Swapping my tweeters - would this work?

[anphex]

Hi everyone,

I am thinking of swapping my tweeters of my large speakers. It's actually pretty easy and I found a suitable model.

The current tweeter is this one in a slightly changed casing: https://doc.soundimports.nl/pdf/brands/Scan-Speak/D2608-913000/pdf_SB Acoustics_D2608-913000_1.pdf

The new tweeter shall be: https://doc.soundimports.nl/pdf/brands/SB Acoustics/TW29BN-B/pdf_SB Acoustics_TW29BN-B_1.pdf

It's kind of a "what if" project to see if this beryllium tweeter with its extended upper range can really provide the so often claimed "holographic transparency".
Since the data is pretty close but not really I wanted to ask you for things to watch out for.

1. How much do I have to worry about phase?
2. The new tweeter has higher sensitity - do I need to put in a power resistor into the path?

What else is there?

Thank you for your time reading this!

 

[TimW]

A new tweeter would require a new crossover circuit for best results. The crossover of a speaker should be fine tuned to give the best frequency response possible. With a different tweeter with different frequency response, impedance, and efficiency you will have a very different sounding speaker. The difference in sound will not just be due to tweeter material. I would recommend not swapping tweeters in your current speakers unless you plan to try your hand at being a speaker designer (measuring, simulating, tweaking, etc.)

 

[anphex]

My naive understanding is that everything "below" the tweeter should perform the same. It's a four way speaker with a beefy crossover network.
Would the whole system behave completely different in a very noticable way when I just change it to a tweeter with the same impedance?

 

[voodooless]

Any idea what the crossover frequency is? Any idea about crossover order? Got any pics of the crossover? Given that it’s a 4-way, it may be suitably high to not cause issues with the wider bandwidth of the SB tweeter. Impedance looks similar enough. There is a 1 to 2 dB efficiency difference though. You may need to add another series resistance to the tweeter to lower the level a bit.

It could work, but it’s a bit of a gamble without any measurements.

 

[anphex]

Yeah, it's a gamble, that's no secret from the beginning. It's just an experiement. If it doesn't work out I'll send the tweeters back. Fortunately there is no milling needed so everything is non destructive except for the small soldering and the lace connectors.

But I know that the crossover is at exactly 2000 Hz with 18dB.

Pics of the crossovers: https://www.nubert.de/thumbnail/52/93/bf/1659709943/nuVero_170_Weiche_1920x1920.jpg

Edit: Oh, the speaker has some shelving eq flip switches to that might contribute to the size of the crossover too.
Edit2: Okay thinking about the shelving flip switches, those might actually be my solution in case the new tweeter is too high in volume due to sensivity. The "soft highs" flip switch reduces the highs about 2dB.
Edit3: And of course I will make a on axis measurement before and after. Should work pretty okay for frequencies this high even in my amateurish treated room.

 

[Rednaxela]

Why ask here?

 

[voodooless]

2 KHz is right where the “old” tweeter starts to fall down. The SB goes about an octave lower. That may be tricky. That it’s a 3rd order helps a bit.

 

[anphex]

This exact mid area I guess you are thinking about also funnily has a flip switch to reduce by ~1,5dB. So I have some remedies without any soldering it seems.

Those speakers aren't super linear anyway, so I'll see where this leads.

 

[levimax]

Yeah, it's a gamble, that's no secret from the beginning. It's just an experiement. If it doesn't work out I'll send the tweeters back. Fortunately there is no milling needed so everything is non destructive except for the small soldering and the lace connectors.

But I know that the crossover is at exactly 2000 Hz with 18dB.

Pics of the crossovers: https://www.nubert.de/thumbnail/52/93/bf/1659709943/nuVero_170_Weiche_1920x1920.jpg

Edit: Oh, the speaker has some shelving eq flip switches to that might contribute to the size of the crossover too.
Edit2: Okay thinking about the shelving flip switches, those might actually be my solution in case the new tweeter is too high in volume due to sensivity. The "soft highs" flip switch reduces the highs about 2dB.
Edit3: And of course I will make a on axis measurement before and after. Should work pretty okay for frequencies this high even in my amateurish treated room.

With passive crossovers the impedance of the tweeter is part of the filter circuit so if you change the tweeter you will most likely change the crossover frequency in addition to any level differences.

