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Sunfire HRSIW8 DSP Subwoofer Amplifier
- Thread starter amirm
- Start date
Believe it or not, that's precisely why I loaned both the Crown XLS2502 and Sunfire HRSIW8AMP for Amir's detailed analysis. I have another vintage option, not on the board yet, which I may offer in a few weeks.
To be fair, neither of these will be used to drive normal speakers or planars. They, if I use them, will be driving heavy tactile response motors (5Hz - 60Hz) with 3.75lb magnetically levitated pistons. They take a lot of real power to start/stop. These are anchored to the main spanning LVL's in my main room's floor. This is quite a different "movie-oriented" "out-of-the-box" workload. That should help our readers explain the limited range of the Sunfire HRS AMP in this application. However, they tested on the low-end of the power needed per specs.
BTW, I love the different points of view presented by members. Sometimes (many times) it's an out-of-the-box thinking and use of something which finds solutions we never considered possible. Call it an "enthusiasts use" maybe. Peace.
To be fair, neither of these will be used to drive normal speakers or planars. They, if I use them, will be driving heavy tactile response motors (5Hz - 60Hz) with 3.75lb magnetically levitated pistons. They take a lot of real power to start/stop. These are anchored to the main spanning LVL's in my main room's floor. This is quite a different "movie-oriented" "out-of-the-box" workload. That should help our readers explain the limited range of the Sunfire HRS AMP in this application. However, they tested on the low-end of the power needed per specs.
BTW, I love the different points of view presented by members. Sometimes (many times) it's an out-of-the-box thinking and use of something which finds solutions we never considered possible. Call it an "enthusiasts use" maybe. Peace.
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OP
- Thread Starter
- #23
Well, with my measurements you know for sure. The frequency response graph had two lines in it: one in LFE mode and one in sub mode. They are indicated on the graph markers to the right:
As you see, the LFE only disables the crossover extending the response. But doesn't do anything for the hump.
As to the rest of the settings, see what I said below that graph:
"Everything I could" means I read the manual multiple times, tried every alternative in the settings.
Now, a remote chance exists that I missed something but please don't assume I get a response like above and don't try to defeat it using the settings.
OP
- Thread Starter
- #24
My beef with this amp is that it doesn't provide the simplest frequency response measurement. If it is going to have a hump like that, it needs to be documented so that people know what they are getting. Or in my case, know that my measurements match the intended design of the unit. As it is, we are sitting wondering what is going on.
If they did not sell it independently from the subwoofer, it would be one thing. But since they do, then people may purchase them and use it this way with other passive subs.
If they did not sell it independently from the subwoofer, it would be one thing. But since they do, then people may purchase them and use it this way with other passive subs.
^^^ Nope. You nailed it with the graphs, with LFE mode (which I missed on first read), the settings and your conclusions about the capabilities within. Great analysis - TY!
D
Deleted member 2944
Guest
It's good for a specific subwoofer.........as has been stated numerous times now in this thread.
https://www.sunfire.com/product/wal...-8-235hx105-wide-requires-hrsiw8amp-HRSIW8CAB
The peak filter being un-defeatable in this amplifier seems perfectly consistent with the intended usage. Since the amplifier should be married to the HRSIW8CAB subwoofer, even when in the "LFE" mode, the peak equalization should stay active because it can't be duplicated by (most) HT processors.
Dave.
Sry, but i still don't get that design. There is a constant 12dB peak at 37Hz. That makes no sense to me.
If it would be build for one special room, and the speakers placed in a special wall. Than maybe ok.
mhardy6647
Grand Contributor
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If all y'all get bored enough, there is a Crown D-150 (original, unsuffixed version) talking up some shelf space here. 
crownies by Mark Hardy, on Flickr
(yeah, there's an original morph of the IC-150 here, too... I'd prefer not to admit that latter tidbit publicly, though, 'K? )
crownies by Mark Hardy, on Flickr(yeah, there's an original morph of the IC-150 here, too... I'd prefer not to admit that latter tidbit publicly, though, 'K?
