keith_correa
Well-Known Member
OT : The term for your TL designs - wasn't it "Advanced TL" before? It's "Advance TL" now.
OT : The term for your TL designs - wasn't it "Advanced TL" before? It's "Advance TL" now.
OK but that is not what I asked.If you ask me , the most scientific term for this design is Linear TL. "Linear" implies -- straight line without any taper. The term "Advance" is used by many to just term the technology - Some call it advance because of the use of different type of stuffing material which they have patented (PMC). I call it advance as it does not follow the classic TL method of calculating the Line length, cross-section area, stuffing density etc. In the classic TL you design your line near your driver resonance frequency. In this design its much higher than resonance. The line length is much shorter but thicker than a classic TL. Also the stuffing density is much higher in this design. This design allows me practical box designs. A classic TL box usually is too huge for practical implementation.
One question: Why the relatively large spacing between the drivers?
I asked about the spacing between the drivers not enclosures.My room area is just around 160 sqft. I have a door opening to the left and practically a wall to the right. Next there is a shoe rack to the left which needs space to open. Hence practicality scores more over reality. Else i will have to find a different home only for speaker listens. Even this distance of over 6 feet from the rare wall gives me superb image depth, well balanced lows, mids and highs as i get to place the speaker in the mid-field. The mid-woofer is around 6.5" which makes it sound better in the mid-field than the far field. Imo the far field should have driver size above 8"+. The space between the drivers is just 7 feet though it may look more in the image.
I asked about the spacing between the drivers not enclosures.
I hv mentioned the science behind them in my very first post. Pls check and get back to me if you did not follow
I just didn't understand what it meant by reading it. Can you explain?The crossover frequency is exactly 1800 Hz which is the distance between the woofer and tweeter center (7.5").
Oh, I'd seen that:
I just didn't understand what it meant by reading it. Can you explain?
All single drivers or concentric driver speakers are phase coherent.
I thought that the ROT is the maximum CTC needed and that closer is ALWAYS better. No?Convert 1800Hz to its wavelength. WL = c/f. Where c is the speed of sound in meters ie. 343.2 m/sec and f is the crossover frequency. That will be 7.5".
This is the distance between the woofer and tweeter center point. This will allow the woofer and tweeter to work like a single driver and not two point source.
I am aware of my room temp and altitude, but dont know its implementation.I thought the SoS depended on the temperature of the air and altitude. But I'm nitpicking.
I thought the SoS depended on the temperature of the air and altitude. But I'm nitpicking.
Hello Hari,
Congratulations on using such good drivers. These are unique where they couple amazing low distortion int he passband at a really low price. they are pretty much the stars of the dayton range in price / performance
One question - Is this advance TL the same single stuffed line design that you were using earlier. or is it something different.
Some points that you would want to explore.
the dayton 7" (RS180) has a terrible breakup mode at 9khz (with break ups starting at 3khz). using it as a 2way with 1st order crossover is extremely inadvisable as the sound will be extremely fatiguing. you need to push the break up point down below the point of audibility (-40db below signal is a good indicator) to ensure a smooth sound. if you want to use a first order network, almost always, avoid an aluminium driver. luckily the Dayton Alumimium tweeter is extremely stable upto 1.2khz as long as used with a high order high pass. Please google Jon Marsh's Modula to get a sense of the complex crossover required to make these drivers work well together in a 2 wa.
the other point with first order is the uneven frequency response caused by driver overlap over a larger frequency range.
finally if you are making this for your own room, which is small and has a lot of bass gain, you probably do not need BSC, but if you are planning to commercialise it and build for others, you should incorporated BSC, otherwise weak bass will be a bit of a problem.
woodwork looks good..
cheers
Thanks for your excellent inputs. Appreciated.
The TL box is still using the same design which i have used before - tune higher than resonance, heavily stuffed.
The first order crossover uses a sollen type network where at the crossover point the response is -6dB than the normal -3dB response. This helps in avoiding the +3dB peak at the crossover point and gives a flat response. Actually the woofer is crossed at 1148Hz and tweeter at 3330Hz to achieve this flat response at crossover.
If you refer to the simulated response in the first post, the response of the woofer at 9KHz is around 53dB which is 33dB down from 86dB. This is more of a non-textbook response where the woofer roll-off is @ of -10dB per octave and the tweeter roll-off @ of -7dB per octave. I am not able to listen any resonance mode breakup at my initial listening test. Maybe my ears are not trained for this. I have not used any BSC as the room where this drivers are installed is standard around 200 sq.ft. Infact the low frequency lift is more than i expected though not boomy.
Will check the articles as suggested by you and try to analyze if i am able to.
Thanks once again.
Gotcha!!!!!!!Its said - one picture speaks more than a 1000 words, so is listening. The proof of the pudding lies in its eating.