[tortugaranger]

DSP solutions don't seem to change quite as fast as DACs, but they still change often enough that I don't know that I'd make the preconfigured DSP the only option.  Some might want to use that DCX2496 they have sitting in the closet...

DSP performed on a computer front end source component is not uncommon either.  For example, I implement the needed driver EQ for my active speakers by defining the points in RoomEQWizard and then saving a convolution filter at its highest resolution setting, which I then import into HQPlayer where it convolves the filter with the music stream, upsampling everything via poly sinc filters to my DAC's native DSD128 input rate.  (HQPlayer runs on my modded Mac Mini, fronted by Roon for the sake of its impressive interface, and I have an analog line level crossover handling the frequency splitting duties between drivers.)

Note that you may want to talk to potential customers about the amp with which they intend to pair these speakers if you don't integrate an amp.  Perhaps the impedance is benign, but +5 dB of boost at lower frequencies may put undue stress on an amp that is marginally sized, if otherwise spectacular.  Avoiding that potential challenge is one advantage to the powered speaker configuration...

Thanks for the input. All very good points worth considering. I suspect there's no "one way" that fits all scenarios here. I do intend to secure a version of the miniDSP that operates entirely in the digital domain and apply the same filters upstream of the DAC and compare efficacy to the downstream analog domain version I'm currently working with. 

Your EQ and active crossover approach sound interesting. I've not worked with HQPlayer yet. I've no doubt that DSP will eventually become the norm especially in computer based audio where it's a natural fit upstream of the analog.

[craig sawyers]

Thanks for the input. All very good points worth considering. I suspect there's no "one way" that fits all scenarios here. I do intend to secure a version of the miniDSP that operates entirely in the digital domain and apply the same filters upstream of the DAC and compare efficacy to the downstream analog domain version I'm currently working with. 

Your EQ and active crossover approach sound interesting. I've not worked with HQPlayer yet. I've no doubt that DSP will eventually become the norm especially in computer based audio where it's a natural fit upstream of the analog.

Siegfried Linkwitz came to the same conclusion.  All of his designs right from the 1970's used analog active crossovers.  Until a year or so ago, when DSP technology evolved to a level of sophistication and quality that made it the method of choice.  So the LX521.4 and LX-mini family designs all use miniDSP based algorithms http://www.linkwitzlab.com/ .  In particular they enable driver EQ that is impractical even with analog active.

I have the LX521 with analog crossover, but given the cost effectiveness of the 4x10 I might upgrade.  Need another two channels of amplification though to do that.

[tortugaranger]

In particular they enable driver EQ that is impractical even with analog active.

Not to mention passive EQ!!  I wouldn't want to attempt what I've done using the miniDSP with either active or passive. It might be doable via active but it would end up being very complex and costly to design/build in smaller quantities. Not to mention that the development time would take months rather than a few hours with the miniDSP.

I owned a Behringer DEQ2496 a few years back. It worked OK but was a real bear to configure. I had to devote hours each time just to figure out how to use it. By comparison the software that comes with the miniDSP is quite straight forward and relatively intuitive. I also think the miniDSP is much more powerful.

I've heard nothing but good things about the LX521.

I just ordered the miniDSP nanoDIGI 2x8 K which is all digital in/out. The only beef I have with it is it doesn't have USB input, only SPDIF and Toslink. I'll post an update when I've given it a spin.

[tortugaranger]

We've been evaluating the Audio Nirvana 10" classic drivers in plain vanilla 2.8 cubic feet cabinet for a few weeks now. With appropriate tuning of the response curve via DSP these drivers are really quite spectacular. Great solid tight bass and amazing detail. Sublime with great recordings and merciless on badly recorded material.

Before making a final decision we're going to also audition the Audio Nirvana 12" Super driver. The 12's should further improve both the bass and the mid range quality. Since it uses the same ALNICO magnet size as the 10's, expectations are a somewhat more relaxed and toned down upper end. Also, due to the size of this driver the physical depth of the speaker cone, we're opting for the Super model with the whizzer cone on these 12's. The whizzers will help the dispersion with the deeper cones on the 12's which might otherwise be a bit to beamy.

