How to make a good three way loudspeaker - which bargain drive units ?

[Tangband]

Goals = 100 dB at listening position with low distortion 30 -20000 Hz inroom, with two loudspeakers. The construction should be a dsp active loudspeaker with 3 power amplifiers and active crossovers.

My suggestion for each loudspeaker :

Tweeter : SB acoustics adc 26 ( crossover at 2.2 kHz 24 /dB linkwitz riley )

Midbass : SB acoustics nbac 15 ( crossover at 220 Hz 18 dB/oct and 2.2 kHz 24/dB Linkwitz riley )

Bass : two paralleled 10 inch 8 Ohm woofers from Daytons reference series , closed box with Linkwitz transformer. ( crossover at 220 Hz 18 dB/oct )

Cabinet : 110 cm high, 40 cm deep and 30 cm wide.

This is my driver suggestion of a DIY threeway loudspeaker , with good, but not very expensive drivers.

Whats yours ?

 

[Digby]

Doesn't it get expensive once you add 3 power amps + DSP though?

 

[eddantes]

I'd just look out for a some KEF drivers or bookshelf speakers on the second hand market and add a sub to the cabinet. Just need a two way dsp amp for the lowend crossover that probably would be in the 80-100hz region and simply reuse the KEF xover for the top. I guess the key is to ensure your housing of that Kef driver respects the original cabinet design somewhat to be sure the X-over doesn't need to be modified.

Why the above:

• possibly cheaper
  • used q-100 or uni-q are pretty reasonable on 2nd hand market
• possibly easier design
  • one cutout (co-axial driver)
  • x-over is ready to go
  • KEF co-ax measure reasonbly well, even in the low end designs (even though Amir didn't recommend q100 - the chart is not that bad - adding ample low-end will hide the foibles in the mids n highs)

Anyways not what you were asking for... but something I myself am contemplating for a project, should I find good (cheap) donor KEFs

 

[Tangband]

I'd just look out for a some KEF drivers or bookshelf speakers on the second hand market and add a sub to the cabinet. Just need a two way dsp amp for the lowend crossover that probably would be in the 80-100hz region and simply reuse the KEF xover for the top. I guess the key is to ensure your housing of that Kef driver respects the original cabinet design somewhat to be sure the X-over doesn't need to be modified.

Why the above:

• possibly cheaper
  • used q-100 or uni-q are pretty reasonable on 2nd hand market
• possibly easier design
  • one cutout (co-axial driver)
  • x-over is ready to go
  • KEF co-ax measure reasonbly well, even in the low end designs (even though Amir didn't recommend q100 - the chart is not that bad - adding ample low-end will hide the foibles in the mids n highs)

Anyways not what you were asking for... but something I myself am contemplating for a project, should I find good (cheap) donor KEFs

Thanks for input..
In this way the crossover for the upper midrange and treble are already fixed, - just make sure the width of the baffle are the same as the original Kef loudspeaker because the baffle step correction is calculated in the passive Kef crossover.

Going this route, I would use the Kef drivers in a closed box and make a subwoofer for each speaker ( underneath as a broad stand for each speaker ) . In this way, a simple active lowpass filter for each sub at 12 dB/oct ( polarity inverted ) is all thats needed for a fairly good integration. Better still is ofcourse to use a real LP and HP crossover, but in my opinion, - then its better to also do the crossover for midrange and tweeter in the dsp processor.

 

[Tangband]

Doesn't it get expensive once you add 3 power amps + DSP though?

Tpa 3255 modules are not that expensive , and you can buy two cheap minidsp crossovers, one minidsp for each speaker. Or use a dbx pa2 , as I did in my 3 way DIY.

 

[Digby]

I had an idea to use any commercial 2-way speakers you like and stick on top of two DIY tower bass units with 10" or 12" driver, a bit like Genelec W371A, but with only front facing driver (no fancy cardioid stuff). Then cross from 2-way to the bass unit higher in frequency than typical subwoofer (say 150hz-500hz). I don't know how good this idea is, but I bet you could make it pretty cheap (with a PA driver) and have a good deal of flexibility around the crossover frequency, as the bass unit is right beneath the two way.

Not done any DIY before, what do you think of that idea?

 

[Tangband]

I had an idea to use any commercial 2-way speakers you like and stick on top of two DIY tower bass units with 10" or 12" driver, a bit like Genelec W371A, but with only front facing driver (no fancy cardioid stuff). Then cross from 2-way to the bass unit higher in frequency than typical subwoofer (say 150hz-500hz). I don't know how good this idea is, but I bet you could make it pretty cheap (with a PA driver) and have a good deal of flexibility around the crossover frequency, as the bass unit is right beneath the two way.

