DIY Bi-Amped Super Speaker System, and some passive super speaker ideas.

Can a simple $2.5 K to $6K DIY speaker sysem completely sonically destroy $50000 stereo systems?  When I say system....I mean DAC, preamp, amp, speaker wires and speakers.  I believe it can.

Here is what is wrong with most $50K systems.....

1. First, most speakers are not made to all out standards.....and even if they are they still have passive xover parts that rob the music of directness and clarity (no matter how much money is in the xover parts, jacks and wires).  Coils especially.....used on midranges and woofers....are not good sonically.  The coil on a typical midrange is over 60 feet of wire (and not even great wire, at that....even in Copper foil wax coils).  Also most speakers are in boxes and those boxes have resonances and colorations.  You also don't get the extra openess you can get with open baffle speakers. Many speakers are not time aligned.....so the tweeter sounds hit your ear before the mids and lows.....so they are not as focused and image as good as they could if they were.

2. Because the woofers are not being driven directly by the amp...the damping factor is not great....so the bass is never as dynamic compared to direct drive systems.

3. A regular system is not equalized.....and room corrected.  So that means the bass always has room nodes and it takes tons of work to make the speaker work in different rooms and environments.

4. The woofers in a normal system have back EMF......when the driver goes backwards it makes voltage and that voltage goes directly into the xover and back into the midrange and tweeter.  This is why bi-wiring and especially bi-amping work better......more clear.

5. Normal systems have tons of components and cables.....every component needs a great stand/footers and a great power cord.  The more amplifying devices the signal goes through......the more the signal is degraded.

So, what is a better idea?  Here goes:

1. Completely open baffle for best sound.
2. Dead baffle and stand
3. Super drivers.
4. Electronic xover....so no passive xover and now you can equalize and room correct.....FLAT bass to 30hz at your listening positon!!!!.........and you can time align the mid/'highs with the woofs...important!
5. Just a two way Bi-amped system.....so not so complex.
6. Use of modified digital amps with a pure digital xover (so no preamp or DAC needed).....or optionally use a digital xover with analog outs so you can use any analog amps (more versatility but longer signal path).

Here are the components and cost for the digital xover with analog out version:

4 Beyma 12 inch woofers (12BR70)....$155 each from US Speaker  $700 delivered.

8 GRS planar midrange/tweeters ($50 or $60 each) depending on which one you get  $500 delivered.  $150 if you use just one mid/tweet per side....Parts Express sells these.  You could substitute 4 $329 10 inch Radian Planars (8 total) for even better sound....however price goes up to $2600 for the mid/tweets.  You can use one Radian per side and it would be just over what the 4 GRS planars would cost.  You can start with one of either mid-tweet and upgrade to a full line source later.

1 Mini-DSP Flex.  $500 or $550 for the balanced out version.....add a $150 LifePo4 battery to power the xover for superior sound and you get $700.  Optionally, you can use the more versatile Minidsp SHD that costs $1300.

1 Fosi V3 amp with optional 48V supply  $150  This amp is for the woofers.  If you already have a bass amp then you do not need this.

Plywood and MDF for baffle and stands..........$300

Wire.......$200 for great hook up wires from amps direct to drivers.

You use your current amp on the planars.  Total....around $2700 or $2400 if only using one mid/tweet per speaker.  Add $700 if using the Minidsp SHD ......add $2000 more if using 4 Radians per side.

For those that already have a great DAC......you can buy the digital only Minidsp Flex or SHD and use it with two external DACs for even better sound.  Use your super DAC on the mid/tweets and use a cheaper DAC for the bass.  This is the ULTIMATE analog based two way speaker

These woofers are the same as what Spatial Audio uses in their $9800 X4 Ultra open baffle speakers (also used in the Caladan speaker) but they have coils and junk in front of them.  You have no binding posts....no extra wire....nada.  The GRS midrange planars are copies of the B&G drivers....no longer available.  The Minidsp is used as a DAC also......so you do not need a DAC.  The volume control is also in the Minidsp and you have a remote that does volume and you can select 4 preset eq settings on the fly.  The DAC in the Minidsp flex is very good and you can also buy the Minidsp SHD which uses an even better DAC and it is also a streamer and has both analog outs and digital outs (and analog input for you turntable folks)......for super flexibility ($1300)....this is what I would buy. The Audiophile Junkie (Youtuber) uses one of these SHDs in his super system.....and he has heard a lot of serious systems.  He loves it.

