# Anyone willing to build Crossovers?



## mayhem13 (Feb 2, 2008)

Hey all. I've been doin DIY subs for some time now and i'm thinking of taking the plunge into DIY speakers. Want to build a new front sound stage but have ZERO experience with crossover design nor do i want to learn-my brain is too full of other stuff already. If i supplied the needed materials and parameters, could someone build the X-overs for me ?


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## Geoff St. Germain (Dec 18, 2006)

Would you be interested in building an already documented design?


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## Anthony (Oct 5, 2006)

I'd be happy to solder things up for you and make it look nice. However, so much of crossover design is trial and error. You can get a perfect design in the tools and then have it sound bad because the woofer is a little high and the midrange a bit low, or the tweeter is a bit hot.

If you use a proven design, the odds of you getting it right are much better, however, variances in drivers could still make you unhappy with the final results.

And maybe I'm a glutton for punishment, but I actually like the trial and error part


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## JCD (Apr 20, 2006)

If you want to skip the crossover design part, you can alway go active. I think most would agree that an active system will be superior to a passive system.

The obvious downside is cost -- you'll need the crossover itself plus the additional amps, but if you can afford it, it'll offer better performance.

JCD


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## JCD (Apr 20, 2006)

Another option you could do, and I have no idea how good it'd turn out, is to have Madisound design the crossover for you. Based on the price, I'd assume that design is pretty theoretical without any real testing.. but it's cheap, and it'll give you something at least "decent".

Madisound Crossover Design

Also, here's another quickie on crossover building.. 


JCD


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## Brian Bunge (Apr 21, 2006)

I'd skip the Madisound design services. Even their Thor speaker kits aren't very good. One of my engineer buddies was so dissatisfied with the design that he started over from scratch. They sound very good now!


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## JCD (Apr 20, 2006)

I didn't think the crossover was designed by Madisound but rather by Joe D'Appolito.
In fact, I thought most of the designs on their website weren't their own -- I could be very wrong of course.

Not trying to sidetrack the OP, but what didn't your friend like about the Thor?

JCD


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## Anthony (Oct 5, 2006)

Hmm, I didn't know that. That might call for some more investigation:

If the crossover was designed by Joe D'appolito, then by all means, give it a try. He is one of the foremost experts in speaker design. It still may have problems due to enclosure size, baffle, and driver variances -- but it would be a good start. If it's just designed by someone at Madisound using Sound Easy, or Speaker Workshop, then I'd wager you should just try yourself.

Again, though, crossover design is about trial, error, and measurement.


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## mayhem13 (Feb 2, 2008)

Any good books about the subject that don't require a degree in engineering??


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## 1Michael (Nov 2, 2006)

You will need the degree
I used Madisound to design the crossover for my wilson watt puppy clones and they did a fairly good job of it. Then I gave the speakers to my friend who then built a center channel with the same drivers and madisound made the xover for it. I must admit that his sytem sounds petty bleedin good now FWIW.


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## Brian Bunge (Apr 21, 2006)

JCD said:


> I didn't think the crossover was designed by Madisound but rather by Joe D'Appolito.
> In fact, I thought most of the designs on their website weren't their own -- I could be very wrong of course.
> 
> Not trying to sidetrack the OP, but what didn't your friend like about the Thor?
> ...


I'm trying to remember exactly. I know I heard them several years ago at a DIY event and didn't like them at all, regardless of the fact that Joe D designed them. They were very cold and analytical; had no bass to speak of which is mostly due to the fact that the TL is too short. 

Jim said the frequency response was far from flat, with a peak in the tweeter's response that causes the cold sound. His are actually a commercial design that were the smaller MTM cabinets similar to the Odins that he bought used (I won't mention the manufacturer, for obvious reasons) but use the exact same drivers. Both the Odins and Thors use the same xo. When he was dissatisfied with the original xo he bought the Odin/Thor xo's from Madisound. He said that they sounded "terrible".

Several people have built his updated version and like it very much. Although I never heard his before the re-design, I can tell you they sound nothing like I remember the Thors sounding a few years ago.