Not done any DIY before, what do you think of that idea?

That way you would need both a HP and LP crossover - what you are describing is turning a two-way into a threeway speaker, a bit like ATC 100.
Many ” dedicated” subwoofer drivers dont play well above 150 Hz, one exception seems to be Daytons reference series.

 

[Ron Texas]

I had an idea to use any commercial 2-way speakers you like and stick on top of two DIY tower bass units with 10" or 12" driver, a bit like Genelec W371A, but with only front facing driver (no fancy cardioid stuff). Then cross from 2-way to the bass unit higher in frequency than typical subwoofer (say 150hz-500hz). I don't know how good this idea is, but I bet you could make it pretty cheap (with a PA driver) and have a good deal of flexibility around the crossover frequency, as the bass unit is right beneath the two way.

Not done any DIY before, what do you think of that idea?

My system is a pair of LS50's (non-meta) crossed over to a pair of Rythmik L12 subs at 160 Hz. Instead of using a single crossover the high pass is done using what is built into my Crown XLS 2002 amp and the low pass is what's built into the subs. It was not planned that way, but that's what it evolved into.

 

[eddantes]

BTW - http://www.meadowlarksings.com/index.htm - they pretty much do what you have in mind, albeit on a professional basis.

 

[Digital_Thor]

Goals = 100 dB at listening position with low distortion 30 -20000 Hz inroom, with two loudspeakers. The construction should be a dsp active loudspeaker with 3 power amplifiers and active crossovers.

My suggestion for each loudspeaker :

Tweeter : SB acoustics adc 26 ( crossover at 2.2 kHz 24 /dB linkwitz riley )

Midbass : SB acoustics nbac 15 ( crossover at 220 Hz 18 dB/oct and 2.2 kHz 24/dB Linkwitz riley )

Bass : two paralleled 10 inch 8 Ohm woofers from Daytons reference series , closed box with Linkwitz transformer. ( crossover at 220 Hz 18 dB/oct )

Cabinet : 110 cm high, 40 cm deep and 30 cm wide.

This is my driver suggestion of a DIY threeway loudspeaker , with good, but not very expensive drivers.

Whats yours ?

Definitely put that 26ADC in a waveguide from Augerpro... then it will be sooooo much easier to make it work amazing with the midrange

The KEF is also a very nice option. I'm about to mate a KEF driver from an R3 with two RS225 - maybe one top and one bottom - like an MTM. I have multi subs - so I do not need the biggest woofers for my room.

I'm also considering either building a complete aluminium baffle - or maybe 3D print it. The 3D printet baffle would be filled up with cement/glue mix to make it totally "dead" and stiff. Like this:

How many liters for the RS270?

 

[Ron Texas]

BTW - http://www.meadowlarksings.com/index.htm - they pretty much do what you have in mind, albeit on a professional basis.

I didn't see any prices, but I bet they are stratospheric.

 

[eddantes]

I didn't see any prices, but I bet they are stratospheric.

Highend drivers. A LOT of high end drivers. Hypex amps. Fine crafted woodworking. Yeah - i'm guessing you're right.

 

[Ron Texas]

Highend drivers. A LOT of high end drivers. Hypex amps. Fine crafted woodworking. Yeah - i'm guessing you're right.

Yeah, high margins and low volumes to absorb design and non production costs.

 

[eddantes]

Yeah, high margins and low volumes to absorb design and non production costs.

"Boutique"

 

[Digby]

Many ” dedicated” subwoofer drivers dont play well above 150 Hz, one exception seems to be Daytons reference series.

You wouldn't use subwoofer drivers, but PA style woofers for playback up into low mids. I reckon many 50-80 pound/dollar/euro drivers would work well in this scenario. Obviously bass won't go super low (50-60hz? -6db), but this would rely on you already having subwoofers for very low bass- as this is seen as best practise anyway, many already do.

My system is a pair of LS50's (non-meta) crossed over to a pair of Rythmik L12 subs at 160 Hz. Instead of using a single crossover the high pass is done using what is built into my Crown XLS 2002 amp and the low pass is what's built into the subs. It was not planned that way, but that's what it evolved into.

How far are subs from LS50s, any problems with bass location? It sounds an interesting setup, I bet the LS50s benefit quite a bit from being relieved of so much of the low end.

 

[Ron Texas]

You wouldn't use subwoofer drivers, but PA style woofers for playback up into low mids. I reckon many 50-80 pound/dollar/euro drivers would work well in this scenario. Obviously bass won't go super low (50-60hz? -6db), but this would rely on you already having subwoofers for very low bass- as this is seen as best practise anyway, many already do.


