General thoughts:
As a general notion, we must be aware that if we design new crossovers or change component types for any speakers, whether they are newer or vintage speakers, we are changing the sound and overall philosophy in a different direction to what the designer of the speakers had in mind for those speakers.
Even if the speakers have some inherit shortcomings and the crossovers are either redesigned or fitted with a better grade of components, there are no guarantees that the changes will be to the listeners liking.
In most cases we get the most immediate change or improvement when upgrading capacitors for the positions that are in direct line with the tweeters and mid-range drivers .
Exchanging or upgrading the induction coils can also have an impact on the sound and performance of a speaker system, but it will in it’s nature often not be as profound a change, as when changing or upgrading capacitors, unless the stock induction coils were incorrectly chosen for the original crossover design, for example using a ferromagnetic cored coil for the tweeter section causing audible noise.
For vintage speakers specifically:
Speaker units, crossover components, and knowledge regarding designing speakers is evolving all the time and we have taken quantum leaps within audio design and component technology and quality since the 1970’s, 1980’s and 1990’s.
So, whether you upgrade your vintage speakers using either completely re-designed crossovers with a e.g. a new filter order and/or new component values or if you only upgrade the stock crossovers with better components, it is important to ask yourself two questions:
- Do you want your speakers to sound different or “better” according to more modern notions of how speakers “should sound”?
- Or do you want to keep the original “vintage” sound of your speakers, even if that means sacrificing things like increased transparency and detail richness that can come from a crossover redesign and/or by upgrading to modern higher grade crossover components?
DIY crossover upgrade kits for vintage speakers:
Jantzen Audio offers some DIY crossover upgrade kits for a handful of vintage speaker models, which were all re-designed by loudspeaker designer, Mr. Troels Gravesen.
The idea behind the re-designed crossovers was to correct what Mr. Gravesen perceived as inherit shortcomings and to make the speakers perform at their full potential.
We would advise that you read Mr. Gravesen’s articles for the re-designed crossovers and the feedback from customers who upgraded their vintage speakers using the re-designed crossovers, before deciding if it is right for you.
General things to consider before taking on an upgrade project:
Do you have the required experience with crossover assembly?
- Will there be room in your enclosures for the larger crossover boards that upgrading to better components will most often require, or are you willing to make external crossovers?
- Mostly relating to vintage speakers, what is the condition of the drivers and are they in proper working condition?
If not, your first step should be to have your drivers repaired / refurbished! - If the drivers are not in optimal working condition, you cannot be sure that the driver(s) will perform the same as it/they did some 30-50 years ago, thus the crossover may need to be re-designed with the necessary changes to factor in frequency response, phase, and impedance changes that may have occurred over time, if the speaker units are not refurbished to original working condition.
Considerations for resistors:
If you are going to upgrade your crossovers and spend both time and money on the project, you may as well also upgrade stock (lower-grade) resistors to some higher grade resistors for example wire-wound, metal oxide or thick film.
Considerations for capacitors:
Generally we would recommend concentrating on upgrading the capacitors that are in direct line with the tweeters and the mid-range drivers.
This goes for both newer and vintage speakers.
For the tweeter and mid-range capacitors, it generally makes sense to use high-end (expensive) capacitors.
For the bass section we recommend simply using good quality electrolytic, MKT or Standard MKP capacitors, as it is overkill to use high-end capacitors for bass section dedicated capacitor positions.
Which specific capacitors to use for upgrades, will depend on many personal preferences, the main ones being budget, sizing limitations on the crossover boards, and personal taste in sound profile.
As general recommendations, we would recommend looking at the examples below:
1. If your current speakers use electrolytic capacitors for the bass / lower midrange positions, we would recommend upgrading to either our Cross Caps (MKP – metalized polypropylene foil) or to our Compact MKT (MKT – metalized polyester film).
2. If your current speakers use electrolytic, MKT or standard type MKP capacitors for the upper midrange positions, you can consider upgrading to either our Superior Z-Caps / Silver Z-Caps (Super MKP) or our Alumen Z-Caps (pure aluminum foil).
3.) If your current speakers uses electrolytic, MKT or standard type MKP capacitors for the tweeter positions, ou can consider upgrading to either our Superior Z-Caps / Silver Z-Caps (Super MKP), our Alumen Z-Caps (pure aluminum foil), or our Amber Z-Caps (pure copper foil).
In out website you will find datasheets for all our capacitors, with more information on the technical data and sound profile of the various capacitors.
We also recommend reading the in-depth reviews / articles written by Mr. Troels Gravesen that offers more insight on the sound profiles and differences between our Super MKP and pure metal foil capacitors:
About Super MKP (Superior Z / Silver Z-Caps):
LINK
About Alumen Z-Caps:
LINK
About Amber Z-Caps:
LINK
Considerations for induction coils:
- What is the condition of stock inductors and is it necessary to exchange them?
- If your speakers use ferromagnetic cored coils for positions crossed too high in frequency and it is causing an audible distortion (hum), you can consider upgrading these positions to air cored coils
- If you want to exchange / upgrade the stock inductors, you will have to pay extra attention to the ohmic resistance of the coils (DCR), as this may be an essential part of the crossover functioning.
- If you wish to exchange the stock inductors, it is necessary to measure the Ohmic resistance of the inductors with a precision milliohm meter. A standard multimeter is not good enough for this, as we are measuring resistance of e.g., 0.1-0.5 Ohm.
Vintage speakers specifically:
the stock electrolytic capacitors could be 30 or more years old and could have issues with evaporation, etc. and it is likely a good idea to test their capacity and exchange them if needed.
It is also important to note that specifically for vintage speakers, the capacitor values used were often from the “old e-row” of values and today it is rare to find values like e.g., 1, 2, 3, 4 and 5uF when it comes modern era high-end capacitors, which are most often only offered in the “modern e-row” of values (e.g, 1.5, 2.2, 3.3, 4.7 uF etc.)
There will therefor often be a need to couple two or more capacitors in parallel to obtain the right capacitor value – take this into account when simulating the new and larger crossover boards.
Considerations for speakers with attenuation knobs / L-Pads:
If your speakers come with attenuation knobs / L-Pads, you must consider if you are able to transfer them and their functioning to the new crossover boards or if it makes more sense to omit their functioning and do any needed attenuation via resistors instead.
The knobs themselves can of course be left in as a decoration, even if their functionality is not transferred to the new crossover boards.
Design of new crossovers:
We cannot offer to design custom new crossovers for both vintage and newer speakers.
It would require that we had the speakers in the workshop, which is an extremely time consuming and unrealistically costly task.
We can offer general advice about component upgrades, if we receive all the information in the checklist below.
Checklist for component advice:
- You will need the crossover schematics with component positions and values (including DCR values for the coils)
- You will need to make good quality photo(s) of your stock crossovers that clearly show what type the stock coils, capacitors, and resistors are
- You will need to send us a full list of the component values, positions and where they are located (bass, mid, tweeter sections).
- You will also need to send us the crossover schematics and the photo(s) of the stock crossovers
Example of a stock vintage crossover versus a new upgraded one:
