Vogo, your sketch of the ML-TL I described and modeled is correct except for the mass-loading port's length. That total length is 44 mm, so twice the thickness of the wall you're using. And, don't forget the stuffing in the top half or so of the cabinet as I stated.
As to what would sound better? Any properly designed and implemented TL, regardless of the specific type, should sound just as good as any other type with similar response and performance. I'll take a look again at a tapered TL to see just how big the cabinet would have to be to get an F3 about the same as this ML-TL and an acceptably smooth overall response.
As to what would sound better? Any properly designed and implemented TL, regardless of the specific type, should sound just as good as any other type with similar response and performance. I'll take a look again at a tapered TL to see just how big the cabinet would have to be to get an F3 about the same as this ML-TL and an acceptably smooth overall response.
Vigo said:
Thumbs down on a tapered TL
Vigo: I don't know if others could be more successful but I sure can't come up with a good-performing tapered TL for these drivers in any reasonable-sized box. I went back an re-read your first couple of posts and realized the cabinet being taller than what I modeled in the ML-TL would be okay with you. So, taking the ML-TL cabinet from my modeling for which you did the sketch, increase the internal height to 1145 mm, and keep the internal width and depth the same. The tweeter's center would again be located 250 mm from the inside of the top; this will likely bring the tweeters' center more aligned with your ears when you sit down to listen. With the increase in height, there's an obvious increase in internal volume, and this allows the port's length to be cut in half for the same F3, which means the port's length is just the 22 mm thickness of the baffle (and still 25 mm high and 200 mm wide). The port is again located at the very bottom. If you have to place your speaker cabinets much less than 12" from the wall behind them, a baffle location for the port is probably best, but if the cabinets can be 12" or more in front of that wall, a rear panel port location is good. With the increased height and cabinet volume, you'll need more stuffing, 500 grams, and it should be uniformly distributed in the top 600 mm of the cabinet's height to achieve a stuffing density of 0.75 lb/cu.ft. I assume you realize you'll need bracing in the cabinet and I'd suggest a "window frame" type brace, and at least 3 or 4 of them strategically located from top to bottom. I'd located on between the tweeter and the lower woofer, another about 1/2-way down the cabinet to act as stop for the stuffing, and one or two more between there and the bottom.
Vigo: I don't know if others could be more successful but I sure can't come up with a good-performing tapered TL for these drivers in any reasonable-sized box. I went back an re-read your first couple of posts and realized the cabinet being taller than what I modeled in the ML-TL would be okay with you. So, taking the ML-TL cabinet from my modeling for which you did the sketch, increase the internal height to 1145 mm, and keep the internal width and depth the same. The tweeter's center would again be located 250 mm from the inside of the top; this will likely bring the tweeters' center more aligned with your ears when you sit down to listen. With the increase in height, there's an obvious increase in internal volume, and this allows the port's length to be cut in half for the same F3, which means the port's length is just the 22 mm thickness of the baffle (and still 25 mm high and 200 mm wide). The port is again located at the very bottom. If you have to place your speaker cabinets much less than 12" from the wall behind them, a baffle location for the port is probably best, but if the cabinets can be 12" or more in front of that wall, a rear panel port location is good. With the increased height and cabinet volume, you'll need more stuffing, 500 grams, and it should be uniformly distributed in the top 600 mm of the cabinet's height to achieve a stuffing density of 0.75 lb/cu.ft. I assume you realize you'll need bracing in the cabinet and I'd suggest a "window frame" type brace, and at least 3 or 4 of them strategically located from top to bottom. I'd located on between the tweeter and the lower woofer, another about 1/2-way down the cabinet to act as stop for the stuffing, and one or two more between there and the bottom.
Yes i remember the port and the stuffing i just did not put it in this very early sketch. Thank you for reminding me
Ok sow it looks like the ML-TL might be the way to go then.
Sow I will start to design a proper drawing form your new specification.
yes i amused that it would need some kind of support.
With "window frame" brace I guess that you mean a big square that covers all 4 side then you have four rectangular holes in them.
How much of the brace need to be open to not have any negative effect on the sound?
When you change the length of the cabinet did you get a lower f3 or any other change in the plot?.
Thanks for all help, it have brought me a very good start to design from.
Ok sow it looks like the ML-TL might be the way to go then.
Sow I will start to design a proper drawing form your new specification.
yes i amused that it would need some kind of support.
With "window frame" brace I guess that you mean a big square that covers all 4 side then you have four rectangular holes in them.
How much of the brace need to be open to not have any negative effect on the sound?
When you change the length of the cabinet did you get a lower f3 or any other change in the plot?.
Thanks for all help, it have brought me a very good start to design from.