How far are subs from LS50s, any problems with bass location? It sounds an interesting setup, I bet the LS50s benefit quite a bit from being relieved of so much of the low end.

The subs are on the floor, around 2' from the centerline of the mains to the centerline of the subs. Partly this was done to get the subs closer to the LP making up for their higher latency.

 

[JRS]

So many excellent drivers. I love the SB Acoustics stuff and plan on building a 2 way around the Be tweeter this year. One place to get lost at if you haven's already is this treasure trove. One overlooked source are pro audio drivers--Fatail is one that comes to mind in thinking about inexpensive wideband and efficient midbass drivers. There are a bunch--I use Acoustic Elegance subs, Sound18, Eminence, JBL, and too many others to mention. Who is making the best drivers besides SBA--I'd vote Bliesma, though prices are not what you had in mind. TangBang makes some great stuff that is sourced for many DIY kits, and is affordable. The midrange drivers used in the superb Philharmonic Audio BMR's are inexpensive--like 35 apiece IIRC. Fantastic low distortion driver.

DIY sound has the largest and most varied forums. But I will always have a soft spot for the Parts Express forum--Tech Talk. Much smaller, but guys that have been doing this forever and will go to great lengths to help. You might also want to look over at Meniscus Audio--sadly they are closing the doors and are in the process of liquidating inventory.

 

[Timcognito]

June Sale 25% off components

Meniscus Audio is coming soon

We are doing some work on our site. Please come back later. We'll be up and running in no time.

meniscusaudio.com

 

[alex-z]

Paul Carmody's DIY Speaker Pages - Pit Vipers

Home > Floorstanding Speakers > The Pit Vipers

sites.google.com

The Paul Carmody Pit Viper is one the best executed cheap 3 way designs IMO. Only major thing I would suggest changing is putting a waveguide on the tweeter to fix up the diffraction.

Although it would be interesting to the swap the DC130-4 woofer for the new SIG150-4. $20 extra for a nicer basket, lower inductance, and supposedly Klippel tested for BL symmetry.

Home

Dayton Audio SIG150-4 5.25” Signature Series Woofer 60W Driver 4 OhmDayton Audio SIG150-4 5.25” Signature Series Extended Range 60W Driver 4 OhmThe Dayton Audio Signature Series was designed to give speaker designers access to the pinnacle of speaker technology at the value expected from Dayton...

www.parts-express.com

 

[badspeakerdesigner]

Paul Carmody's DIY Speaker Pages - Pit Vipers

Home > Floorstanding Speakers > The Pit Vipers

sites.google.com

The Paul Carmody Pit Viper is one the best executed cheap 3 way designs IMO. Only major thing I would suggest changing is putting a waveguide on the tweeter to fix up the diffraction.

Although it would be interesting to the swap the DC130-4 woofer for the new SIG150-4. $20 extra for a nicer basket, lower inductance, and supposedly Klippel tested for BL symmetry.

Home

Dayton Audio SIG150-4 5.25” Signature Series Woofer 60W Driver 4 OhmDayton Audio SIG150-4 5.25” Signature Series Extended Range 60W Driver 4 OhmThe Dayton Audio Signature Series was designed to give speaker designers access to the pinnacle of speaker technology at the value expected from Dayton...

www.parts-express.com

I made these, but with some modifications that I thought I could work around, namely moving the drivers around on the baffle. While I speculate that my placement may have resulted in the stock xover not really working, I still find that the integration it offered would still have problems (designer is still using xsim). They mostly measured pretty flat in room, by that I mean they're tuned way too bright. I felt imaging was poor which makes sense with the driver combo, so I swapped the d27 for an nd25fw and found that to be a pretty big improvement. I also ditched the passive xover which sucks to eat the cost on (I may attempt my own passive xover with some of the parts) and have been really enjoying the ease of use and results of active xovers. I mean dang after being able to quickly test filters and add time delays, idk if I'd ever be happy with a passive integration.

I've also toyed with tossing a bmr tebm46 as a mid and it does the job well, I'm 3d printing a little mount with shallow flare for them as I was more pleased with their sound than the dc130, although that driver seems like it's pretty dang good. Honestly if you've got active xover capabilities it seems you can make a lot of drivers work fine. If one can work out a passive xover for the sd315+dc130+nd25fw, then it'd be one of the best values in diy imo. The dynamic capabilities of having two 12" woofers in front of you can't be understated. The mid range not giving up or suffering from IMD with bass is lovely.

Dayton SIG looks interesting, wish it were just slightly smaller overall then it could be a drop in fit for my dc130 route. Not like I need anymore drivers to play with though.