I thought it would be fun to have a new project during the current covid-19 work from home situation so I picked up a pair of "custom" speakers cheap that were made from Rectilinear III Highboys. After doing a little research about speaker design I realized I was in way over my head.
I've got tools and I'm handy with wood and steel but know very little about speaker design or audio wiring in general.
So what here is what I am starting with:
Yes, those are the original tweeters and super tweeters covered over with silicon caulk. I know, the horror. I have enough OCD that it wouldn't let me leave these as is even if they sounded perfect.
One speaker sounded OK (not great, but OK) and the other one was was flat like when the caps have gone bad in the crossover. I took them apart annd this is what I am left with:
Box outside dimensions 31 7/8"H x 17 7/8"W x 12"D (baffle is recessed 7/8")
Made from 3/4" panels. There is a 3" foot on both speakers.
The baffle is easy to remove and I plan on replacing it with the new configuration.
I calculate the volume at 2.77 cubic ft (78.5 Liters) before subtracting volume of bracing etc.
The salvageable components I pulled are:
Dayton Audio DC300-8 12" woofer 8 Ohm with
Peerless 821639 2" Poly Dome Midrange 4 Ohm
JAMO 20134 1" Soft Dome Tweeter 8 Ohm
all tested and working.
So my first question is are any of the drivers worth re-using? I'd like to at least re-use the woofers in the new design as long as they are not dogs.
Thanks.
I've got tools and I'm handy with wood and steel but know very little about speaker design or audio wiring in general.
So what here is what I am starting with:
Yes, those are the original tweeters and super tweeters covered over with silicon caulk. I know, the horror. I have enough OCD that it wouldn't let me leave these as is even if they sounded perfect.
One speaker sounded OK (not great, but OK) and the other one was was flat like when the caps have gone bad in the crossover. I took them apart annd this is what I am left with:
Box outside dimensions 31 7/8"H x 17 7/8"W x 12"D (baffle is recessed 7/8")
Made from 3/4" panels. There is a 3" foot on both speakers.
The baffle is easy to remove and I plan on replacing it with the new configuration.
I calculate the volume at 2.77 cubic ft (78.5 Liters) before subtracting volume of bracing etc.
The salvageable components I pulled are:
Dayton Audio DC300-8 12" woofer 8 Ohm with
Peerless 821639 2" Poly Dome Midrange 4 Ohm
JAMO 20134 1" Soft Dome Tweeter 8 Ohm
all tested and working.
So my first question is are any of the drivers worth re-using? I'd like to at least re-use the woofers in the new design as long as they are not dogs.
Thanks.
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Hi Clang,
I like your idea using the Dayton woofers you already have and then mate them with Dayton RS150P-8A midwoofer and Dayton RST28-4F tweeter. You will need to build a small separate chamber for mid range (easy enough to do). I’m sure others may suggest a different approach but if it were my project this would be my choices.
Seems like a fun project to me.
Best,
Rich
I like your idea using the Dayton woofers you already have and then mate them with Dayton RS150P-8A midwoofer and Dayton RST28-4F tweeter. You will need to build a small separate chamber for mid range (easy enough to do). I’m sure others may suggest a different approach but if it were my project this would be my choices.
Seems like a fun project to me.Best,
Rich
No problem at all that it is 4 ohm. When you get to the crossover design phase, you will realize that resistors will be required to match tweeter response to mid and woofer. Thus, impedance will be increased and you will be looking at a nominal 6-8 ohm speaker overall. Either the Dayton RST28 tweeter would be good. I have the Dayton RST28-4a waiting for a project to use in (don’t know when).
Best Regards,
Rich
Best Regards,
Rich
Hi clang,
You may want to follow the thread ‘Crossover Critique’ that is current going. Lots of good information for those just starting out. Once you selected and installed the drivers of your choice than the next frontier is designing a crossover that ties everything together. That is one reason I recommended the Dayton drivers is that from parts express you can download both .frd and .zma files for easy use in simulation programs like Xsim, Vituixcad, PCD7, among others. If this is your first diy speaker building project, than why not make it as easy as possible? Hope this helps.
