DIY Speakers

**ironglen** · **11-12-09, 02:11 AM**

Hey, I'm trying to put together a full 5.0 speaker system for my ht and will begin with upgrading my mains, possibly front three. I'm hoping to get some feedback on the feasibility of this plan.

I've been reading this thread regarding active system design. What I really want to do is build a fully active 2.5 way TMWW using the anarchy 6.5's for the M & W in mains that can handle whole-house filling stereo for music, without being monkey-coffins.

I'd like to use the two lower 6.5's for W duties, and run them 25hz-300/400hz, using the active xover's 25hz hpf, as Kevin of DIY recommended and port them at 30hz as he did. Then use a lone 6.5" as the midrange, with a tweeter up top. Now, I have an samson s-convert to boost signal to an active crossover (a Behringer CX3400 3way, or the like). I was going to pick up a samson 4060 amp (4x60w @4ohm) to power the tweeters and mids (not sure about this idea). I have a samson 550 amp (2x285w @4ohm) to use for the woofers..

One of the concerns I have is whether the samson 4ch amp will be enough for the highs & mids. As an alternative, I could use the signal from the active crossover sent to the samson 4ch amp (bridged into 2x120W @8ohm) and drive the TM in a ~2.5khz 2 way passive crossover setup. Another concern I have is expandability, specifically, adding a nice center to this pair without having to revamp everything not too far down the road.

Perhaps there is a better way I am unaware of, but would appreciate feedback-thanks!

**evilskillit** · **11-12-09, 11:57 AM**

One thing about most active crossvers from behringer or rhane is while they can do high pass, low pass and band pass you can't really do notch filters. They'll get you pretty close, and its a lot more efficient and has better dampening than using passive crossovers but usually with that sort of equipment if you need a notch filter to tame some cone break up or something I dont think there is anything you can do about that. But it'll probably still get you to 80 or 90%. For getting the nicest sound and flattest response a well designed passive crossover would be better, either that or a purpose built active crossover complete with notch filters and everything like is used in the Linkwitz Orion.

Thats all I have to contribute at the moment, hopefully it's helpful.

**ironglen** · **11-12-09, 01:05 PM**

Hey Matt, the preliminary response of the anarchy didn't show notable breakup within this range, so I figured it would be ok. Perhaps I should look at the Behringer DCX2496 to see what it adds in the way of functionality as it is popular for this use. Anyone else have an idea or two regarding this application? Oh, and my budget cannot afford $300+ components for mains crossover duty, unless I can get it used for significantly less, maybe half that

Ideally it could handle the center as well without additional cost.

**evilskillit** · **11-12-09, 02:16 PM**

Right now I'm looking at building the Zaph Waveguide TMM 2.5way design. You might look into it, its supposed to be pretty good, as is his ZDT3.5.

I priced out the Waveguide TMM and it comes out to about $380 for drivers and $125 for crossover components so around $500 for a pair not including cabinets and misc. He also offers what he calls the minimalist crossover, which only has 3 components, I didn't price them but I bet its less than $80 for a pair. They're pretty highly regarded, have plenty of bass and play VERY loud as they are fairly highly efficient.

Tho I have always wanted to try an active 2 or 3 way, it should be fun. But I'm trying to get a really nice set of speakers for listening to keep me happy for years before I start tooling around and trying different crazy stuff.

Otherwise yeah there are plenty of people who do the active 2 and 3 way set-ups, and as I stated before there are plenty of advantages. But I haven't done enough research to know what would be the best electronics to buy, hopefully someone who has will chime in.

Zaph Waveguide TMM Project

Also this guy has plans and PCBs for active crossovers. In the end it wouldn't really be any cheaper than a behringer but it might be better audio quality and slopes. I don't know, but you can check em out, if nothing else you might learn something.

DIY Active XO

**ironglen** · **11-12-09, 03:58 PM**

Those look nice, with a different tweeter application. I love that he has tinkered with it, and posted the changes in sound: makes me want to duplicate them, so I can hear what he described, eh? Thanks for sending ideas my way!

**evilskillit** · **11-12-09, 04:08 PM**

Yeah either way you go, good luck. I'm going to build a pair of Zaph Waveguides but I don't have a lot of money to throw around so it could be a couple of months before I'm anywhere on them so don't expect anything from me soon. I'll try to post when I do work on them tho.

**Drew Eckhardt** · **11-13-09, 11:03 PM**

Quote:

evilskillit wrote:

Also this guy has plans and PCBs for active crossovers. In the end it wouldn't really be any cheaper than a behringer but it might be better audio quality and slopes. I don't know, but you can check em out, if nothing else you might learn something.

DIY Active XO

Rod's cross-overs are textbook circuits that don't provide any driver equalization or time alignment.

For most applications you'll be better off with Siegfried Linkwitz's boards.

The ASP is good for a 3-way with up to 4th order slopes, with two all-pass sections on each of the midrange and tweeter channels, level adjustments on woofer and tweeter, two notch filters for the midrange and one for the woofer, shelving low-pass on the midrange for dipole or baffle step compensation, and Linkwitz Transform or shelving low pass on the woofer channel.

http://www.linkwitzlab.com/orion_asp.htm

The Pluto boards include LM3886 chip amps and 3-terminal regulators to drive the cross-over, are good for a 2-way with up to 4th order slopes, have a single tweeter amp and bridgable mid-bass amplifiers, all-pass on the tweeter, level adjustment for the tweeter, notch filters for both channels, and a Linkwitz transform or shelving low-pass filter on the woofer. You could probably adjust the shelving high-pass filters on the power amps to be in the audio pass-band if you wanted.

http://www.linkwitzlab.com/Pluto/electronics.htm

The boards have pads for proper op-amp power supply bypassing and low-pass capacitors in the feedback loops where practical for low-pass filters with RF cut-offs.

Both are dead quiet and $100/pair.

**ironglen** · **11-14-09, 12:29 AM**

I looked at those links and while they look nice, I'm seeing those circuits costing over $400/pr, and I'm afraid the costs have gone up since this design was published. $80 just for the schematics and design notes, no parts whatsoever, and those boards along with the numerous parts on them bring the cost up to $410. I can solder as I was an electronic tech many years ago, but these will be prohibitively expensive unless I built several so the the notes cost would be spread out over more builds. I was looking at using 2.5 way (3 way), so it would cost even more than this design. I'm also not sure I would be able to change the crossover freq successfully, unless the designer had that information provided, which would definitely be needed to change the 1khz crossover to suit my build.

**ironglen** · **12-04-09, 04:48 PM**

I've finally decided on my plan. I'm going to use these bookshelf MB Quarts along with Anarchy bass bins for my front three, actively crossed and driven by pro-amps

I could use some help on bass bin design ideas

I'd like to be creative/elegant, so I could use some help as elegant is not my forte

What I've got to start: 8 of these MB Quart 2ways (for 5.1 or 7.1 use), a samson stereo 3way active crossover, and 2 samson amps: 120wx2 @4Ω and 55wx2 @8Ω. I am planning to drive a L/R pair of these MB's with the 55w and use a pair of Anarchy 6.5's in bass bins for L/R (center also, later). The MB's are 12"H, 8"W, 9"D. I was thinking of topping the bins with a 3/8" thick black/white granite tile. I also want to use the 6.5" driver size to keep them narrow and place the MB's at optimal height. The anarchy drivers need ~1.5ft³/pr and will be front ported. I have most tools at my disposal...but not a ton of money-

Any ideas?

**evilskillit** · **12-04-09, 10:03 PM**

Interesting, what made you decide on the MB Quart 2 ways?

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