3 way driver selection

[Adhiraj]

Hey guys,
Am embarking on a new project,thought of making a 3 way set.The drivers I am considering using are

Hertz DS 300 -beautiful paper,92db sensitivity,and Italian,for the woofer cut off at around 180 to

RCF L8S800- Mid/Bass also 92db,carbon fibre,and Italian,cut off around 2.2 Khz to

LCY 130-Ribbon Tweeter,Looks good,havent heard one tho,reviews are good however they are chinese and expensive ,specs look really good.

All components are going to be housed in their own separate enclosure,I am toying with the idea of decoupling them completely using some sort of suspension.Woofer is going to be in a vented box,mid/bass also in a vented box.

X overs are going to be of a high order 12 to 24 db/octave and will be made using the highest quality components I can get my grubby little paws on.
I would really appreciate if the diy gods would kindly go through my selection an plans and approve and or bless me with potential audio bliss,atleast till the itch starts again.

I would also really appreciate it if someone could perhaps advise me on the best capacitors,resistors,and general other crossover bits and bobs available in India.

Many thanks!

 

[suri]

Hey guys,
Am embarking on a new project,thought of making a 3 way set.The drivers I am considering using are

Hertz DS 300 -beautiful paper,92db sensitivity,and Italian,for the woofer cut off at around 180 to

RCF L8S800- Mid/Bass also 92db,carbon fibre,and Italian,cut off around 2.2 Khz to

LCY 130-Ribbon Tweeter,Looks good,havent heard one tho,reviews are good however they are chinese and expensive ,specs look really good.

All components are going to be housed in their own separate enclosure,I am toying with the idea of decoupling them completely using some sort of suspension.Woofer is going to be in a vented box,mid/bass also in a vented box.

X overs are going to be of a high order 12 to 24 db/octave and will be made using the highest quality components I can get my grubby little paws on.
I would really appreciate if the diy gods would kindly go through my selection an plans and approve and or bless me with potential audio bliss,atleast till the itch starts again.

I would also really appreciate it if someone could perhaps advise me on the best capacitors,resistors,and general other crossover bits and bobs available in India.

Many thanks!

sounds like a good project - and you have been doing this since you were 15 years old!

i have heard that the heart of a good-sounding loudspeaker is the cross-over-

how have you/your friend planned to design this? -

the hertz is a car subwoofer - how will it meld with the other drivers - the mid bass seems to a professional application design-

your answers are eagerly awaited - i, too, have been dreaming (fat) dreams of a buxom three-way

 

[freshseasons]

From where are you sourcing the Xovers from.What are the damages till now?
The project sure looks tempting.Do keep us updated with the pictures..

 

[Adhiraj]

I believe that a transducer is a transducer,as long as it does its job in my setup.I dont think it makes much of a difference if it was designed for a car or for PA application.Only thing that I think you might have to keep in mind is the sensitivity and power handling and ofcourse the axial response.
The L8S800 is carbon fibre,very light resulting tight and fast sound.The reason I chose this is because I am going with a ribbon tweeter.Ribbons are notorious for having fast attack and decay,I wanted something that could keep up.That apart I chose an 8inch over regular 5 or 6.5s because I feel that there is ultimately no replacement for displacement.Carbon fibre delivers far more transparent imaging and clarity as opposed to PU or paper,purely because it is stiffer than paper.One drawback is that it starts to breakup and has a charecteristic two peak response curve in the higher ranges.
http://www.rcf.it/en_US/c/document_library/get_file?p_l_id=251786&folderId=22488&name=DLFE-2195.pdf
Hence,I chose to cross it over before the problems begin.
But I need a high with an Fs of around 500hz and frequency range begining from around 1800 hz to be safe.Hence the best fit was the LCY which operates from 1800Hz to batman can hear this 60000 htz!
also the sensitivity of the LCY @ 92 db is almost a match with the L8 at 93 db.If I factor in the loss that the crossovers are going to cause in the Mid/bass (considering that I am using top end components for x overs) the difference will more or less be zilch.
Now,as it turns out the DS300 is one of the highest sensitivity woofers in its class at 92 db ,also a perfect fit.I had the option of using PA drivers for the LF like an eminence or a fane 12 inch,which I have seen used,to produce some awesome sound (old school Arphi Aquarius used 2 twelve inchers) but I wanted further LF extension.The DS 300 has an Fs of 28hz .Also I liked the fact that it was pressed paper and not some heavy PU or the likes you get these days.That means that is will be fast.Mated with an appropriately designed cabinet the back waves should be minimised and I should get some tactile bass that is fast enough to match the other components.That apart the driver is quite well designed with a vented pole piece.