Best,
Rich
You may want to follow the thread ‘Crossover Critique’ that is current going. Lots of good information for those just starting out.
Once you selected and installed the drivers of your choice than the next frontier is designing a crossover that ties everything together. That is one reason I recommended the Dayton drivers is that from parts express you can download both .frd and .zma files for easy use in simulation programs like Xsim, Vituixcad, PCD7, among others. If this is your first diy speaker building project, than why not make it as easy as possible? Hope this helps.Best,
Rich
I'd go sealed myself; just in case in the future you need even more bass. By the time you make a secondary chamber for your desired midrange the box should be a very good size for that woofer sealed. I'd be crossing it as low as I could, say 300 or 400Hz and using a decent midrange capable of working well form 200/300Hz as recommended above
Bi-amping might be worth while with a DSP integrated plate amp too. Passive between the mid and tweeter
Bi-amping might be worth while with a DSP integrated plate amp too. Passive between the mid and tweeter
@clang,
I ran a simulation of the Dayton woofer last night using Unibox. It would work equally well in either sealed or ported box. If going the ported route you will achieve better low frequency extension with an f3 in the low 30’s. Sealed gives you in f3 in the low 50’s. That may be adequate for most music but you probably would need a subwoofer if this was also in a HT setup playing movies as well. Do keep in mind that if you go ported, maintain as much box volume as possible. I’m with Moondog55 though that this woofer really should be crossed over to mid in that 200-300 right in range where impedance begins to rise sharply. The Dayton RS150P-8a that I recommended would be a good choice in this application. Hope this helps.
Best,
Rich
I ran a simulation of the Dayton woofer last night using Unibox. It would work equally well in either sealed or ported box. If going the ported route you will achieve better low frequency extension with an f3 in the low 30’s. Sealed gives you in f3 in the low 50’s. That may be adequate for most music but you probably would need a subwoofer if this was also in a HT setup playing movies as well. Do keep in mind that if you go ported, maintain as much box volume as possible. I’m with Moondog55 though that this woofer really should be crossed over to mid in that 200-300 right in range where impedance begins to rise sharply. The Dayton RS150P-8a that I recommended would be a good choice in this application. Hope this helps.
Best,
Rich
Designing a speaker properly is best done after measuring the drivers in the cabinet which I don't see happening here. The next best way is with just computer simulations. As a beginner, you will need someone here, or multiple people even better, to do that for you. As such I would be looking at inexpensive drivers that provide reliable specs to work with. Dayton is 1 of those as Montana has suggested. But it's not hard to trace the FR and/or the impedance curves from other brands either so I wouldn't limit myself to just that 1 brand.
Going sealed or vented with that woofer works either way, it simply depends on how low you want the speaker to go and if you want to deal with a little more complexity with a ported woofer or not. Room size might make a bit of a difference as well - sealed might be best for a smaller room, ported for something bigger.
In terms of the other 2 drivers, I would probably go with something new. You can do better than both of those without spending too much money. Something that we need to know though before recommending drivers is how you are going to place these in your room - out from the walls or right up against a back wall. This will make a difference in the sensitivity required for the mid and tweeter because of something called baffle step loss. Read about it HERE in Speaker Topics 1 & 2 and more HERE especially post #6.
Going sealed or vented with that woofer works either way, it simply depends on how low you want the speaker to go and if you want to deal with a little more complexity with a ported woofer or not. Room size might make a bit of a difference as well - sealed might be best for a smaller room, ported for something bigger.
In terms of the other 2 drivers, I would probably go with something new. You can do better than both of those without spending too much money. Something that we need to know though before recommending drivers is how you are going to place these in your room - out from the walls or right up against a back wall. This will make a difference in the sensitivity required for the mid and tweeter because of something called baffle step loss. Read about it HERE in Speaker Topics 1 & 2 and more HERE especially post #6.
Thanks jReave,
Those are very good points you mentioned. It is always difficult to know how much information to give at once for someone just starting out. I’m with you that replacing the mid and tweeter is a must. He probably could purchase the remaining drivers for less than $200.00. Please keep in mind I have no stock with Dayton. My favorite cost vs. performance drivers are from SB Acoustics. Very good build quality.
