Rolls SX45 Review (Analog Crossover)

[amirm]

This is a review and detailed measurements of the Rolls SX45 analog, 2-way crossover. It is on kind loan from a member and costs US $99.

As you see, it is a compact box, powered by a small external power supply:

I like the clipping indicator in addition to mono low frequency output to drive a subwoofer. The former lit up when driven by 2 volts input at the position you see. To get the same 2 volt output, I had to set the controls for low/high outputs to max.

Rolls SX45 Measurements
Let's see the distortion and noise in pass-through mode by testing the high frequency output with 1 kHz tone:

Not bad. Harmonic distortion dominates SINAD giving us basically what you can get out of 16 bit audio output. What I don't like is the channel discrepancy. That is going to cause a stereo image shift. You can see it again in frequency response test:

It persists in both outputs so must be caused by the input potentiometer. Another thing I don't like is the inaccuracy of the frequency dial. I thought I was selecting the common 80 Hz by eye but what is there is over 100 Hz. I had the dial below 90 so it shouldn't have been that high. So best to measure before trusting what it says.

Dynamic range is good:

Crosstalk is not great but probably OK for the application:

Performance relative to level at 1 kHz is very good for the product that it is:

Alas, when we sweep from 50 Hz up (to accommodate the crossover cut off), distortion rises at all but the middle frequencies:

So in that sense 1 kHz testing was showing the best case scenario.

Conclusions
In some respect the SX45 does better than I expected such as noise and distortion at 1 kHz. But channel matching is poor and distortion rises rapidly as frequencies go down. So a mixed message here and hard to rate the device.

I will give a marginal recommendation to Rolls SX45 if you can deal with its channel balance some other way.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[respice finem]

IDK what would be the intended use for these this day and age, DIY experimenting?
For what it is, it seems OK to me, as long as its channel imbalance will counter the (almost always present) imbalance of the speakers behind, and not add to it, so one must swap channels if it does.

BTW: Potty panther?

 

[amirm]

IDK what would be the intended use for these this day and age, DIY experimenting?

It is to build an active speaker or allow addition of a subwoofer to a typical 2-channel system.

They are easier to use than digital products since you can just turn the knobs and get different results.

 

[DWPress]

Or spend a tiny bit more and get a miniDSP.

 

[H-713]

Or spend a tiny bit more and get a miniDSP.

You could also use a BSS BLU-160. Or Q-Sys. Or an FDS360 (if you have the right cards). Or an XTA DSP box. Lots of options.

There is a time and a place for boxes of this nature. Yes, something with DSP is a better and more capable box, but it's also more complicated. Having something that doesn't require a computer for configuration can be handy for testing, troubleshooting, experimenting, etc.

The lack of balanced IO on this one does limit its usefulness a bit...

 

[DWPress]

doesn't require a computer for configuration can be handy for testing, troubleshooting, experimenting, etc.

Better have a mic handy to verify anything you change so still need the computer.

It does have a pretty steep filter slope so that's helpful with less chance of blowing tweeters. This sort of thing or similar is what we used in the 80's before we could afford real stage gear.

But you're right, lot's of options out there.

 

[dasdoing]

IDK what would be the intended use for these this day and age

a small bar with a small band playing in the corner? coupled with one of their mini-mixers?

but with RCA conections?

 

[JayGilb]

Amir, thanks for reviewing this crossover.

 

[hansik]

MiniDsp … if you have pc and a few braincells will make this obsolete. But for fun, why not.

 

[PeteL]

MiniDsp … if you have pc and a few braincells will make this obsolete. But for fun, why not.

I've been looking For Crossovers+ EQ options. You have the mini DSP? I read the MiniDSP 2X4 HD review here and it's lukewarm, close to bad. most of the comment section too, me I have to use it between an analog preamp and A Hypex Power amp crossed over to Subs. Many say it's not Ideal to use attenuation in the front and the High 29 dB Gain of a Power amp right after it. Analog in is my only option in my setup and I read that this kind of config is not ideal in term of the noise floor, audible hiss may occur with the margin needed for DSP, the attenuation + the soso performance of the ADC-DAC chain. I am still willing to try but what's your thought about it? I am also considering simply classic Pro audio reinforcement chain, like DBX Crossover and dual Klark Teknik DN410 Analog parametric EQ instead. With digital boards all across the pro audio world, these types of units are all over the used market for cheap. Currently I am using the natural roll off of my speakers and my sub crossed very low. It is not that bad really my room is quite decent, not fully optimal of course, but subjectively it's a great sounding system. Not willing to add some gear in the chain if there's payback on fidelity obviously. If returns are allowed mini DSP might be what I'll try first for the flexibility but unsure what's really best. Toughts?

edit:
Terms of Sales on the miniDSP WebStore
- All sales are final, No exchange, No refund, No return policy.

