Building a 3-way TL speaker

[mpw]

The boxes were delivered last weekend and this is how they look

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I have assembled only one box, for designing the crossovers. The final buffing will be done just before delivery.

Look like raspberry dollies ...

Hope they sound sweet like raspberry and vanilla

)

Take it easy...just on a light hearted note...

 

[jls001]

Looking very good, Hari.

 

[keith_correa]

Aren't you taking all measurements on the tweeter axis?

 

[Hari Iyer]

Aren't you taking all measurements on the tweeter axis?

Not for designing the crossover. I am taking measurements at each driver axis now. I am keeping the same input level though. The final voicing will be done at the midrange axis. The tweeter axis merge with the midrange axis at 97.5 cm due to the tilt

 

[Dr.Lakshay]

The boxes were delivered last weekend and this is how they look

View attachment 41828

View attachment 41829
View attachment 41830

View attachment 41831

I have assembled only one box, for designing the crossovers. The final buffing will be done just before delivery.

Looks absolutely gorgeous. Hope it sings the way you want it to.

 

[Hari Iyer]

Looks absolutely gorgeous. Hope it sings the way you want it to.

Cross over design in progress, components yet to be ordered. Keeping my fingers crossed

 

[mallikreddyk]

I did some measurements after mounting of the raw drivers and simulated a crossover network suitable for this speaker system. The drivers are not broken-in much and may have around 15 to 20 hrs of listening in my first iterations. Check out graphs below,

Cross-over frequncies 200Hz, 2150Hz as per simulation.
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The mechanical Q is well damped by the line and stuffing and the resonance peak of woofer is very low.
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Crossover components will be purchased later in this week.

Thanks for looking.

My humble suggestion based on my experience with the exact mid and tweeter combination. , roll off the mid quicker,This can avoid the 3k bump where our ears are more sensitive and also helps get rid of sibilance if you encounter any, and the tweeter can be rolled up towards the top instead of downwards.

 

[Hari Iyer]

My humble suggestion based on my experience with the exact mid and tweeter combination. , roll off the mid quicker,This can avoid the 3k bump where our ears are more sensitive and also helps get rid of sibilance if you encounter any, and the tweeter can be rolled up towards the top instead of downwards.

Thanks for suggesting for an earlier mid rolloff. I am actually planning for a 1.6 kHz rolloff, but for that the tweeter need to be atleast -18 dB/ octave filter.

I have done some modifications to the crossover to incorporate the floor distance from woofer, woofer to midrange and midrange to tweeter as per their relative distance from each other. The idea is to have a proper polar response to reduce phase error and beaming issue. They are half WL, quarter WL, double WL respectively.

 

[Hari Iyer]

Last week was busy fine tuning the crossover design and assembled them after receiving components. This is how the testing crossover look



After initial listening applied some tweak to the mids and highs and these are rest of the curves to feast your eyes


-10dB response extendss till 20Hz and i can feel them too in my listening. My classic room boom at 74Hz is noticeable in this curve and the spectrogram. This is a minimum phase speaker for the entire bandwidth from 100Hz to 20KHz.



Text book perfect impulse response.




Though i would have loved a better step response, but the driver integration is superb and on the dot. This was measured at a distance of 1 meter from the midrange axis which is the ear level.



Very even spectral response with my room boom at 74 Hz. The extension below 20Hz can be seen in this response which is quite tight.

Thanks for looking.

 

[balavignesh002]

Just curious if can a Dsp be used instead of a passive xover. Not sure if a home audio Dsp exists in market, but i use car audio dsps in my cars for 4way active. Makes it easy to deal with xovers, slops TA and phase.

 

[saikatbiswas82]

Just curious if can a Dsp be used instead of a passive xover. Not sure if a home audio Dsp exists in market, but i use car audio dsps in my cars for 4way active. Makes it easy to deal with xovers, slops TA and phase.

To answer your query - Minidsp is there.

 

[Hari Iyer]

Just curious if can a Dsp be used instead of a passive xover. Not sure if a home audio Dsp exists in market, but i use car audio dsps in my cars for 4way active. Makes it easy to deal with xovers, slops TA and phase.

I have never designed a active crossover till date and am not looking for it too.

 

[balavignesh002]

Minidsp

Got it. Thanks.

 

[balavignesh002]

I have never designed a active crossover till date and am not looking for it too.

What a purity and passion towards Analog audio. Appriciate it really in deed.

 

[Hari Iyer]

Past 2 days i was working on the step response for even more better driver integration and have some success in getting the mids and tweeter to integrate better. In post #53 if you notice the step response the tweeter goes up first at 0us and midrange goes down and later the woofer picks it up. Now the tweeter and midrange integrates together as one as below,



The goal will be get the tweeter, mids and the woofer to integrate even more better as one coherent sound stage. Its quite difficult to achieve that as there are some more variables involved

 

[sachu888]

Any specific reason to use motor run AC caps in crossover?

Regards
Sachin

 

[Hari Iyer]

Any specific reason to use motor run AC caps in crossover?

Regards
Sachin

I have done apples to apples comparison with so called audio grade capacitors and these run Metalised polypropylene capacitors beats them by light yesrs. I may eventually finalize with Mundorf EVO Oil capacitors when the crossover freezes.

 

[newlash09]

Hi all

Thought I could jump in now into the discussion

First and foremost.. I would like to say that iam thankfull that Hari sir has accepted my request to undertake this time consuming build on my behalf.

Money is always secondary.. I could never make up for the months of simulation that went into the cabinet design or the driver choice or the cross over design. So I will be ever gratefull to hari sir..for undertaking this build on my behalf. Just for kicks..it might help to know that each speaker weighs 100 kg +

This is a one of a kind build. Which is very very custom to my specific room and listening habits.

I started this journey with a thread called...has anyone heard the new Kef r series. And I was coming from PMC twenty 26 speakers. So they were really big boots to fill for my next speaker.

As the conversation prolonged...I realised that no ready made speaker could satisfy my exact needs.
So on a hunch, as suggested by @prem...I reached out to hari sir. With a request to kindly build my next speakers that would gell in my room, and still best the present PMC speakers . We just spoke and discussed it down to the last detail for months.. before the whole build started.

So I guess what You see in those pics is pretty much my next speaker

But please bear in mind that this is not a cheap build. Every single driver here is top of the line from their respective companies . And the component cost alone is huge. But Iam still very very happy I went down this custom route.

Thanks a ton for reading

 

[prem]

newlash09, I would suggest do come down to Mumbai and hear the speaker before it’s sent to you. Once you hear them, any changes that you may want could still be incorporated.

 

[spirovious]

I have done apples to apples comparison with so called audio grade capacitors and these run Metalised polypropylene capacitors beats them by light yesrs. I may eventually finalize with Mundorf EVO Oil capacitors when the crossover freezes.

Mundrof looks good choice as many HiFi speakers(B&W, Dynaudio) do use them.Budget HiFi speakers use PP caps from Bennic, Spirit or Yontex.