# Is its necessary?



## Guest (Aug 16, 2008)

Alright, I have lurked these forums for awhile now and I have discovered very useful information. Although I haven't been sure on this:
Do I really need to dish out ~$130 for crossover parts, or can I manage with out it until I can afford it later down the road?
Right now I am planning to make a WWMT pair, which I want to have decent bass response, but not need the larger woofers. So I picked out the Hi-Vi B4N's for the Woofers and the B3N for the mid and the B1S for the tweeter, I picked them because they fit the ranges that I prefer, and are very aesthetically pleasing to myself. I decided to use two woofers per speaker for the added power handling, but I dont understand the purpose of having more than one, other than power handling.. 
I chose these small woofers only because I don't want the hassle of building huge 80-100lb speakers for my room. I listen to plenty of music so I like to have everything clear, and hard hitting bass, but sadly at night my 10" 120 watt sub is wayy too much, and I picked up a pair of 6" HTIB unpowered subs for night time listening, and paired with my current mcguyver style speakers the sound quality suffered and looked very messy. 

Now, will I need to port the B4N's or will they do fine sealed? According to PE's specs they get down to 50hz, which I am satisfied at 80hz which is what the 6"subs I have now are tuned at.. I would assume because they are so small it would be a no, but then with two of them it could be a different story... I would prefer not to port them, saves a little time and hassle of finding the right size and length.. 

My room is not that large, so they dont need to be insanely loud, and they will be powered by an old Sony DE-635, which if I remember right puts out 75 watts per channel and 85 watts max at 8 ohms.. So I am sure the 68 watt power handling of the ones I picked out will be sufficient, my current ones are only about 45watts and they sound fine even with music or movies cranked up to well above what it would take to fill my room up with sound..


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## Bill Fitzmaurice (Jun 14, 2008)

Knowsknone said:


> Do I really need to dish out ~$130 for crossover parts


I can't imagine spending more than half that much unless it includes a passive crossover from the sub to the mains, and that's a bad idea from the get go.


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## cixelsid (Mar 6, 2007)

3-ways double the crossover cost compared to a 2-way. If you know nothing about loudspeaker design you'd be better off going with someone's tested design..

These are an exceptional value for the minimal price 
http://www.zaphaudio.com/BAMTM.html


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## E-A-G-L-E-S (Sep 15, 2007)

Bill Fitzmaurice said:


> I can't imagine spending more than half that much unless it includes a passive crossover from the sub to the mains, and that's a bad idea from the get go.


I am currently pricing two-way builds and the crossovers typically run ~$30 per speaker on average.
So he should only have to spend ~$60 for two.

Bill....any links for a person looking for designs that are ~$100 per speaker?(components only, not enclosure)


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## Guest (Aug 16, 2008)

Thanks for the replies.. 
I will admit I probably dont know as much as most of the people on this forum, but this will be my third build. My first sounded impressive for scrap plywood and a 5.25" woofer with a full range 4".. But was was way too big for my liking, so I decided to use the same configuration only eliminate the 4" so then I ended in w WMT 2 foot tower, and it seemed to lack bass. Which is where I came to those 6inch unpowered subs.. My original plan required ~$130 in parts but it was because the inductors alone I needed were $19 a piece so by eliminating those thats $40 less, and of course I might not spend as much on these since the actual response ranges are much different. 
Also, my original question still stands, will I survive without a crossover for say a few months? 
I would like to also know if said picked out woofers, mid and tweeter are a good setup for what I want to do with them?

Oh and just to clarify, I am talking for the pair, not just one. Im just asking to see if I can eliminate the xo for the time being...


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## cixelsid (Mar 6, 2007)

Knowsknone said:


> Also, my original question still stands, will I survive without a crossover for say a few months?


It would be surprising if the tweeters lasted a few minutes without the protection of a crossover. 


> I would like to also know if said picked out woofers, mid and tweeter are a good setup for what I want to do with them?


Sorry to say but it's a rather nonsensical mix of drivers. There's little need for a midrange when the midwoofer is only 4" in diameter.

How about these?
http://www.partsexpress.com/projectshowcase/indexn.cfm?project=HiviJuniors


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## Guest (Aug 16, 2008)

Yeah? I assume its the lows that will kill the tweeter then.. Well from the looks of it I still dont see how $30-$60 per crossover set is realistic.. The ones I need for a 70hz high pass will cost me almost 40 per speaker alone, I still need caps for the tweeter and I think it was about $7 per cap though so no worries there..
Although, if I eliminate the 3" mid I will only need the cap for the tweeter and I should be set correct? 
Also, I wanted the 3" mid so I could cross at a bit higher than ~2500, I was aiming for 3-4k, since the 4" tops out around 3k.. 
I would a 8.2uF cap with a 5% tolerance should be plenty and it should put me around 2.7k or so right?


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## cixelsid (Mar 6, 2007)

You don't need a 70Hz hi-pass since the receiver has a built-in crossover.

Beyond that you're basically just throwing stuff at the wall to see what sticks, and that's not how loudspeakers are designed.

1st order crossovers have limited use in a situation like this...

You should take a long hard look at the HiVi-Jr design I linked to earlier. Money spent on a 2-way with a decent crossover is a better investment than a 3-way with little or no crossover.


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## Bill Fitzmaurice (Jun 14, 2008)

E-A-G-L-E-S said:


> I am currently pricing two-way builds and the crossovers typically run ~$30 per speaker on average.


You're paying too much. For a 2 way you don't need to spend more than five bucks per inductor and three per cap. You can, but you don't need to, you'll never hear the difference.