I was also going to suggest going with a ported enclosure design and have the option of stuffing the ports if a sealed box is desired down the road. What do you think of that idea?
Best Regards,
Rich
Those are very good points you mentioned. It is always difficult to know how much information to give at once for someone just starting out. I’m with you that replacing the mid and tweeter is a must. He probably could purchase the remaining drivers for less than $200.00. Please keep in mind I have no stock with Dayton.
My favorite cost vs. performance drivers are from SB Acoustics. Very good build quality.I was also going to suggest going with a ported enclosure design and have the option of stuffing the ports if a sealed box is desired down the road. What do you think of that idea?
Best Regards,
Rich
I know I'm a little late. But I thought I may as well pitch in my 2 cents.
First of all, I'm not sure what type of music you primarily listen to, or your preferred sound signature. If you listen to electronic music, I would go ported so you get the extra extension from those woofers, which I would highly suggest you keep. You can try running them through a software such as WinISD to calculate the overall "estimated" response graph of the woofer in your cabinet. However, if you listen to more acoustic music like jazz and whatnot, then I would go sealed as it offers better transient response.
Now for the mid range. You could either go with a dome mid range, which similar to a tweeter does not need it's own enclosure. There are pros and cons to a dome mid range, such as that it needs to be crossed higher, e.g. double it's resonate frequency. Also, they tend to be higher sensitivity so make sure you do tame them properly when paired with the woofer if you do decide to go with a dome mid range. Or, like other members suggested you could go with a traditional cone mid range and stick it in it's own sealed enclosure, which you can tune however you want. I would suggest going paper cone as opposed to something like aluminum for the mid range. This also brings me to the question, how are you powering these speakers, are you tri-amping them?
Lastly is the tweeter. I would also go soft dome as opposed to hard dome. If you have extra to spend then look for something with a replaceable diaphragm and from a reputable manufacturer.
Oh and I almost forgot. Don't skimp out on crossovers. Invest in film caps over the more budget end electro's. That is if you are going with a passive crossover. If you are going with an active crossover, then that's a topic for a different forum category.
I hope I helped, let me know if you have any other questions.
First of all, I'm not sure what type of music you primarily listen to, or your preferred sound signature. If you listen to electronic music, I would go ported so you get the extra extension from those woofers, which I would highly suggest you keep. You can try running them through a software such as WinISD to calculate the overall "estimated" response graph of the woofer in your cabinet. However, if you listen to more acoustic music like jazz and whatnot, then I would go sealed as it offers better transient response.
Now for the mid range. You could either go with a dome mid range, which similar to a tweeter does not need it's own enclosure. There are pros and cons to a dome mid range, such as that it needs to be crossed higher, e.g. double it's resonate frequency. Also, they tend to be higher sensitivity so make sure you do tame them properly when paired with the woofer if you do decide to go with a dome mid range. Or, like other members suggested you could go with a traditional cone mid range and stick it in it's own sealed enclosure, which you can tune however you want. I would suggest going paper cone as opposed to something like aluminum for the mid range. This also brings me to the question, how are you powering these speakers, are you tri-amping them?
Lastly is the tweeter. I would also go soft dome as opposed to hard dome. If you have extra to spend then look for something with a replaceable diaphragm and from a reputable manufacturer.
Oh and I almost forgot. Don't skimp out on crossovers. Invest in film caps over the more budget end electro's. That is if you are going with a passive crossover. If you are going with an active crossover, then that's a topic for a different forum category.
I hope I helped, let me know if you have any other questions.
Wow, lot's of great info gents. Let me answer the questions/provide more info:
Planned location is a larger room in the basement - 6 inches or so from the walls maybe 8' apart but not in the corners. I'd prefer to place them directly on the floor, but if I have to raise them I can. Power is an old Technics solid state Integrated amp 95 watts per channel. I also have an old Onkyo amp and pre-amp 135 watts per channel that might make the rotation. No sub-woofer.
I'd prefer the music to fill the room with clean sound vs sitting in one prime location.
