Active Crossovers with vintage Polk speakers

jimmypet · February 27

Hi Guys,
My first post in this forum. I have been a lurker on this forum for many years and mostly hang out in the vintage speakers area, but I think this post would be OT for that subforum. If it is OT for here I am happy to delete and move it.

Background: over on the Vintage Speakers sub there is tons of bandwidth on crossovers and crossover updates, crossover rebuilds, crossover modifications, etc. mainly because the speakers are quite old and much better components exist now.

My Query: When using multiple external amplifiers Is there anyone who has just taken out the old tired crossovers of old speakers and wired each driver (or sets of drivers) to individual sets of binding posts and gone to a real active electronic crossover?

Are there compelling reasons to stay with passive crossovers in old speakers?
Heck in any speakers, but especially in older ones that need sometimes hundreds of $$ in rebuilding.
One could easily buy an active crossover and for the cost of a few crossover rebuilds.
I'm just curious why its not more prevalent.
Some people spend alot of money and lots of hours soldering on passive crossovers.
Wouldnt a good active be better?

I swear I searched this and some (a few threads hit with "Active Crossover") but most of those threads de-volved into amp selection and spoke very little about the actual crossover part.

I appreciate your knowledge.
Thanks!!
Jimmy P

VR3 · February 27

So as someone who has been interested in trying a fully active system...

I would only consider it if everything was in the digital space.

There are companies that make products where you can run 3 or 4 independent dacs and all of the room correction, crossover, delay etc is done before it reaches the crossover.

The obvious downside besides complexity is just cost. 3 or 4 dacs, 3 or 4 amps, etc.

At the end of the day having a simple high quality system is just the way to go unless you have deep pockets wanting to play around

Most external crossovers that distribute in the analog space are pro oriented, noisy and don't belong in a true 2 channel system

jimmypet · February 27

Thanks Trey,
Because over the past 40 years I have been around these things, in the live world we always looked down our noses at anything that had a passive crossover in it, hence my question about going active.

Now again, my gut would be to buy a nice DBX or Ashley type crossover and try that but it would definitely be a science project and may or may not yield any good result.
I have the amps, it would take the physical rewire of the speakers etc.
---BUT---
Giant but,,,
I also use pro amps in my system which I know many real audiophiles are not onboard with.
I also have a Klark technique EQ in my system as well which I am sure many audiophiles would not think was a good idea either.

To me it sounds great, and I believe it's quiet and has no noise, but someone like yourself may think differently.

The KT EQ alone made such a huge difference to the system, it allowed me to get my RTiA9s to such a sweeter space than they had without it. I can now actually listen to music through them with a smile.

It also allowed me to get a little better sound out of my other old 11T and LS90s.
By dumping off all the super high and super low stuff you cant hear anyway the speakers got tighter and louder. EQ-ing out alot of the super highs and a tiny tiny notch at 3.5k makes my 11Ts not trip as easy. Im still sending those crossovers to you for rebuilding 100% but a little EQ-ing made a difference in how easy they tripped and the overall sound.

Same with the LS90s, a tiny shaping in the low end tightened the bottom up massively.

I appreciate your input.
I had not even thought about anything digital. I was 100% thinking an analog balanced, XLR pro-type rack piece. There are so many available and for not alot of $$

Cheers
Jimmy P

VR3 · February 27

This hobby is so wildly personal for everyone! We all enjoy music differently and have different expectations.

At the end of the day I don't see any issues here. Go ahead and wire them for active use and you can then build an external passive crossover and compare them.

Part of what makes the hobby fun!

jimmypet · February 27

VR3 wrote: »

This hobby is so wildly personal for everyone! We all enjoy music differently and have different expectations.

At the end of the day I don't see any issues here. Go ahead and wire them for active use and you can then build an external passive crossover and compare them.

Part of what makes the hobby fun!

I may do one set as a hobby project when I have some downtime (which is not now LOL), but may be a fun winter project for next Jan-Feb.
That will give me time to investigate and plan an attack.

Probably use my A9s at the test bed, because for some reason even though they cost me the most of any speakers I own they are not near as precious to me as my 11Ts and my LS90s LOL

F1nut · February 27

Talk to @gp4jesus. He tri amps his RTiA7's.

