New project.

[Starre]

I just finished a speaker project but now I am thinking of the next, this time designing myself. I was thinking of a 2.5-way speaker with closed cabinet. This woofer might be a good choice since I want to make a rather cheap speaker: Europe Audio
Then I need to find a good cheap tweeter. My thought was to build a floorstander, narrow and about 1 meter high. This speaker should be compact to use as a TV speaker to avoid those awful built in TV speakers.
Closed cabinet to make them easy to place and to build.

[a_tewinkel]

How about this for a tweeter from about 2,5 kHz? It's decent and cheap as well

Or perhaps this crossed at 2 kHz?

[Starre]

Thanks, I have been looking at those, I will have a look tonight trying to figure out what will suit the woofer best. I have to learn a lot, but from what I know if you use 2 woofers in a 2.5-way you get 3dB more sensitivity so since the woofer is about 88dB sensitivity the tweeter should at least be 88+3=91dB, right?

[giralfino]

While the gain for two drivers running in parallel is 6dB, you are completely forgetting the baffle step effect. This should give you a loss of 6dB at low frequencies, while retaining the nominal sensitivity at high fr. Here Low and High are in terms of the baffle width.
The normal approach of a x.5 design is to completely compensate for this baffle effect, in which one of the woofer runs "full-range" and the other (the .5 woofer) has a 1st order low pass centered at the baffle step frequency. See for example: ZDT3.5

As for the tweeter's choice, using a 6.5" mid-woofer, I'd opt for a tweeter able to be crossed at 2KHz LR4. A Vifa DX25 should be able to do that. For a higher price there are the Seas 27TDFC or 27TBFC/G.

Ralf

[Starre]

Thanks giralfino, like I said I have some learning to do. I have read somewhere about that way to compensate for the baffle step and my intention is do it like that.
I want a tweeter that is rather cheap but at the same quality level as the woofers. Hope this is possible.

[giralfino]

The Vifa tweeter I suggested and your mid-woofer of choice have already been used together: Tarkus

Ralf

[Starre]

I think I am choosing between the Vifa DX25 or Seas 27TDFC. Best choice for a simple crossover work? Should be the Seas? What do you think?

[EngelholmAudio]

Originally Posted by Starre

I just finished a speaker project but now I am thinking of the next, this time designing myself. I was thinking of a 2.5-way speaker with closed cabinet. This woofer might be a good choice since I want to make a rather cheap speaker: Europe Audio
Then I need to find a good cheap tweeter. My thought was to build a floorstander, narrow and about 1 meter high. This speaker should be compact to use as a TV speaker to avoid those awful built in TV speakers.
Closed cabinet to make them easy to place and to build.

I am not too impressed with the frequency response of this driver.

The resonance at ~5kHz is visable also in the off axis responses and my experience is that one can hear this in some extent.

[Starre]

Hi EngelholmAudio. Yes I have seen that and maybe it will be problematic. However it should be possible to remove it with the crossover, I think they did that with the "Tarkus", se link above. The woofer is very cheap at the moment at that dealer, maybe because of the problems you mentioned.

[giralfino]

I think I am choosing between the Vifa DX25 or Seas 27TDFC. Best choice for a simple crossover work? Should be the Seas? What do you think?

I don't have first hand experience with either drivers, but I think that both can be used with a 2KHz LR4. The Seas can go a bit lower though. The hard part for the crossover is in the woofer part, with the 5KHz breakup, but as seen in the Tarkus project, you have a starting point.
Ralf