 

[DavidK442]

Finally. Bass management for the hi-end hi-fi crowd. It's about time.

 

[peniku8]

a small bar with a small band playing in the corner? coupled with one of their mini-mixers?

but with RCA conections?

Let's hope nobody brought their phone with them, then RCA might not even be an issue!

 

[peniku8]

I've been looking For Crossovers+ EQ options. You have the mini DSP? I read the MiniDSP 2X4 HD review here and it's lukewarm, close to bad. most of the comment section too, me I have to use it between an analog preamp and A Hypex Power amp crossed over to Subs. Many say it's not Ideal to use attenuation in the front and the High 29 dB Gain of a Power amp right after it. Analog in is my only option in my setup and I read that this kind of config is not ideal in term of the noise floor, audible hiss may occur with the margin needed for DSP, the attenuation + the soso performance of the ADC-DAC chain. I am still willing to try but what's your thought about it? I am also considering simply classic Pro audio reinforcement chain, like DBX Crossover and dual Klark Teknik DN410 Analog parametric EQ instead. With digital boards all across the pro audio world, these types of units are all over the used market for cheap. Currently I am using the natural roll off of my speakers and my sub crossed very low. It is not that bad really my room is quite decent, not fully optimal of course, but subjectively it's a great sounding system. Not willing to add some gear in the chain if there's payback on fidelity obviously. If returns are allowed mini DSP might be what I'll try first for the flexibility but unsure what's really best. Toughts?

edit:
Terms of Sales on the miniDSP WebStore
- All sales are final, No exchange, No refund, No return policy.

I don't think 5 bands of PEQ will be enough for room correction, especially since you only have one sub. And those analog PEQs look like they're gonna be a chore to work with, for precise things like this use case.
I have a 2x4HD and was pretty happy with it. The only thing I disliked was the fact that is doesn't have balanced connectors, which caused hum issues in both my subs. I can measure its SINAD. Maybe I'll do that today if nobody here has done it yet.

 

[dasdoing]

now I saw it is $99. wtf?
for $109 you get this https://www.amazon.com/Behringer-Ef...3466199&sprefix=behringer cros,aps,219&sr=8-1

Let's hope nobody brought their phone with them, then RCA might not even be an issue!

I don't understand

 

[eric-c]

I have this cross over, rolls passive mixer and a small headphone amp (one in, four out). I use these (no longer use the x over) for my computer / work desk setup. The super small footprint of the devices is the primary reason. I have a Soundmatters low-profile sub and the rolls cross over as I didn't want to send a full range signal to both the sub and speakers and use the sub cut off and boost controls to try to "get it right" as the sub only has an input. I no longer need the x cover as one set of my my pc speakers are active and have a sub out. I still have the cross over if I want to quickly test different xover points with small sats that I have in storage (Gallo, Nanosat etc) to get an idea how it will sound before installation. Small foot print, inexpensive and simplicity are the big selling points for me.

 

[peniku8]

now I saw it is $99. wtf?
for $109 you get this https://www.amazon.com/Behringer-Effect-Processor-CX2310-V2/dp/B07J37C68Z/ref=sr_1_1?crid=2DLCRYQMQMLWR&currency=USD&keywords=behringer crossover&language=en_US&qid=1643466199&sprefix=behringer cros,aps,219&sr=8-1

I don't understand

Maybe you're too young

And I agree, these cheap Behringer devices offer an amazing feature set at that price point and don't sound bad either (I've owned two of these crossovers, a GEQ and a compressor/limiter).

