Driver Opinions/Help

I have had four of the HiVi A5+(Link) buyouts and two TB W3-871's(Link) laying around for a while. I know the TB is more or less a FR driver, but have come across some using it as a tweeter. Any opinions on these being used in a TM or MTM configuration? If these drivers might perform decent or better together, crossover help would also be greatly appreciated.

TIA,
Brian
 
It would be helpful to see the response graph on the HiVi, to get a better idea of where to put the crossover point. The TB driver could be run fullrange, with maybe some cutoff towards the bottom end to let the HiVis take over down there. But you would probably want to put a higher order lowpass on the HiVis to let them do the bass as much as possible.

I think an MTM is your best bet here - a TMM is possible but that would be a 2.5 way and need a more complex crossover. Keep it simple for now.
 
Well the HiVis are nice and smooth all the way through the midrange but start to get ragged above 1K. I think what you'll want to do here is let the TBs be your mid-high drivers but get them out of the bass region because small drivers like this will just bottom out if you try to drive them fullrange into high SPLs.

The HiVis can serve primarily midbass and bass, but could share the midrange too. If you want them to do most of the bass work then a lower crossover point is better.

I'm guessing here that you don't want to spend a lot of money on crossover parts, so you may be able to get away with a first order crossover for each driver, and see what you end up with. It would really be best if you could model these with software though, otherwise we're both guessing. I have some software loaded but I haven't used it yet - maybe this would be a good place to start!

If I had to nail down a crossover point I'd want to keep it out of the voice region so maybe 300 Hz is a good spot, but both drivers roll off rather gradually so a second-order XO may be appropriate if you want to really get the most out of these. Save money and use electrolytic capacitors, and go MTM.
 
Hmmm.........

the A5 and the TB might work as an MT with a first order series
crossover and the c/o point set to reflect baffle step, its hard to
say without modelling.

For parrallel (4ohm) MTM the TB is not sensitive enough
and a standard good tweeter is far better idea IMO.

I have Zaph's 871 files archived, Timn8ters site has some info.

:)/sreten.
 
streetscholar said:
So is this Crossover Guide(Link) the place to start or should i be looking elsewhere?

thanks again,
Brian

IMO those charts are OK as a starting point but it really depends on your budget and tastes. If you're willing to model with software you'll likely end up with different (better) component values and better performance. You may not have to spend any more money either.

As far as the MTM goes, yeah it may be a bad idea - the TB could get "lost" in the HiVis - but if you want to use both the HiVis in each speaker you'd need to go TMM 2.5-way. Sreten can this be done with just an inductor for the .5 woofer? Or?

Also Brian - I'm assuming you do want to do something with these drivers - if that's wrong and you're willing to invest in others, let us know and the advice may take a different path. If not it's no problem - build something and learn, and if you like the sound then you've been successful.
 
sdclc126 said:


IMO those charts are OK as a starting point but it really depends on your budget and tastes. If you're willing to model with software you'll likely end up with different (better) component values and better performance. You may not have to spend any more money either.

As far as the MTM goes, yeah it may be a bad idea - the TB could get "lost" in the HiVis - but if you want to use both the HiVis in each speaker you'd need to go TMM 2.5-way. Sreten can this be done with just an inductor for the .5 woofer? Or?

Also Brian - I'm assuming you do want to do something with these drivers - if that's wrong and you're willing to invest in others, let us know and the advice may take a different path. If not it's no problem - build something and learn, and if you like the sound then you've been successful.

If possible to pull off an MTM with these drivers without spending a small fortune to make it work, that is what i would really like to do.

As far as the possibility of using different drivers, i would still want to use the HiVi mids but would consider a good, dedicated tweeter. Again, I don't want to go crazy on xo components as the drivers cost about $60.00 with buyout and sale pricing. So I don't want to spend more on components than i did on drivers.

thanks,
Brian
 
That actually gives you a lot of headroom. Look at

http://www.zaphaudio.com/tweetermishmash/

Given what you've already purchased, I would stay in the same price/quality category. The HiVi K1 is a good candidate, and you can save money on crossover components by going with the higher XO point.

It is possible to run the A5s without a crossover, but I'm concerned about the response peak at 5500 Hz - a notch filter is probably worth serious consideration here.

To go MTM means either 4 ohm resistance for the woofers if wired parallel, or 16 if wired in series; 16 will be easier on your amp but the tweeter may need padding (a resistor) as a result - but resistors are cheap.

As for the TB widerangers - maybe use those for surrounds or computer speakers, or build something for a friend - it doesn't have to be a waste of money.
 
We can try. Look at this Zaph design:

http://www.zaphaudio.com/audio-speaker20b.html

You could probably use the same filter for the ND20FA, in fact it might roll the tweeter's low end off a bit more steeply, which would be a good thing.

We could work on a notch filter for the HiVis, but the issue will be the resultant 4 ohm resistance the MTM parallel set up would present. The Dayton is a relatively efficient tweeter, with a 6 ohm impedence, so it might work out OK.

With these variables I think this would need to be modelled to see the predicted response. Do you happen to have the T/S parameters for the HiVis?

Also, we can do this together - read this tutorial:

http://www.rjbaudio.com/Audiofiles/FRDtools.html

Then download the necessary software - this is as good a time as any to learn how to do this so you'll be on your way to self-sufficiency. It's also a good motivator for me to get off my lazy [email protected] and use these tools myself.