I have a Subaru Ascent with an active 2-way setup. I previously had used tweeters (SB29RDNC) and Alpine Z15W (5.25") for my front stage powered by a helix p six. I recently made the switch to a wideband (the Audiofrog GS25) in the stock corner dash location and have really like avoiding the rainbow effect with all of the sound >= 300 Hz up on top of the dash. I don't feel that the top end is lacking with these speakers.
I couldn't help myself though, and I got the HAT Unity U2 speakers as well. I thought I'd post a comparison for those thinking of these two speakers.
Specifications: GS25 U2 Nominal Impedance: 4 ohm 4 ohm RMS Power Handling (w/ suggested crossover): 70 W 75 W Sensitivity (2.83 V/1 M): 87 dB 80 dB Recommended High Pass Filter Frequency and Slope: >= 200 Hz, >= 12 dB/oct >= 250 Hz, >= 24 db/oct Diameter (mounting holes): 71 mm 68.6 mm Diameter (basket): 61 mm 57.8 mm Sd: 23 cm2 0.01386 cm2 Mms: 3.21 g 1.034 g Cms: 242 uM/N 766 μM/N Vas: 0.181 liters 0.21 liters Fs: 180.5 Hz 165 Hz BL: 3.38 TM 1.9 TM Qms: 7.07 2.155 Qes: 0.73 1.07 Qts: 0.66 0.715 Xmax (1-way linear): 4 mm 2.5 mm (2-way) Voice coil diamter: 25 mm 20 mm Frame/body material: Metal Cast ABS
What stands out (to me) from above is that:
- the U2 has a slightly lower Fs despite being a little smaller in diameter
- the xmax of the audiofrog is greater than the U2, and if the U2 is truly 2-way, than by a sizable amount
- the GS25 is more efficient
Here are their published frequency response graphs:
Audiofrog GS25
U2
What stands out when comparing their frequency response graphs above is that:
- above 250 hz, the GS25 varies less from the lowest valley to highest peak (82-89 dB); so a range of ~7 dB) where the U2 varies from 76 to 86 (so a range of ~10 dB)
- the U2 seems to rise generally from 2K to 10 kHz
- the GS25 has a noticeable peak at ~16 kHz
I then took measurements in my car with no EQ applied and no crossover applied for each driver (left and right side) to compare their response curves in car to give people an idea of what sort of tuning would be needed.
I actually was a little surprised:
GS25 - Left side - no EQ, no crossovers
U2 - Left side - no EQ, no crossovers - same volume / levels at head unit and within DSP/amp
Both GS25 and U2 - Left side - no EQ, no crossovers - displayed on same graph
What strikes me about the above is that:
- the rising response of the U2's response curve (in the published specs) appears to level off on it's own while in car - could this be engineered by design (as it is made to be played facing a windshield)?
- the GS25 has a peak around 10 kHz where the U2 does not
- the U2 does NOT rolloff the top end as quickly as the GS25
- the GS25 seems to be louder below 4kHz - maybe this is due to its better efficiency? Maybe this is due to its better xmax (as you need more xmax at lower frequencies to maintain the same volume)?
- the GS25 has a greater peak at ~200 Hz which is in the downward crossover slope (it does need to be EQ'ed out)
GS25 - Right side - no EQ, no crossovers set
U2 - Right side - no EQ, no crossovers set
Both GS25 and U2 - Right side - no EQ, no crossovers set
What strikes me about the above on the right side is that:
- it's a very similar story as the left side (see above)
Overall, I was surprised with the U2 as from the published frequency response graph it seemed like it varied a bit more than the GS25, but in my car, it actually appears to vary less and offers a bit of a flatter response. It also seems to offer a top end that is less rolled off which might be possible due to it's smaller size.
The GS25 may be capable of some "better" lower end output with a larger xmax, but honestly, the U2's lower end output is keeping up just fine with it's higher frequency output and from a quick listen today I didn't notice anything lacking.
Here are some photographs for comparison:
U2 (wideband) on the left, SB29RDNC (tweeter) on the right:
GS25 on the left, U2 on the right:
The U2 is VERY similar in size to the SB29RDNC so I was able to re-use the baffle I created for the SB29RDNC for the U2 where I only had to shave ~1mm from the mounting opening to make it fit (the U2 is on the right below, the GS25 is on the left). If anyone currently has the SB29RDNC, this is an EASY replacement if you ever want to try a wideband.
The U2 mounted in car below:
Long post, I know, but I thought it might be interesting / useful for anyone considering these two drivers.
Overall, they both are great and are well suited for OEM locations on the dash pointed up at the windshield.
Interested to hear people's thoughts on the above. I am sure I missed some things...