Old post from BWaslo about the TF1525 (QSC buyout driver) on the diysoundgroup forum:
That's a $50 woofer 'beating' a $400 high-end product.
That's a $50 woofer 'beating' a $400 high-end product.
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Very much thanks! For now I'm limited to ~90L and will sacrifice sensitivity and max SPL.
150l tuned @ 40 Hz:
You could also use the drawings of Tony Gee's Calpamos with slightly less depth and adjust the tuning.
You could also use the drawings of Tony Gee's Calpamos with slightly less depth and adjust the tuning.
You won't sacrifice sensitivity and SPL, on the contrary. You'll sacrifice low freq. extension, but the mid bass should 'kick' butt.
90l @ 45 Hz:
This alignment also features a kind of built-in protection against overexcursion, provided you refrain from using DSP to boost the low end excessively.
If the room is not too large, such an alignment (with room gain) approaches the very best low freq. reproduction imaginable: agile and extremely well defined.
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Specialty product:
High-end 15" woofer for HiFi applications, mainly in the home. The SUPRAVOX 400GMF is mainly composed of an exponential profile paper membrane, external fabric suspension, ferrite magnet and a robust die-cast aluminum basket.
The general characteristics of this speaker are of a very high level. The frequency response, although not outstanding for linearity, extends up to very high frequencies with well-controlled break-ups. Even up to 30° the regularity is rather good.
The average sensitivity stands out with about 97 dB, a considerable value in relation to the resonance frequency of only 20 Hz.
Some parameters, such as the Mms, differ greatly from those indicated by the manufacturer. A moving mass of just 62 g, in a 15", on the other hand, seems really unrealistic to us, however some rather "extreme" data emerge, with a high Qms and a very low Qts, not easily found in professional-style speakers, with which the 400GMF does not want to get confused.
The THD analysis shows a favorable trend, although the low frequency clearly shows that we are not in the presence of a "stage" speaker. The declared power, moreover, is far from the extreme values of modern professional woofers, a detail that denotes the "domestic" connotation of this woofer.
The SUPRAVOX 400GMF , therefore, is a product intended above all for lovers of tube electronics, which is particularly suitable for use in horn, RJ, Onken systems or in a classic bass-reflex. In the latter case, a cabinet between 140 and 200 liters tuned to 25 - 30 Hz can be used, which ensures a very extended low range and great dynamic impact.
Measured Mms turns out to be 111g, instead of 62.
The awareness of the importance of low Mms seeps into this, but this is not realized.
Low Fs never goes hand in hand with low Mms and high efficiency, unless compromised.
I still think this is a good woofer, but there are many alternatives available for €750.
High-end 15" woofer for HiFi applications, mainly in the home. The SUPRAVOX 400GMF is mainly composed of an exponential profile paper membrane, external fabric suspension, ferrite magnet and a robust die-cast aluminum basket.
The general characteristics of this speaker are of a very high level. The frequency response, although not outstanding for linearity, extends up to very high frequencies with well-controlled break-ups. Even up to 30° the regularity is rather good.
The average sensitivity stands out with about 97 dB, a considerable value in relation to the resonance frequency of only 20 Hz.
Some parameters, such as the Mms, differ greatly from those indicated by the manufacturer. A moving mass of just 62 g, in a 15", on the other hand, seems really unrealistic to us, however some rather "extreme" data emerge, with a high Qms and a very low Qts, not easily found in professional-style speakers, with which the 400GMF does not want to get confused.
The THD analysis shows a favorable trend, although the low frequency clearly shows that we are not in the presence of a "stage" speaker. The declared power, moreover, is far from the extreme values of modern professional woofers, a detail that denotes the "domestic" connotation of this woofer.
The SUPRAVOX 400GMF , therefore, is a product intended above all for lovers of tube electronics, which is particularly suitable for use in horn, RJ, Onken systems or in a classic bass-reflex. In the latter case, a cabinet between 140 and 200 liters tuned to 25 - 30 Hz can be used, which ensures a very extended low range and great dynamic impact.
Measured Mms turns out to be 111g, instead of 62.
The awareness of the importance of low Mms seeps into this, but this is not realized.
Low Fs never goes hand in hand with low Mms and high efficiency, unless compromised.
I still think this is a good woofer, but there are many alternatives available for €750.
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Is this something you've found reflected in measurements?
Think it´s hard to "explain" sound, better if you listening for your self.
For me a 155 gram mms get´s dull compered to "most" " midrange" drivers.
Great drivers allways have " pron and cons", but for me midrange isen´t JBL 2235h.
The distortion is not low
The HD of this woofer in the bass range is not low, considering it's a 15". The efficiency is not exceptional either, although much higher than the average hifi driver. So what is the advantage of 20 Hz Fs? There is any?
Yes, but it depends... as usual.
One cannot rely on (manufacturer) measurement data alone.
As a local audio freak and former manufacturer often said, "some things require experience, insight and feeling".
Good question! (but you would have to submit it to the manufacturer 😉 )
I know this driver sounds good, but I'd rather buy a 15PR400:
This is the THD of a highly regarded hi-fi (sub) woofer, the SB ACOUSTICS WO24P-8:
Comment:
9.5" woofer from the prestigious SATORI series. The WO24P-8 features a paper membrane, low-loss suspension, triple demodulating ring, glass fiber voice coil support, die-cast aluminum basket with aerodynamic structure, ferrite magnet with perforated central pole.
Our test shows some interesting results. Even if after a long break-in the parameters are not very in line with the declared ones (apart from the BL and the moving mass), the rest of the readings show a positive picture. The distortion, above all, is very favorable.