The only problem is that IF I want extension down to 28 hz I have to make a massive cabinet.I am also considering my earlier design of using 2 PA woofers in a sealed box or vented,depending on the TS parameters.As the HS300 will cause my speakers to become room dominators,not that I mind really but them things are going to be big like beeeeeeg.

X overs I am getting the scematics made from an ex sonodyne dude, custom for the set.The components from the Xovers will come from the States.

As far as sourcing goes I am getting the tweeters from Madisound,yes I am paying the duty,you dont do this everyday.

That apart RCF drivers are available in India,Mumbai.Will be happy to pass off numbers,you guys should also check out FANE, Eminence and StudioMaster.The L8s cost around 9000 a pop.If I bargain I might get them cheaper.

The Hertz is car audio so should available at your local car systems dealer.Cost about 5000.

All in all my cost ,just components, is probably going to be around 50 thousand,including all drivers ,duty and crossovers.(I hope).

freshseasons,as of now the only thing I have spent is a good bunch of sleep deprived nights everything is still in R&D phase.

I need second opinions as to wether I should go ahead and build the Monster using the DS300 or if anyone has used PA basses ,please tell me which ones will work well in this design

I would really love to see more projects using 12inch woofers and some mad tweeters.Mixing old school with state of the art.Re incarnate the Arphi aquarius,improving the sound usinf top end components.

Please message me if you want the numbers of the distributors,maybe we can get some kicka** ,cant care less about size, face peeling projects as a result!

 

[suri]

.Only thing that I think you might have to keep in mind is the sensitivity and power handling and ofcourse the axial response.

hi adhiraj,

yes, but spider construction, spider ventilation and construction of the surround of the particular driver - and how these relate to the others - and how they gel with each other in a multi-driver set-up - you might have to consider these disparates to create a homogenous whole?

 

[Adhiraj]

quoteistortion?
That too,sorry.

quote:Carbon fibre delivers far more transparent imaging and clarity as opposed to PU or paper

only IMHO.From what I have heard so far.Obviously cabinet design plays a huge role.CF drivers, I feel, tend to be a little more resilient to back waves as it is more acoustically opaque.And with a moving mass of 21grams I feel this driver will be pretty responsive.

As far as the crossover goes I will be using 24db/oct.Thank you for suggesting the notch filters ,I did not think of using them.The droop below 1khz should be eliminated through trial and error.

I hope he is the right guy too ,I will closely supervise and co design the xover but my background is in Business and my technical knowledge is for lack of a better word, limited.I hope you are up to give me advice as far as being discouraging goes ,sir,I can sincerely say that getting by plans due dilligenced by guys like you is actually encouraging.It throws up questions and will help further my ambitions.

I will definitely take a look at the betas,I am not sure if my guy here can arrange them for me tho.Will crosscheck and report.

I think I will need some major help with the fine tuning of the cross overs.I hope I can come to you for advice.

Hi Suri,
You are absolutely right,I am somewhat limited in my depth of knowledge ,could you please advise me with regards to the same.
As far as I have seen, the L8s have an Mroll? damped surround.No information with regards to the spider.I have no clue how the surround and construction of the driver will affect the synergy of the system.Please advise.

Thanks.

 

[suri]

Hi Suri,
You are absolutely right,I am somewhat limited in my depth of knowledge ,could you please advise me with regards to the same.
As far as I have seen, the L8s have an Mroll? damped surround.No information with regards to the spider.I have no clue how the surround and construction of the driver will affect the synergy of the system.Please advise.

hi adhiraj,

there is no way i can be of help to you in your endeavour.

to illustrate the complexity of the process ( and also why i cannot help you) -

see this-

Leap Crossover Design Service from Madisound Speaker Components, Inc.

these guys take the selected drivers, test their parameters individually and use software (that is expensive) to design the crossover - taking into account your cabinet volume, shape, the way your drivers will be mounted - and the more exact inputs you give, the better designed (and suited) the crossovers will be.

i think this process is beyond the average DIY'er, and best left to professionals to do -(for a small fee).

once this is done - the tryst is between you and your carpenter (unless you are a professional/expert wood-worker) - and regular plywood is no substitute for birch ply - marine ply is not suitable - MDF is the best bet.

