Building Two way speakers with Ahuja 12" and Compression driver

[Naveenbnc]

Hey guys,

I started building two way speakers with Ahuja12" + Compression driver with horn.

Sharing some pics.
Current status: Build is half way through. The enclosure is sealed. But i have not added internal bracing and rear panel yet. So currently they are like unfinished OBs.




It was a last minute decision before cutting the sheet. I decided to keep the tweeter detachable.
That way I can keep it modular, and use those tweeters with my future builds.
Ofcourse, the crossover changes with different bass drivers.

Our FM ANIKET is designing the crossovers.

its only a temporary recording guys. Not of any high quality, just captured with mobile.
And the speakers are not fully built.
positioning is also near to rear wall, which may give boomy effect.

But here I want to share some info.
When I played some audiophile "kind of" slow instrumental songs, I was blown away.
The vocals are too good that I never heard of earlier. Particularly at this price point.
I felt like size does matter !! They filled the room and gave a great sound stage effortlessly.
And at just 25% volume they go crazily loud.

I was too impressed and felt like I should finish them off without adding a tweeter.
But When I played fast beat bollywood, tamil and telugu songs, the fast beat music was ok, but not very detailed.
Ordinary people may not catch it, but critical listeners will surely notice.
After lot of trails and errors, It is clear that a tweeter is necessary to handle highs in a better way.
Work in progress.

 

[sadik]

I too somewhat felt like the highs were not in the front.

 

[Naveenbnc]

Actually for the kind of songs I shared in the video. We will definitely say a big "NO" to an additional tweeter. I was all smiles and felt like why the hell do i need a tweeter. These are doing excellent job alone !!!!

But when I played fast beat bollywood, ARrahman, Yuvansankar Raja, etc...and some kinds of electronic trans music, dance hits, etc.... the highs are not clear and distinct. Instrument separation is not impressive. They are a bit muddled up. Ok for regular audience, but not ok for critical listeners.

For some specific category music, I would say these are more than what we need.

But for other fast beat songs, we will not be impressed. And atleast for pure experimentation and learning, I can't resist from adding a tweeter.

I will try to upload few more videos.

No need for a tweeter. Big boxes are really helping the driver breathe easy and open. Very nice ! Share some lossless tracks. What is the sealed volume ?

I started with 40L and kept on increasing the volume. At around 115L, I got better results. But I made the box a little less than that due to space constraints. Il check and share the details.

But even in terms of driver break-in, it's a bit early to judge the drivers full potential.

@drkrack if you see this thread, please add a few words about your observation on "rock music" and "fast beat electronic music" with Ahuja driver.

 

[VSTEREO]

But when I played fast beat bollywood, ARrahman, Yuvansankar Raja, etc...and some kinds of electronic trans music, dance hits, etc.... the highs are not clear and distinct. Instrument separation is not impressive. They are a bit muddled up. Ok for regular audience, but not ok for critical listeners.

For some specific category music, I would say these are more than what we need.

Good job Naveen. This driver is excellent as I have mentioned in few other FR posts. I too use this driver in similar ported box (again due to space constraints) and I do listen AR Rahman & Yuvan songs most of the times.

Tweeter is not needed (IMO). Here is my fav tracks to testing highs,
1) Narumugayea ( from Iruvar) - Trust me, this is one of the song with great recording and lovely in terms of all departments (Vocals, separation)
2) En Veetu Thotathil (from Gentleman) - Nice highs
3) Ennavalea Adi Ennavalea (from Kadhalan) - This is a surprise. Highs follows throughout the song and it goes from center-top-bottom (don't know how to explain) of the speaker.

When comparing these songs with Dayton RS-100 (costlier than Ahuja), Dayton outshines Ahuja in all departments but it is not fair to compare apples to oranges. So, you shall try adding a tweeter but I recommend to let the driver sing in the cabinet at least for 100 Hrs.

 

[Naveenbnc]

Good job Naveen. This driver is excellent as I have mentioned in few other FR posts. I too use this driver in similar ported box (again due to space constraints) and I do listen AR Rahman & Yuvan songs most of the times.

Tweeter is not needed (IMO). Here is my fav tracks to testing highs,
1) Narumugayea ( from Iruvar) - Trust me, this is one of the song with great recording and lovely in terms of all departments (Vocals, separation)
2) En Veetu Thotathil (from Gentleman) - Nice highs
3) Ennavalea Adi Ennavalea (from Kadhalan) - This is a surprise. Highs follows throughout the song and it goes from center-top-bottom (don't know how to explain) of the speaker.

When comparing these songs with Dayton RS-100 (costlier than Ahuja), Dayton outshines Ahuja in all departments but it is not fair to compare apples to oranges. So, you shall try adding a tweeter but I recommend to let the driver sing in the cabinet at least for 100 Hrs.

Thank you so much for songs recommendation !!!! I will try them. And as you said, i will not hurry. Currently even the cabinets are not fully done. So its too early to judge.

