Bought some half-way finished 3 way DIY tower speakers. Need a ton of help

Those drivers are pretty nice I bet.


Looks like he knew more about woodworking than building speakers. The spacing between the mid/tweeter is farther than I'd be comfortable with. The midrange cabinet volume looks pretty large. Don't know how well the back panel will seal up with those few screws and no foam or any "ledge" to seal onto. And I'd prefer to have more bracing. But some of the old-pros around here would know more than me.


The cabinets are very pretty though. Verry nice craftsmanship.


If the speaker spacing ends up being okay, then I think you could rework those cabinets by making the midrange enclosure volume smaller and the woofer volume larger, as well as adding a vent out the back. Put some more bracing in. Then make something for the rear cover to screw onto and make it airtight.



Quote:
Originally Posted by CZ Eddie /forum/post/18264056


Those drivers are pretty nice I bet.


Looks like he knew more about woodworking than building speakers. The spacing between the mid/tweeter is farther than I'd be comfortable with. The midrange cabinet volume looks pretty large. Don't know how well the back panel will seal up with those few screws and no foam or any "ledge" to seal onto. And I'd prefer to have more bracing. But some of the old-pros around here would know more than me.


The cabinets are very pretty though. Verry nice craftsmanship.


If the speaker spacing ends up being okay, then I think you could rework those cabinets by making the midrange enclosure volume smaller and the woofer volume larger, as well as adding a vent out the back. Put some more bracing in. Then make something for the rear cover to screw onto and make it airtight.

Click to expand...

The thing is he actually had these built by a local cabinet maker. Im guessing these were one of his first forays into diy.


How big should the midrange cabinet be? and how much bigger does the cabinet for the woofer need to be?


I would probably prefer to keep these sealed, im not going to run them with a sub for music but i dont want to rear port them simply because placement becomes pretty difficult with my somewhat confined space.


Ive had people comment about the tweeter to midrange distance, how big of a deal do you think it is? I can always cut another hole above the midrange possibly and then maybe make a big "pill" shape with the hole beneath it (its complicated so i may need to sketch it) then fill that in with something. Right now the aesthetics of the speakers are pretty important to me because of the cabinetry being so high grade, so i would rather not touch the front at all. As for bracing i guess ill glue some 1x2s in there or something.


edit: also i think ill throw a 1" lip around the rear of the cabinet and then put some gasket along the whole thing so when i screw in the back with the 5 holes it *should* be air tight



Quote:
Originally Posted by omegaslast /forum/post/18264395


The thing is he actually had these built by a local cabinet maker.

Click to expand...

Wow, then he really lost some money on this project. $600 in drivers and he probably spent at least as much on the cabinets.

Quote:
Originally Posted by omegaslast /forum/post/18264395


How big should the midrange cabinet be?

Click to expand...

I dunno. If you don't get an answer on this thread, then maybe you could post the question here:

http://www.htguide.com/forum/forumdisplay.php4?f=6

Quote:
Originally Posted by omegaslast /forum/post/18264395


how much bigger does the cabinet for the woofer need to be?

Click to expand...

Best thing to do is ask Madisound when they work up a crossover for you. Or use WinISD to model the woofer.

What you have right now is somewhere around 1 cu.ft.

Quote:
Originally Posted by omegaslast /forum/post/18264395


I would probably prefer to keep these sealed, im not going to run them with a sub for music but i dont want to rear port them simply because placement becomes pretty difficult with my somewhat confined space.

Click to expand...

How about front porting them?

Btw, If these are going to be close to a wall, then you'll want to reduce the BSC in the crossover.

Quote:
Originally Posted by omegaslast /forum/post/18264395


i think ill throw a 1" lip around the rear of the cabinet and then put some gasket along the whole thing so when i screw in the back with the 5 holes it *should* be air tight

Click to expand...

Sounds like a plan. You'll probably need to add some wood filler to the areas where the lip sections don't butt up properly to each other.




Curt C has some experience with the tweeter you want to use.
http://speakerdesignworks.com/



Btw, is that .5" or 3/4" wood? I can't tell from the pictures.



Quote:
Originally Posted by omegaslast /forum/post/18264395


The thing is he actually had these built by a local cabinet maker. Im guessing these were one of his first forays into diy.


How big should the midrange cabinet be? and how much bigger does the cabinet for the woofer need to be?


I would probably prefer to keep these sealed, im not going to run them with a sub for music but i dont want to rear port them simply because placement becomes pretty difficult with my somewhat confined space.


Ive had people comment about the tweeter to midrange distance, how big of a deal do you think it is? I can always cut another hole above the midrange possibly and then maybe make a big "pill" shape with the hole beneath it (its complicated so i may need to sketch it) then fill that in with something. Right now the aesthetics of the speakers are pretty important to me because of the cabinetry being so high grade, so i would rather not touch the front at all. As for bracing i guess ill glue some 1x2s in there or something.


edit: also i think ill throw a 1" lip around the rear of the cabinet and then put some gasket along the whole thing so when i screw in the back with the 5 holes it *should* be air tight

Click to expand...

The midrange chamber should be much smaller. The theoretical size would work out to about .1 cu-ft. I would increase that to about .3 cu-ft and use lots of foam or fiberglass damping.


The woofer section should be about 1.7 cu-ft or larger. You could cut some openings in the divider. Depending on your room and bass tastes, you could go over 3 cu-ft. At 1.7 or 2 cu-ft, the f3 will be in the low 40s, and should be more than adequate without a sub.


For a tweeter, I would find one that can be crossed very low due to the spacing between it and the mid. The Dayton RS28s is reported to be good for a very low x-over. The spacing might not be that much of a problem, but it will tend to make the listening height a little more critical. If you don't mind tilting the cabinet slightly to adjust it, then it will be less of an issue. I have a speaker that the spacing is about 9.5 inches, and it is OK. Closer would have been better though.