Here are the components and cost for the pure digital xover using modded pure digital amps version:

Same woofers, planars, wood and wire....except you need two digital coax cables to go from the xover to the digital amps.

You can use the $500 MiniDSP Flex (digital out versions) or the Minidsp SHD $1300.

2 modified (by me) Peachtree GaN 1 amps (200 watts a channel fully digital using GaN output devices...basically powerDACs).  Each amp is $1300 delivered and my mod is $500.....so $3600 plus shipping to you for both amps.  You would place one amp directly behind each speaker with short wires going directly from the WBT binding posts on the amp to the drivers. Total.....around $5850 add $700 for Minidsp SHD....add $2K for substituting the 10 inch Radian drivers

The pure digital version would be super transparent.  However, even though you can equalize it....you cannot really "color' the sound like you can with an analog based system where you can use tube preamps, tube amps and tube DACs.  Me, I want the pure transparency of the pure digital path.  Listening to a single modded Peachtree GaN1 right now driving my simple two way custom speakers (no xover on the woofer and just a cap and resistor on the tweeter). Incredible sound!

Do you want to go totally crazy?  How about 6 12 inch woofers on a separate baffle wired in series parallel and next to it you have 8 eight inch planars in series parallel.....62 inch line source of mid-tweets and a 72 inch line source of woofs.....OMG....it would cost you about $2K more.  Still practically nothing.  Imagine the scale and low distortion from such a line source.....OMG x infinty.  Would knock some plaster off the wall.....he he.

So, how do I make these amazing things?   Please show me......Of course, you can use your imagination and come up with your own ideas.....but here is an idea from me:

1. Main baffle would measure 18 inches wide and around 45 inches tall if you are using just one mid/tweet.  The baffle would be around 65 inches tall if using the 4 mid/tweets in series parallel....all mounted vertically on top of each other.  You can see a pic of the approximate size on the Spatial website....the X4 is 45 inches tall and uses the same 12 inch woofs I suggest.  I would mount the woofers closer to the floor when using the 4 mid/tweets so the baffle is not so tall.  I would use three layers of three quarter inch plywood and mdf sandwich....hardwood plywood on the front, mdf in the middle and regular plywood on the back.  If you can afford hardwood on the front and back...it would better yet....but baltic birch or other very hardwood plywoods are spendy.  You would want a solid base made out of the same contruction.  The drivers could be flush mounted or just mounted from the front for an easy fast trial.  I would put a felt strip one half inch wide around the tweeters on the front.  The opening for the mid/tweeters should be angled back in the rear at 45 degrees so the back wave does not go through a tube.  I would also mount some thin felt on this 45 degree angled back.  If you are doing a version where you have a separate baffle for the 2 12s and are mounting a shelf on top to try various drivers...then the main baffle would be around 36 inches high including the base mounted on the bottom.

2. The woofers are wired in parallel and if using 4 mid/tweets they are wired in series parallel.  Easy to find a pic of that on line.  If you can...please wire your woofer wires directly to the voice coil wires....rather than soldering to the tabs....never use push on connectors.

3. I recommend you start with a 400 cycle xover point and use 24 db per octave if using active xovers.  Of course, you can play as you like (some like to use 48db per octave with planars).  Once you have downloaded the software for the xover and hooked up your measurement mic (either comes with the xover or you buy a separate one) then hook up the system and measure it using pink noise (using one speaker with the mic about 3 feet away from the speaker).  Adjust the levels of the amps so they are basically the same...and then start to do eqing to make the speaker flat.  This is not very hard.  Even if you have never done this before.....you can do this whole thing in a couple of hours max.  You measure....and it shows a dip or rise in frequency....and you go into the software and compensate for that rise or dip.....then you re-measure.....and keep going till you have the speaker reasonably flat and extended to 30hz.  Then copy what you did on that channel to the other channel.  Sit back and enjoy.  After a while you can play with delaying the tweeter. This is explained in the Minidsp manual.

All it takes is a table saw and a hole cutter....pretty simple.  Those with no skill could have a local woodworker put these together very simply.....and you could get someone to spray them with super paint, if you like.  If you have the tools and space you could make a crude version in a day and be listening the next day. Just use one layer of normal plywood on the front and green glue it to some mdf on the back (after making the holes)....then make a base and wire it up and fire it up.  Once you have played with the settings and did some felting and moving the speakers around and your hair has settled down on your arm.....yes, you will be getting goosebumps!.....then you can plan your good looking all out assault.  All of this is very simple.....even a 10 year old could do this (with supervision....if they do not know tools).  Soldering is necessary unless you want to use the sonically worse push on connectors.