Once we've evaluated the 12's we'll make a final decision on driver and cabinet size.  The CAD pic below shows the prototype cabinet size with the 12's. It would be 16" wide x 17" deep x 41" tall and be roughly 3 cubic feet in volume. Oh, and the walls are 1.5 inches thick including the top and bottom. PLUS there's longitudinal X & Y bracing running internally between the driver opening and the baffle opening. A most stiff rigid beast of a cabinet that will also be a beautiful head turning piece of audio gear artwork.

[tortugaranger]

Having tried the 10" Audio Nirvana Classic in our test cabinet, I decided it wasn't quite good enough for what we are looking for. Good but not great. So we moved on to the 12" Audio Nirvana full range driver. Except this time it was the Super and not the Classic. The Supers have the whizzer cone. The concern being that with the a full range driver as large and deep as the AN12S there would be horizontal dispersion and beaming issues with the classic which has no whizzer.

Even though we only have a dozen hours on the 12" so far, it really delivers especially in the mid-bass and with vocals which just come across so naturally. We are still tweaking the response curve with a DSP to optimize the sound quality and the results are really wonderful. The 12" really projects sound efficiently and we noticed we tend to run these turned down further than the 10's. Bass is good as well.

The pic below is speaker sausage making at its finest. This is just a test cabinet and obviously not a boat hull. Note the round covers on the right side which is where the 10" drivers used to be. The 12's just wouldn't fit so we rotated the cabinet 90 degrees and made new openings for the 12" driver and port. The cabinet is 14" wide and 12" drivers only have about 3/4" room on either edge.

We are going with the 12's. Next  step is to build our first full size 3 cubic foot boathull cabinets for these 12" drivers.

[tortugaranger]

Time to give up and move on. After numerous iterations with various full range drivers of various sizes in various cabinets together with extensive listening and tweaking the equalization via DSP I've come to a conclusion and a decision.

My conclusion is that while full range drivers show promise and can sometimes hit the mark (I've owned/used them for several years now) they tend to: a)  be beamy/shouty, and/or  b) be a bit too bright, and/or c) have weak bass with the larger drivers (which have the best mids/voicing by the way) unless you use refrigerator size cabinets. Nothing unique or new about these observations if you've ever worked with full range drivers. I'd hoped to thread the needle on all those issues and find a perfect happy place where it all just fit together into something superlative. Couldn't get there. Time to move on.

Meanwhile I've just auditioned some high end Scanspeak drivers in a 2-way configuration (woofer/tweeter) using external crossovers and biamping and OMG do these sound smooth and sweet in moderately sized 1.5 cubic foot towers. The search for drivers is officially over!

Time to proceed with new 1.5 cubic foot boathull cabinets for the Scanspeaks. 

[DaveC113]

Time to give up and move on. After numerous iterations with various full range drivers of various sizes in various cabinets together with extensive listening and tweaking the equalization via DSP I've come to a conclusion and a decision.

My conclusion is that while full range drivers show promise and can sometimes hit the mark (I've owned/used them for several years now) they tend to: a)  be beamy/shouty, and/or  b) be a bit too bright, and/or c) have weak bass with the larger drivers (which have the best mids/voicing by the way) unless you use refrigerator size cabinets. Nothing unique or new about these observations if you've ever worked with full range drivers. I'd hoped to thread the needle on all those issues and find a perfect happy place where it all just fit together into something superlative. Couldn't get there. Time to move on.

Meanwhile I've just auditioned some high end Scanspeak drivers in a 2-way configuration (woofer/tweeter) using external crossovers and biamping and OMG do these sound smooth and sweet in moderately sized 1.5 cubic foot towers. The search for drivers is officially over!

Time to proceed with new 1.5 cubic foot boathull cabinets for the Scanspeaks. 

There are very few satisfying single drivers ime... Louis at Omega makes ones you'd probably like, as would Feastrex and AER, but they are proprietary or very expensive. AER drivers in Lamhorn cabinets are the best I've ever heard, but $19k retail.

Many have had good results from adding a woofer (and tweeter) to a full range driver, allowing the full range to cover most of the frequency range, say 250 to 400 Hz on up. Depending on the driver a super tweeter could be a good idea too.

