I am not sure how many followed my older thread of a modern day Polk Audio SRS... Pretty sure those that did where smacking themselves in the head because it was obvious how much I really knew about speakers and DIY. The thread was very valuable for me as it helped narrow down what I want for a set of speakers.
Since that time I had been looking at speaker design, individual driver specifications and the entire gambit. Just learning if you will. What I came up with is that I wanted a musical system that will do theater as well. I mostly watch movies but love to just listen to music. While this is my first set of speakers its also a very ambitious build because I wanted something to cross a whole gambit of requirements. Originally I was looking at using the scanspeak classic 8" woofers, SEAS prestige mid, and a sb acoustics tweeter. The 8" woofer had a bottom end that was amazing and a great price. Everyone was warning against a 3 way system and the work involved. In the end I found a set of 7' Scanspeak woofers on sale here. They were about $200 off retail so I couldn't pass them up. To match those woofers I also picked up a set of Scanspeak tweeter. So my first build is going to be:
Scanspeak Illuminator 18WU/4747T-00, 7"
ScanSpeak Illuminator D3004/6620-00 1" dome tweeter
From what I have seen these two combined should give me a very flat frequency response. They should have great imaging and have a range from 50-30 hz by themselves. The down side is the ohms, these will require a 4 ohm stable amplifier so that is something I have to consider purchasing as well now.
Now on to the tools. I choose to get DATS for woofer testing, then use a Condenser Microphone in combination with either, true rta, or room eq wizard. Then I also found you can use LEAP on a trial and of course I have winISD. Now all these programs are great but its been a huge nightmare to try to get DATS to work with my computers. I am not sure why but its just not working out right with Windows Vista 64 bit. The staff have been nothing if not helpful at Parts Express. Also the rest of the programs have steep learning curves except winISD. So it was my decision to have Madisound create the specifications for the cross over. I know kind of cop out but I want to get this as close to right from the start. They have also given me box specifications as well.
With that starts the build and new set of issues...
First get the DATS or WT3 or w/e, then if you have Office, specifically Excel, download Unibox, BoxyCad, and Jeff Bagby's Passive Crossover Designer, these 3 tools will help you TREMENDOUSLY. Once you've designed and built your enclosure, drop some drivers in and get ready to measure...
I recommend you get yourself a calibrated mic, from say, Cross Spectrum (I have one), and a Blue Icicle USB interface. Then download Holm Impulse (for FREEEEEEEEE), and there's even a writeup here on PETT to show you how to use it. Now, once you've measured the room, the mic, the speaker, the everyhting else as well 5000x, you'll need a POWER AMPLIFIER so that nothing else is going on (EQ, Crossovers, etc.) like is in an AVR.
Finally, once you've got really good measurements, it takes quite a bit of Trial and Error, you need to learn how to use PCD, it's really awesome. And you'll need to post up every single crossover sim you do, so that it can be critiqued (Quite Harshly, I might add) by the resident crossover gurus, over and over and over again, until you get something usable.
Now, after you've invested a couple hundred bucks in crossover parts, No No No, you're not even close to being finished! It's time to voice the speakers in the room you intend to listen to them in. Wire up your PETT-approved crossovers and setup you speakers, try swaping out parts here and there to get the sound that you like best (once you've gotten to this point it will be apparent which ones you'll want to swap out for VOICING).
Once you've finished this and you're sure it's the Best you can do, finish it up, sit down and enjoy.
Then take them to MWAF and see how everyone else likes them........ and then do another crossover and some more voicing, haha.
BTW, this was not meant to scare you off, but more or less let you know what you're getting yourself into. I wish I had gone this route. I've invested probably $1500 into a speaker that I could never sell for that much in this lifetime becuase I didn't do it like I've said previously. So Learn from my mistakes, I don't know how many times I've typed this out and usually I'll convince them to do it.
