Table Tuba upper frequency suitability

For livingroom sound better than in a theatre.
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Skip Pack
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Joined: Fri Jan 12, 2007 1:40 pm
Location: Hollister, CA

Table Tuba upper frequency suitability

#1 Post by Skip Pack »

Hello Bill,

I was curious about how high you can cross the TT over with a clean result. One thought was that several nominally 'full' range drivers probably work much better from 300hz or so up, and the TT might work very well from there down as well as bing a suitable stand. I noticed that the LS11 alternative driver is spec'ed up to 300hz.

Thanks, Skip

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AntonZ
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Re: Table Tuba upper frequency suitability

#2 Post by AntonZ »

The TT may work well up to 300Hz, but the downside is that it's location becomes audible to our ears from about 100Hz up. Usually the sub is some distance away from the mains, since the optimal position for subs is drastically different from the optimal position for main speakers. For that reason the TT should be crossed over below 100Hz: our ears will not be able to tell where it is located. This is not a "nice-to-have", it is an absolute requirement.

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Bill Fitzmaurice
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Re: Table Tuba upper frequency suitability

#3 Post by Bill Fitzmaurice »

Skip Pack wrote: Mon Feb 22, 2021 2:38 pm the TT might work very well from there down as well as bing a suitable stand.
99 times out of 100 subs should not be placed under mains.

Skip Pack
Posts: 8
Joined: Fri Jan 12, 2007 1:40 pm
Location: Hollister, CA

Re: Table Tuba upper frequency suitability

#4 Post by Skip Pack »

Thanks to you both. The directivity issue makes perfect sense.

I had one further musing/question: What happens when you face a TT into a corner on the 45 degree bisector of the corner and engage the walls and floor as a horn expansion i their own right? This is reminiscent of Wayne Parhan's 6Pi and 7Pi corner horns, but, with the TT, you are interfacing one horn somewhat loosely with a second. Lots of additional factors, I imagine.

Skip

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Bill Fitzmaurice
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Re: Table Tuba upper frequency suitability

#5 Post by Bill Fitzmaurice »

There is some horn expansion effect, but it's slight, because best case you're only adding a couple of feet to a 14 foot horn. Adding a couple of feet to a five foot horn, for instance, would have a much greater impact. From what I've seen the 6pi and 7pi appear to be very short horns, with the room corner accounting for most of what little horn there is.

Skip Pack
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Joined: Fri Jan 12, 2007 1:40 pm
Location: Hollister, CA

Re: Table Tuba upper frequency suitability

#6 Post by Skip Pack »

This leads onward to the question: Does the additional expansion from the corner change the directivity of the higher frequencies? Maybe it's time to build them and see/hear/measure for myself.

Thaniks again, of course.

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Bill Fitzmaurice
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Re: Table Tuba upper frequency suitability

#7 Post by Bill Fitzmaurice »

There is no directivity much below 500Hz, with any speaker. If what you mean is being directionally locatable the speaker location doesn't affect that. The distance between your ears does. Your brain triangulates the source location if the wavelength is sufficiently short compared to that distance by sensing the phase difference of the signal at the two eardrums.

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