125 dB - ouch!!!
In addition to sound addiction, you've now added risk addiction to your list of hobbies ? 🙂
Did your hair stand up like they show in the movies?
Good one, Derek!
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Don't forget typing replies into forum posts, so many distractions 😀
I'll take some more pictures tomorrow of today's progress, too dark now for them to come out properly.
It was 50 of them playing at once...
I was measuring with REW at that time and briefly used Audiolense and went back to REW to do "a" measurement. Didn't pay attention to where my levels were at that time. I thought my room would collapse! I sat in wonder for a couple of minutes wondering if I broke anything... my ego among other things.
Looking up old measurements shows I didn't keep that one. I only have a few at 116 dB peaks which were my normal levels.
This didn't rattle my ceiling 😉.
I think my ceiling made more noise than the arrays did at that point! (lol)
Distortion plot didn't look clean and I was scared I broke my arrays after only one month of fun.
It made me painfully aware to be a lot more careful.
I was measuring with REW at that time and briefly used Audiolense and went back to REW to do "a" measurement. Didn't pay attention to where my levels were at that time. I thought my room would collapse! I sat in wonder for a couple of minutes wondering if I broke anything... my ego among other things.
Looking up old measurements shows I didn't keep that one. I only have a few at 116 dB peaks which were my normal levels.
This didn't rattle my ceiling 😉.
I think my ceiling made more noise than the arrays did at that point! (lol)
Distortion plot didn't look clean and I was scared I broke my arrays after only one month of fun.
It made me painfully aware to be a lot more careful.
Out performing worlds best 15 inch Pro drivers?
I assumed you were listening to both speakers.... 129 dB @ 1 meter from a single speaker would have been impressive....
Using 800 watts to 1.2Kwatts, depending on size of voice coil (4 or 5 inch ventilated inside / outside windings), the very best Pro sound 15 inch bass mid drivers (same Sd as each one of your 25 driver arrays) struggle to reach 129dB @ 1 meter....
Cheers
D.
I assumed you were listening to both speakers.... 129 dB @ 1 meter from a single speaker would have been impressive....
Using 800 watts to 1.2Kwatts, depending on size of voice coil (4 or 5 inch ventilated inside / outside windings), the very best Pro sound 15 inch bass mid drivers (same Sd as each one of your 25 driver arrays) struggle to reach 129dB @ 1 meter....
Cheers
D.
I wouldn't call it listening 😀....
It was one sweep I'll never forget. It didn't sound like music or even noise, more like a jet plane flying over, inches above my head. Everything was rattling. I was very scared I blew up everything in the process. The next sweep I did was around 70 dB (lol).
I never want to repeat that moment ever again. It was my second or third measurement.
I've done lots more measurements after that, never had that kind of accident again.
It was one sweep I'll never forget. It didn't sound like music or even noise, more like a jet plane flying over, inches above my head. Everything was rattling. I was very scared I blew up everything in the process. The next sweep I did was around 70 dB (lol).
I never want to repeat that moment ever again. It was my second or third measurement.
I've done lots more measurements after that, never had that kind of accident again.
600/800/1000/1200 watts into 1x PD.1550, now take 2x PD.1550 to have same area as 50x TC9 😛
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Max 123dB single = 126dB for pair at full XMax
Thanks Brytt,
My guess was not bad... 123dB at XMax for a single driver, or 126dB for a pair.
The PD 1550
PD.1550
is a great value driver, but no longer state of the art... PD have higher output lower distortion drivers available that will go about 3dB to 4dB louder with lower distortion..... But they cost double what the 1550 retails for.
Assuming you have an accurate set of measurements or are working with a trusted manufacturer (Precision Devices are very honest) a good guide to a drivers true output capability is:
Average the SPL over the bandwidth you are intending to use the driver and multiply up the 1 watt graph until you get to max AES power handling.
Using the attached 1550 graph that might be 80Hz to 500Hz.
Average SPL over that band is approx. 96dB or 97dB at a quick guess.