I am not sure what cross spectrum is? I have purchased the Icicle usb interface already and the Behringer ECM8000 Condenser Ultra-Linear Measurement Condenser. These two should give me a decent measurement. Thank you for the software recommendations. Anything I can use I will. Also your reply does not scare me. I kind of figure this is the case to speaker building. The cross over and box dimensions I was given by madisound I figure are a good start. Here is the design they came up with:
Also they suggested a 18 x 12 baffle. I am going to build the box in such a way that I can get easy access to the crossover. The front baffle will not be glued down. My choice of wood is 3/4 mdf with butted ends. This way things don't have to be 100% accurate on the cutting (which I will save for a later thread). I have already built most of the box and hope it will be dead quiet.
Cross Spectrum sells calibrated measrement mics, both the Behringer like you have and the Dayton version as well. You may have gotten a "calibration file" with yours, Dayton does include them, but it's for the model of the microphone, not the individual microphone.
Did you use their LEAP crossover design service? I believe there was a member here once before that did the same, but they didn't like the sound, so they ended up learning the PCD software and designing their own in the end.
If you build it from 3/4" wood, it should be dead enough. Most builders recommend bracing every 6 inches or so front-to-back and side-to-side, unevenly with dowels. The uneven bracing causes uneven resonances in the panel and you have smaller peaks and dips in the low-to-mid frequency range, IIRC.
If you were going to get a DATS, you would be able to measure the T/S Parameters needed to design a properly aligned enclosure. In your case, you didn't get any specifications of the enlcosure other than the fact that it's 0.75ft3 and has a 5" long, 2" diameter port. What's the Tuning? What's the F3 and F10? At what frequency does it break Xmax and Xlim, given X amount of power? These sorts of things are really necessary to know, and can be found by plugging in a few numbers to either Unibox (my preference) or WinISD...
I did get some measurements but they don't make sense to me. I was told to go with a baffle that is 18 x 12. That is way too big because a 18 x 12 x 12 box will be 1 cubic foot. I really don't understand the programs thus far and decided to get the service from them on the crossover as a start. I will probably not like that as well but wanted something to start with. This way I can see what a cross over should be designed as and when I start really diving into LEAP hopefully I will come to the same results. I say hopefully because then I will be on the right track. There will be lots of tuning from that point I am sure.
I ran through winISD and it looks like he is targeting a F3 of 35 hz. I am not sure if the xmax can really target that without causing some issues. Also I don't have the xmax measurements. Would anyone else know for sure on this?
I would LOVE to be able to design and build my own speakers, but every time I think about biting the bullet and ordering the software and equipment to do it I read one of these threads. Thats so much time and money; and it's something you have to either do or not do, you can't just do it a piece at a time. I know you (generally) only have to spend it once, but ooooohhh would the wife ever object! I think at this point I've decided to just use everyone else's designs and live w/ the subtle tweaks I'll never be able to perfect.
Good luck in your venture utahsaint, may the force be w/ you! I very much look forward to reading your future posts on your results.
I have given up on the idea of doing it once. I could write a whole thread on what a nightmare its been just building a box. The thing is the speakers are the only thing I want to buy once (even that I am questioning if I should have just done the Stentorians). This is why I went crazy with speakers and bought what I did. At the end of it all I should have a decent sounding system. I have already built three different boxes just trying to get cutting down. I even bought a cheaper table saw that I then returned because it was a nightmare. I know people say measure your speakers first and measure against the baffle... I couldn't even cut a straight line before. Its taken a bit to figure out what works. What I came up with is that I need a guide that was created custom by me for my circular saw. Then I need to measure very consistently. Currently I am just using a circular saw and its old so it doesn't cut always the best. Also be sure to purchase a new blade just for smooth cuts. What I have been able to build well here is an example:
Also I found that the jasper circular jig does not have a large enough hole to build the flush mount area on the baffle. So what I did and someone will cringe was to make the hole bigger. This way I could measure and use it first to build the flush mount then cut the hole after the fact. It works for me but the image above was my first attempt at a baffle and will be tossed out. Even with a guide and measuring four, to six little marks then writing the line I am still a 1/2 a mm off at times. I have sanded all the panels to be close but still off. Here you can see that:
This is why I am going to put another piece over the top of that. Then with sealing it off as well there should be no air leaks.
