Hi all,
I recently ordered a new subwoofer speaker for my first build and I decided to tested if it worked connecting it to the plate amplifier it will be paired to. I sadly found out later that this is not recommended as the driver can be damaged from overexcursion, not having air resistance from the enclosure.
Lesson learnt.
Used for about 15 minutes, playing two songs and some sounds from a frequency generator. Is there a way I can measure if the speaker was damaged? for instance with a multi meter?
At the moment the driver doesn't make any "scratching" noise when is pushed down.
Also I noticed that the driver was extremely quiet when used, I could barely hear it unless my ears were literally next to it. Is it because the waves from the front and back cancel each other out, or is the power from the amp too low?
It is a dayton DCS165 powered by a 80W RMS plate amp.
Thanks
I recently ordered a new subwoofer speaker for my first build and I decided to tested if it worked connecting it to the plate amplifier it will be paired to. I sadly found out later that this is not recommended as the driver can be damaged from overexcursion, not having air resistance from the enclosure.
Lesson learnt.
Used for about 15 minutes, playing two songs and some sounds from a frequency generator. Is there a way I can measure if the speaker was damaged? for instance with a multi meter?
At the moment the driver doesn't make any "scratching" noise when is pushed down.
Also I noticed that the driver was extremely quiet when used, I could barely hear it unless my ears were literally next to it. Is it because the waves from the front and back cancel each other out, or is the power from the amp too low?
It is a dayton DCS165 powered by a 80W RMS plate amp.
Thanks
I think its probably ok.
But I would test voice coil impedance in case some damage did occur.
And if the speaker doesn't crape when pushed in and out then you probably got away with it.
It will of course sound much louder in an enclosure.
But I would test voice coil impedance in case some damage did occur.
And if the speaker doesn't crape when pushed in and out then you probably got away with it.
It will of course sound much louder in an enclosure.
I have actually heard of people doing basically what you did (being careful with the volume control, of course) intentionally to "break in" a driver before testing it. This was done because as the suspension of the driver gets worn out, the T/S parameters will change a bit. Come to think of it, my old Woofer Tester 1 (the one that ran on DOS and plugged into a serial port), I believe had a set of rca jacks on the front which, according to the instructions, were intended to eventually allow the device to have a "break in" function where it played sine waves to an amplifier that the end user would provide. As far as I know, this feature was never added in any software update, however...
If you didn't hear any loud popping noises during your testing (a sign of the driver's voicecoil former hitting the back plate), then the driver's likely fine.
Nice driver, btw. I used its bigger brother, the DCS205, in my "Boom Unit" build (a tapered TL). I'm very satisfied with the results.
Nice driver, btw. I used its bigger brother, the DCS205, in my "Boom Unit" build (a tapered TL). I'm very satisfied with the results.
Not likely enough to matter. It would be your ears that would get damaged first from over-driving.
Do you have a good notion of how strong a signal you are putting into your amp that seems to result in a low signal coming out that seems to result in a low signal from your driver?
B.
I'll get my hands on a multimeter today, what would you specifically look for? Ohm measurement at 0 or just lower/higher than the specs?
Glad you liked it! The DCS165 seemed to have a very similar frequency response to the 205, just with a bit less volume. I was a bit concerned about the overall volume of the speaker when I tested it, so I really hope it will be louder in the enclosure. What amp did you use your with?
Also I came across your website when I was researching for my build, and it was a great read to get started. Great content!
I have to say, I thought about it as the driver sounded a bit fuller at the end of the my test. It could be a way to break it in quicker.
I'm confused. Which probably means no...
Right now I'm using it with the built-in amp that came with the Logitech multimedia system, so I'm not sure how much power that actually provides. As it's located right below my desk, it doesn't have to be fed a lot of power to get loud enough for my needs.
I think I got away with it. The meter is reading 3.7 ohm and the value is stable, just occasionally oscillating to 3.6 and 3.8. Which looks fine to me. I'll look for any noise once the driver is in the enclosure but finger crossed it will be fine. Thanks all for the help!
As mentioned above, main damage cause for an unmounted speaker, doubly so a high compliance woofer is mechanical damage when voice coil hits the back plate, HARD.
But that´s a horrible clackety-clack sound and you report none, so .... no big deal.
But that´s a horrible clackety-clack sound and you report none, so .... no big deal.
Myself, and many many others like to do a break-in/burn-in on new drivers before mounting them in the cab. That loosens up the suspension and spider and such, and simply gets the speaker closer to its specs.
For subwooferdrivers I usually run a 30hz sinewave at 10V, for about 10-12hours, with the driver hanging in free air. Doesnt make much sound but you get a healthy bit of movement (well below Xmax of course).
I´ve really only done it with Pro audio drivers though, that are meant to take atleast 60+ volts when installed in the cabs, for a driver with less Xmax and powerhandling one may want to run the break in at a bit less voltage?
So I really cant imagine that you damaged your driver from that test, since as others have said, the driver doesnt seem to have made any bad noises so should be fine 🙂
Over-excursion and cooking the voicecoil with to much longterm power are the only ways you can damage a driver with signals.
For subwooferdrivers I usually run a 30hz sinewave at 10V, for about 10-12hours, with the driver hanging in free air. Doesnt make much sound but you get a healthy bit of movement (well below Xmax of course).
I´ve really only done it with Pro audio drivers though, that are meant to take atleast 60+ volts when installed in the cabs, for a driver with less Xmax and powerhandling one may want to run the break in at a bit less voltage?
So I really cant imagine that you damaged your driver from that test, since as others have said, the driver doesnt seem to have made any bad noises so should be fine 🙂
Over-excursion and cooking the voicecoil with to much longterm power are the only ways you can damage a driver with signals.
It really depends on how hard you drive the speaker.
I did a free-air burn-in of 4 15" drivers for about 6 days. I just adjusted the volume to limit the excursion a little below maximum and checked the temperature of the drivers continuously.
As long as you didn't do crank the volume with a 10hz test tone, you most likely didn't damage the driver.
Try pushing on the cone gently and if you don't hear any rubbing noises, then combined with the ohms measurement, I wouldn't think it is damaged
I did a free-air burn-in of 4 15" drivers for about 6 days. I just adjusted the volume to limit the excursion a little below maximum and checked the temperature of the drivers continuously.
As long as you didn't do crank the volume with a 10hz test tone, you most likely didn't damage the driver.
Try pushing on the cone gently and if you don't hear any rubbing noises, then combined with the ohms measurement, I wouldn't think it is damaged
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