3 way driver selection

[grubyhalo]

Hi Cranky,
How good an option would this be, compared to the DCX or the DBX?

MiniDSP

Thanks!

 

[grubyhalo]

Hmm, I see. Thanks for your input, very useful, as always.

 

[suri]

hi adhiraj,

here is an article which may be of use to you-

ACTIVE LOUDSPEAKER SYSTEM: Subwoofer, Construction, Cabinets, Electronic Filter/Tube Crossover, Amplifiers, Units.

 

[grubyhalo]

hi adhiraj,

here is an article which may be of use to you-

ACTIVE LOUDSPEAKER SYSTEM: Subwoofer, Construction, Cabinets, Electronic Filter/Tube Crossover, Amplifiers, Units.

That's a fantastic article. On first glance, it appears that even I could understand! Thanks for posting it.

 

[Adhiraj]

Here are the crossover possibilities
DBX DriveRack 260
Electro Voice DC-One ,Two-In-Six-Out
Lab Gruppen Lake Technologies LM26
Ohm Audio CLEO MKII
BSS turning out to be way too expensive

I have no clue how to rate the audio quality .Could some kind soul please have a look and tell me which one would suit my application as in which one has the better AD/DA converters and dynamic range.

Many thanks!

 

[Adhiraj]

Hi,
I have been modelling the bass section for the project.Here are the results so far (see attached ) Please let me know what you think.

Driver specs are as follows

Component: Subwoofer

Size mm 300 (12)

Power peak 300

Handling continuous program 150
(Watt)

Impedance Ohm 4

Frequency Hz 28 - 300
Response

Sensitivity dB/SPL 92

Outer mm 305
Diameter

Mounting mm 275
hole diameter

Magnet size mm 125

Total depth mm 139

Mounting mm 129
Depth

Total driver lit 1.8
Displacement

Weight of one Kg 2,655
Component

Voice mm 38
coil diameter

Magnet High density flux ferrite

Cone Water repellent, pressed paper

Xmech* mm 10


D mm 255
Xmax mm 4
Re Ohm 3,5
Fs Hz 28
Le mH@1kHz 2,04
Le mH@10kHz 0,83
Vas lit 176
Mms gr 66
Cms mm/N 0,48
BL T-m 9,10
Qts 0,46
Qes 0,49
Qms 6,40
Spl (1m/2,83V) dB 92

I am using 2 of them in series in a sealed enclosure powered by a 500wpc at 8 ohms professional amp.

What do you think is the ideal effective upper frequency limit that I can push this driver to?

I am thinking of housing them in a 180 litre sealed cabinet which I will be lining with dampening materials.This gives me an f3 of about 43 Hz but as cranky pointed out that by factoring in the room gain I should be able to get extension down to the high 20s.

Should I also stuff the enclosure for good measure to get an additional volume effect? Probably using differnt and mixed stuffing materials ,polyfil ,glasswool and some wool.

The enclosure will most probably be made of 1inch thick BWR grade plywood,with adequate cross bracing.

I have managed to get my hands on bitumen roofing felt ,which I am thinking of using as a liner as well as 6mm 3m rubber doormat (the kind that has squiggly wiry lines) .In my experiment these turned out to be very good at absorbing sound and increasing box volume.Works like a sponge but with much larger chambers.

I hope I am not overlooking anything,please whet this setup ye wizards of hifivision .

Warm regards.

 

[sachi]

I love classic 3 way speaker systems and I wish you luck on your endeavor. I will be watching this thread with some interest as I have plans of redoing my first ever DIY project. somewhere down the line.

You'll have to excuse the picture quality as i only had my webcam as I had forgot to bring my Canon digicam along on my trip..

An active 3 way speaker system. Completely built by me with help from a mentor who manufactures speakers for a living in my hometown of Bangalore ( Arasu from Laya Acoustics). A friend Junia Alva helped in procuring thee drivers for me from the US.

I remember working on this even on the day i was due to leave to the US over 3.5 years ago. Only now am I getting the chance to enjoy (albeit for only a few days) the fruits of 2 years of blood sweat and tears.

I must say they sound effing great for something built by a complete novice at the time.
At the initial planning stages I was written off (by friends on other forums) when i made my plans for this project known saying that it was too ambitious for a first ever DIY build. I loved building this thing every step of the way though there were times when i just wanted to trash it all :tongue: (like when the amp lost a transformer and i had to redo it completely including replacing 4 amplifier channels).