Yes, the window frame brace is as you described it. I usually use that type of frame and depending on the specific design, I make the width of the four sides and the two cross pieces either 3/4" or 1". For this design, that would mean the four rectangular holes will each be about 2-7/8" wide by about 5-5/8" deep. With this increase in height and volume, F3 didn't go more than about 1 Hz lower, ending in the 36-38 Hz range.
Vigo said:Yes i remember the port and the stuffing i just did not put it in this very early sketch. Thank you for reminding me
Ok sow it looks like the ML-TL might be the way to go then.
Sow I will start to design a proper drawing form your new specification.
yes i amused that it would need some kind of support.
With "window frame" brace I guess that you mean a big square that covers all 4 side then you have four rectangular holes in them.
How much of the brace need to be open to not have any negative effect on the sound?
When you change the length of the cabinet did you get a lower f3 or any other change in the plot?.
Thanks for all help, it have brought me a very good start to design from.
Vigo, your sketch is correct but make sure the top of the second brace, the one used as a "stop" for the stuffing, is the correct distance from the top. Also, I feel it's necessary for a cautionary comment. I modeled with the T/S values as published by Tymphany, which you provided, and if the actual T/S values for your four drivers are appreciably different than those published, the model may not be as optimum as it could be.
Yes the second brace is but sow that the stuffing stops at 600mm from the top.
Yes i understand that it depends on that the values for the driver is correct. But i dont have the possibility to test them. Sow lets hope that the people at Peerless know what they are doing.
But what i read, it seam like Peerless driver normally is quite correct with the data official data.
Sow i will continue with the work and hope for the best.
Thanks for all your support
Yes i understand that it depends on that the values for the driver is correct. But i dont have the possibility to test them. Sow lets hope that the people at Peerless know what they are doing
.But what i read, it seam like Peerless driver normally is quite correct with the data official data.
Sow i will continue with the work and hope for the best.
Thanks for all your support
I am thinking about were to place the treble?
I have to options, to but it between the mid/bass or on top.
If I put it on top it will be easier to time align with the rest, but i am am afraid that it will be positioned to high above my ears.
Any one have any thoughts on the subject to help me decide?
I have to options, to but it between the mid/bass or on top.
If I put it on top it will be easier to time align with the rest, but i am am afraid that it will be positioned to high above my ears.
Any one have any thoughts on the subject to help me decide?
Attachments
Vigo, there are basically two problems with placing the tweeter on the top of the cabinet. The first is that it will be quite a bit above your ears when seated, and the second is that both of the midwoofers are a lot further away from the tweeter, making it difficult, maybe impossible to properly integrate their outputs with that of the tweeter in the crossover design (and each of the woofers will be a different distance away, compounding the crossover design even more). The lack of time aligning with the tweeter between the midwoofers is a far lesser problem than what you'll create with the tweeter on top of the cabinet.
Vigo said:
Me together with the material put together to see the fit of the mdf.
Looks bigger in real life then expected,
Thank you for the answer and good points.
When i see the speakers size in real life i can see that it is way to high to put the tweeter on top.
This together with the input from pkitt made me decide to put the tweeter in the middle.
Happy day
Today i put the speakers together for the first time to test them.
No finish yet and i will spend some time now to adjust them amount of stuffing.
I built them after pkitt simulations and suggestions with 500g of sheep wool in each speaker.
My first impression is really good. The simulations really hit the spot. Bas is firm and deep with a good punch. Much better than i hopped for.
Overall i am very happy with the sound sow far, clear and many details with a impressive low end.
Sow for then nearest time i will listen and test with more and less damping to see what happens. Then i will put a finish on it when i feel it is as good as i can get it.
Just want to say many thanks for all help from pkitt and all others.
/will upload picture soon.
Today i put the speakers together for the first time to test them.
No finish yet and i will spend some time now to adjust them amount of stuffing.
I built them after pkitt simulations and suggestions with 500g of sheep wool in each speaker.
My first impression is really good. The simulations really hit the spot. Bas is firm and deep with a good punch. Much better than i hopped for.
Overall i am very happy with the sound sow far, clear and many details with a impressive low end.
Sow for then nearest time i will listen and test with more and less damping to see what happens. Then i will put a finish on it when i feel it is as good as i can get it.
Just want to say many thanks for all help from pkitt and all others.
/will upload picture soon.
An externally hosted image should be here but it was not working when we last tested it.
Inside of the speaker with 3 support frames.
An externally hosted image should be here but it was not working when we last tested it.
Speaker from the side, the front shield is made from oak.
An externally hosted image should be here but it was not working when we last tested it.
The speaker drivers, the two preerless drivers and one Fostex FT3R
Vigo, you certainly can adjust the stuffing density to best suit your ears, but FWIW, I've never had to change the stuffing density in any of my TLs after installing the amount dictated from the modeling results (and I always make sure I can do that easily if necessary). So far, it seems you are pleased with the results and that makes me happy, too. And, you cabinetry works looks very good.
Vigo said:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.