My advice if you are looking for a easy way to save money and get it close to right up front use a kit. They will sound worlds better than what you can come up with, will have a cross over that is okay and sound better than what you could afford for a retail name brand speaker. Even with the speakers I choose they have a kit at madisound with everything already, even the boxes. DIY is for those that want to get crazy, measure the room, the speakers everything down to a science then put it together. This way we know its tuned just to that room and the power we have going to it. That is why I wanted to go this route even though its nuts...
As far as the building goes, I've actually done a few of some other people's designs (Tritrix, Statements, and I actually have a build thread here in the project gallery for the ER18s I'm working on now). I just don't think I have the ambition or money right now to tackle the design aspect. My hat's off to you though, and I really look forward to your end results.
If you have any woodworking questions at all, feel free to pm me and I'd be glad to help out. I was a remodeler for quite a while and did a few custom kitchens as well. I've heard some of the guys here will take a cutlist to a cabinet shop and have them make the cuts; and they say it's for a pretty reasonable cost. Not sure how that would work for trial cabinets though, something like that might get pricey.
You were on the right track w/ the table saw, but you may have better results w/ a used one on craigslist (more bang for your buck). Just some thoughts. Like I said, feel free to ask questions, I'll be glad to help in the woodworking area. Just don't look to me for speaker design advice
One more thing, the Jasper jig is a great jig, you just can't use a bit larger than 3/8" diameter in the one that only goes to 7". So if I'm understanding what you said, you can't make a larger than 3/8" diameter cutout for the recess, correct? I just make 2 passes. When I'm routing out my speaker cutouts w/ a Jasper jig, I'll first drill my 1/8" hole for the jig's pin, then route out the recess for the driver to sit in, then cut the hole.
I've been working in the shop with my dad since I could wield a hammer and put nails into a scrap 2x4 haha...
What advise I have, I'll give.
As far as building a straight box, the best way I've found to do it is this:
Start with the Top/Bottom/Sides, cut one long strip, long enough for the height of the sides and depth of the tops and bottoms, so that when you glue them together, all the edges that the front and rear baffles will attach to will be pretty flat.
This is how you would assemble them:
Once you do that, cut the front and rear baffles by cutting one measurement (width or height) at a time, so you're not moving the fence and therefore, changing the cuts. BUT, you'll want to cut the front and rear baffles about a 1/4" or so larger than you need. Once you've glued them on, and they're dry, you can go around the edges with a flush cut bit in your router and everything will be nice and flush!
I really don't have any advise on the driver recesses, becuase, as much as I seem to know about this, I've never used a router circle jig, and the Deadhorse drivers both have truncated frames, so I'll likely be getting them CNC'd or have a pro do it, only because I want to get these done after fooling around with them for almost 2 years now.
Great idea... My thought was to build the box the way I did so I could go back sand it down and glue another sheet on the front and back. This way my measurements won't matter so much. I like your idea though as well.
The jasper jig that I have is plastic. So I have already made the hole larger. I know probably not supposed to but it works wonderfully that way. I can now mount a 1/4 inch bit on it. That was how I built the baffle in the picture.
Great idea... My thought was to build the box the way I did so I could go back sand it down and glue another sheet on the front and back. This way my measurements won't matter so much. I like your idea though as well.
The jasper jig that I have is plastic. So I have already made the hole larger. I know probably not supposed to but it works wonderfully that way. I can now mount a 1/4 inch bit on it. That was how I built the baffle in the picture.
That's odd. All the Jasper jigs are plastic, but yours should already accept a 1/4" bit; that's what all the incremental sizes marked on it are based off. Are you sure you're using the right mounting holes?
The jig I have accepts only about a 1/16th inch bit maybe its a little bit bigger. I have the 200 model and maybe the 240 already accepts a larger bit. Really I didn't see why I would need the 240 model but maybe that is the the difference. Either way since its plastic you can easily change that . Its odd that the one they show on here the middle pops out, mine was not built that way at all. Okay I just looked again and the center does come out with quite a bit of force... Mine must have been stuck either way yeah there is a lot more room now. To be honest I like it better with the plastic in the middle and a larger hole. It kind of keeps the sawdust from building up when cutting. So I will probably put this back in.
