Harrison Labs In-line Crossover Review (RCA)

[restorer-john]

Input impedance of the analyzer is 100 kHz:

Typo: 100k Ohms.

 

[Vladimir Filevski]

What happens if you stack two of them? Do you get 24dB/oct?

No, in-line RC filters are working OK only when plugged into the high input impedance of a (pre)amplifier.

 

[solderdude]

What happens if you stack two of them? Do you get 24dB/oct?

You will be incorrectly loading the first filter so won't be exactly 24dB/octave and the -3dB point will shift to a lower frequency.
You will also get more attenuation at 20kHz.

 

[Plcamp]

My OB speakers need only 2nd order crossovers, so building line level inline versions (to drop post amp crossovers) might work well. From what I have seen, anything beyond 2nd order isn’t normally viable as you suffer too much end to end attenuation…the higher the power amp input impedance the better.

 

[martin900]

I wonder if they do tours of their 'laboratory'

I thought these were 'the' Harrison PA guys from the UK, known for their amps and consoles but it's probably a one 'tin foil' hat man company:

Harrison Labs Crossovers - FMODS, PFMODS, FMOD CABLES, BASS BLOCKERS, Contract Manufacturing

Harrison Labs manufactures high quality electronic products. Hlabs provides contract manufactures for partner companies.

www.hlabs.com

 

[Multicore]

In my world I just call that a low pass filter.

I think that's the engineering name for it but doesn't suggest why use it, while its marketing name does. After all, once it is packaged as a consumer product its purposes expands beyond filtering to pass lows. It's supposed also to make a little profit for everyone in it's supply chain who might reasonably ask: Why?

And it's really cool how our ASR friends elaborated on that.

 

[Billy Budapest]

They sell a version that can be used as a rumble filter and it probably would work well in that application.

 

[Glitch]

Yeah this would be way more useful if it had the LP and HP pair and show how they sum up.
Sorry if this a stupid question but would the impedance of the amp affect the slope?

 

[TheBatsEar]

What happens if you stack two of them?

You don't want to know.

 

[Plcamp]

Yeah this would be way more useful if it had the LP and HP pair and show how they sum up.
Sorry if this a stupid question but would the impedance of the amp affect the slope?

The impedance of both the source and amp matters.

 

[rebbiputzmaker]

You will be incorrectly loading the first filter so won't be exactly 24dB/octave and the -3dB point will shift to a lower frequency.
You will also get more attenuation at 20kHz.

They still make these so no corrosion … People can get them new and they could get different rolloffs and frequencies if necessary.

 

[ROOSKIE]

Back in the day (mid 90's) I used these to high pass my 2 main stereo channels.
Best decision I even made. I learned real fast the benefit of doing that and blending my powered sub in was also much easier.
That old Boston Accoustics & Harmon Kardon set-up sounded really good to my young ears. Music became art.
Bet it would sound kinda crappy to me now though. Progress and all...
Glad to see they are accurate, I had no mic back then, only trust.
Great review!

 

[MakeMineVinyl]

What, no SINAD?

 

[Angsty]

Tried a similar, but high pass filter from this company as a rumble filter for my turntable several months ago. Did not like how it impacted the higher frequencies and sent it back. Likely that the RC network didn’t play well with my cartridge and phono.

 

[TheBatsEar]

Tried a similar, but high pass filter from this company as a rumble filter for my turntable several months ago. Did not like how it impacted the higher frequencies and sent it back. Likely that the RC network didn’t play well with my cartridge and phono.

Wouldn't you use it hat line level between phono pre-amp and pre-amp?

 

[Angsty]

Wouldn't you use it hat line level between phono pre-amp and pre-amp?

Yes, but the phono is part of an integrated amp.

 

[Slayer]

This is a review and measurements of the HLabs in-line RCA 50 Hz crossover. It was kindly sent to me by a member and costs US $27.95.

While I appreciate the time spent on this review and the member sending them to you.
These are not genuine Harrison products. These are knock-offs. Nothing about the product or packaging appears to be genuine.
I can't count the number of these I have bought and installed for numerous people over the past 10-20 years. I would bet money these are knock-offs.

 

[Bill Brown]

It is important when using these to consider the output impedance of the driving preamp, the input impedance of the filter, the output impedance of the filter, and the input impedance of the amplifier.

In many cases it will be fine, but an example: I have an RME ADI2, balanced out to my amp, unbalanced outputs to 4 subs (with splitters). Using these in combination, the subsequent input impedances in parallel become quite low and could put quite the strain on the driving preamp (though when I tried it it seemed to be fine).

In addition, the crossover frequency depends on the input impedance of the amplifier. Demonstrating some of these effects could have added to the review.

From the manufacturer re. turnover frequencies:

20hz black bands (25hz @ 10K / 17hz @ 47K)
30hz 2 black bands (37hz @ 10K / 26hz @ 47K)
50hz brown band (54hz @ 10K / 46hz @ 47K) (62hz @ 10K / 43hz @ 47K)
70hz purple band (76hz @ 10K / 65hz @ 47K) (87hz @ 10K / 60hz @ 47K)
100hz has no band (108hz @ 10K / 92hz @ 47K) (125hz @ 10K / 85hz @ 47K)
150hz 2 blue bands (162hz @ 10K / 138hz @ 47K) (187hz @ 10K / 128hz @ 47K)
200hz blue band (216hz @ 10K / 184hz @ 47K) (250hz @ 10K / 170hz @ 47K)
300hz 2 white bands (375hz @ 10K / 255hz @ 47K)
500hz white band (540hz @ 10K / 460hz @ 47K) (625hz @ 10K / 425hz @ 47K)
1000hz light blue band (1080hz @ 10K / 920hz @ 47K) (1250hz @ 10K / 850hz @ 47K)
2500hz light green band (2700hz @ 10K / 2300hz @ 47K) (3125hz @ 10K / 2125hz @ 47K)
3500hz gray band (3780hz @ 10K / 3220hz @ 47K) (4375hz @ 10K / 2975hz @ 47K)
6500hz orange band (7020hz @ 10K / 5980hz @ 47K) (8125hz @ 10K / 5525hz @ 47K)

Bill

 

[KxDx]

I thought these were 'the' Harrison PA guys from the UK, known for their amps and consoles but it's probably a one 'tin foil' hat man company:

Harrison Labs Crossovers - FMODS, PFMODS, FMOD CABLES, BASS BLOCKERS, Contract Manufacturing

Harrison Labs manufactures high quality electronic products. Hlabs provides contract manufactures for partner companies.

www.hlabs.com

After 10 seconds on that Geocities-quality eye cancer, I know I'd never give them a dime. Anyway...

 

[amirm]

Agree, it would be nice to see THD and noise on this unit.

A filter changes frequency response which in turn changes measurement bandwidth/noise and harmonics. So while I could easily produce such a number, you would have no reference to compare it to.