Hello, I've been using a pair of Dayton Audio ND90-8 with a wondom, tpa3116d2 amp, running from a 5s battery pack 15-21 volts. The amp should be able to output around 30wats on 24v, the speaker can handle 20watts rms. I feel like many times i am not getting the max output out of these drivers, nor i am able to hear them distort or clip. I was thinking that the voltage of the battery is not enough to fully power these drivers. Would changing to the 4ohm version of the same driver increase the output ?
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If you cannot drive the speaker into distortion/clipping then it sounds the gain distribution of your signal chain is suspect... as in not enough overall signal voltage gain. The battery voltage doesn't come into it at this point if you are not able to reach the limits of the power supply by turning the volume up.
A different speaker may or may not sound 'louder', it all depends on the speaker sensitivity.
A different speaker may or may not sound 'louder', it all depends on the speaker sensitivity.
I am sorry I didn't make clear what the replacement would be. I was talking about the 4 ohm version of the same driver, their sensitivity is the same. let me correct the original post. Moreover the gain is indeed low, but i am able to make amp clip if i use a wired connection like a dac, but not when using the built in bluetooth moduel of the amp, which seems to have a low output.
So, would the woofer above make any difference in the output volume?
Half the impedance using an otherwise similar driver will result in 3dB louder sound. That is noticeable, but no huge change. If i'm not mistaken for most people 3dB ist just noticeable.
All things being equal, the 4 ohm driver as stv says would be 3db louder at the reference of 1w applied and 1 metre distance.
This might help explain it:
https://soundcertified.com/how-does-increasing-speaker-impedance-affect-db-output-power/
this is exactly the essence of the question.
I know that these two drivers might be showing a difference of 3db in their spec sheets, but that's on 2.8v/1m. Which is misleading because the 8ohm one win 2.8v will be pulling 1W but the 4ohm version with 2,8v will be pulling 2W (doubling of power will indeed result in 3db increase), but their sensitivity is essentially the same. Now given the fact that they both have a 20W rms power ratting, wouldn't that mean that at 20w they will both have the same db output?
Have I not understand this correctly?
My reasoning behind this change, is because (as i mentioned above) the signal might be too low, in combination with the relatively low the gain of the amp which doesn't allow the amp to drive the speaker at full output, maybe (given that the amp can output a specific voltage dictated only by signal input and amp gain, in this case) regardless of the week signal, changing the driver to the lower impedance one would result in a increase in output volume. I am afraid I might have misunderstand something.
I would change the driver completely but I have already built and tuned the enclosure.
You have to think in terms of voltage as well. If you set the amp to deliver 12.7 volts rms then that will dissipate 20 watts in an 8 ohm load. Now replace the load by a 4 ohm one and the voltage stays the same (assuming the amp is 4 ohms capable). The power dissipated is now 40 watts. The amplifiers output would need turning down to 8.9 volts to maintain 20 watts into 4 ohms.
So I think what you are asking is that yes, the SPL will be the same for the same power dissipation in the speaker but the amp can deliver much more power into the 4 ohm load than the 8 ohm. Don't confuse 'power' with applied voltage. The amp puts out voltage, the power depends on the load.
The 4 ohm version should give the same maximum SPL with an amp of lower voltage output capability.