Here are some other high frequency driver options:  You can use one 10 inch Radian Planar driver.  These cost $329 each so about $700 delivered.  Super low distortion but somewhat limited horzontal dispersion and very limited vertical dispersion because the driver is so wide and tall.  If you listen in one spot then they will work incredibly.  Using 4 in a line source would allow you to stand and still hear full frequency response plus be a lot more dynamic and lower distortion.

16 one inch Titanium drivers in a line source. These Aurasound drivers, I believe, are used in the $30K Note speakers by Mark Porzilli...who says his new speaker is better than his Pipedreams and his Scaena line source speakers (raved about by Harry Pearson and others)....the Note uses 48 drivers in a line source.  Do a search.  16 of these drivers per side would make a 24 inch line source.  The 32 drivers would cost you about $550 and would be at least 90 db sensitive.  Of course, you can spend twice as much and do a 32 driver line source (that is a lot of wiring...he he). The advantage of these drivers is that they would have super horizontal dispersion because they are so small.  16 in parallel would play....very, very loud....remember they are only playing from 400hz on up.  You could mount them on an open baffle along with the 12 inch woofs....and put lots of felt around the entire front baffle above the 12 inch woofs.....incredible sound.

Another option would be to use a Minidsp with digital outs and run it into two even better DACs. Use the better DAC on the mids and highs and a cheaper DAC on the woofs.  The DACs in the stock latest Minidsp units (Flex and SHD) are very good but not the best.  The SHD has both digital and analog outputs.

These speaker systems will be so transparent and dynamic and image so well.....your marriage is going to suffer.  You will never want to stop listening.   Call me if you want more info or help. See links below.

 

 

DIY Clayton Shaw Caladan Speaker and other passive speaker ideas

The Caladan speaker is so simple, that it is easy to DIY a pair that is sonically superior to the original.  If you use better xover parts, better wire, a better baffle and use felt around the tweeter you will get superior sound.  You could also try time aligning the tweeter by mounting it on a separate baffle above the woofers.  More on this below.  The Caladan uses the same woofers as discussed above.  It runs two in parallel with a 12 db per octave xover at 1K hz (a coil in series with the signal and a cap to ground).  The tweeter is a Dayton Audio tweeter (link below) that has the same sensitivity as the two woofers so there is no need to pad the tweeter with a resistor.  It is also crossed over at 1K at 12 db per octave (a cap in series and a coil to ground).  

All the speaker ideas on this page are based on two way speakers using a pair of 12 inch woofers on an open baffle (or a larger separate baffle with 4 or more 12 inch woofers and another panel with planars, or whatever mounted on it).   If you build a baffle with 2 12s on it and mounted a shelf on top of them you could try various mid-tweets or tweeters in combo with the bass units.  You could play for years....and for very little.  Let's look at some of the various possible options:

1. A Caladan clone using the exact tweet that the Caladan uses.  By mounting it on a separate baffle above the woofs you can push it back to time align it with the woofs (putting felt in front of the tweet on the top of the shelf to kill the reflections).  This is passive xover speaker version (non biamped)

2. Use a single GRS 8 inch planar ($50-60 each) on a separate open baffle above the woofs. I would first try it without a cap on the planar because on an open baffle the planar will roll off by itself at 300hz.  If you play really loud then a cap in series (100uf?) would be necessary to protect it and lower distortion. The woofers would just have a coil on them (2mh?).  This could be killer and really cheap. The planar and the two woofs in parallel have almost the same sensitivity so you would probably not need a resistor in front of the tweeter.  We are talking  $1200-$1500 dollars for all the drivers, wood and everything.  Would compete with most $10K speakers and is 93db sensistive and easy to drive   This is just so easy and so good.  This is simply incredible!!!

This is so easy to do!!!!!  Go to Home Depot and buy a 4'x8' sheet of 3/4 inch Oak plywood and have them cut the 4 pieces for the front panels (18x30) and the four pieces for the bases (18x12).  Two layers of 3/4 inch ply used everywhere.  Mark where the holes go for the woofs and cut them out using a jigsaw.  Get two tubes of Green Glue and put in between the layers and screw together with screws......mount the drivers and the bottom plate and wire it up......add feet to flavor.  Mount the planar on a small baffle and cover the front with felt and felt in front of the planar baffle on the top of the front panel.....Put the coil in series with the woofs (wired in parallel) and wire the tweet....turn it on and listen....come on.....it could be done in one day.