 

[Adhiraj]

Hi suri,
I am actually using their services for the HF component I am sourcing from them.The Crossover for the LCY130 or Raal 70-10 I will have designed at madisound.The only problem is that since I am not sourcing the mid/bass or the low drivers from them I will have to experiment and optimise.But I guess that is the true joy of DIY.Otherwise everyone would be producing Alexandria 2s in their backyard.With the resources at hand I hope I will be able to create something of value.With the current driver selection ,is it worth the attempt? I mean if I end up spending 70K on a set I really hope it sounds a great deal better than what I would get off the rack.

 

[Adhiraj]

thats why I hope and pray if nothing else,hey I have a bunch of components to sell! If it pans out the way I hope it will,well next. heheh

 

[Adhiraj]

Orders placed!
DS300 x 4 (using 2 per speaker)
L8S800 x 2
and the LCY 130 x 2

Delivery time 2 weeks (eagerly rubbing hands till then)

 

[anilva]

Cranky,

You mentioned Eminence range is available in Kolkata. Would you know if Eminence Alpha 15s are stocked? Planning an OB next...

Cheers.

I think you have a heap of advice here Adhiraj.

I would look at two options:

1. A real full range driver like the BG ribbons - a true line source, and they start at 150Hz though would probably be happier with a 250-300Hz crossover. You can mate them to a PA-style bass bin, as home woofers are too slow and have very poor transient response compared to even a low-end driver like the Eminence Beta (which, by the way, is very easily available in Calcutta along with the entire Eminence and JBL Professional range).

2. If you are hell-bent on a 3-way, I would look at a published design. Expense is not an object - Zaph, Troels, Tony Gee etc have made some stunning designs with a lot of thought, they are free for a DIY'er and the crossover designs are tested and published, all you have to do is implement. granted that takes some of the thrill of discovery away, but it is a safer approach for sure.

If you still want to experiment with DIY, I suggest you procure tools for yourself and learn. There's no substitute for starting to learn yourself - a measurement microphone and a computer is all you need - the software is free. Start small - a build with Peerless drivers will start you off on the right path.

DIY is not cheaper than buying readymade, that's for sure. If you are thinking of saving money by building speakers yourself, your goals are not achievable. Upfront cost is much higher, and the chance of failure is also very high unless you go for a tested design.

Here are some sites to get you started:

Zaph|Audio

www.troelsgraven.dk

Humble Homemade Hifi

 

[Adhiraj]

I have been thinking about this long and hard and have now come to a decision, I am scrapping the crossovers entirely as the cost to get top end components and compexity would have been too great to manage.
I am going to Tri amp this setup and use an active loudspeaker management system

Has anyone used an active crossover such as the Ultradrive DCX2496 or a similar DBX ,BBS model ?
Are there any other companies out there ?

 

[suri]

I have been thinking about this long and hard and have now come to a decision, I am scrapping the crossovers entirely as the cost to get top end components and compexity would have been too great to manage.
I am going to Tri amp this setup and use an active loudspeaker management system

Has anyone used an active crossover such as the Ultradrive DCX2496 or a similar DBX ,BBS model ?
Are there any other companies out there ?

hi adhiraj,

looks like this is going to become a very expensive project - you need six amplified channels downstream from the active cross-over - ?

regds

 

[Adhiraj]

Yes,I figure that the high stage amplification I can utilise my existing amplifier.All in all I am looking at either 2 stereo power amplifiers one set for the mids and a higher power set for the lows.Since I am going to use a digital management system ,the amplifiers can have different ratings as the gains and delay can be addressed by the Digital crossover.
This actually would better fit my budget ,I dont have to use Silver/gold oil caps/inductors/resistors.My capacitors alone were costing double of what I was spending for the active crossover.Few of the claritycaps and equivalent go for more than 170 dollars a piece for the values I was looking at.
The active crossover costs only about 18000 Inr.At present I am going to probably buy a couple of good P.A. power amps,in the future I will upgrade to Krells or Quads and switch to a Tube amp for the high frequency stage.
I feel that using an active system and Tri/Bi amping would definitely be more economical and flexible.I do not want to end up using high end caps and end up having to pad any stage using a couple of grotty 20 dollar or less resistors.Here I can just adjust the gain and adjust crossover points and types on the fly!

Regards

 

[sridhar-v]

Hi!

