I built 8 or 10 speaker cabinets and DIY tube amp cabinets with tolex. The last few I have made I did with Duratex spaker cabinet paint/coating. I will never go back to tolex or the like. You don't have to worry about corner seams etc. Game changer! No sticky overspray and killing brain cells if your mask does not fit well. Easy water cleanup for brushes and rollers. I don't use the texture rollers they supply, just use regular smooth mini-rollers. Good looking, uniform coverage and very durable coating. Put corner protectors if you are worried about roadie dings, but for me not necessary.
Fantastic work, Jeff! Nicely done! 😃 You should definitely get a cheap multimeter. It would be a breeze to measure the final result. 😉 Anyway, stay safe there with your family! 🖖😊
Very nice job! If you had wanted a 2 ohm load, you just use a single voice coil, you don't have to use both. The true power rating of a loudspeaker includes both thermal and mechanical components neither of which are simple. While the one you chose likely has a power capacity far in excess of your needs, it could also be damaged by an amplifier with much less output than the speakers rating. It depends on things like what frequency is playing, whether or not the signal is clipped etc. Just a few watts at just a few Hz, might damage that woofer if played for an extended time. Normal use however it will never be an issue. The amplifier and speaker impedance ratings don't need to match, at least not for solid state amplifiers. Amplifiers are voltages sources, they supply some amount of voltage and the load "draws" some amount of current as a result. A voltage source attempts to maintain the same voltage regardless of load. At 28.3 volts across 8 ohms, the power is 100 watts. The same voltage across 4 ohms is 200 watts. Across 1 ohm, 800 watts, ... If the amplifier has a maximum power rating of 200 watts, it simply could not supply enough current to meet the demand from the lower impedance load. If you connect a 16 ohm speaker, that's fine but if the maximum voltage is about 28 volts, the max power is just 50 watts. So, just make sure you don't attach a load to the amplifier with a lower impedance than the amplifiers minimum impedance rating. Higher isn't really a problem other than it limits maximum power. With exception of Planar, Ribbon, and AMT drivers, loudspeaker impedance is non linear. Conventional cone speakers like your woofer have an impedance peak at the resonance frequency which includes capactive reactance. While your two coils in series might be rated 4 ohms, the actual impedance at resonance may be several times higher than this. Depending on what range of frequency you drive the woofer, it might not be necessary to have the rated impedance within the amplifiers specification due to this much higher actual impedance. This capacitive reactance is due to stored energy from the mass/spring system of the cone so the reduced max power in this range is compensated for by increased efficiency. In this range, woofers don't really need much power to have significant output. I've been designing/building speakers for about 50 years but rarely do conventional box speakers anymore. I mostly stick to open baffle and CBT line arrays. Still, watching videos like yours brings back the memories of the early days when I built lots of speakers! Great video!
Thank you, and thanks for the technical details. Definitely helpful. I was however under the impression that its not a great idea to only wire one side of a Dual Voice Coil speaker. I was told it wasn't good for the speaker, so thats interesting to know.
I built 8 or 10 speaker cabinets and DIY tube amp cabinets with tolex. The last few I have made I did with Duratex spaker cabinet paint/coating. I will never go back to tolex or the like. You don't have to worry about corner seams etc. Game changer! No sticky overspray and killing brain cells if your mask does not fit well. Easy water cleanup for brushes and rollers. I don't use the texture rollers they supply, just use regular smooth mini-rollers. Good looking, uniform coverage and very durable coating. Put corner protectors if you are worried about roadie dings, but for me not necessary.
I did see that when I was researching coatings. I'll have to keep that stuff in mind. Thank you for the suggestion.
Fantastic work, Jeff! Nicely done! 😃
You should definitely get a cheap multimeter. It would be a breeze to measure the final result. 😉
Anyway, stay safe there with your family! 🖖😊
Thanks my friend. I do have a meter I could have used. I didn't think about that. Lol
Great Video!
Thanks for sharing.
Thank you!
Very nice job! If you had wanted a 2 ohm load, you just use a single voice coil, you don't have to use both.
The true power rating of a loudspeaker includes both thermal and mechanical components neither of which are simple. While the one you chose likely has a power capacity far in excess of your needs, it could also be damaged by an amplifier with much less output than the speakers rating. It depends on things like what frequency is playing, whether or not the signal is clipped etc. Just a few watts at just a few Hz, might damage that woofer if played for an extended time. Normal use however it will never be an issue.
The amplifier and speaker impedance ratings don't need to match, at least not for solid state amplifiers. Amplifiers are voltages sources, they supply some amount of voltage and the load "draws" some amount of current as a result. A voltage source attempts to maintain the same voltage regardless of load. At 28.3 volts across 8 ohms, the power is 100 watts. The same voltage across 4 ohms is 200 watts. Across 1 ohm, 800 watts, ... If the amplifier has a maximum power rating of 200 watts, it simply could not supply enough current to meet the demand from the lower impedance load. If you connect a 16 ohm speaker, that's fine but if the maximum voltage is about 28 volts, the max power is just 50 watts. So, just make sure you don't attach a load to the amplifier with a lower impedance than the amplifiers minimum impedance rating. Higher isn't really a problem other than it limits maximum power.
With exception of Planar, Ribbon, and AMT drivers, loudspeaker impedance is non linear. Conventional cone speakers like your woofer have an impedance peak at the resonance frequency which includes capactive reactance. While your two coils in series might be rated 4 ohms, the actual impedance at resonance may be several times higher than this. Depending on what range of frequency you drive the woofer, it might not be necessary to have the rated impedance within the amplifiers specification due to this much higher actual impedance. This capacitive reactance is due to stored energy from the mass/spring system of the cone so the reduced max power in this range is compensated for by increased efficiency. In this range, woofers don't really need much power to have significant output.
I've been designing/building speakers for about 50 years but rarely do conventional box speakers anymore. I mostly stick to open baffle and CBT line arrays. Still, watching videos like yours brings back the memories of the early days when I built lots of speakers! Great video!
Thank you, and thanks for the technical details. Definitely helpful.
I was however under the impression that its not a great idea to only wire one side of a Dual Voice Coil speaker. I was told it wasn't good for the speaker, so thats interesting to know.
Hey Jeff, You could have played a snippet from Sanguine Addiction and not get a copyright strike. 😉
Oh yeah, That would be crazy if I did somehow get a copyright warning on my own music. Lol.
I would curious if you put a small piece of glass insulation in the box if you find a small improvement in the sound quality???
Looks like the speaker box turned out pretty good. Did you attach the box to the floor of the car or just set it in?
Thanks Robert, Right now its just sitting there. I probably should bolt it down though.