[tworedballs]

Good morning! I recently came across Danny's YT video (https://www.youtube.com/watch?v=65eFr2rKy3M) about rolling off bass with in-line filters BEFORE getting to the amp. This got me thinking why I would want to go this route instead of the built-in Xover on my powered sub?

Currently I have a small analog system: TT connected to Sansui G5700 receiver/amp to B&W ASW610 Sub with integrated Xover then out to my B&W 685 bookshelf speakers. The sub allows for Xover from 60-120hz (dial) and volume/gain. Would using Dannys DIY in-line filter give better results (sending full signal via RCA to the sub utilizing its low-pass filter BEFORE the amp) and only the higher filtered octaves through the Sansui to the bookshelf speakers?

I have PLENTY of power in my Sansui for these bookshelf speakers, so being more "efficient" with my power isn't really a concern. I'm looking for more clarity and want to get my components wired correctly before I focus on the speakers and upgrades/replacement. I'm the future I'll also be integrating a BSR 10-band EQ I have and a DAC/Pre-amp for streaming. They will all run through the Sansui.

[nlitworld]

Not to put words in Danny's mouth, but the high pass filter crossover in the sub amps are made with cheesy electrolytic caps and seriously degrade sound quality. Using an in line filter is possible between preamp and amp as it will allow volume control of both sub and speaker.

In your current configuration, your best bet is to run your speakers full range from sansui speaker A output straight to speaker and also run your subs from speaker B output to the speaker wire inputs on your sub and then adjust your crossover to match where the speakers naturally roll off around 40-50hz depending on your room. Play around with your phase control on your sub to be in-phase at your crossover point for best clarity. You'd be surprised how much of an impact that has on the entire sound of your system.

Once you get a preamp in the mix, you can easily play around with in-line filters to roll off the bass for your speakers.

As for other upgrades to play with before jumping into the big gear changes, focus on room setup and acoustic treatments. A large amount of sound quality improvement will be in this area. Check out New Record Day video on L.O.T.S. speaker placement and try your hand at some DIY absorption panels placed at your first reflection points. Also invest in a UMIK-1 and play around with REW to see how your room measures and changes with all these adjustments. Get these steps right and you'll be set to notice other small gains in the system much easier.

[tworedballs]

Thanks, @nlitworld ! I'll give that a try. I got the BSR from the guy I acquired the Sansui from, so I can use that to help bring any levels up/down to my listening preference, but wanted to start with [as close to] 100% neutral as possible. I love the Sansui stuff (has a nostalgia to me growing up with one next to my bed as a kid) and want to keep that as part of my set-up. I'll give this a try and see how it goes.

[nlitworld]

Another tip if you are using that EQ is to only cut the main major peaks in frequency response, never try to boost the nulls. Mess with speaker and listening position placement and room treatments to try and eliminate the nulls naturally. This hobby is about learning to love the tinkering process along the way, not just rushing to the end result for instant gratification. 

[mlundy57]

In your current configuration, your best bet is to run your speakers full range from sansui speaker A output straight to speaker and also run your subs from speaker B output to the speaker wire inputs on your sub and then adjust your crossover to match where the speakers naturally roll off around 40-50hz depending on your room. Play around with your phase control on your sub to be in-phase at your crossover point for best clarity. You'd be surprised how much of an impact that has on the entire sound of your system.

Big Fat WARNING!!!! here. I did that once with an NAD C 372 amp I had run bi-amped to both speakers and sub successfully before. When both pairs of speaker wires (the one to the speakers and the one to the sub were connected to the Speaker A output it worked fine. However, when I moved the pair of speaker wires going to the sub from the Speaker A output and connected them to the Speaker B output, as soon as I switched from Speaker A to Speaker A+B the amp blew up.

[Danny Richie]

Not to put words in Danny's mouth, but the high pass filter crossover in the sub amps are made with cheesy electrolytic caps and seriously degrade sound quality.

Yep, that is pretty much what I would have said.

[nlitworld]

Big Fat WARNING!!!! here. I did that once with an NAD C 372 amp I had run bi-amped to both speakers and sub successfully before. When both pairs of speaker wires (the one to the speakers and the one to the sub were connected to the Speaker A output it worked fine. However, when I moved the pair of speaker wires going to the sub from the Speaker A output and connected them to the Speaker B output, as soon as I switched from Speaker A to Speaker A+B the amp blew up.