Music - rock, alternative, bluegrass, jazz, some old country - and a little bit of everything. I usually prefer studio albums over live recordings.
From what I hear so far, a ported box with the base extension would be the way to go. I have no problem isolating the mid-range driver so a paper cone is fine by me.
Does Rich's mid and tweeter suggestions still make sense? Can we do this with a crossover that a noob like me can put together (with some serious help from you guys).
Planned location is a larger room in the basement - 6 inches or so from the walls maybe 8' apart but not in the corners. I'd prefer to place them directly on the floor, but if I have to raise them I can. Power is an old Technics solid state Integrated amp 95 watts per channel. I also have an old Onkyo amp and pre-amp 135 watts per channel that might make the rotation. No sub-woofer.
I'd prefer the music to fill the room with clean sound vs sitting in one prime location.
Music - rock, alternative, bluegrass, jazz, some old country - and a little bit of everything. I usually prefer studio albums over live recordings.
From what I hear so far, a ported box with the base extension would be the way to go. I have no problem isolating the mid-range driver so a paper cone is fine by me.
Does Rich's mid and tweeter suggestions still make sense? Can we do this with a crossover that a noob like me can put together (with some serious help from you guys).
@clang,
You may want to consider mid and tweeter from other companies other then Dayton as jReave suggested. It is not terribly difficult to trace frequency response and impedance graphs to compile our own .frd/.zma files. Once we know what your budget is for drivers than it will help with coming up with some recommendations.
Concerning crossover design, you will find several willing to lend you a hand. jReave has helped me out on a few projects and he is an absolute ‘Ace’ when it comes to this stuff.
Have fun,
Rich
You may want to consider mid and tweeter from other companies other then Dayton as jReave suggested. It is not terribly difficult to trace frequency response and impedance graphs to compile our own .frd/.zma files. Once we know what your budget is for drivers than it will help with coming up with some recommendations.
Concerning crossover design, you will find several willing to lend you a hand. jReave has helped me out on a few projects and he is an absolute ‘Ace’ when it comes to this stuff.
Have fun,
Rich
@Rich,
Thanks again for the kind words.
@clang,
If you've soldered before you'll have no problem putting a xo together. If you haven't, a youtube tutorial and a little practice and it'll still be no problem.
Given the speaker placement and the width of the baffle, I would expect 3dB to 0dB of baffle step loss. Which means that your woofer starts with 90dB of sensitivity and will end up with about 87-90dB afterwards. This is one of those hard to tell until it's in the room kind of things. Regardless, you'll need a mid and tweeter that can match the highest of those numbers. So also a minimum of 90dB sensitivity. That rules out the RS150P-8 but makes the RS150P-4 acceptable. That's as long as your amp choices are 4ohm compatible?
Budget wise, I was thinking you couldn't beat the sale price of the SB13PFC-8 but its sensitivity is too low. Maybe the SB13PFC-4 but I'm not quite as happy with its FR. I'd have to sim it 1st to be sure. Puts the RS150P-2 at the front of the queue. Here's a nice tweeter by Peerless that's also on sale at Madison right now too. The next 1 up I'd probably look at is the SB21SDC.
If you want to go a little higher quality, I'd look at some of the SB15 4ohm drivers and maybe another SB tweeter. But again - are your amps happy with 4ohm?
Also, for a 3-way you can probably expect the xo to be a minimum of $100. More if you want better parts.* That's something that beginners don't realize and are often not told about until the end of the process. Better to know out front.
*And actually more too because you are probably going to need a few extra parts to see what is actually going to sound better with your room placement. What I would do with sims in this type of situation is do them twice - once at 3dB of baffle step loss and once at 0. You'll then see the range of values that would be necessary to make either case work.
Thanks again for the kind words.
@clang,
If you've soldered before you'll have no problem putting a xo together. If you haven't, a youtube tutorial and a little practice and it'll still be no problem.
