer about 200Hz, no higher than 300. I didn't see any graphs for the mid or tweeter you chose so I can only offer a "generic" opinion.
Perhaps you should post some more information; such as box size type and constuction, along with a diagram of the XO with the values you used showing. and whether or not the box has any stuffing or damping material inside it.
Regards and welcome
XO for a 5.25" mid should probably be quite a bit lower at around 2700/3200
Regards
Ted
Perhaps you should post some more information; such as box size type and constuction, along with a diagram of the XO with the values you used showing. and whether or not the box has any stuffing or damping material inside it.
Regards and welcome
XO for a 5.25" mid should probably be quite a bit lower at around 2700/3200
Regards
Ted
The volume of the box is 6688 inches cubed or 3.87 ft cubed. I planned on having it vented but I havent made the hole yet and I havent really thought about damping yet but I know I need it. To be honest I used the calculator on Lalana.com for my crossover. But I would like to learn how to do all the callculations on my own. Do you know of any good sources for me to learn from.
Thank you
Dustin
Thank you
Dustin
Have to agree with Moondog55 on the crossover points. WAY too high on the 15. I would say start with 200 hz if going passive. 12db per octave or more. If you could post a diagram of what you built, we might could start there.
The enclosure size is a bit large for sealed. (if that is internal), but I am wondering if all three drivers are in the same space? If you have a cabinet within the cabinet for the mid and tweet, that would be better. Still that much air will need the port. According to PE, a 3.5 in port 10.8 inches long is about right. I haven't simmed the driver, but I am betting that won't be far off.
Other than the 15 sounding distorted too early, how do the mid and tweet sound? The xo could probably stand to be lower for the mid, but that might depend on the characteristics. There are people here with a lot more experience than me on that one. With this set up, you will run into all sorts of issues with the crossover. Not a bad selection of drivers. I don't know how well they will interact in the same box, but I can certainly think of ways I would use them.
Take care,
Robert
The enclosure size is a bit large for sealed. (if that is internal), but I am wondering if all three drivers are in the same space? If you have a cabinet within the cabinet for the mid and tweet, that would be better. Still that much air will need the port. According to PE, a 3.5 in port 10.8 inches long is about right. I haven't simmed the driver, but I am betting that won't be far off.
Other than the 15 sounding distorted too early, how do the mid and tweet sound? The xo could probably stand to be lower for the mid, but that might depend on the characteristics. There are people here with a lot more experience than me on that one. With this set up, you will run into all sorts of issues with the crossover. Not a bad selection of drivers. I don't know how well they will interact in the same box, but I can certainly think of ways I would use them.
Take care,
Robert
Just ran some numbers in a box program.
Transient perfect box if you add some polyfill and/or fibreglass to control standing waves inside the box, the box itself is a little small for vented according to Jeff Bagbys box calculator.
That box Fc = 37Hz, F6 = 20.25Hz.
75 watts will give about 109dB at about 100Hz and a shallow roll-off after that.
More than 90 watts in a box that big and X-max plus 20% so the box can be smaller ( if the mid is in its own smaller internal box. Have you deducted that volume from the internal volume you gave us??
Transient perfect box if you add some polyfill and/or fibreglass to control standing waves inside the box, the box itself is a little small for vented according to Jeff Bagbys box calculator.
That box Fc = 37Hz, F6 = 20.25Hz.
75 watts will give about 109dB at about 100Hz and a shallow roll-off after that.
More than 90 watts in a box that big and X-max plus 20% so the box can be smaller ( if the mid is in its own smaller internal box. Have you deducted that volume from the internal volume you gave us??
I attached a photo of the schematic I used. I added some resistors for the tweeter values were 5 ohm parallel and 20 ohm in series.
The mid is not in its own internal box. The volume I gave you was of the entire box. If I put it in it own internal box it will it improve the speakers overall performance.
The Midwoofer right now sounds really good the tweeter sounds ok.
Thank you for all of the help you are giving me
Dustin
The mid is not in its own internal box. The volume I gave you was of the entire box. If I put it in it own internal box it will it improve the speakers overall performance.
The Midwoofer right now sounds really good the tweeter sounds ok.
Thank you for all of the help you are giving me
Dustin
Attachments
Definitely needs a seperate section/box but only a couple of litres or so, sealed and fully stuffed; I think you need to rethink your box.
I have retrofitted small mids with a sealed section using largish steel coffee cans glued in with epoxy if reworking the box isn't an option.
If you have the mid sharing the same box the back pressure from the woofer makes the mid move in time with the woofers motion, really muddies up the sound, and worse.
Loosing a few litres to a small container for the mid will allow the woofer to handle a little more power and give you a better F3.
