Underpowered subwoofer at low volumes. Velodyne fsr-15 and Dayton amp

So I have velodyne fsr-15 and f1500(drivers and wiring are identical btw)
Amps looks a little different

I bought Dayton audio spa250dsp

Forgot to measure subwoofer impedance. Both measure 6ohm. So looks like these velodyne drivers are 8ohm. I noticed most speakers impedance is 2ohm less than resistance measurements with multimeter

So now I have 125w available into 8ohm sub

I don't blast music loud. Sub is more for sub 50-60hz sounds. Usually i set it at the minimum cross over point around 40hz

Will the sub sound bad at lower volumes.. or do you think it will clip

Original velodyne amp does not look like 250watts per channel
Maybe 100watts

Attached are images of velodyne amp. Maybe we can estimate real power

output

4 50v 4700uf filter caps, 2 stk4040ii power amplifiers
 

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Thanks for feedback. Sounds reassuring. Ill give it a shot anyway. Original velodyne amp was a lot more than I needed out of this sub. Never needed to crank volume past 9-10 o'clock.

I have servo connect cables and chip. Do you mean those 4black wires that supposedly compensate for distortion?
Someone said in another thread that there is a chip under dust cap and 4 wires running to the amp.
Issue with fsr-15 was that dc voltage oscillated +-.7v and woofer was moving in and out at around 10hz frequency. Oscillation was only noticeable when woofer was out of the box.. when sealed can't see oscillation with your eye. I recapped amp and replaced 2 transistors that ran very hot(traces of overheating on board). But issue still remained.

But driver is pretty good . 8ohm will be easy on amp. Need to call parts express to see if spa250dsp is rated at 8ohm
 
I think you will be fine - especially at lower listening levels.
That original amp only has a 70-watt chips (at +/-42vDC and 0.4% THD), so with 2 in bridge configuration, you might get 100-120 watts clean power from the Velodyne amp, so you are going to have close to the same power.

that heat sink doesn't look sufficient for bridged operation. At +/-42VDC you need a heat sink with thermal impedance less than 1.0 ohms. I pulled down the Nat Semi Overture design guide -- as the same analysis applies for the STK parts:
 

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