Given the speaker placement and the width of the baffle, I would expect 3dB to 0dB of baffle step loss. Which means that your woofer starts with 90dB of sensitivity and will end up with about 87-90dB afterwards. This is one of those hard to tell until it's in the room kind of things. Regardless, you'll need a mid and tweeter that can match the highest of those numbers. So also a minimum of 90dB sensitivity. That rules out the RS150P-8 but makes the RS150P-4 acceptable. That's as long as your amp choices are 4ohm compatible?
Budget wise, I was thinking you couldn't beat the sale price of the SB13PFC-8 but its sensitivity is too low. Maybe the SB13PFC-4 but I'm not quite as happy with its FR. I'd have to sim it 1st to be sure. Puts the RS150P-2 at the front of the queue. Here's a nice tweeter by Peerless that's also on sale at Madison right now too. The next 1 up I'd probably look at is the SB21SDC.
If you want to go a little higher quality, I'd look at some of the SB15 4ohm drivers and maybe another SB tweeter. But again - are your amps happy with 4ohm?
Also, for a 3-way you can probably expect the xo to be a minimum of $100. More if you want better parts.* That's something that beginners don't realize and are often not told about until the end of the process. Better to know out front.
*And actually more too because you are probably going to need a few extra parts to see what is actually going to sound better with your room placement. What I would do with sims in this type of situation is do them twice - once at 3dB of baffle step loss and once at 0. You'll then see the range of values that would be necessary to make either case work.
I'll defer to the others on XO simulation and design because I am far from expert in that regard but if you find that the room you are listening in is far too live and reverberant there are many cheaper techniques for improving that.
However another option these days is Bi-Amping as small crossovers such as the Behringer are often cheaper than the same slopes in passive components of good quality.
YouTube
I bought one here a while ago for $99- used and use it in my own set of big speakers. An option for the top end might be to copy the upper level of Paul Carmodys Tarkus and borrow his design for the XO with modifications to suit your existing box
Tarkus - undefinition
Mainly because the driver used in the midrange is such good value for money
However another option these days is Bi-Amping as small crossovers such as the Behringer are often cheaper than the same slopes in passive components of good quality.
YouTube
I bought one here a while ago for $99- used and use it in my own set of big speakers. An option for the top end might be to copy the upper level of Paul Carmodys Tarkus and borrow his design for the XO with modifications to suit your existing box
Tarkus - undefinition
Mainly because the driver used in the midrange is such good value for money
That's actually a good suggestion. You could do it active but I think that might work as well all passive - essentially a monkey box version of the Tarkus. The mid/tweeter xo would need some small changes though because of the serious differences in the baffle widths between the 2 speakers. But modeling with the Tarkus xo offers a good summed target filter to start off with.
Note that if you went active, the sensitivity requirements I mentioned above for the mid and tweeter no longer apply, so the SB13PFC-8 becomes another good candidate again.
My personal preference would be to keep it simple and stay with passive xo's but it's good to see more than 1 point of view.
Note that if you went active, the sensitivity requirements I mentioned above for the mid and tweeter no longer apply, so the SB13PFC-8 becomes another good candidate again.
My personal preference would be to keep it simple and stay with passive xo's but it's good to see more than 1 point of view.
Thanks again gents,
A "monkey coffin" version of the Tarkus is just what I'm looking for. I want a pair of 3-ways that remind me of speakers I had years ago. The mids and tweeters are priced right too.
It will also get me all together for about $200 if crossover parts are going to cost another $100.
So more dumb questions:
Do you think the Tarkus mids and tweeters will match up OK with my woofer?
If front porting much different than rear porting? The Tarkus ports are longer than my cabinets are deep,
FYI - My amps supposedly run speakers from 4-16 Ohm, but everything I have is 8 Ohm.
A "monkey coffin" version of the Tarkus is just what I'm looking for. I want a pair of 3-ways that remind me of speakers I had years ago. The mids and tweeters are priced right too.
It will also get me all together for about $200 if crossover parts are going to cost another $100.
So more dumb questions:
Do you think the Tarkus mids and tweeters will match up OK with my woofer?
If front porting much different than rear porting? The Tarkus ports are longer than my cabinets are deep,
FYI - My amps supposedly run speakers from 4-16 Ohm, but everything I have is 8 Ohm.
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