Here's a tweeter that is 110mm. Might be worth considering.
http://www.madisound.com/catalog/pro...roducts_id=569



Quote:
Originally Posted by CZ Eddie /forum/post/18265210


Wow, then he really lost some money on this project. $600 in drivers and he probably spent at least as much on the cabinets.


I dunno. If you don't get an answer on this thread, then maybe you could post the question here:

http://www.htguide.com/forum/forumdisplay.php4?f=6


Best thing to do is ask Madisound when they work up a crossover for you. Or use WinISD to model the woofer.

What you have right now is somewhere around 1 cu.ft.


How about front porting them?

Btw, If these are going to be close to a wall, then you'll want to reduce the BSC in the crossover.


Sounds like a plan. You'll probably need to add some wood filler to the areas where the lip sections don't butt up properly to each other.


Curt C has some experience with the tweeter you want to use.
http://speakerdesignworks.com/



Btw, is that .5" or 3/4" wood? I can't tell from the pictures.

Click to expand...

I would probably be fine with front porting it but im still a little apprehensive about cutting into the front of it with a router + jasper jig cuz it would be a big pain in the ass no doubt plus gotta buy the jasper jig. plus could screw up the finish...

Quote:
Originally Posted by kbgl /forum/post/18267157


The mirange chamber should be much smaller. The theoretical size would work out to about .1 cu-ft. I would increase that to about .3 cu-ft and use lots of foam or fiberglass damping.


The woofer section should be about 1.7 cu-ft or larger. You could cut some openings in the divider. Depending on your room and bass tastes, you could go over 3 cu-ft. At 1.7 or 2 cu-ft, the f3 will be in the low 40s, and should be more than adequate without a sub.


For a tweeter, I would find one that can be crossed very low due to the spacing between it and the mid. The Dayton RS28s is reported to be good for a very low x-over. The spacing might not be that much of a problem, but it will tend to make the listening height a little more critical. If you don't mind tilting the cabinet slightly to adjust it, then it will be less of an issue. I have a speaker that the spacing is about 9.5 inches, and it is OK. Closer would have been better though.


Here's a tweeter that is 110mm. Might be worth considering.
http://www.madisound.com/catalog/pro...roducts_id=569

Click to expand...

That tweeter can play lower than the ribbon im guessing. Also whats very low? like 2000hz?


as for the sizes of the enclosures for the woofer do you think it would have an f3 of 40hz sealed with 2 cu ft? what about 3 cu ft?


this project is on hold right now and in storage, next weekend ill take some better pictures, measure everything, and figure out exactly what modifications im doing to the cabinet.



Quote:
Originally Posted by LTD02 /forum/post/18269217


"thanks for the info. youre a real asset to this forum. pat yourself on the back."


if you want to get into it, for the cost of modifying the speakers in the o.p., a much better solution can be had. have a look at the econowave project at audiokarma. cheap drivers, cheap horn, cheap enclosure, cheap crossover...awesome performance. i have no idea how you could equal such performance given all the crossover engineering, parts, room treatments, etc. that will be required with your speakers. sorry if you don't like what i have to say, but i'd still cut your losses short and sell those to another guy and build some real speakers. maybe that is what the previous owner decided to do?

Click to expand...

i might get into this more later but you havent sold me at all.


Why are two way horn speakers so much better than a 3 way design with a nice 10" woofer, nice 5" midrange, and a nice tweeter? (Lets assume im going to actually end up modifying the front of the cabinet so the midrange isnt so far away, and possibly add a front facing port, although i still would like to entertain the possibility of keeping them sealed.)


are they objectively better or subjectively? btw these are mainly going to be used for 2 channel music, so getting speakers from gedlee (which all but the largest require a sub) makes no sense. a ported 2 way horn speaker is good and all for full range but what makes them better for music.


If 2 way horns were so amazingly better than conventional loud speakers you would think zaph audio and gravesen's webpage would be filled with them.. but they arent.

This design is almost done.


1. Get a nice 1" silk dome tweeter in your price range.


2. You don't need esoteric and expensive "stuffing". Just slap in

some polyfil from Walmart in the midrange chamber, loosely filled, but

packed. It should work like a champ and give you nice midrange

sound. Lightly fill the bass section with polyfil.


3. Have Madisound build you the crossover.


4. Crank some tunes and you are set. The resell value should be nice

if you get bored with them.



Quote:
Originally Posted by omegaslast /forum/post/18269174


So a smaller sealed box has a lower f3 than a bigger one?? hmm, thats a big confusing

Click to expand...

Assume that 1.8 cu-ft (plus or minus 10%) has the lowest f3 of 43 hz (approx.). Going bigger will gradually move the f3 up toward 50 hz. Going smaller will also gradually move the f3 up toward 50 hz. The shape of the rolloff is a little different though.


Take for example, your midrange box size. You can leave it as it is now as suggested by thylantyr, or make it smaller as I suggested. Both will work just fine. But, if you look at the manufacturers frequency response graph where it shows a nice flat response from 200 hz through 1k, the response at 400 hz and below would start rolling off earlier in the bigger box. This is OK, but your x-over requirements may change slightly to compensate for the rolloff. I think the bigger well stuffed box would actually be better for midrange quality.


A sealed f3 of 43 hz should have all the low end you want for music. If you wanted more deep bass, a bigger ported box would be needed. I didn't actually calculate the size, but likely 4 cu-ft or more. I'll run the numbers in the next day or two to confirm the size. I don't think your box is big enough to go ported.


If you can rework the tweeter hole, there are more smaller flange tweeters to chose from. Don't worry too much about the spacing, just plan around it. I have several ideas already. What is the center to center spacing?