)May I suggest that what @amirm found here with this amplifier is why he should continue to look at active speakers as a unit and not analyze each component separately. It is possible that analyzing the Sunfire subwoofer combined with this amplifier may generate a good result. The sum of the parts may be better than each part alone, especially if they were designed to go together.
This does not exclude the issue with the missing watts.
This does not exclude the issue with the missing watts.
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Yes that would be viable. In this case, I purchased only the amp to drive the workloads I mentioned earlier. Yes, I'm a bit peeved about those missing watts b/c if it had been correctly rated for what he found, it would have never been on my short list. Live and learn.
jasonhanjk
Active Member
- Joined
- Mar 24, 2019
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Amir.
Please use 2 ohms and you will get your power.
I suspect it's 4ohm driver connect in parallel.
Please use 2 ohms and you will get your power.
I suspect it's 4ohm driver connect in parallel.
This has been at the back of my mind. The documentation somewhere states that the amp is capable of driving two subwoofers. If it can, it would indeed be driving the rated power, but into 2 Ohms. That would leave the problem being in the wording of the specification, since it does clearly state that the power, and distortion levels at power, is as delivered into 4 Ohms, not two. I would be prepared to forgive what would be little more than a typo if it really did deliver into this load.
^^^ I agree 100%. The doc is crystal. It never ever states 2 ohms in ratings (see below). But my guy says that's probably the marketing game on. I've highlighted below some specs / elements directly from the manual including the CYA statement about use.
-> http://resources.corebrands.com/products/HRSIW8AMP/pdf_HRSIW8AMP_manual.pdf
-> http://resources.corebrands.com/products/HRSIW8AMP/pdf_HRSIW8AMP_manual.pdf
- DSP soft limiter prevents any clipping at the speaker and limits to 1.5% THD...
- DSP system equalization for perfect frequency response
- ....
- The amplifier is designed to power only the Sunfire HRSIW8 in-wall subwoofer. No other subwoofer or speaker should be connected, or this may lead to serious damage to your equipment.
- ....
- Amplifier Output 520 watts rms into 4Ω
- High Cut Filter 40 Hz - 160 Hz adjustable, with an LFE bypass position 12 - 36 dB/octave adjustable slope
- Frequency Response 33 Hz - 150 Hz (-3 dB) ...
- AC Line Power Consumption: 75 watts average, 0.5 watts in standby 815 watts maximum ....
- Input Sensitivity (full output): 23 mV rms at 38 Hz with volume control set to maximum
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It is worth re-iterating and explaining a bit more about the measured frequency response. Earlier I linked to a description of the Linkwitz Transform, as described by its inventor Siegfried Linkwitz. (If you don't know who he is, you probably don't know enough to be able to comment sensibly on this subject.)
The point of the transform is that if you are given a loudspeaker in a sealed enclosure, you can find the precise parameters that describe its operation, and these can be expressed in either mechanical (mass, dampling and compliance) or electrical (inductive, capacitive and resistance) terms. (This is also true of vented systems, but here we are concerned only with second order, aka sealed designs.) What you are then able to do is mathematically define exactly the correct inverse parameters to apply to the drive signal to remove the roll-off inherent in the system, and then apply exactly the new roll-off you want. There is no such thing as a free lunch, and the cost is that your drivers must be able to cope with the excursions needed to deliver the lower roll-off. You need to limit the signal at lower frequencies to ensure the drivers don't get destroyed. But the upshot is that you get what amounts to exactly the same bass performance in a small box as you would get from similar drivers in a much larger box.
To quote Linkwitz from his description:
A majority of drivers exhibit second order highpass behaviour because they consist of mechanical mass-compliance-damping systems. They are described by a pair of zeroes at the s-plane origin and a pair of complex poles with a location defined by Fs and Qt. The circuit above allows to place a pair of complex zeroes (Fz, Qz) on top of the pole pair to exactly compensate their effect. A new pair of poles (Fp, Qp) can then be placed at a lower or a higher frequency to obtain a different, more desirable frequency response.
