Quick question.
Making an MTM style T-line with 6" Tang band mids and 1" Tweets.
The Fs of the tweeters is 1,4kHz, so I don't know if I can make a lower crossover point than 2,8kHz?
Should I place the tweeter in between the mids or put the mids closer and the tweeter next to them?
The tweeter seems to have pretty optimal response at that width, when it's on the side, when I looked at it with a baffle simulator.
That would also get the mids closer together, but I have heard that the off-axis response will be unsymmetrical.
What would be better?
Making an MTM style T-line with 6" Tang band mids and 1" Tweets.
The Fs of the tweeters is 1,4kHz, so I don't know if I can make a lower crossover point than 2,8kHz?
Should I place the tweeter in between the mids or put the mids closer and the tweeter next to them?
The tweeter seems to have pretty optimal response at that width, when it's on the side, when I looked at it with a baffle simulator.
That would also get the mids closer together, but I have heard that the off-axis response will be unsymmetrical.
What would be better?
Personally i like the tweeter off to the side. It allows for the centre-to-centre to be smaller, and it gives more placement options.
One of the MTM ML-TLs we have done .
dave
One of the MTM ML-TLs we have done .
dave
Do you notice the difference in off-axis response and angled imaging?
What cons would be less noticeable and/or easier to fix somehow?
We never did one not like this, and the XO is low enuff that the off-axis response and imaging are pretty much all from the midTweeter. It does a really good job.
At the XO used the only real reason is to get the centre-to-centre closer. Everything is within a quarter wavelength and the drivers essentially become a single source. Closer gives me more flexibility in terms of XO point (highe ris OK if i needed)
The big compromise (not. big one IMO) is the use of a midTweeter to cover theh top 5+ octaves instead of a dome that barely does 3.
dave
At the XO used the only real reason is to get the centre-to-centre closer. Everything is within a quarter wavelength and the drivers essentially become a single source. Closer gives me more flexibility in terms of XO point (highe ris OK if i needed)
The big compromise (not. big one IMO) is the use of a midTweeter to cover theh top 5+ octaves instead of a dome that barely does 3.
dave
I can see the quarter wavelength rule helping make a better point source (vertically).
Unfortunately, mtm (with tweet) usually can't do that.
Take a pair of 6" framed woofs.
Make room between them (say 2")
Now we have basically a 14" woofer (vertically) if you look at vertical dispersion.
So If you have a tweet between them (2" framed tweet), the 14" woofer basically has 90 degree dispersion at maybe 900hz, so ideally you cross there.
No way that tweet will survive 900hz crossover point, let alone crossing near/below its resonance.
But, now we're see more 3" tweets, or 6db crossing fullrange crossing even lower than the above 900hz ideal.
Unfortunately, mtm (with tweet) usually can't do that.
Take a pair of 6" framed woofs.
Make room between them (say 2")
Now we have basically a 14" woofer (vertically) if you look at vertical dispersion.
So If you have a tweet between them (2" framed tweet), the 14" woofer basically has 90 degree dispersion at maybe 900hz, so ideally you cross there.
No way that tweet will survive 900hz crossover point, let alone crossing near/below its resonance.
But, now we're see more 3" tweets, or 6db crossing fullrange crossing even lower than the above 900hz ideal.
Joseph d'Appolito put it in the middle and used an odd-order Butterworth crossover filter, if I recall correctly.
That is where he started. But he was only the one to popularize the arrangement with his Speaker Buikder article (at a tie when i eagerly awaited the mag in the mail), but it certainly pre-dates his article.
Ted & i built an MTM triangulaed TL in 1975 (2xHarbeth 8" clear poly). And i’m pretty sure the arangement was inspired by something earlier.
dave
Ted & i built an MTM triangulaed TL in 1975 (2xHarbeth 8" clear poly). And i’m pretty sure the arangement was inspired by something earlier.
dave
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I only read his AES preprint, I didn't know he also wrote a Speaker Builder article. (I could read AES preprints in a library, but it didn't have Speaker Builder as far as I know.)
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I do also have a pair of Tangband W2-2243s widebands I bought when drunk on black Friday just because I read that you need a lower XO-point for this arrangement.
They need to be crossed over at 500Hz or higher. They seem to be very good to be a 2" driver, with a sensitivity close to 90dB, but the sensitivity and power handling isn't enough.
Could it be beneficial to integrate these widebands as a midrange to these speakers? Or would it be a viable option with 2x of them?
E.g. if I made a BMTMB, Bass, Mid, Tweet, Mid, Bass.
This would be a shame as the 6" play smoothly up to 10kHz.
The mids are 176mm wide, tweeter is 54mm high and widebands are 57mm high.
Wouldn't an MTM with the widebands be able to be crossed over at 3kHz?
Would I be able to wire the 6" in parallell because they just become 4Ohm and the 2" in series because they are already 4Ohm?
Then I would have 120W power handling for bass, 40W for mids and 10W for tweets, my amp can produce 170Wx2 @4Ohms.
This would be a shame as the 6" play smoothly up to 10kHz.
The mids are 176mm wide, tweeter is 54mm high and widebands are 57mm high.
Wouldn't an MTM with the widebands be able to be crossed over at 3kHz?
Would I be able to wire the 6" in parallell because they just become 4Ohm and the 2" in series because they are already 4Ohm?
Then I would have 120W power handling for bass, 40W for mids and 10W for tweets, my amp can produce 170Wx2 @4Ohms.