I have retrofitted small mids with a sealed section using largish steel coffee cans glued in with epoxy if reworking the box isn't an option.
If you have the mid sharing the same box the back pressure from the woofer makes the mid move in time with the woofers motion, really muddies up the sound, and worse.
Loosing a few litres to a small container for the mid will allow the woofer to handle a little more power and give you a better F3.
The tin can is something I did a while ago as a cheap fix for a friend, basically an enclosure has to be airtight and as non resonant as possible.
We used a few layers of ducktape on the outside to stop it flexing too much, glued a bit of scrap mdf on the base ( building speakers generates lots of round discs as offcuts ) and filled it with polyfill after punching a hole for the wires.
The speaker wire holes are sealed with a dab of silicon and a small cable tie.
We mixed up some epoxy. spread it thickly around the rim where the press seal lid goes and reached up through the woofer hole and put it where the cutout for the mid was, fiddly to do as the epoxy sets too slow, but it worked and we didn't have to cut the box up and start again.
If you do a web search you should find plastic enclosures meant for mid ranges, Visaton do them, coffee can does the same job.
I like big sealed boxes, so IMO loosing a few litres for a midrange enclosure is fine, others may disagree, after all it's only my opinion.
If you use this idea make sure you use a friction top type tin can, as you need the lip for the glue to grab and seal, in Australia the cans I use run about from about 2litres to about 5/6 litres.
Use a big one in this instance and some foam and polyfill inside it.
Luck
Ted
We used a few layers of ducktape on the outside to stop it flexing too much, glued a bit of scrap mdf on the base ( building speakers generates lots of round discs as offcuts ) and filled it with polyfill after punching a hole for the wires.
The speaker wire holes are sealed with a dab of silicon and a small cable tie.
We mixed up some epoxy. spread it thickly around the rim where the press seal lid goes and reached up through the woofer hole and put it where the cutout for the mid was, fiddly to do as the epoxy sets too slow, but it worked and we didn't have to cut the box up and start again.
If you do a web search you should find plastic enclosures meant for mid ranges, Visaton do them, coffee can does the same job.
I like big sealed boxes, so IMO loosing a few litres for a midrange enclosure is fine, others may disagree, after all it's only my opinion.
If you use this idea make sure you use a friction top type tin can, as you need the lip for the glue to grab and seal, in Australia the cans I use run about from about 2litres to about 5/6 litres.
Use a big one in this instance and some foam and polyfill inside it.
Luck
Ted
dustruss said:
Not at all. I like all three of the drivers. I am a bit surprised to hear the mid sounds good being in the same enclosure with the woofer. Moondog already said why that would duff up the sound somewhat. The air pressure from the giant 15" driver moving in a sealed box means the little mid is being forced to act like a passive radiator. A tin can or a plastic cup strengthened with fiberglass would make for a pretty easy fix without messing the existing enclosure up too badly. Of course, that could change the way the mid sounds. It would still be my suggestion. Making the enclosure big enough to leave the woofer sealed isn't a bad idea at all. If you can get the woofer down to (I am guessing) something like 2.5 cubic ft, that might work very well. I will try to draw up some numbers for you this week. A little stuffing and you are off to the races.
You mentioned adding resistance to the tweeter and also said the tweet sounded "ok". I would definitely look into this part of the crossover first. Again with the number running, lol. At least this is the easiest part to play with usually. I don't usually recommend resistance additions. It goes against a lot of beliefs, but personally I like to use as few crossover components as possible. I also like to use shallow slopes on most of mine. With that in mind, I will try to find time to take a look at this part of it tomorrow and offer my suggestions. I hope some others will take a close look as I am not the best with crossovers. I can do the math pretty easy, but there are a lot of factors that muddy up the sound sometimes.
Good luck with this one, give me a few days and if you don't see my answers, send me a kick to remind me to get on it for you.
Take care,
Robert
OK I just had a few minutes to use my handy dandy calculator. I am interested for some of the crossover gurus to come tell me why this is wrong. I am serious about that. Crossovers have always interested me and there are people (like Zaph) who make the explanations sound so easy. aI typically take a very minimalist approach and my understanding is that phase issues occur this way. My math tells me a bit about phasing, but I think I look at the drivers inherent ability along with the enclosure and then try to keep the electronics out of the way.
