3 Way crossover details...

[Lambo240z]

Hi all, I am new here, but I have been reading a lot of stuff over the past 3 weeks trying to learn as much as possible for my project and I have seen there are lots of very knowledgeable people here so here goes my question.
I already have the speakers for the 3 way I am doing, they are not the perfect match, but they should be good enough since I am not an audiophile that is looking for perfection but simply something that sounds nice and can shake the room if need be without distortion.
The speakers:
Woofer: Peavey Black Widow 15028 ( 15" )
Peavey.com :: Low Frequency Drivers
Midrange: Dayton PK165-8 ( 6" )
Parts-Express.comayton PK165-8 6" Professional Kevlar/Paper Cone Midrange | 6" woofer 6 inch woofer midbass driver pro sound sound reinforcement PA
Tweeter: Dayton PT2C-8 Planar Tweeter
Parts-Express.comayton PT2C-8 Planar Tweeter | tweeters pt2c-8 planar tweeter ribbon tweeter dayton audio dayton loudspeaker dayton DayAudiTweetWoofMid050109

I also have a subwoofer that can take care of the really low frequencies.

So, they might not be the perfect combination but at least the frequency ranges intersect pretty good for crossovers in the 400Hz and 4000 Hz to keep the most important vocal range in 1 single speaker (as I have read that it is important)
Now, the question is, what do you guys think would be the best crossovers to use that will not cost me more than the speakers
I have 2 choices so far:
2 of these: Parts-Express.comayton XO3W-500/4K 3-Way Crossover 500/4,000 Hz | crossover speaker crossover crossover network lc network 3 way crossover daytoncrossovers-10408 2w3wcrossovers090109
Or this: Parts-Express.com:Behringer CX3400 Super-X Pro Crossover 3-Way/4-Way | Crossovers crossover 3-way crossover 2-way crossover active crossover

Is there any benefits from one over the other because one is passive and the other active I think?
Any other important things I have to look into?
By the way, I haven't done the cabinets yet so I am open to suggestions regarding the type, being vented or closed.
I kinda like the closed ones because of a more punch in the low frequencies but I dont know that much so I could be wrong and also with those Peaveys, I am almost sure I will have a good punch one way or another.
Thank you very much in advance for any help.
Leo

[PeteMcK]

pre-built passive crossovers are sacrilege 'round here, for the good reason that there's no way they'll match any given set of drivers properly - they need to be tailored for the individual drivers you're using.

Active crossovers give better sound, but will require more amplifiers...

[wintermute]

Have to agree with PeteMcK on that one (as I think pretty much everyone here will do). Having been down the path of off the shelf units myself, if you haven't seen it, have a read of this post I made on another thread about my experiences. If you don't have the option of designing the crossover yourself (since you have already bought the speakers) then the active route will probably give you more flexibility for modifying the sound to your liking (but will no doubt be a LOT more expensive than the off the shelf unit that you linked to), but even with active, to get it "right" you will need similar tools to what you would for designing a passive crossover.

You could consider getting the off the shelf unit as a stopgap so you can listen to something now, until you have the knowledge and equipment to design a proper crossover yourself. I'm suggesting that since you have already purchased the drivers, otherwise I'd suggest reconsidering and do what most suggest, and build a proven design Not that I can talk

Tony.

[Lambo240z]

Ok cool, thanks Pete. By more amplifiers you mean more power or Bi-amping ?
I have a typical home theater receiver ( I know that is not the best solution power and quality wise ) but could maybe think into the bi-amping scenario if it was not too expensive.
If it gets to be too expensive, then I will have to solve it in another way for the time being unfortunately until I get the money to do better.
Leo

[Lambo240z]

Thanks Tony. Then the active crossover will have to do for now until I have the knowledge to do it myself.
As I ask in my last post (that should show before this one but I dont see it yet I wanted to know what are the options for the bi-amping, money wise. Is there something I could buy/build that will not break the bank?
Thanks.
Leo

[Inductor]

Another possibility is this xover from Peavey ECS 3X (500 Hz/2500 Hz)
Peavey.com :: Crossovers
that has EQ and attenuations built-in, that can help with a primary set-up, before getting more complex adjustments or a definitive xover.

[PeteMcK]

re: 'By more amplifiers you mean more power or Bi-amping ?' - using active crossovers, the crossover comes before the amp and you have an amp for each driver. You may be able to do this if you have enough channels in your HT amp.

[ThorstenL]

Hi,

Originally Posted by Lambo240z

I already have the speakers for the 3 way I am doing, they are not the perfect match, but they should be good enough since I am not an audiophile that is looking for perfection but simply something that sounds nice and can shake the room if need be without distortion.

Hmmm.

Maybe next time spend more time researching before buying...

Here is why:

Originally Posted by Lambo240z

Woofer: Peavey Black Widow 15028 ( 15" )

SPL ~ 99dB/W/m & Fs ~ 50Hz. This will go loud, but not low.