So 1 watt = 97dB
2 watt = 100dB
4 watt= 103dB
8 watt = 106dB
16 watt = 109dB
32 watt = 112dB
64 watt = 115dB
128 watt = 118dB
256 watt = 121dB
500 watt = 124dB
600 watt = 124.5dB .... This is the Max AES continuous power handling limit including the quoted manufactures spec of 2.7 dB power compression ie the drivers true MAX SPL at 600 watts = 121.8dB... Way lower than any Sim will suggest....
Running the driver into extreme power compression.... Gives a distorted :
1,000 = 127dB
2,000 watt =130dB
Hope this helps clarify the difference between Sims and real world results...My best sims are mdf test box and measure....
Cheers
Derek.
Thanks Brytt,
My guess was not bad... 123dB at XMax for a single driver, or 126dB for a pair.
The PD 1550
PD.1550
is a great value driver, but no longer state of the art... PD have higher output lower distortion drivers available that will go about 3dB to 4dB louder with lower distortion..... But they cost double what the 1550 retails for.
Assuming you have an accurate set of measurements or are working with a trusted manufacturer (Precision Devices are very honest) a good guide to a drivers true output capability is:
Average the SPL over the bandwidth you are intending to use the driver and multiply up the 1 watt graph until you get to max AES power handling.
Using the attached 1550 graph that might be 80Hz to 500Hz.
Average SPL over that band is approx. 96dB or 97dB at a quick guess.
So 1 watt = 97dB
2 watt = 100dB
4 watt= 103dB
8 watt = 106dB
16 watt = 109dB
32 watt = 112dB
64 watt = 115dB
128 watt = 118dB
256 watt = 121dB
500 watt = 124dB
600 watt = 124.5dB .... This is the Max AES continuous power handling limit including the quoted manufactures spec of 2.7 dB power compression ie the drivers true MAX SPL at 600 watts = 121.8dB... Way lower than any Sim will suggest....
Running the driver into extreme power compression.... Gives a distorted :
1,000 = 127dB
2,000 watt =130dB
Hope this helps clarify the difference between Sims and real world results...My best sims are mdf test box and measure....
Cheers
Derek.
Thanks for the input guys, this quote tells me loud enough and low enough for music.
Just for wesayso here is a couple of shots to show that there is plenty of room for excursion under fabric, difficult to take a picture of but I think you get the idea.
Test sock on bottom with test base attached
Elastic for the top to put some tension on the fabric
Hardwood base blanks roughed out ready for flush routing
Just for wesayso here is a couple of shots to show that there is plenty of room for excursion under fabric, difficult to take a picture of but I think you get the idea.
Test sock on bottom with test base attached
Elastic for the top to put some tension on the fabric
Hardwood base blanks roughed out ready for flush routing
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Very nice! My arrays are all bling bling compared to your sleek inconspicuous columns
Well sleek and inconspicuous is what I'm going for so I am happy with that!
Nothing wrong with a bit of bling and I think you have managed to stay on the right side of too shiny. I think the contrast of your baffle against the textured paint has come out very well. The super polished wood finish you had may have been too much for the long term.
I got a look at the whole column covered in a sock today and it was pretty nice. I didn't want these to obviously look like speakers.
Unfinished bases with the spikes mounted, with and without the pads for hard surfaces.
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Nice. My thought about low frequencies was not concerned with loudness itself. I bet these line arrays can get painfully loud-50 drivers are 50 drivers. But it has more to do with Fs - would it be possible to harmlessly equalize this line array in order to properly produce a 30 hz note? It's not necessary to be loud - 92-95 db at the listening spot would be fine. Of couse I argee that it would be more appealing to achieve that without subs, thus avoiding phase issues...
Wesayso has plenty of measurements and graphs in his Two Towers thread that show that they can be equalised very low and still maintain reasonable distortion in the lower frequencies. He has an F3 of 17Hz with his EQ.
The EQ isn't "harmless" in the sense that it reduces maximum output and increases excursion but it is reasonable. Think of it like a long thin driver of equivalent size to a 15" driver in terms of Sd at low frequencies.
Subs are more useful for Home Theatre where the biggest peaks can be below 20Hz and handling those will mean a reduction in maximum output that might be detrimental. Also if you wanted PA type levels then subs below 80Hz with a crossover to relieve the lines would let you take the levels much higher.