If I were going to try this I would not rely on the "eq switches" and would wire a potentiometer to the tweeter so you could get at least get the level correct even if the crossover frequency changed. Just dropping in a tweeter that fits the hole has a low probably of improving things.

 

[raindance]

If the impedance, sensitivity, directivity and frequency response matches closely, then you could try the substitution. However, this would be rare.

 

[TimW]

My naive understanding is that everything "below" the tweeter should perform the same. It's a four way speaker with a beefy crossover network.
Would the whole system behave completely different in a very noticable way when I just change it to a tweeter with the same impedance?

The octave below the tweeter crossover at 2000 hertz may be impacted since analog crossovers are not brick wall filters. Also 2000 Hz and up is a considerable range and if it is not tuned properly the speakers will sound off.

 

[anphex]

It's done, I ordered two of those Berylli-boys. We'll see how it turns out. At the very least I and maybe you will learn a little bit
I'll report back this weeked with looot's of pictures and graphs.

 

[TimW]

How do you know the current tweeter is that SB? The speaker with the crossover you posted has a cosmetically very different tweeter.

vs

 

[anphex]

I took it out and was greeted by this exact product number .
Wait, picture following.

Ta-da!

 

[MaxwellsEq]

If you enjoy experimenting and don't mind writing off the cost of the new tweeters, it could work.

But it almost certainly won't work as you expect. Each drive unit is actually part of the crossover network.

It's a common mistake to think that great speakers are great because each of the drivers is brilliant. A great speaker is created through balancing compromises with cabinets, crossovers and drivers. There's a lot of design work and quite a lot of measurement and tuning.

 

[anphex]

I actually thought that each path has it's own separated "zone" of electronics but thinking about it that's just impossible for passive speakers, so yeah, I get what you all mean.

So another reminder: it's an reversible and refundable experiment, so why not. It's not like the very similar new tweeter will cause the remaining speaker to burn.

Still it baffles me then. By this reasoning, the flip switches should also change the whole frequency response and not just some part of it?

 

[voodooless]

I took it out and was greeted by this exact product number .
Wait, picture following.

Ta-da!

How is all of this mounted? Is the tweeter bolted to that asymmetrical face plate? Does the assembly use the original faceplate as well, or does the face plate replace it?

How do you want to do this with the new tweeter?

 

[fpitas]

"8 ohm tweeter" is about as descriptive as saying my gf is a brunette.

 

[anphex]

"8 ohm tweeter" is about as descriptive as saying my gf is a brunette.

The current tweeter is this one in a slightly changed casing: https://doc.soundimports.nl/pdf/brands/Scan-Speak/D2608-913000/pdf_SB Acoustics_D2608-913000_1.pdf

The new tweeter shall be: https://doc.soundimports.nl/pdf/brands/SB Acoustics/TW29BN-B/pdf_SB Acoustics_TW29BN-B_1.pdf

How is all of this mounted? Is the tweeter bolted to that asymmetrical face plate? Does the assembly use the original faceplate as well, or does the face plate replace it?

How do you want to do this with the new tweeter?

The current plate is symmetrical in terms of the screw placings. The new tweeter plate is about 6mm smaller in diameter and I'll see how it fits.
I can quickly make a makeshift 3d printed adapter for testing. But yes, it's also a thing that will decide the fate if this experiment.

 

[Vladimir Filevski]

I am thinking of swapping my tweeters of my large speakers. It's actually pretty easy and I found a suitable model.

It's kind of a "what if" project to see if this beryllium tweeter with its extended upper range can really provide the so often claimed "holographic transparency".

No, it will not. Holographic transparency is not just an extended high range.

Since the data is pretty close but not really I wanted to ask you for things to watch out for.

1. How much do I have to worry about phase?

2. The new tweeter has higher sensitity - do I need to put in a power resistor into the path?

1. Be afraid... Be very, very afraid...
Different tweeter - different phase.

2. You need a power resistor and a new crossover.

My naive understanding is that everything "below" the tweeter should perform the same.

It will not be the same around the crossover frequency, including some part of the spectra below tweeter.

Would the whole system behave completely different in a very noticable way when I just change it to a tweeter with the same impedance?

Yes, it will be completely different.
Tweeters with the same nominal impedance have wildly different impedances.