I hope to be finishing off the boxes today with the final baffle and have them together. Also I will be working on trying to get the measurement software setup. Do you know where the post is on Parts Express on how to use Holm Impulse? I tried to search for the thread and didn't find anything. I did find that true rta already has a generic calibration file for my microphone. So that was a find but I really need to learn how to use it from there. Also I sold my old speakers yesterday which kind of sad. I have had those speakers forever, since college days. So it was with some sadness that I let those go. That will push me to complete this however and give me some funds for my trip next week.
I have put almost the rest of the cabinet together now. I decided to brace it around the top and sides. Then also I wanted a baffle that I could remove for easy access to the crossover network. My concern with that will be vibrations and air leaks so I have some rope caulking to fit between the baffle and the front (let me know if there are other better ideas). I am not sure if that would be the best way but I do need it air tight and able to be opened. Also I have put taps in for the speaker mounts and the front baffle. Here are some pictures:
I put the speakers in to get a rough idea what it would look like. From this point I will put in the ports, do some wood filling, and more sanding of the boxes. Then they are getting primed for paint. They weigh about 27 lbs each and I still have a lot work left on the other box. I have to sand it and put all the taps in on it. I should have them both to this same state next week. Then I am off on a vacation.
Looks to be braced pretty well, put a chamfer bit on the back of the woofer hole to let it "breathe" easier, and a chamfer or roundover on the port hole will help with chuffing if there is any.
Like em! Good work bro. I used some weather stripping from the home store when I made the BR-1 cabinets for my first and only (so far) build. I wanted the speakers and the back removable, and from reading figured the rope caulk might be a pain. It seemed to work well for me. Looking forward to more pics!
So its taken me a while to get back to these. I was on vacation for a week and this last weekend was able to work once again on them. I should really rename the project, "The Bondo Box." Before you say you shouldn't use bondo on these, I didn't I happen to use a wood filler. It just smelled and act a whole heck of a lot like bondo. The wood filler also happened to come with a hardening agent and worked very well. I chose the wood filler based on the fact that it is very high strength. I didn't want to use a soft filler and have issues down the road.
I also was able to put one speaker together before the primer and port. I know that it was not complete but had to listen. My first impression is that these speakers are ultra reveling. I know that even if the cross over is off they are going to be amazing. The mid is so detailed, it got me excited to try to finish them off this weekend. I didn't complete them by any means. Here are the latest pictures though. I will be finishing these off with a ultra high gloss black. At this point I have put over three cans of high quality sand-able gray primer on them. There are some runs (hate spray cans) but those will sand out.
I have attached the initial response curve as well. Keep in mind this is without a port, poly fill or even all the screws attached. So I expect the final curve to be even smoother.
I was also missing one of the front baffle as well. Someone mentioned using a chamfer bit on the port and the back of the woofer. This shows the front port with the modification. Thank you for the suggestion.
Looks good. Seems your tweeter is about 5dB too hot, and you have a dip at the crossover point, did you sim this from OEM measurements? What did you measure with?
Yes I agree on your speculation. Also I expected it to be a lot smoother. I have used the cross over that was on post 3. Something is not quite right. I expect that the woofer will have some gain once I have all the screws in, and the port in. I don't know that I expect it to be that much higher. One question I have is that the cross over on the woofer section had a 4x2 15w resistor. I read that as two 4 ohm resistors rated at 15w. Is it possible that I read that wrong and removing one would give me that boost?
Also I measured this with holm impulse and the Behringer condenser. I know that will be a bit off and it always seems to have that dip at the 1k range. My other speakers measured had a huge dip in the same spot.
First build ever, The Scanspeaks
![$vboptions[bbtitle]](images/techTalkHeader-leftGray2.jpg)
![$vboptions[bbtitle]](images/techTalkHeaderRepeatGray3.jpg)
Reply With Quote
Originally Posted by utahsaint
. Its odd that the one they show on here the middle pops out, mine was not built that way at all. Okay I just looked again and the center does come out with quite a bit of force... Mine must have been stuck either way yeah there is a lot more room now. To be honest I like it better with the plastic in the middle and a larger hole. It kind of keeps the sawdust from building up when cutting. So I will probably put this back in. 