There's a 4 page thread on HTGuide about the re-design if anyone is interested in reading it. 

http://htguide.com/forum/showthread.php4?t=26754


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## mayhem13 (Feb 2, 2008)

Seems like DIY crossovers is gonna be outta my league sorry to say. As an alternative, what do you guys think about full range drivers like the TB titanium 4" drivers ?


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## Brian Bunge (Apr 21, 2006)

The TB titanium drivers will require some sort of response shaping filter for them to be listenable as a full range speaker. If you want full range with no filter, try the 4" bamboo TB's. I built a pair of bipole surrounds with them and tested them out as the L/R speakers in my system. They sounded very good with no filter at all.


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## Anthony (Oct 5, 2006)

Actually, you have a good idea here: start with a full range driver as an introduction to crossover design.

Full range speakers usually only need a notch filter and a protective filter to make them sound good. The protective one is usually a bass filter, designed to limit over-excursion. The notch filter is usually around the breakup node, to keep the peaks or harsh distortion from getting through.

The best part about both of these is that they can be designed using online or simple calculation tools. Still trial and error, but you don't have to match slopes, or pad tweeters, or use impedance compensation circuits, etc.

You may still want to invest in a mic to help you find out where to put the filters -- but using RoomEQWizard and posting the measurements here, we can probably help with something that simple.

Then once you get some confidence in your crossover-fu you can start trying two and three way speakers


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## BoomieMCT (Dec 11, 2006)

mayhem13 said:


> Seems like DIY crossovers is gonna be outta my league sorry to say. As an alternative, what do you guys think about full range drivers like the TB titanium 4" drivers ?


I agree with you, Brian and Anthony - full rangers aren't a bad place to start. I spent a lot of my early design time on full rangers. They are neat and are excellent for vocals but tend to not do so great on the highest and lowest octaves. 

I'd also suggest buying some cheap drivers and doing some experimenting. Crossover design seems daunting at first but with a little reading and hands-on experimenting it rapidly stops being black magic. I'd say with less than $100 in cheap drivers and electronic parts you can get a very solid foundation in crossover design which will allow you to do more complicated and impressive designs.


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## JCD (Apr 20, 2006)

You could do a line array with a bunch of inexpensive drivers. With a little judicious eq'ing, you should be able to get decently low. The high end may be a little more problematic, but depending on which driver you use, you might be able to get some decent upper octave extension too.

JCD


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## mayhem13 (Feb 2, 2008)

After much thought i think i'll give some full range drivers a try. I've heard some great things about those TB 4" titaniums so i was thinking to buy some 5" aluminum spheres and make my own gallo type drivers mounted above a ported enclosure with two 6.5" dayton woofers crossed at 150 hz.Not sure if 1 or 2 4" will be needed. Not too much in materials and at least i'll start a collection of drivers to play with.


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## BoomieMCT (Dec 11, 2006)

mayhem13 said:


> After much thought i think i'll give some full range drivers a try. I've heard some great things about those TB 4" titaniums so i was thinking to buy some 5" aluminum spheres and make my own gallo type drivers mounted above a ported enclosure with two 6.5" dayton woofers crossed at 150 hz.Not sure if 1 or 2 4" will be needed. Not too much in materials and at least i'll start a collection of drivers to play with.


A few things. First off the flange of the 4" titanium drivers is 4 15/16" so take that into account when buying the spherical enclosures - 5" may be a tight fit. Also take a look at the PE "Sphericles" for ideas on how to mount drivers into round metal enclosures. I wouldn't copy that design though - as pretty as they are I won't use a speaker with an F3 above 100Hz much less almost 200Hz. It's a pity as those 3" bamboo Tang Bands are great in ported or horn loaded enclosures. The Hi-Vi B3N's would be much better for small sealed enclosures.

The second thing is about the 150Hz crossover. Typically you want to cross over at least an octave away from a speaker's frequency range to keep distortion out. Also passive crossovers at low frequencies can get very expensive as larger caps and inductors are needed. You may want to try a higher x-over frequency.

Third having a single 4" reasonably efficient wide range driver and two 6.5" drivers may mean you need to excessivly pad the woofers to keep the levels the same. If you are married to having two 6.5" drivers provide bass you may want to look into more efficient mids - something like most Fostex drivers. 

