Second build - help deciding on speakers/boxes for a 3 way sealed setup

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Hello guys,

last year I finished successfully my TABAQ build, thanks to the help received from the community.

I learned a lot and I would like to progress further with the second build.

The idea is to do three ways with separate boxes and active crossover PC based with an Okto DAC:


  1. Woofer up to 120 Hz ~250 Hz
  2. Full-range from 120 Hz to 5 KHz ~250 Hz
  3. Tweeter from 5 KHz

I need your help defining the boxes and the speakers, because I lack knowledge. These are my restrictions:


  1. I like full-range sound for mids but I prefer tweeters for high frequencies. I will start with a simple WAV setup first, then eventually go for the tweeter if I'm not satisfied.
  2. The boxes will be stacked up, but I can think about doing a single sub and moving it away. I guess this will require crossing at ~ 80 Hz though.
  3. Budget per speaker, possibly below 100 €. The cheaper the better, I will compromise if I need to.
  4. I'd go for sealed boxes if dimensions and frequency response allow it. I would like to go deep to 30 Hz at least.
  5. My listening includes rock, metal, electronic, ambient and jazz.

Waiting for your advice! Thanks in advance, cheers :cheers:
 
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There is enough potential in Visaton WS line of woofers/midwoofers for a well performing set of loudspeakers. Peerless sds line of woofers(6.5")/midwoofers(5.25") and tweeters (BC25TG15-04) should be within budget.
 
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I like your thinking of using a full range as mid as much as possible into other frequency ranges as well.
Especially 250Hz-2.5kHz is an important range.

I'm using a mark audio alpair 7.3 which for most of us does not need a tweeter but I often think it might benefit ever so slightly. I'm trying to mate a seas tweeter with it at the moment but progress is slow and it's open baffle.
Others, much more experienced than me will tell you that an even smaller mark audio will smoke lots of tweeter around (like the 5.2). I personally haven't heard them.

If you're absolutely sure about wanting a tweeter, I'd buy an alpair 10 and mate that with a peerless 830668 and your choice of tweeter.

You could also try a Mark audio 5.2 with said peerless woofer as a 2-way and be very happy.

Seomebody here recently said full range drivers are a bit like wine and thus you'd have to try and see how you like it.
Some like a scanspeak 10F-xxx, some fostex, others mark audio...

You got lots of possibilities.
You probably have to narrow it down somewhat and even if it's the budget.
Oh, and look around here of you haven't already. There's lots of designs that fall into that category or could be used partially at least.
 
Thanks for your feedback guys.

Since I had the chance to listen to a pair of full range drivers (TB W5-2341 and Faital 4fe32) I loved that sound, though I always found myself appreciating tweeters for high frequencies.

I didn't have the chance to listen to anything else, so I have to rely on the community. The Alpair 10 gets a lot of recommendation in the full-range section.

Do you know of any sealed box enclosure suggestion?
 
If you want to stack your enclosures, you could also start with a smaller fullrange+woofer. If you still miss treble, just stack a third box.
Just keep distances between drivers in mind and so, make drawing for all the possibilities.
If I´d have to buy again and would do a book-shelf or floor stander, I´d be tempted to buy a Alpair 5.2 (and get by without a tweeter).
For these to reach as low as 125Hz, you might have to go vented for the mid-enclosure. (as you go active you could also just boost and make the transition smooth if you really want to cross that low which would be pushing it with that little driver and also not necessary with most woofers)

I hope Dave (planet10) chimes in; he knows lots of fullrange speakers and especially Mark Audio drivers inside out.

But as it seems you are in love with fullrange in general and pretty open.
If you liked that Tangband so much you should probably use it?

Otherwise look around here and digest for a while:
(just links to the fullrange forum, and a few random and recent threads that might give you ideas)
https://www.diyaudio.com/forums/full-range/index2.html
Mark Audio alpair 5.3 FAST / WAW enclosure size
10F/8424 & RS225-8 FAST / WAW Ref Monitor
Alpair 7.3eN/12pw WAW build
 
For C2C spacing issues you could go old school with a vifa XT25SC90-04 ... An exceptional performer for the money.

I'm also very keen on the SB acoustic SB21RDCN-C000-4, which was recently reviewed by hifi compass and is an excellent performer.

At least with a digital/virtual crossover you can try different crossover types and frequencies and see what works best for you with your enclosure/environment.

Tbh If I was committed to a propper full range driver I'd rather spend more on a larger diameter and tang band than deal with the hassle of integrating a tweeter, I've heard great things about the w8 1808, but haven't heard it in person so can't vouch for it.
 
Can you expand regarding C2C?

Sadly my understanding is still limited, so I will mostly try to squeeze as much as I can from you guys regarding the building. For the setup and crossover stage I will rely on somebody with the expertise.

As you said, probably to keep thing simple at first it would be wise to stay with a WAV setup. But I prefer to keep the boxes sealed... Eventually I can cross higher, around 250 Hz or more.

Question. Any chance to have a woofer in a sealed box that can go low to 25-30 Hz without being massive.
 
Regarding Center-to-Center spacing (CTC): With a crossover of 5k, you should aim to put your mid driver and tweeter as close together as possible. If the frames touch, so much the better.

Ideally the CTC distance between a mid and tweeter should be 1/4 wavelength, but this is almost impossible to achieve in real world. It requires an unusually small mid and a low crossover frequency between mid and tweeter.