 

[dasdoing]

Maybe you're too young

lol. no, I remember that shit hahaha. we didn't need a ring-tone back than, as this was faster lol

these cheap Behringer devices offer an amazing feature set at that price point and don't sound bad either

Behringer is best value....not your option if you want the best quality, but their stuff gets the job done for cheap

 

[PeteL]

I don't think 5 bands of PEQ will be enough for room correction, especially since you only have one sub. And those analog PEQs look like they're gonna be a chore to work with, for precise things like this use case.
I have a 2x4HD and was pretty happy with it. The only thing I disliked was the fact that is doesn't have balanced connectors, which caused hum issues in both my subs. I can measure its SINAD. Maybe I'll do that today if nobody here has done it yet.

Hum issue is a pretty big deal to dislike, more of a no go if you ask me. My setup is also balanced. I don't have much to correct. I think 5 bands is plenty, what I have to correct is minimal, from experience 5 bands of PEQ is better than 31 bands of GEQ. I also already own a Measurment mic and I use SMAART, mini DSP I would need to change a workflow that I already know well, which is not a big deal really but still, the no return is the main thing. I am still willing to go with the solution that will give me the best for my money, but absolutely hum and hiss free is an absolute must in my book much more important than extreme accuracy of the correction. Analog PEQ are easy to work with, it's the same thing, I actually prefer knob to mouse.

 

[anotherhobby]

This was my device that I sent into Amir, who is also kind enough to slap my UPS label on it and return it to Amazon instead of to me.

I got this because I had just built 2 new subs for my office and needed a 2-way crossover to integrate them into my desktop system. After messing with this for 2 weeks, I realized it was not the best fit for what I was doing, and struggled to get enough gain from both of the balanced amps I have (PA5 and a Crown XLS1500).

I ended up getting the new miniDSP Flex in the balanced configuration, which is obviously vastly superior, but also costs $575. For a desktop setup where controls by your hands is of value, I think this device can have a place, but as Amir points out you definitely need to sort out the channel imbalance and crossover point with measurements. I did not do this, which is probably part of why I wasn't happy with it, in addition to not having enough output voltage for my balanced amps.

On a side note, I'm surprised by how many people are okay with only using the low pass on their sub(s), but don't high pass their mains at a matching crossover point. I've never had as good of a mix without a 2-way crossover point. I'd rather run this Rolls unit (working around it's limitations) than not run a high pass filter on my main when running subs. That said, the cheaper miniDSP units are a better option for not much more money.

 

[YSC]

This is a review and detailed measurements of the Rolls SX45 analog, 2-way crossover. It is on kind loan from a member and costs US $99.
View attachment 182665
As you see, it is a compact box, powered by a small external power supply:
View attachment 182666
I like the clipping indicator in addition to mono low frequency output to drive a subwoofer. The former lit up when driven by 2 volts input at the position you see. To get the same 2 volt output, I had to set the controls for low/high outputs to max.

Rolls SX45 Measurements
Let's see the distortion and noise in pass-through mode by testing the high frequency output with 1 kHz tone:

View attachment 182667

Not bad. Harmonic distortion dominates SINAD giving us basically what you can get out of 16 bit audio output. What I don't like is the channel discrepancy. That is going to cause a stereo image shift. You can see it again in frequency response test:

View attachment 182668

It persists in both outputs so must be caused by the input potentiometer. Another thing I don't like is the inaccuracy of the frequency dial. I thought I was selecting the common 80 Hz by eye but what is there is over 100 Hz. I had the dial below 90 so it shouldn't have been that high. So best to measure before trusting what it says.

Dynamic range is good:
View attachment 182671

Crosstalk is not great but probably OK for the application:

View attachment 182669

Performance relative to level at 1 kHz is very good for the product that it is:

View attachment 182670

Alas, when we sweep from 50 Hz up (to accommodate the crossover cut off), distortion rises at all but the middle frequencies:

View attachment 182672

So in that sense 1 kHz testing was showing the best case scenario.

Conclusions
In some respect the SX45 does better than I expected such as noise and distortion at 1 kHz. But channel matching is poor and distortion rises rapidly as frequencies go down. So a mixed message here and hard to rate the device.

I will give a marginal recommendation to Rolls SX45 if you can deal with its channel balance some other way.

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

can't see the point of this when the main use of it setting the xover correctly and with acceptable channel balance isn't done..