3. A single Radian 10 inch planar ($329) mounted on a separate open baffle above the woofs and again crossed over around 400hz.  You might have to use a notch filter to tame the rising highs....but otherwise you might be able to get away with no xover...or just a cap in series to for protection.  Again almost the same sensitivity on the tweet and the woofs.

4.  4 GRS or Radian mid-tweets on an open baffle above the woofs and set back for time aligning (the same as the first 3 mentioned).  These would be wired in series parallel and would need a resistor in front of them to pad it down to match the woofs.   

More to come.

Below is a pic of someones speaker using one of the $50 GRS 8 inch planars on a separate open baffle on top of an open baffle cabinet (no back on this thing) with two $20 12 inch woofs.  With two 12s on a simpler open baffle it would take you one day to build it.......MIND BLOWING!!!!

Below are two pics of baffles I had stored in the Barn.  I made these years ago for two 12 inch servo woofs with mids and tweets above it.  I cut off the top and put a shelf on it.  These baffles are what I will use to make my speakers.  These baffles are made from 3 3/4 inch pieces of highly refined MDF with Green Glue in between the layers.  The brace is made from the same thickness of plywood.  Pretty dang rigid.  Two layers would be fine....maybe hardwood plywood or hardwood for the front layer and then highly refined MDF in the rear.  The top shelf was just an afterthought.....you can make something that looks way better.


2-13-2024 :  I have the $50 planars here and the 4 Beyma woofs have been ordered.  In about a month I should have it all tuned up and ready to go.  If it sounds as good as I think it will, I will open my place here to serious DIYers (bay area) and they can bring some tunes and hear what is possible.  2-16-2014: ....woofers arrived today.... pic of a woof and a tweet to the right.

Wild Fosi V3 amp mod....he he. 

4-14-2024:   I needed a new amp for my system and a friend had sent me a Fosi V3 to play with......so play I did.  The Fosi amp is loved stock my many and you can upgrade the opamps to better ones for even better sound.  Well........I went crazy with the thing:

Changed the stock 32 volt cheap 5amp supply with 20 gauge power supply cable and connector to a 1200 watt 42 volt Hypex Power supply.  I am also using the plus and minus 12 volt from this supply to fire up my custom input stage.  The power supply is mostly hardwired from the power supply to the boards using cryoed OFC foamed Teflon wire from VH Audio. 

I removed the pot and power indicator LED and the entire input stage and have created my own differential input stage suing modded Sparko Labs SS3601 op amps.  This stage is fully balanced.  I run directly from my DACs output stage (PCOCC Litz wire interconnect hardwired inside the DAC) and use the digital volume control in the DAC.  I set the gain in the DAC and the amp input stage so I use very little of the 32 bit volume control in the DAC.  The only coupling caps are 1uf modified Wima caps that the amp module requires.  The input op amps are mounted off the board on tiny wires and damped using contrained layer damping material (very little amount).  The power supply is bypassed by Elna Silmic caps that have small damping pads on them.....bypassed by .33 uf modified Wima caps.  The input wire from the xlr jacks is cryoed Mogami and the same wire is used from the input boards to the amp board.

The output stage filter caps are changed from the steel leaded Wima Polyester caps to modified Wima Polyprops that are put in the correct direction (outside foil to ground). 

The output wires and input AC wire is 14 gauge cryoed OFC in Teflon foam....from VH Audio.  Output connectors are my plastic clamps (worlds most pure connector.....none....just a clamp!

The parts are mounted? on a piece of chipboard taken from a 3 ring binder.  Should I sell these amps?.....he he.....you want one?

This amp is giving me the best sound I have ever heard with my DAC based system.......simpy amazing the amount of detail and purity this cheap thing (with a ton of mods) can do. 

This amp idles at 14 watts.....and that includes the 9 watts idle of the power supply.....crazy effecient.  I run my whole system on an inverter which shows the current draw.  My entire system (transport, DAC and amp) draw 32 watts total. 

Future mods.  I am going to add modified Sparko labs regulators for each input stage and buy another Fosi V3 and make the amp more dual mono (you can buy a Fosi V3 without power supply for $63 delivered from China).  More to come.

Now that I have the amp and my system sounding great I can bring in the open baffles and have my new speakers up and running this week...stay tuned.  I will have pics.