Total cost incurred was about 50000 INR (back in 2005/6) including speaker cabinets, drivers (Vifa D27 tweeters, Scan Speak 13M/8640 paper cone midrange drivers, dayton 10 inch classic woofers), amplifier chassis, 7 channels of gainclone amplification (LM3875 for highs, LM4080 in bridged mode for mids and lows, OPA541 for a center channel in case i want to move this to my HT here) and 3 way active xover which is housed inside the amplifier chassis (Linkwitz 24dB/octave).

The dream is ambitious, but it can definitely be done...

 

[grubyhalo]

Looks pretty neat!

 

[Adhiraj]

Bravo! Those look so sweet,and for 50K im damn sure they will pull the pants off many speakers on the market today.:clapping:

I remember the first set I made,boy were they loud ,not much else there save for some good bass performance and midrange, treble was as harsh as could be and would cause fatigue so I had to equalize like a mad man .But the satisfaction I got I dont think I can get from something I might buy off the shelf anymore.They were the best speakers to me.The effort made them sweet.Its addictive this bug.

You would laugh if I told you what I used (8inch blaupunkt coaxials) I was 15 at the time with technical know how amounting to a little more than nought.
Blaupunkt Coaxial for High and Low 8inch,Philiips MidBass Loaded in some horn idea I thought might be nice,hehehehehe,and an 8inch Apex Bass ,all routed through a 3 way crossover.Sealed cabinet,heavily cross braced,internally the cabinets feature rounded corners,weight of each tower a full 56 kilos (my weight at the time )

Yay for DIY.

Forward ho!

 

[suri]

Bravo! Those look so sweet,and for 50K im damn sure they will pull the pants off many speakers on the market today.:clapping:

I remember the first set I made,boy were they loud ,not much else there save for some good bass performance and midrange, treble was as harsh as could be and would cause fatigue so I had to equalize like a mad man .But the satisfaction I got I dont think I can get from something I might buy off the shelf anymore.They were the best speakers to me.The effort made them sweet.Its addictive this bug.

You would laugh if I told you what I used (8inch blaupunkt coaxials) I was 15 at the time with technical know how amounting to a little more than nought.
Blaupunkt Coaxial for High and Low 8inch,Philiips MidBass Loaded in some horn idea I thought might be nice,hehehehehe,and an 8inch Apex Bass ,all routed through a 3 way crossover.Sealed cabinet,heavily cross braced,internally the cabinets feature rounded corners,weight of each tower a full 56 kilos (my weight at the time )

Yay for DIY.

Forward ho!

hi adhiraj - that is a keeper! - preserve it for your grandchidren!

and your "forward ho" reminds me of this poem i wrote long ago about doctors who give anaesthesia in the surgery room-

"forward ho! - to the theater i go
please, please - start the ether flow
it is the reason i go to the theater
more than the patient, my need is greater.
A leak in the tube- to this i see
half goes to the patient, half gets to me!
when i go for exams of other gases they speak
but i swear by ether - and, of it i reek!
so they fail me and fail me- but i don't mind
As long as (in the theater) SWEET ETHER i find!

well, hehehe - anesthetist anesthetizing himself!!!!

but ether was dangerously addictive - so, i have read!

 

[grubyhalo]

Bravo! Those look so sweet,and for 50K im damn sure they will pull the pants off many speakers on the market today.:clapping:

I remember the first set I made,boy were they loud ,not much else there save for some good bass performance and midrange, treble was as harsh as could be and would cause fatigue so I had to equalize like a mad man .But the satisfaction I got I dont think I can get from something I might buy off the shelf anymore.They were the best speakers to me.The effort made them sweet.Its addictive this bug.

You would laugh if I told you what I used (8inch blaupunkt coaxials) I was 15 at the time with technical know how amounting to a little more than nought.
Blaupunkt Coaxial for High and Low 8inch,Philiips MidBass Loaded in some horn idea I thought might be nice,hehehehehe,and an 8inch Apex Bass ,all routed through a 3 way crossover.Sealed cabinet,heavily cross braced,internally the cabinets feature rounded corners,weight of each tower a full 56 kilos (my weight at the time )

Yay for DIY.

Forward ho!

That's a pretty neat job right there! :thumbsup:

 

[Adhiraj]

hehe thanks!