Entry level (basic/budget/universal) 15" Sica woofer, similar to the Celestion TF-series:
1 WO24P-8 costs €250.
I paid €50 for a new pair of the bigger and slightly better brother of this Sica (with 3" magnet).
Satori's specified Fs: 24.5 Hz, measured 30.6 Hz.
Sica: 47 Hz vs 45.42 Hz.
Don't get me wrong, the Satori is good, but I would pick the Sica (any day) for a 2-way crossed around 1000 Hz.
The Satori's 10 dB break-up peak at 3 kHz requires a steep LP, and what's the 'use' of the low Fs?
Comment:
9.5" woofer from the prestigious SATORI series. The WO24P-8 features a paper membrane, low-loss suspension, triple demodulating ring, glass fiber voice coil support, die-cast aluminum basket with aerodynamic structure, ferrite magnet with perforated central pole.
Our test shows some interesting results. Even if after a long break-in the parameters are not very in line with the declared ones (apart from the BL and the moving mass), the rest of the readings show a positive picture. The distortion, above all, is very favorable.
Entry level (basic/budget/universal) 15" Sica woofer, similar to the Celestion TF-series:
1 WO24P-8 costs €250.
I paid €50 for a new pair of the bigger and slightly better brother of this Sica (with 3" magnet).
Satori's specified Fs: 24.5 Hz, measured 30.6 Hz.
Sica: 47 Hz vs 45.42 Hz.
Don't get me wrong, the Satori is good, but I would pick the Sica (any day) for a 2-way crossed around 1000 Hz.
The Satori's 10 dB break-up peak at 3 kHz requires a steep LP, and what's the 'use' of the low Fs?
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- Cone Mass and Distortion: As seen in the first column of the scatter plot matrix, there appears to be a general trend of increasing distortion with decreasing cone mass (Mms). However, this relationship isn't strictly linear, and there are some notable outliers. This suggests that while cone mass plays a role in distortion, other factors are also involved.
- Motor Strength and Distortion: Looking at the relationship between (BL)²/Re (motor strength) and distortion, there isn't a clear linear trend. However, some woofers with higher motor strength do exhibit lower distortion. This indicates that motor strength might have a mitigating effect on distortion, but its influence is likely intertwined with other factors like cone mass and material.
- The Interplay of Cone Mass, Motor Strength, and Distortion: The most intriguing relationship appears to be the combined influence of cone mass, motor strength, and their ratio ((BL)²/Re : Mms) on distortion. Woofers with lighter cones and stronger motors (higher ratio) tend to have lower distortion. This suggests that a well-balanced design, where a lighter cone is driven by a sufficiently strong motor, can achieve lower distortion.
- Sensitivity Considerations: While not directly shown in this particular scatter plot matrix, recall that sensitivity is also related to cone mass and motor strength. Lighter cones tend to have higher sensitivity, but as we've seen, they might also be more prone to distortion. This highlights a potential trade-off between sensitivity and distortion in woofer design.
Just some stuff I created using AI, take with a grain of salt.
There is a woofer that i did not see mention here that i think is a very good one for this kind of alignment: The Faital 10FE330. It's only a 10", but it goes loud in a wide frequency range, usable from 35Hz to 2kHz. It's bigger brother the 12FE330 could also be good i thinnk.
I never saw independent measurments of the 10FE330, but it looks good on paper and in the config i heared it (with a Selenium D220Ti in a Dayton Audio H812 horn) it worked very well. A pair was used as small pa speaker without subs for a folk concert for about 50 people in a bar and it could hold up. It was made by the bar owner himself based on the econowave concept and driven by an old QSC amp and sounded very hifi for a bar system. So hifi that i'm designing a similar speaker with it with a much better Faital HF108 compression driver in a XT1086 horn. I'm still in the planning phase altough...
i
I never saw independent measurments of the 10FE330, but it looks good on paper and in the config i heared it (with a Selenium D220Ti in a Dayton Audio H812 horn) it worked very well. A pair was used as small pa speaker without subs for a folk concert for about 50 people in a bar and it could hold up. It was made by the bar owner himself based on the econowave concept and driven by an old QSC amp and sounded very hifi for a bar system. So hifi that i'm designing a similar speaker with it with a much better Faital HF108 compression driver in a XT1086 horn. I'm still in the planning phase altough...
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Basic (semi-budget) woofer that looks good & should sound good.
Why? Uncoated cone with a small roll surround.
However, the Mms isn't particularly low (58.2 g) and Bl = 12.6 N/A; therefore, the 'hi-fi signature' isn't surprising.
The FR illustrates the damping.
I'd be tempted to use 2 in a 2.5 way configuration with the HF103-16 on top.
Why? It features the same diaphragm as the HF108, but with a less powerful ferrite magnet (resonance peak just below 600 Hz).
By bringing the technical characteristics of the drivers closer together, you'll end up with a more homogeneous (sounding) system.
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There's some truth in this.
Due to (electro-magnetical/mechanical) damping, harmonics are also supressed. This also 'affects' effciency ~ maximizing outputs with given inputs.
So this makes sense:
"Woofers with lighter cones and stronger motors (higher ratio) tend to have lower distortion. This suggests that a well-balanced design, where a lighter cone is driven by a sufficiently strong motor, can achieve lower distortion."
A number of high-end (hi-fi) woofers with relatively heavy cones have been highlighted, incorporating all kinds of modern bells and whistles.
These (expensive) features yield (marginally) better figures and nicer plots, but (often) at the expense of efficiency.
These (expensive) features yield (marginally) better figures and nicer plots, but (often) at the expense of efficiency.