By the way....
Dear all...I did not mention about the driver in the first place.

This is not SK12FRX full range.
Thia is DX12 F200

Good job Naveen. This driver is excellent as I have mentioned in few other FR posts. I too use this driver in similar ported box (again due to space constraints) and I do listen AR Rahman & Yuvan songs most of the times.

Tweeter is not needed (IMO). Here is my fav tracks to testing highs,
1) Narumugayea ( from Iruvar) - Trust me, this is one of the song with great recording and lovely in terms of all departments (Vocals, separation)
2) En Veetu Thotathil (from Gentleman) - Nice highs
3) Ennavalea Adi Ennavalea (from Kadhalan) - This is a surprise. Highs follows throughout the song and it goes from center-top-bottom (don't know how to explain) of the speaker.

When comparing these songs with Dayton RS-100 (costlier than Ahuja), Dayton outshines Ahuja in all departments but it is not fair to compare apples to oranges. So, you shall try adding a tweeter but I recommend to let the driver sing in the cabinet at least for 100 Hrs.

https://www.hifivision.com/threads/songs-music-for-testing-diy-speakers.71775/

 

[elangoas]

The enclosure is sealed.

Great work @Naveenbnc .. They look massive.. Just using the subwoofer build logic of enclosure, ported Vs sealed.. If the enclosure is sealed, shouldn't the overall size be lesser?..

 

[Naveenbnc]

im learning phase now...so as per my understanding...

EBP (efficiency bandwidth product) =Fs/Qes
if that is less than 50, the driver is suitable for sealed.
50-100 (suitable for both sealed & ported
100+ (suitable for bass reflex)

something like a general thumb rule, i read somewhere.

Also, if Qts< 0.4 (ported)
0.4 to 0.7 (sealed)
Seniors can correct me please.....

Great work @Naveenbnc .. They look massive.. Just using the subwoofer build logic of enclosure, ported Vs sealed.. If the enclosure is sealed, shouldn't the overall size be lesser?..

Coming to your question, as I keep increasing the box size, i get better graph.
Variation is not too much, but still it gets better with bigger box. Please see the below pic

But since we can't go on increasing the size, we just have to stop at some point based in space we have.

Great work @Naveenbnc .. They look massive.. Just using the subwoofer build logic of enclosure, ported Vs sealed.. If the enclosure is sealed, shouldn't the overall size be lesser?..

By general understanding, what you said seems convincing. I'm also curious, lets wait for others to give better explanation...

 

[elangoas]

By general understanding, what you said seems convincing. I'm also curious, lets wait for others to give better explanation...

I said it purely on the sealed subwoofer vs ported subwoofer enclosure.. Sealed is always more compact then ported.. So in that regard, was thinking.. I don't have a good understanding of speaker parameters like Qts and stuff..

 

[Kannan]

I started with 40L and kept on increasing the volume. At around 115L, I got better results. But I made the box a little less than that due to space constraints. Il check and share the details.

How did you arrive at the enclosure volume?
Since you have the driver on top, do solid bracing, atleast 3 layers.
Mass load the base. Put same weight of sand on both speakers bottom and deal with a panel.
I would do one similar sand fill on top also.
The idea is to make the enclosure inert. Add another 18inch to only the front baffle.

I saw the specs. The compliance volume is not provided, so I wondered how you arrived at the mentioned volume.

 

[Naveenbnc]

I saw the specs. The compliance volume is not provided, so I wondered how you arrived at the mentioned volume.

I think you are asking about VAS.
I asked a question in this forum for formulae to calculate Vas. And our people suggested to fill the rest of parameters in the software. And the software gave an estimated Vas. I went ahead with it. I had no other choice at that time. Two different softwares gave two different Vas values with slight variation.

Even now I would love to find the formula for Vas. (To crosscheck the software estimated number)

 

[Naveenbnc]

Use Basta. It does things very fine and simulates the response for a particular design. Further the roll off is above 10k so a super tweeter will be needed. However is your CD good to handle a high xo point or you may end up underutilizing it ?

I would love to try Basta. Too many graphs overlapping in a single window scares me
I need to get better understanding on graphs for sure. Particularly i need to study how to combine impedance and db-spl graph and understand them.

 

[Naveenbnc]

How did you arrive at the enclosure volume?
Since you have the driver on top, do solid bracing, atleast 3 layers.
Mass load the base. Put same weight of sand on both speakers bottom and deal with a panel.
I would do one similar sand fill on top also.
The idea is to make the enclosure inert. Add another 18inch to only the front baffle.

I don't mind adding another front baffle it it's necessary. Although it's been discussed many times earlier, i would like to ask one more time. What areas in SQ will improve by making the box more and more inert ??

 

[Kannan]

If your enclosure design is right, making it inert will ensure mimimal box resonance.

The viscereal effect will not only be better controlled lows, but an improvement to the overall balance.