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## E-A-G-L-E-S (Sep 15, 2007)

Bill....please send me somewhere to find accomplished designs, please.
Those prices are from projects on parts express and ZaphAudio.

If I could do my X-overs for $20 each or even less I can use better components.


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## Bill Fitzmaurice (Jun 14, 2008)

E-A-G-L-E-S said:


> Bill....please send me somewhere to find accomplished designs, please.
> Those prices are from projects on parts express and ZaphAudio.
> 
> If I could do my X-overs for $20 each or even less I can use better components.


The only designs I build are my own, so I can't make any recommendations. Sorry. But where a $20 foil inductor and a $10 Aura cap are specified I can pretty much guarantee a $3 coil and $2 Dayton poly cap will work just fine.


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## Guest (Aug 17, 2008)

Thanks for the help again guys..
Yes I have gone through all of proven designs, and the only ones that caught my eye were the Hi-Vi juniors, but I wanted something a tad bit bigger.. I am mostly worried about power handling, because I dont wanna build them, then crank up some music or a movie to test them out and I blow them out. I have used just a single 20 watt full range driver and pushed it very far and never came close to its Xmax... 
Im not worried about the crossover cost anymore, I discovered those 1-4 dollar caps and inductors and I know for a fact they will never get to the 150/200W they are rated for... 
So, with a crossover will my original plan work? Or shall I still drop the 3"? 
Also, could I drop both the 1" and 3" and replace them with the B2S 2" and get a WMMW design? Im not really worried about the 15-20k range, honestly most of the music I listen to barely gets up to 16k and even then when that frequency is set to +/-12db on an EQ I really don't hear much of a difference.


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## Pancakes (Jan 16, 2008)

When designing the XO for my mains I didn't have the rig for testing impedance so I used cheapy bits and my ears. Started using an online XO calculator and the nominal imp of the speakers. I got a cap above and below the one specified and three coils so I could just unwind them a bit. The coils were spot on and the caps were later changed for good ones but I didn't notice any difference. Cheap amp and drivers wouldn't have helped there I guess but yeah, I would take music now over a theoretical perfect setup (that you will probably tweek anyway) one you can afford the bits. Get your hands dirty with whatever you can afford now and you'll be able to learn what you do/don't like for the future. Also, are you going to experiment on bits you sold your soul to buy or on easily replaced parts and you will need to experiment to build knowledge of speaker building.


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## Guest (Aug 19, 2008)

Yeah, right now I am pretty sure getting what I can afford and learning is whats best for now.. I mean I have a pretty sad setup, nothing I have really matches, minus my surrounds, and it EQ'ed on every point possible at the moment to make them sound remotely good.. So I am sure anything I can conjure up will sound better then what I currently have.. Ill just need to go slow with it for now as to not blow anything..


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## BoomieMCT (Dec 11, 2006)

Bill Fitzmaurice said:


> The only designs I build are my own, so I can't make any recommendations. Sorry. But where a $20 foil inductor and a $10 Aura cap are specified I can pretty much guarantee a $3 coil and $2 Dayton poly cap will work just fine.



I agree however I do notice (and can measure) the difference between a Dayton poly cap and an electrolytic cap.

<opinion>As to whether you should use an already existing design or not I suppose it depends on how much you want to get into the hobby. If you intend to only make one set of speakers using an existing design is okay. If you want to make your own designs or play around with designs someday you have to start somewhere and might as well start now.</opinion>


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## Mike Cason (Mar 17, 2007)

cixelsid said:


> 3-ways double the crossover cost compared to a 2-way. If you know nothing about loudspeaker design you'd be better off going with someone's tested design..
> 
> These are an exceptional value for the minimal price
> http://www.zaphaudio.com/BAMTM.html


I just finished up my new center speaker crossover design and built this crossover a couple of weeks ago. I spent about $75 bucks and had an extra 12 mH inductor and a couple of caps left in my stock, so for my one xover, my cost would be around $125 for this 3 way, 12 dB, APC crossover with good Jantzen Cross-caps and air coils. My mains use more components and resistors so are they are a little more expensive to build. 

The copper prices have doubled or tripled my cost of building good crossovers since a couple of years ago. 

There are cheap inductors too, but my time is worth a lot to me so I want to use at least an air coil type of inductor. They sound better to me IMHO. 

I agree with the other posters here. I won't throw my money away on foil inductors or AudioCaps or the other high cost caps as you will probably never hear the difference anyway.

If you don't use a crossover, the cost and time of replacing blown drivers by not using a crossover will end up costing you more because you have to buy more drivers. There are shelf made ready built units for about 35 to 45 bucks and will give you some sound, but they won't match your driver's specs and you will be missing a lot from your precious drivers.

It's all about what you want, what you expect from your speakers, and of course what you will spend to get the best sound you can get for your dollars.

Mike


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## Bill Fitzmaurice (Jun 14, 2008)

Mike Cason said:


> There are cheap inductors too, but my time is worth a lot to me so I want to use at least an air coil type of inductor. They sound better to me IMHO.


I use air cores in the signal path so long as their DCR is less than 10% of the driver impedance. There is the notion that air cores always sound better than solid cores due to saturation issues, but not when the lowered saturation point is gained at the expense of excessive insertion loss.


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## Mike Cason (Mar 17, 2007)

Bill Fitzmaurice said:


> I use air cores in the signal path so long as their DCR is less than 10% of the driver impedance. There is the notion that air cores always sound better than solid cores due to saturation issues, but not when the lowered saturation point is gained at the expense of excessive insertion loss.


Whew....that wen't way over my head! My speakers still sound fantastic as they are. It's always a learning process with audio!


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