 

[Adhiraj]

Hey people,
Just got my hands on the bass drivers for my build! I tested them out ,the pressed paper cones are keep up at 155 bpm easily ,not sluggish at all.Now to figure out how to load these puppies hyeah:
Pics attached

 

[suri]

Hey people,
Just got my hands on the bass drivers for my build! I tested them out ,the pressed paper cones are keep up at 155 bpm easily ,not sluggish at all.Now to figure out how to load these puppies hyeah:
Pics attached

hi adhiraj -

balls-to-the-wall bass guaranteed:yahoo:

BTW - looking at those attached wires - i cannot help but think - have you cannibalized these drivers from a balls-to-the-wall ICE demo??!!!

regds

 

[Adhiraj]

@audio_engr- I was thinking 180 litre sealed.It should give me an f3 of 43 Hz,I should get,as cranky pointed out,in room response down to the high 20s .Got any other ideas?

@suri-more like balls to my neighbourhood bass,hehe.Those wires were jerry rigged by me in a hurry just to test if everything was in order hyeah: .I actually had to hunt for these drivers they are about the only woofers out there with a 150 watt nominal power handling.Anything else I saw was a minimum power of 300 watts,which would mean atleast 800 wpc :lol: amplification if I used two of these in series.One of my reference tracks has been

YouTube - Psytrain-Black Powder

Lol they need to keep up!

 

[Sujit]

Adhiraj,

A lot of friends of mine have used the Hertz subs in their car's. I can tell you from personal experience that they can get nice and loud loud and they are very very fast. They don't need too much power either - I have seen them kicking butt even with 100 watt amps. I obviously have never seen it used in a home setup - hence cant hazard any guesses there ... but FOUR of them does indeed look like an overkill and could make the bass section overbearing. If you are planning to go active, you can try mating them with any basic Class D car amplifier and it'll work well (yes you might have to build a 12V supply but that's easy) - best advantage is it will give you gain, crossover (and some phase ) controls on the amp itself.

 

[Adhiraj]

Adhiraj,

A lot of friends of mine have used the Hertz subs in their car's. I can tell you from personal experience that they can get nice and loud loud and they are very very fast. They don't need too much power either - I have seen them kicking butt even with 100 watt amps. I obviously have never seen it used in a home setup - hence cant hazard any guesses there ... but FOUR of them does indeed look like an overkill and could make the bass section overbearing. If you are planning to go active, you can try mating them with any basic Class D car amplifier and it'll work well (yes you might have to build a 12V supply but that's easy) - best advantage is it will give you gain, crossover (and some phase ) controls on the amp itself.

Hi Sujit,
I actually first encountered this sub in a friends car setup and I was quite surprised at the accuracy and finesse of this driver.I guess it has to do with the fact that they use light paper cones and dont soak up mad amounts of power.As far as the power goes ,since I am using two in series my minimum power requirement is going to be 300 watts nominal.I am inclined to give it more power for headroom.Somewhere in the range of 400 watts (sounds a little mad I know,but atleast this will allow me to play them at most levels without clipping )

I am planning a tri-active system and will be using the DBX PA+ active loudspeaker management system mated to a Crown or QSC pa amplifier(for the bass section).This should allow me to control the Phase and equalize as needed I can also adjust the crossovers on the fly.

The woofers have a sensitivity of 92db ,If i use two I get +3db but when I wire them in series I get -3db so the sensitivity remains the same.I am using two because I want an overall impedance of 8 ohms. Plus in a sealed config the bass should be nice and tight,just the way I likes it!
Overkill,well that is a matter of perspective,quite frankly I hate the speakers made these days with their puny 6.5 inchers,I yearn for the days when speakers were the sizes of fridges but you could feel the hit of a snare and rip of a bass guitar ,not just hear but actually feel :licklips:
In the future I plan to ship these out to my farm house,atleast I know I can bring the boogie with these things if I ever need to throw a partay :yahoo:

Also ,I have seen this done,instead of building an a power supply for car amps for use at home just use a high rated computer PSU.Google this on how tos,but it works well.You will however need something hefty.Someone I know used a 850 watt dell server power supply to power his 350 watt sony amp at home.Worked pretty good.

Cheers !

 

[Adhiraj]

Anyone got any other ideas on loading these? 180 litre sealed is what I have thought of so far.

 

[Adhiraj]

Hi Cranky,
After a bit of tweaking this is what the 130l graph looks like,
please tell me what you think.

 

[suri]

if 180L is size of a small refrigerator - then 130L = size of mini-bar? adhiraj?