A more achievable goal is 1/2 wavelength... however, with your stated goal of using a wide-band driver up to 5k means you will probably not be able to meet the 1/2 wavelength CTC guideline. It's just one of the compromises that are part of the process. No speaker is perfect, they are all flawed in some way. So don't get too concerned about CTC distance... just accept that your design will have a ragged vertical dispersion in the crossover region... Not the end of the world.
 
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frugal-phile™
Joined 2001
Paid Member
Someone pinged me.

With the quality of many FRs available today you have to really watch adding a tweeter, it can make things worse (because you are adding an XO and as Jim says, you aren’t going to get anywhere near the magic quarter wavelength c-c (at 5kHz you want it less than about 1.2”).

I’d also push the lower XO to the woofer up. Ideally, besides maintaining less than quarter wave c-c, you want the woofer XO somewhere between 0.707 times <BS(-3)< 1 times.

You are unlikely to have a baffle that is wide enuff to support 125 Hz.

Are you goin gto multi-Amp?

Any of the Mark Audio A7.3/7ms, P7HD, A6.2m, A5.2/3, even CHS-50 make very good midTweeters. The bigger ones can go lower. The A10.3 and A11ms should probably slot in as well, but are larger than i would use. The mono-suspension (A7/11ms, A5.2/3) are capable of more finesse midTop without 2 suspensions fighting each other.

If you really want to add a tweeter, perhaps A6.2p, A10p, or maybe A12p. Due to there more vintage (softer) top. Or if you want to play loud th elatter 2. The A12pw could also be used, but then a woofer starts to look extraneous.

We have used the FF85wKeN, stock it has some issues which the treatments work to kill… tweaked up the FF85wKeN and A5.2eN are VERY close. Stock the Faital Pro 3FE22 is in the same league as stock FF85wk, maybe near A5.2/3.

dave
 
diyAudio Moderator
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With a full-range driver you could use a higher frequency but lower order cross for a gentler blend of directivities. Not only this but if you cross higher, the audibility of issues like this begins to reduce. Not saying it will be a piece of cake.
 
I also think (with my limited experience) that crossing at 125Hz is not a good start. Maybe more like 250Hz is realistic with the added benefit to relief the fullrange driver of even more bass duties and let it concentrate on that important frequency range.

To improve spacing between fullrange and (if) tweeter you can opt for a small tweeter which is what I´m trying to do. Got a Seas TFFNC/G with a very small diameter. There are other small Dayton´s, Monacors and other drivers out there.

But as Dave said, to integrate them really well with the fullrange is difficult and might never sound as round as the fullrange on its own and indeed make things worse. I say might and I certainly wouldn´t want you discourage you.
My tweeter for example is still on and in the design but I´m nowhere near finished with it.
 
Yeah, thinking to increase crossing somewhere around 250 Hz or a little more (I updated the OP). I confirm that I'll avoid a tweeter at start. Maybe I will try to integrate it at a later time, after I'm satisfied by the woofer+fr setup.

To answer some questions, yes I will use multiple amps, class D, TPA3255.

I have read a lot about the Alpair 7MS. The price is right and I can find it in Italy. Thank you lot Dave for the insight regarding the XO, but the theory is still behind me to be able to perform calculations. Anything to say regarding a possible simple box for this driver and where to cross it? Can it be done sealed?
 
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but the theory is still behind me to be able to perform calculations.
You could also use a program like "Basta" to simulate what you want to do.
Start with a sketch and see what it might look like.
I´ve been pretty lucky with the simulation and that program; it fitted reality pretty good.
Maybe the TS-parameter of Mark Audio drivers are pretty near to the ones given in the datasheet.
This way you also get a feel for baffle effects (BSC) etc. and learn that your electrical filter is not the resulting acoustical filter.

Prepare for measuring your speaker too. I´d say it´s nearly impossible (especially as an unexperienced) to judge what you´re hearing.
I remember thinking how little treble and bass my speaker has, only to realize that "the little bump" in the mids totally imbalances the whole sound of the speaker.
If you wanna go the DIY route, aka not following some proven design, you should at least account for a Dayton IMM-6 the least. Maybe you can borrow one from a fellow DIYer in the neighbourhood.
 
actually crossing at 130hz is about perfect....its all about midrange being on one driver...its also about getting vocals all on one driver...Male vocals definitely go lower than 250hz...but I say that 130hz is perfect because....I have my 3 way crossed there and I have a 4" mid....when I crank it....I can barely see it move. So if 4" can handle it....

120hz is THX subwoofer crossover iirc

What is the Intended driver again?
 
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frugal-phile™
Joined 2001
Paid Member
Anything to say regarding a possible simple box for this driver and where to cross it? Can it be done sealed?

If you have the room i would do an aperiodic midTL. Second choice would be a dagger like (XRK) sealed enclosure. < 5 litres at 1st guess.

Between Scott & i we have dome a number of quarter and half-wave aperiodic midTLs for these already.

I will XO mine at about 180 hz, but that is a quite wide baffle. For more “normal” box-widths, 250350 Hz might be more appropriate.

Cannot suggest a bass enclosure without a. suggested bass driver. A whole lot more choice there.

dave
 
No idea regarding the woofer, so I need to rely on your suggestions again. Something that can blend well with the A7MS. Available space in cm is W30, D42, H60, so there are more than 70 liters of volume at hand, hopefully enough to go sealed. Depending on the height of the full-range enclosure, woofer's one can be taller (max combined of 90 cm).
 
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