2 Way speakers wothout crossover

[sudhirbhosale]

Hi all
I bought 3" full range driver for some project. Giving very sweet sound especially at high, as diameter is 3". Little bright also but listening experience is good. Sound was very sweet. I just put in wooden box and connected to 15 watt DIY amp.

I have floor standing speakers with peerless TL26SG tweeter. That gives flat response I am planning to replace.

So one idea I am thinking. If I use small full range which I liked, in my 2way speaker to replace tweeter , then no need to use cross over as it support full range but higher frequencies. And woofer is mid-bass (peerless S16NI) having freq response supported to wider range i.e. 80-5K .

Logic: Mid bass would deliver low-mid frequency but weak in higher side. Small full range driver would deliver wide range of frequency but strong in higher side. There would be overlap of wide range, so no single specific point where sound around crossover region change its path i.e. some from tweeter and some from woofer. (however crossover of 3Khz ensure that all vocals are managed by one driver)

Reason for doing this :
Current tweeter is not satisfactory
Avoiding Cross over - So minimum processing components

Challenges would be,
The Power handling capacity is low for small full range driver - Can be controlled by adding resistor
Some frequencies coming from both drivers may have higher levels.

Pl note : I do not have any instrument to measure SPL or entire response
hence would judge by ears only.

Would like to know thoughts suggestions or any expert comments from FM. If anyone know such kind of design. Any pros-cons of this approach.

Thanks

 

[shaan]

I once did the exact same thing. Had a pair of small satellites made with 4" full rangers that were low above 8K. Also had a couple 3" drivers from Sunvoice (Noida), primarily made for TVs but I noticed the HF response to be very good. So brought them into play in the following way as unlike tweeters which have a sealed back these could not be installed in the same enclosure due to interaction between the two drivers' cones. The end result was very pleasing and I had them like that for 3 years before moving to bigger/better full ranges.

As apparent, the smaller driver is open baffle (didn't notice any complain in the sonics for that, in fact the soundstage expanded a bit). It's connected with a 10uF electrolytic in series but no resistor as their response merged well (lucky shot for sure).

 

[sudhirbhosale]

Great Shaan
From your post Could not understand : interaction between the two drivers' cones. What kind of interaction take place if multiple drivers kept in same box? In 3 way speakers, we see multiple drivers in same box. So what are design consequences? Want to learn more on this aspect.

I once did the exact same thing. Had a pair of small satellites made with 4" full rangers that were low above 8K. Also had a couple 3" drivers from Sunvoice (Noida), primarily made for TVs but I noticed the HF response to be very good. So brought them into play in the following way as unlike tweeters which have a sealed back these could not be installed in the same enclosure due to interaction between the two drivers' cones. The end result was very pleasing and I had them like that for 3 years before moving to bigger/better full ranges.

As apparent, the smaller driver is open baffle (didn't notice any complain in the sonics for that, in fact the soundstage expanded a bit). It's connected with a 10uF electrolytic in series but no resistor as their response merged well (lucky shot for sure).

 

[shaan]

When used in the same enclosure, every driver with opening on the back of the cone and difference in power/sensitivity/cone area/impedance should be isolated from each other. Otherwise they will interfere with each other through the inside air of the enclosure. Apart from audibly compromised sonics, this can potentially result into the weaker/smaller/low-power driver's cone mechanism to blast off from its frame with loud transient music material.

 

[avesbilal]

Great Shaan
From your post Could not understand : interaction between the two drivers' cones. What kind of interaction take place if multiple drivers kept in same box? In 3 way speakers, we see multiple drivers in same box. So what are design consequences? Want to learn more on this aspect.

The 3 way speaker boxes look as single box externally but will be separated internally with each driver having its own enclosure to avoid driver interaction.

Regards
Bilal

 

[sudhirbhosale]

The 3 way speaker boxes look as single box externally but will be separated internally with each driver having its own enclosure to avoid driver interaction.

Regards
Bilal

So how this would be taken care in transmission line design as TL have single air channel inside the box. I have 2way TL and tweeter was shielded. But planning to build 3way. In this case mid and woofer would share common back area.
In other words does it mean TL design support only 2way? Or For 3way further separation needed for mid inside?

 

[avesbilal]

So how this would be taken care in transmission line design as TL have single air channel inside the box. I have 2way TL and tweeter was shielded. But planning to build 3way. In this case mid and woofer would share common back area.
In other words does it mean TL design support only 2way? Or For 3way further separation needed for mid inside?

You need to have a separate chamber for mid and bass drivers, tweeter will be not have any vents at back hence doesn't require any chamber. I'm enclosing a pic for you to have a basic ideas of internal chamber for mid and bass drivers.

You can see that the bass driver chamber is extended all the way upto tweeter back side using vents to utilise the space. Mid driver has a small sealed chamber for itself.

Regards
Bilal

 

[avesbilal]

Even if you are going to have transmission line for bass driver, you need to have separate chamber for mid driver.

Regards
Bilal