Finally I have a question for you - if you are comfortable making a crossover for the woofers then why not try crossing to a tweeter too? Using a wide bandwidth mid means you can cross to a tweeter higher up than normal which means you can use cheaper tweeters, cheaper x-over parts and the crossover isn't in the ear's most sensitive region (1kHz - 3kHz).

Anyhoo you are on the right path and are asking the right questions. Keep asking questions, listening and learning and you will be soldering up x-overs in no time!


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## icenoir (Jan 21, 2008)

you might want to look at a digital xo like the DBX driverack pa or 260. this will let control many different things including numerous xo points and slopes etc. it will require an amp for all drivers, like any active XO. it will also be far easier to change than anything else.


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## mayhem13 (Feb 2, 2008)

Thanx Boomie. As you mentioned, the 2 woofs may be a bit much. Thats why i was inquiring about using 2 of the 4" TangBangs as well. What do you think ?


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## BoomieMCT (Dec 11, 2006)

mayhem13 said:


> Thanx Boomie. As you mentioned, the 2 woofs may be a bit much. Thats why i was inquiring about using 2 of the 4" TangBangs as well. What do you think ?


A few things. What impedence do you want the speaker to be? If you are looking of 8 ohm having two of the TB Titaniums will be tough as just one is 8 ohm. Connecting them in series will be 16, parallel 4.

Another thing is that if the titanium drivers are acting as tweeters too you will get something called "comb filter effect" if you have more than one. This is why most speakers (other than line arrays) only have one tweeter. Do a Google on it.


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## mayhem13 (Feb 2, 2008)

Thanx again boomie, these little bits of info are really helping. I've been reading up a bit on the subject and i'm gonna try a three way design with ready made x-overs. I can probobly experiment with these by swapping components trail and error if i miss on the first try.This way i can learn as i go. My design requirements are for front main towers for 50/50 music and HT in a fairly high power system. When i'm listening to music i would like to use the fronts only no sub through my sony es3200. I'm considering 2 Dayton 7" 4 ohm woofers in series ported in 2 cuft tower design.This should give me very flat response down to 40hz. I'd like to cross these at 150 hz. For HT i can then cross my sub a bit lower at around 80hz-low end should blend nicely here. At the top of the tower at 26" i'd like to mount a 4" driver in a 6" spun aluminum sphere aka B&W sealed with 1/2 of the sphere exposed on top of the cab. I will need to mount a tweeter and i'm thinking another 3" sphere suspended at 38" on center above the top of the cab-thinking the Morel neodyn dome. For starters what xover points would you suggest for the mid-highs ?


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## hddummy (Mar 9, 2007)

If I'm reading you right, you are talking about puting 12" between your mid and tweeter. How far away from the speaker will you be seated? I ask because with that kind of seperation between the drivers, I'd wager you will get some funky phase nulls and peaks between the two drivers in the xover region. If you sit quite far, it might not be an issue. If you sit up close, you'll hear it for sure. I'd recommend you bring them closer together.


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## BoomieMCT (Dec 11, 2006)

mayhem13 said:


> For starters what xover points would you suggest for the mid-highs ?


This is totally a question of personal preference (so there is no "right" answer) but for 3-ways I like x-over points around 500Hz and 3.5-4kHz or so.


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## mayhem13 (Feb 2, 2008)

Ok, so i looked at it on paper and aesthetically i can bring the tweeter down four inches for 8" of seperation between the two on center. My seating distance is 12 feet. The tweeter housing will have the ability to pivot up and down so i should be able to find a sweet spot and lock it in place. Thanks for the feedback.


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## Timelord (Oct 22, 2008)

I have experimented with ready made cross overs mostly 2 way design with great success.
First determine what cross over points are available in ready made x-overs. Then decide if these points are sufficient.

Things won't always be perfect, even if you were designing your own x-over.
The same applies to ready made x-over, it'll be trial and error depending on other variables.

Parts express sells these and I think madisound also does.
Try it out and as your confidence level builds up you can start designing your own simple x-overs.
This a hobby so have fun while learning.

Just my opinion!
:T


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