Originally Posted by Lambo240z

Midrange: Dayton PK165-8 ( 6" )

SPL ~ 93dB/W/m. Your midrange will be 6dB quieter than your Bass/Midrange. In other words, it is useless in a passive system, as you would have to attenuate the woofer by 6dB.

Originally Posted by Lambo240z

Tweeter: Dayton PT2C-8 Planar Tweeter

SPL ~ 94dB/W/m. This will match the midrange okay.

Originally Posted by Lambo240z

So, they might not be the perfect combination

You can say that again. Either your Woofer is completely inappropriate for the Midrange and Treble, or the Midrange and Treble are totally inappropriate for the woofer.

Originally Posted by Lambo240z

Now, the question is, what do you guys think would be the best crossovers to use that will not cost me more than the speakers

As the others have said, probably nothing off the shelf.

You could get away (it won't sound great, but it will work okayish) using a passive first order crossover at maybe 4KHz between Midrange and Tweeter. A 2nd order active crossover at around 200Hz would probably be a good idea for LF and MF.

But you need an active crossover and likely some equalisation to get a sensible match to Midrange and Treble out of that woofer. If you do that anyway, you might as well invest into a 3-Way Digital Crossover that allows you you to drive the system 3-Way active with EQ.

An Example that is also well supported for modifications to improve sound quality much is the Behringer DCX2496. Using such a crossover means you need three seperate stereo Amplifiers to drive the system, you would still need two if you use a passive crossover between midrange and treble and only active to the woofer.

However, any active system, even buying very cheap Amplifiers (eg. cheap Alesis or Behringer Studio Amplifiers) gets expensive quickly. On the plus side it would offer good flexibility and an almost guarantee that you can get good end results (if you make sure you can measure the results).

Originally Posted by Lambo240z

Any other important things I have to look into?

You will also need some measurement setup to actually be able to get good results. I would say that if you can take measurements outdoors you can probably just use a so-called RTA (Real Time Analyser) which is quit easy to use and interpret. Indoors you need to grips with a system that uses something like MLSSA which are harder to use and interpret, as it behaves differently and tends to show more artefacts related to the measurement process.

Originally Posted by Lambo240z

By the way, I haven't done the cabinets yet so I am open to suggestions regarding the type, being vented or closed.

You may wish to look up a project by Dick Olsher called "BassZilla" for some inspiration.

The Midrange you may wish to try on on open baffle, or with an open-backed box.

For the woofer you probably will have to use a vented box to get any sensible LF Extension. Try for a system that is called EBS6 (Extended Bass Shelf 6dB). Susch a system requires a large box but allows very low tuning. At the tuning frequency such a system is normally 6dB down compared to the midband.

As the so-called "room gain" (this is a living rooms version of cabin gain in car audio) will usually give around 6db boost at 30Hz compared to 100Hz (note, this is an average of many rooms, individual rooms vary) such a system usually produces a clean and punchy but low reaching bass, sounding more like a sealed box (clean, punchy), but with the extra LF output/extension the vented system provides.

As you have enough efficiency from the woofer you add some extra qualisation and likely get rid of any need for a subwoofer.

Ciao T

[PeteMcK]

Driver selection - I got a chance to look at the driver specs, sorry but it ain't good news: The Peavy woofer is a PA/guitar mid bass speaker & won't do that well a the low end by themselves without a huge ported cabinet, at least 120 litres. If you can EQ the low end then it is good in a closed 37L box. But if your sub can handle from 80Hz down, then 60L boxes tuned to around 65Hz looks OK.
The mid has break up peaks from 2KHz, & while the tweeter shouldn't really be crossed over below 4KHz, you may be able to get away with a 3rd order xover at 2KHz.

[Lambo240z]

OK, thanks everyone for the comments and words of wisdom.
Yes the Peavey speakers are a little out of place in here but I had them for some time and just wanted to use them and not let them go to waste.
The sub I have should be able to pick up the frequencies under 80 Hz so I would need the Peavey to go from around that area and up to maybe 400? That hopefully should make the size requirement of the cabinet smaller.
Also I am ok by attenuating the woofer by 6dB since I couldnt find a midrange or tweeter that had that level of dB without spending more money that I wanted to.
Also the tweeter is already on the way but the midrange I can still stop the buy if there is something better under $50 that you guys can recommend.
I dont know if its better to have just the woofer stand out from the rest with more dB or the tweeter alone with less dB?
ThorstenL, the frequency for the crossover on the woofer/midrange you are saying that should be around 2Khz, but could it be at around 4Khz since the 2 drivers allow for it and since I read everywhere so much about trying not to have any crossovers in before 4Khz if possible? Is there a reason to do the 2Khz cross?
PeteMcK, regarding the midrange having the break up peaks in the 2Khz area, will it be so bad that I will have to cross it lower like you said?
If there is another midrange driver I could use to get rid of the problem of the dB and break up problems please do not hesitate to suggest.
Thank you very much for your input again guys.
Leo