WIth that said, my recommendation is to go with a 2.5 cu ft sealed chamber for the woofer and use whatever is left over as a separate space for the mid and tweeter. Then my calcs show the following crossover components
1 coil on the woofer- 6.4mH
1 coil and one cap on the mid- 100mF and .4mH
1 cap on the tweeter- 6.2mF
That would be where I would start, but I bet there are people here who will give you a much better solution. There are probably reasons to go with a steeper slope. That is only 6db per octave and is a bit low for such a shallow crossover on that tweeter. You might want to either raise the freq (my normal solution) on the tweeter by using something like a 4.7mF or raise the slope by adding additional components. Other than that, I don't see any reason why the woofer and mid 6db slopes wouldn't be sufficient.
Hope that helps. Let us know how you work it out!
Take care,
Robert
WIth that said, my recommendation is to go with a 2.5 cu ft sealed chamber for the woofer and use whatever is left over as a separate space for the mid and tweeter. Then my calcs show the following crossover components
1 coil on the woofer- 6.4mH
1 coil and one cap on the mid- 100mF and .4mH
1 cap on the tweeter- 6.2mF
That would be where I would start, but I bet there are people here who will give you a much better solution. There are probably reasons to go with a steeper slope. That is only 6db per octave and is a bit low for such a shallow crossover on that tweeter. You might want to either raise the freq (my normal solution) on the tweeter by using something like a 4.7mF or raise the slope by adding additional components. Other than that, I don't see any reason why the woofer and mid 6db slopes wouldn't be sufficient.
Hope that helps. Let us know how you work it out!
Take care,
Robert
Hi Dustin, can you post a picture or diagram of your box so we can see the CTC spacing on your drivers and tell us a little more about the way you built them and what you built them from??
All of the above will have some effects on the "Total sound picture" so to speak.
I'd say that a first order on the woofer may work, but perhaps what some people refer to as a partial zobel will be needed as well, basically a"Strange" second order, you'll either need help from a forum member better at XOs than I am or experiment with different values until you get it right.
I'm some-one who prefers steeper slopes on the transition from one driver to another but first on the woofer and second on the mid and tweeter may work, if you can find some more graphs and info on your selected drivers that will help, specially the tweeter if crossing at 3000 or so
All of the above will have some effects on the "Total sound picture" so to speak.
I'd say that a first order on the woofer may work, but perhaps what some people refer to as a partial zobel will be needed as well, basically a"Strange" second order, you'll either need help from a forum member better at XOs than I am or experiment with different values until you get it right.
I'm some-one who prefers steeper slopes on the transition from one driver to another but first on the woofer and second on the mid and tweeter may work, if you can find some more graphs and info on your selected drivers that will help, specially the tweeter if crossing at 3000 or so
Fore what its worth, my crossover looks like this, sorry...no values 
Its not as complicated as it may look, and would be like the "strange" 2.order mentioned by moondog, and can be quite difficult to get right it does something exactly right, but probably also have its own flaws, like everything else
Its not as complicated as it may look, and would be like the "strange" 2.order mentioned by moondog, and can be quite difficult to get right
it does something exactly right, but probably also have its own flaws, like everything elseAttachments
Starting point for that strange second order, use the closest nominal value of cored inductor close to 6.5mh. then 25uF and 10/12ohms, you wil need ( I think) at least 20Watt rated resistors so use 2 * 10 in parallel, see how it sounds and then fiddle.
I would use second order on the mid, 200 is too close to the resonant frequency of the mid to use a first order.
Rule of thumb working here, XO = Fs* 4 ( 2 octaves) 73*4 = 292
I would use second order on the mid, 200 is too close to the resonant frequency of the mid to use a first order.
Rule of thumb working here, XO = Fs* 4 ( 2 octaves) 73*4 = 292
Hi Dustin
General rule of thumb is to get the tweeter and mid as close together as possible.
I guess it is too late to build new boxes; so I'm trying to help you ( as best I can ) to get the best out of these I suppose.
Have you done any reading on general box building techniques yet?? As shown these will have problems with panels flexing & vibrating adding unwanted noise.
Do you want to continue with these boxes or start again??
Don't give up and don't get discouraged 3-ways are HARD as I'm finding out.
If you want to use thes existing boxes you will need to find some way to get that mid-range into it's own section.
Thats a big woofer hole so probably more than one solution to that problem
Regards
Ted
General rule of thumb is to get the tweeter and mid as close together as possible.
I guess it is too late to build new boxes; so I'm trying to help you ( as best I can ) to get the best out of these I suppose.
Have you done any reading on general box building techniques yet?? As shown these will have problems with panels flexing & vibrating adding unwanted noise.
Do you want to continue with these boxes or start again??
Don't give up and don't get discouraged 3-ways are HARD as I'm finding out.
If you want to use thes existing boxes you will need to find some way to get that mid-range into it's own section.
Thats a big woofer hole so probably more than one solution to that problem
Regards
Ted
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