What is important is that this is isn't simply a matter of applying some arbitrary bass boot. The parameters chosen exactly cancel the inherent characteristics of the subwoofer, no more and no less. They leave a system with no ringing or weird phase issues or nasties, and certainly don't result in a boomy bass or the like. But the filter parameters must be matched to the speaker. There is no simple generic form.
This is a well known transform, and many speaker design programs offer calculation of the transform as a standard function. I would guess that the vast majority of powered subs are built using it. (All sealed ones that is.) The only reason that it seems to be such a controversial thing is that by measuring the amp alone we have exposed its operation, whereas most powered subs build the amp into the sub box. Since this amp is specifically designed to be used with a thin in-wall subwoofer, one that has no room for an internal amp, we see it in its naked glory.
Really that is all there is to it.
The point of the transform is that if you are given a loudspeaker in a sealed enclosure, you can find the precise parameters that describe its operation, and these can be expressed in either mechanical (mass, dampling and compliance) or electrical (inductive, capacitive and resistance) terms. (This is also true of vented systems, but here we are concerned only with second order, aka sealed designs.) What you are then able to do is mathematically define exactly the correct inverse parameters to apply to the drive signal to remove the roll-off inherent in the system, and then apply exactly the new roll-off you want. There is no such thing as a free lunch, and the cost is that your drivers must be able to cope with the excursions needed to deliver the lower roll-off. You need to limit the signal at lower frequencies to ensure the drivers don't get destroyed. But the upshot is that you get what amounts to exactly the same bass performance in a small box as you would get from similar drivers in a much larger box.
To quote Linkwitz from his description:
A majority of drivers exhibit second order highpass behaviour because they consist of mechanical mass-compliance-damping systems. They are described by a pair of zeroes at the s-plane origin and a pair of complex poles with a location defined by Fs and Qt. The circuit above allows to place a pair of complex zeroes (Fz, Qz) on top of the pole pair to exactly compensate their effect. A new pair of poles (Fp, Qp) can then be placed at a lower or a higher frequency to obtain a different, more desirable frequency response.
What is important is that this is isn't simply a matter of applying some arbitrary bass boot. The parameters chosen exactly cancel the inherent characteristics of the subwoofer, no more and no less. They leave a system with no ringing or weird phase issues or nasties, and certainly don't result in a boomy bass or the like. But the filter parameters must be matched to the speaker. There is no simple generic form.
This is a well known transform, and many speaker design programs offer calculation of the transform as a standard function. I would guess that the vast majority of powered subs are built using it. (All sealed ones that is.) The only reason that it seems to be such a controversial thing is that by measuring the amp alone we have exposed its operation, whereas most powered subs build the amp into the sub box. Since this amp is specifically designed to be used with a thin in-wall subwoofer, one that has no room for an internal amp, we see it in its naked glory.
Really that is all there is to it.
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^^^ precisely stated. FWIW. I knew these specs when I opened the rabbit hole. I had hoped the output ratings were true @ 4 ohms especially given the stated frequency response and that the DSP adjustments for the paired sub were fully bypass-able as per the manual implied. I inferred from those it is a pretty descent 1u SUB amp for my “off-label” use.
Amir has show neither of the big infers to be true for my use case.
That does not mean it fails at doing what it is designed to do and maybe do it well. Peace.
Amir has show neither of the big infers to be true for my use case.
That does not mean it fails at doing what it is designed to do and maybe do it well. Peace.
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audioBliss
Active Member
I have to admit I don't know that much about LTs but I have played around with them and I don't remember ever seeing a peaked curve like that. I know what you are saying but what I'm saying is that that's usually not how a Linkwitz Transform looks..at least with any sort of descent subwoofer.
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