I couldn't resist to take some pictures of the full sock over the cabinet with the wooden base. Terrible pictures due to no natural light but I think it conveys what they will look like when finished.
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Looking great fluid! I have to say, you build super fast! I haven't seen a whole speaker covered by a fabric sock before, but I have to say that it looks good!
I'm sold on doing a line array of the TC9's in the future. I'm curious what internal volume you and Wesayso are using for each driver. I modeled the 8Ohm TC9, TG9, and 10F 8414 and the TC9 had the best combination of low frequency response and power handling. It also had the flattest impedance curve; a steal at the cost of each driver. The only thing that concerns me is that in modeling I came to the conclusion of 2 - 4.2 liters per (sealed) enclosure, which gives a very high Qts of 1.1 - 1. 😱
Just incase it helps anyone, power handling so xmax is not exceeded all the way to 20hz, without EQ boosting the bass, is 10W in a 2L enclosure per driver, and 7 Watts in a 4.2L enclosure per driver.
I'm sold on doing a line array of the TC9's in the future. I'm curious what internal volume you and Wesayso are using for each driver. I modeled the 8Ohm TC9, TG9, and 10F 8414 and the TC9 had the best combination of low frequency response and power handling. It also had the flattest impedance curve; a steal at the cost of each driver. The only thing that concerns me is that in modeling I came to the conclusion of 2 - 4.2 liters per (sealed) enclosure, which gives a very high Qts of 1.1 - 1. 😱
Just incase it helps anyone, power handling so xmax is not exceeded all the way to 20hz, without EQ boosting the bass, is 10W in a 2L enclosure per driver, and 7 Watts in a 4.2L enclosure per driver.
Those speaker binding posts you showed back a few pages look like the ones I once used, they are very inexpensive, sold by Parts-express, jantzen kits, ebay, etc. Troels uses them in all of his kits, even the most expensive ones. They come in 5 different metallic paint colors but don't let the colors on them fool you, they are cast zinc and they sound horrible. They are brittle and will snap off if you tighten the installation nut too hard, then you see the gray/white metal inside. The improvement in sound quality when I replaced them was profound. Friends don't let friends use zinc connectors. 😉
You're making great progress! I'm looking forward to reading your initial impressions of the sound, and following your tuning procedure.
You're making great progress! I'm looking forward to reading your initial impressions of the sound, and following your tuning procedure.
Then you haven't seen a Vandersteen 2Ce
Model 2Ce Signature II | Vandersteen Audio
or OPC's line array 🙂
http://www.diyaudio.com/forums/multi-way/193015-stupid-cheap-line-array-4.html#post2648779
I have been able to devote a lot of time to this in the last week so I have been trying to make the most of it. I have finished the bulk of the time consuming parts now but it will still be a while before it is all completed.
My enclosure will work out to be about 2L effective volume when the stuffing is taken into consideration. I think wesayso's was about 2.3 to 2.6L.
This driver does not model properly in all software and you really need to take account of the change in effective volume the stuffing causes. Bassboxx pro can do this and it gives a pretty good model.
Have a read of this post and the surrounding if you haven't seen it. I made some calculations from a posted impedance plot from wesayso. You can see that the Q of the speaker in the cabinet is about 0.77 which is pretty much what Bassboxx pro predicts.
http://www.diyaudio.com/forums/full-range/290677-wall-integrated-corner-loaded-line-array-vifa-tc9-drivers-29.html#post5001148
I wanted to use Jeff Bagby's woofer designer as that has a linkwitz transform that would have given a pretty good indication of x-max vs boost but it would not model properly so I couldn't do it 😡
Applying EQ will increase excursion and limit headroom.
They are definitely the same as I got them from parts express when I bought the drivers. I had no illusions that they were anything else other than what they are. Disappointing to hear that your's cracked. The ones I have seem sturdy enough so far.
As to a profound change in sound quality from changing the binding posts...
Unless they had an unusually high contact resistance or were actually broken then I find it hard to see how. Thanks for pointing it out as it's always good to be aware of potential issues and I do have some speakon's to use should my sound be brittle 😉
Thanks, my pace is usually glacial so it's good to be moving quickly for a change!