People do the knuckle test, but with towers where the weight is not proportionally distributed, there will be problem of high resonance passing to the floor and also to the music.

Use solid rubber (not plastic) or any of the anti skid pads under the speaker as spikes for isolation.
Also use Namtha carpets atleast on the inner rear wall of the enclosure and the base.

Also seal all joints internally with silicone sealant. You can get it from hardware stores along with the sealant jet applier

 

[Naveenbnc]

How did you arrive at the enclosure volume?
Since you have the driver on top, do solid bracing, atleast 3 layers.
Mass load the base. Put same weight of sand on both speakers bottom and deal with a panel.
I would do one similar sand fill on top also.
The idea is to make the enclosure inert. Add another 18inch to only the front baffle.

I placed the driver on top because... if I add a tweeter in future, it will be as close to it as possible. Hope we don't have a disadvantage if the driver is close to the top of the enclosure. I don't know at the moment ....

 

[Naveenbnc]

When I built boxes, it was always double walls for me, which always sealed the joints by the design itself and gave good edges to the front baffle. Namda lining was spot-on.

Using silicon sealant was very smelly and and lingering for days. Was not needed after I used double walls. For double walls you may use 15mm ply/mdf instead of 18mm.

I wish you had used slanted side walls, on the two sides. Bass would have been much nicer. Or you could have experimented with a three side triangle box. A great design with FRDs.

Here a picture of a beautiful DIY using full range / extended range drivers :

View attachment 30203

View attachment 30204

View attachment 30205

Fishing for these pictures took me to this one also:

View attachment 30206

I was 8 years old when my parents took me to Munich to stay for about an year. Sundays were always exciting as grocery shopping took us to malls and there I saw these speakers in a showroom. Of course I dare not tell my parents to buy them for me but my innocently greedy stares took fancy of the sales girl and she gladly handed me over these catalogues.

The burning passion never subsided and it took me another 10 years to save money and build them in the first year in college.

With every question we ask here...we get some answers, and some bonus too !!
Thank you for sharing pics !!! Looks great !!

I wanted to make an odd shaped box instead of simple rectangles. The only problem is getting the edges cut at a precise angle.
Finding a good carpenter is a challenge, and they are charging toomuch now a days.

Have to find if cnc guy can do it. Either he has to use an angular cutting bit, or tilt the cnc spindle at an angle. Not sure if its possible in his facility.

In my current situation with a 2 year old kid, i can't do any cutting, finishing operations at home.

 

[Kannan]

Double walls are a super idea as well, but increases cost. The silicone smell goes off is a day or two.

Though slanting walls diffract the standing waves, they have their own issues. There are any number of weird designs that claim to minimize standing waves and other enclosure issues, but for a beginner, it is better to stick with ideal designs to start with before going on with varied experiments.

@Naveenbnc one thing you could have tried before closing the back panel is to play it is a kind of open baffle

 

[Naveenbnc]

If your enclosure design is right, making it inert will ensure mimimal box resonance.
The viscereal effect will not only be better controlled lows, but an improvement to the overall balance.
People do the knuckle test, but with towers where the weight is not proportionally distributed, there will be problem of high resonance passing to the floor and also to the music.
Also use solid rubber (not plastic) or any of the anti skid pads under the speaker as spikes for isolation.
Also use Namtha carpets atleast on the inner rear wall of the enclosure and the base.

Thanks a lot for good suggestions. !!!
Asking the right questions is important. Since im a beginner, please bear with me if I sound like repeating the question

Let's say I made be box much more rigid and inert. There is no dout the SQ improves.

But may I ask..... Can an ordinary person like me observe the improved SQ by listening???
Or only a critical listener can observe?? Or only audiophiles or measuring instruments can tell ??

I mean .... I'm just trying to understand how obvious the change in SQ can be. Hope I'm not irritating

 

[Naveenbnc]

Double walls are a super idea as well, but increases cost. The silicone smell goes off is a day or two.

Though slanting walls diffract the standing waves, they have their own issues. There are any number of weird designs that claim to minimize standing waves and other enclosure issues, but for a beginner, it is better to stick with ideal designs to start with before going on with varied experiments.

@Naveenbnc one thing you could have tried before closing the back panel is to play it is a kind of open baffle

I haven't closed the back panel yet. The video i posted was kind of OB

 

[Naveenbnc]

We all have same ears but mine are a bit aged. However bracing or rigid box makes a clear difference to sound.

Since you are passionate about music reproduction, so you are an audiophile already !

That's a compliment too heavy for me to carry.

However, That's a good enough lead for me to focus on rigid cabinet. Thank you

 

[Naveenbnc]

We all have same ears but mine are a bit aged. However bracing or rigid box makes a clear difference to sound.

Since you are passionate about music reproduction, so you are an audiophile already !

Quickly gone through some websites and it looks like bracing is as important as the cabinet itself !!! Looks like I should not ignore it at any cost !!