Interesting. Perhaps having no real load on the speaker B side made it freak out. Crazy. I know the high level inputs go in and are dropped down to line level so the load the amplifier sees is almost 0.

Well there you have it, strong suggestions for double speaker wire runs from ONLY the speaker A outputs. Ya learn something new every day. Thanks for the tip Mike!

[tworedballs]

Thanks, guys! OK, here is another question (I did make the swap yesterday and it sounds great)... Would there be any benefit in swapping out the internal components of the Sansui (caps, resistors, etc.) to "better" components to max out it's capabilities or is that a no-no?

[mlundy57]

Thanks, guys! OK, here is another question (I did make the swap yesterday and it sounds great)... Would there be any benefit in swapping out the internal components of the Sansui (caps, resistors, etc.) to "better" components to max out it's capabilities or is that a no-no?

Based on it's age, recapping it could be a good idea. Over time, electrolytic caps dry out and since the G5700 was built in 1979-80 it's caps could likely stand replacing. No idea about the other components though.

[Early B.]

Thanks, guys! OK, here is another question (I did make the swap yesterday and it sounds great)... Would there be any benefit in swapping out the internal components of the Sansui (caps, resistors, etc.) to "better" components to max out it's capabilities or is that a no-no?

It would probably cost a lot more to recap it than the value of the component.

[tworedballs]

The receiver is definitely worth recapping at some point.

Moving back to my original question that started this thread...

If I was going to build one of these in-line filters there are certain input values I need to calculate the specs of the filter. What exactly are those specs and are they listed in the below information?

Tuning range: FM, MW

Power output: 75 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 75kHz

Total harmonic distortion: 0.03%

Damping factor: 50

Input sensitivity: 6mV (mic), 2.5mV (MM), 150mV (line)

Signal to noise ratio: 78dB (MM), 95dB (line)

Channel separation: 55dB (MM), 65dB (line)

Output: 150mV (line)

Speaker load impedance: 8Ω (minimum)

[Hobbsmeerkat]

The receiver is definitely worth recapping at some point.

Moving back to my original question that started this thread...

If I was going to build one of these in-line filters there are certain input values I need to calculate the specs of the filter. What exactly are those specs and are they listed in the below information?

Tuning range: FM, MW

Power output: 75 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 75kHz

Total harmonic distortion: 0.03%

Damping factor: 50

Input sensitivity: 6mV (mic), 2.5mV (MM), 150mV (line)

Signal to noise ratio: 78dB (MM), 95dB (line)

Channel separation: 55dB (MM), 65dB (line)

Output: 150mV (line)

Speaker load impedance: 8Ω (minimum)

There are 3 bits of information needed:
Input impedance of the power amplifier
desired roll off point
RCA or XLR

However it's unlikely that your receiver can be modified in this way.
The inline filter Danny is referring to will only really work if you are running a separate preamp and power amp(s).
Integrated amplifiers and receivers cant be easily modified for this to work unless they have a build in coupling cap between the pre and power amp sections of your receiver.\
Some receivers have their own built in high-pass function by setting your speaker size to "small" but it really depends if your receiver has such a function or not.

[tworedballs]

I possibly missed something in his YT video somewhere along the way...  The way I understood it to work was that between your source and your amp you put in a filter that had a highpass RCA out and an unfiltered RCA out. The value of the component that created the high pass filter was determined by the input resistance of your amp. Removing the first octave would via filtering would create more headroom for the amp to push power out to the speakers. I would then use the unfiltered RCA out to connect to my sub's RCA in (using the corssover on the sub for low pass). I didn't think I would be updating anything inside of the amp/receiver - only filtering the analog signal going into it.

[Hobbsmeerkat]

The filter is to be placed between separate pre-amp and power amp(s), it cannot be used before a receiver or integrated amp, such as your Onkyo.
Putting the filter before the preamp would remove volume control going to the subwoofer.

The only way to add a high pass filter to a receiver or integrated unit would be to modify the internals of the receiver where the preamp section connects to the power amp section, which isn't going to be possible for most users, assuming you can even find the input impedance of the power amp section for your Onkyo.

[tworedballs]

Got it. That makes more sense now that you mentioned the volume control on the sub. Thank you, @Hobbsmeerkat