Look at the Behringer CX3400 .It is available from Audioplus - mumbai. Cost around Rs. 10000. Is a good 3 way active crossover with 24db/octave.
I was about to buy the crossover & speaker driverss but got stuck at the 6 channel amp stage as the setup would become too complicated for my folks at home to handle. I also need to work out a way of integrating a DAC before the active crossover.

I agree with Adhiraj that the carbon fibre cone will be less sensitive to back pressure from the internal waves. I am actually planning to use Pioneer car speaker elements either 1720 or 1520 (basalt fibres with aramid reinforcement). Just planning a visit to Lithos to audition their speakers for a make or buy decision.

 

[Adhiraj]

The Beri DCX2496 Ultracurve pro is about 16000 also available at audioplus.This model has the additional benefit of computer interfacing and a digital input.Hook up your cd player directly and you lose one whole D/A conversion.Also,what I gather from the specs,is that you can hook up a microphone and allow the crossover to equalize the system,correct the phase and account for the room.

Another model I have seen is the DBX PA+ which is similar,but a little more expensive,the DBX comes bundled with a calibration mic.

some of the issues I think I am going to face is,one, protecting my precious tweeter from odd bumps and thumps amps/crossovers make when powering up or down.Usually this is accounted for by the passive components.Any ideas on this issue will be much appreciated.

Secondly,what kind of power am I going to require.Considering that I am going for (per channel)
2 x 12inch woofers (4ohm in series) power handling 150 nominal ,300 max.
1 x 8inch mid bass (8 ohm) power handling 170 watts nominal,350 max.
1 x ribbon tweeter (8 ohms) power handling 150 watts nominal

What I have figured so far is that I can use my existing 85 watts/ch yamaha amplifier for the tweeters
I will go for a 250 watt/ch for the mid/bass
and something in the range of 500 watt/ch for the low
(So basically my power outlay is translating into a holy moly scenario of around 850 watts per channel with plenty of headroom)

Moreover,the Lcy tweet as indicated by the manufacturers has a sensitivity of 92db,this seems a little circumspect as according to Zaph audio in their test this tweet is rated at 88db.When looking at the graph ,there is a significant increase in spl above 6 khz.Which is why they recommend using a parallel trap circuit.When used the spl is around 88 db.
My problem is that since I want to not end up using any passive components,will I be able to take care of this effect using active equalisation provided by the digital crossover?

Also the mid/bass is rated at 93db and the woofers at 92db .I think the gain controls in the active crossover should be able to handle this.The only problem is how this relates to amplifier power I have selected and if it will make a difference?

Thanks and regards,

 

[suri]

hi adhiraj,

have you looked at this elegant solution? -

KSC Digmoda DDC552 Mono Three-Channel Plate Amplifier with Integral D-Pro DSP from Madisound

there is also one for two-channel

expensive - but elegant - and instead of multiple amplifier boxes - one single unit mounted on the speaker.

regds

 

[Adhiraj]

Hi Cranky,
The winISD box calc,with a 170 litre sealed enclosure gives me an spl rating of 93 db and an f3 of 43hz.I am assuming this software is considering the 2 woofer configuration in parallel, I will be using them in series to get 8ohms ,I am a little unsure as to how this will affect the sensitivity,I think it will decrease by 3db.
Need a little help here.

Checked out the operettas ,they look spot on! you are a compendium of audio knowledge,many thanks.Any others in a similar price range?

regards,

 

[Adhiraj]

Hi,
I am looking at the 2 channel operetta,300 watts per/ch class a power. This is purely for the mids, the multichannel I will probably only get in a 2 channel configuration,70 watts per channel to power the highs.What are some other amplifiers I can use purely for the tweeters.I am thinking that 70 watts should be quite sufficient.On the other hand since the tweeter is probably getting crossed over low around 2.2khz ,70 Watts might be a little wimpy.

I have several times thought of binning the yammie,I think i might trade it in for some rebate on the PA amps.Another option I have is to change all the caps on my vintage Cosmic Lab 3000 MkII to mundorf or claritycaps and use that.I love the sound of the Cosmic ,not the greatest transparency but incredibly smooth.

For the lows I am thinking of going for Crown or Ohm professional.I think something in the range of 500 watts per channel should give me good control and a good transient response.25 hz! Blimey,thats more than good enough I was starting to get upset about f3 of 43 Hz.What is the usual estimation here?

Cant wait to get this going full steam!

 

[Adhiraj]

Will keep the posts coming , need some suggestions on new innovative box designs/concepts I can try