SeleniumFalcon · February 27

There were some beautiful active speaker crossover components, such as this one made by Pioneer:

jimmypet · February 27

SeleniumFalcon wrote: »

There were some beautiful active speaker crossover components, such as this one made by Pioneer:

Damn, that is really pretty

gp4jesus · March 1

Thanks for the kudo , Jesse😊
I continue to experience fascination w/the different paths people use to get where they’re going in this hobby.

Jimmy: I’ll PM my build-threads later

gp4jesus · March 1

PM sent

jimmypet · March 2

gp4jesus wrote: »

PM sent

Thanks replied.

mhardy6647 · March 4

FWIW (which ain't much!), here's what I'd do*:
1) acquire a decent DSP device (e.g., miniDSP box) and some measurement tools (at the least, a calibrated mic and REW s/w).
2) experiment with crossover point(s), slope(s), and delay(s) while monitoring the performance qualitatively (ears) and quantitatively (mic & s/w).
3) establish optimal (ahem, or close enough)

parameters, then build passive XO(s) to afford similar performance (single or multi-amped) -- or use dedicated analog active XOs of high quality, with multi-amping.
I don't like the kerfuffle of hopping between analog and digital domains, if for no other reasons than latency and complexity.

This being said, if the source is digital, and all of the processing is done in the digital domain (DSP) without an intervening D to A and A to D, that would be perfectly reasonable. Some of us, though, still use analog sources now and again.

________________
* I have thought about going this route more than once with my Frankenaltecs, but fortunately I am awfully lazy.

mhardy6647 · March 4

1) @SeleniumFalcon mentioned the Pioneer active XO above. Yup, they're both sexy and expensive.
Many if not most of the big-name Japanese brands offered similar products at one time/for a time, so there are myriad options in that product space.
A not-at-all random example

source: https://www.hifiengine.com/manual_library/yamaha/ec-1.shtml
Papa Nelson (Pass) made or makes an active XO, too.

None was particularly mass-produced, and none will be inexpensive in the present day. Decent quality DSP is not expensive at all nowadays, thanks to several vendors (miniDSP being just one, and a lower-end option at that).

2) Cello Palette. When your bank account really does need to be drawn down substantially -- here's a great way to do it!

OK, it's not an active XO, it's a preamp/EQ -- but... oh, my...

https://www.stereophile.com/solidpreamps/692cello/index.html

SeleniumFalcon · March 4

It's interesting that, at one time, active crossovers and multiple amplifiers were very common in home audio systems. But, that branch of audio migrated to car audio enthusiasts somewhere in the '80's. Now if you search for "active crossover" the majority are related to 12 volt application. Placing the frequency shaping ahead of amplification has lots of benefits, especially eliminating inductors and capacitors inside the speakers. One answer might be that as speaker designers developed more and more complex crossovers (adding more components) it was harder to achieve this with a general external crossover.

gp4jesus · March 15

mhardy6647 wrote: »

FWIW (which ain't much!),

you kinda hard on yourself. It IS worth more than the credit you give yourself.

mhardy6647 wrote: »

I don't like the kerfuffle of hopping between analog and digital domains*

You make good point ⬆️ A/D &/or D/A is never perfect. It’s fractionally like translating from one language to another - a little “gets lost in the sauce.”

mhardy6647 wrote: »

, if for no other reasons than latency and complexity.

gp4jesus · March 15

These⬇️ could “keep it analogue.”

I’ve pondered this EXO alternative/upgrade WHEN I’m confident I have the XO frequencies and slopes optimized.

https://www.xkitz.com/collections/active-crossovers-and-bi-amplifiers-1/products/linkwitz-riley-3-way-active-crossover-fully-balanced-xover-3b
For the curious…
https://www.xkitz.com/collections/active-crossovers-and-bi-amplifiers-1/products/linkwitz-riley-3-way-active-crossover-fully-assembled-xover-3

Each available as 2-way

Active Crossovers with vintage Polk speakers

Welcome!

Comments

Welcome!

Welcome!

Quick Links