[tortugaranger]

Many have had good results from adding a woofer (and tweeter) to a full range driver, allowing the full range to cover most of the frequency range, say 250 to 400 Hz on up. Depending on the driver a super tweeter could be a good idea too.

I played around with this a little as well. In the end I concluded there were better solutions that were not as costly. Most really good full range drivers are pricey to begin with given the huge ALNICO or Neodymium magnets they typically have. Add a decent woofer and tweeter plus crossovers etc. and you've paid for a whole loaf but only eating the center third plus buying two more to make up for it...and the knives to slice it all up. Ok, enough with the food analogy.   

[EdRo]

Sounds like you might have skipped the most important meal of the day.

[DaveC113]

Sounds like you might have skipped the most important meal of the day.

The midrange meal? Yep, that's important! 

IMO, full range drivers can make for amazing extended midrange drivers and the cost is well worth it, crossovers are often simpler as well. The Lotus Audio Grenada is one of the best speakers I've ever heard, but the cost of the drivers is also jaw-dropping. This is Omega's big advantage, the proprietary drivers are amazing and you get the entire speaker for less than the cost of many other drivers. If going for bare drivers AER is not cheap but they are probably the best and prices are reasonable vs Feastrex (expensive but awesome) and Voxativ (horribly overpriced and over rated) When done right and paired with a good SET amp a full range driver can make conventional speakers sound a bit dull and boring.

[JLM]

The Audio Nirvana drivers are just OK.  Their prescribed cabinets are horribly under braced and have been for years (since David Dicks changed the name of his company to get a "fresh start").

If I were going through the effort to build nice cabinets, I'd:

- Go with a design with a bit more imagination than sealed or ported.

- Consider internal and external diffusion of sound waves (an egg is probably the best shape).

- Use really good drivers (not just nice off the regular shelf drivers that lots of decent speakers use).

- Have a well designed room for them to be used in (the biggest mistake nearly all audiophiles make).

- Use materials that are acoustically inert (like synthetic resins).

- Use a swarm (search Audio Circle) of subwoofers and limit bass output of the mains to say 80-120 Hz.

[xieqiao]

It just occurred to me that traditional headphones usually have 1 driver each ear. Obviously it seems a single full range driver is more practical in headphones. If you can do one driver well, there is no need to mess with crossovers and phase and other multi driver complications. So is it correct to say that the performance of most headphones is more like that of single driver full range speakers?

[FullRangeMan]

It just occurred to me that traditional headphones usually have 1 driver each ear. Obviously it seems a single full range driver is more practical in headphones. If you can do one driver well, there is no need to mess with crossovers and phase and other multi driver complications. So is it correct to say that the performance of most headphones is more like that of single driver full range speakers?

+1.
So is it correct to say that the performance of most headphones is more like that of single driver full range speakers?
I cant say ''most'' as the cheaps but certainly a good headphone are similar to FR drivers, a great HP is much more detailed than a FR, let alone speakers with xovers.

[Mark Korda]

Hi, those enclosures sure are beautiful. When I saw the word boat hull it grabbed my eye. Andy Paynor from Rockport Maine came out with a mega priced large speaker. I can't remember the name without looking it up but it was about 10 years ago when I first saw it. It might of been the Anteries. Rockport is just outside a town called Rockland which is a famous boat town. I grew up in Maine and worked around boat yards . His 300 pound enclosure reminded me of a boat hull except it was made out of fiberglass like a modern sail boat. At first he broke into the audio field with a mega priced turntable, Rockport Technology. Being a transplant and living in Rockport I know he got that idea from his love of sailing and the idea of his enclosure by being around boats. Do a knuckle rap test on any fiberglass hull and you will understand. That speaker won awards for being the best by both Stereophile and Absolute Sound. Although using the finest drivers like Dynaudio or Scanspeak when I saw the article about him boat hull was the first thing that came to my mind as his enclosure was just that. If I'm not mistaken I think some of his help were boat builders from Rockland.....The Tortugas are beautiful! Boat hull and speakers grabbed my eye. I hope I didn't ramble too much. ...thanks Mark Korda