FYI
This page is essentially an update to the previous guide I made for repairing the Monitor 5v2. Since it was quite long and detailed I chose to create a new page instead of just adding to it.
This overview goes into far less detail the previous repair guide for the Monitor 5v2. If you are looking to fix a set yourself give the first guide a read to familiarize with my process. This repair still requires making a spacer for the tweeter and cabinet and crossover modifications. Soldering is required.
Materials
- Spacer to mate new tweeter up to stock Paradigm tweeter faceplate (see my other guide to make this)
- new tweeters - Peerless H26TG4506
- 2.7uf bipolar cap, look for a inexpensive poly cap
- 1.4mh iron core inductor
- 3.4ohm 10ohm resister
- 18uf bipolar electrolytic cap
- 18awg wire for jumpers
You might notice this time I went with the Peerless H26TG4506 instead of the usual Scan-Speak Discovery series. The owners of these speakers wanted to this to be as cost effective as possible and the Peerless tweeters were on a kickass sale at the time. Using these gave me the opportunity to do some comparisons between the Scan-Speak D2606/9200, Peerless D27TG3506 and this Peerless H26. They all share the same design and lineage going back to the original Vifa. The main difference is the Peerless versions are made in China and Scan-Speak still builds them in Denmark.
I'm not setup for running distortion comparisons and I'm pretty sure I can hear differences between them. In terms of frequency response and efficiency they are almost identical. In fact I swapped between them while doing this project and they measured so close that no crossover changes were needed for this rebuild. My order of preference was a tie for Peerless H26TG4506 and Scan-Speak D2606. Runner up was the Peerless D27TG3506. I think this may be related to the larger chamber of the H26 giving it a lower fs. It could also just be my mind playing tricks on me. Without distortion data to back up any claim it’s just subjective. Bottom line any of these is a fine option if it means keeping a good set of speakers in service and the crossover presented in this page will work.
Quick note on the inductor needed for this rebuild. The stock inductor is has too small of value to keep it as is. There are a couple options. Grab the cheapest 1.5mh iron core inductor you can find at Parts-Express and take about 10 turns of wire off. It doesnt have to be perfect, a range of 1.33mh to 1.40mh is fine. For those of us in Canada finding the right size inductor is more difficult. Solen does not carry iron cored inductors and an air core inducor with low enough resistence is just not worth it. So heres what you do. Buy a single .20mh 20awg air core inductor to use as donor wire to increase the value of the stock coil.
Remove the original inductor from the crossover pcb. Cut about 3ft of wire from the donor coil and clean about .25" of the expoy coating from one end. Solder the end of the donor wire to the free lead of the stock inductor then put a piece of heat shrink over it to give some protection. Wind more coils on the inductor until the value is where it needs to be, about 11 turns. My coils both measured 1.39mh with 11 turns of wire,perfect! Try to keep the wire as snug as possible while you wind. If you have the ability to measure inductance now is the time to crack out your meter. Don't show your snob, golden-eared audiophile friends this or they will laugh you out of town. For this application where the inductor in the low-pass and in series with the driver(s) then DC resistance and power handling are the only concerns to pay any attention to.
Design
After reading previous rebuild of the Monitor 5, modifications to cabinet and tweeter faceplate should be completed. A spacer to mount the new tweeter to the face should also be constructed. This spacer is very important to the design. I have tried numerous times to get good sound without it and it just doesnt work as well. The tweeter response is rougher and seems to have a "beaming" quality. Notice the tweeters on the market of this design from Peerless and Scan-speak are made with faceplates which have the dome recessed almost completely. Clearly designed to sound their best with this configuration. I try to have some of these spacers on hand for those who don't wish to build them. Contact me for more info.
For the low pass section the 22uf cap and 8.6ohm resister are removed and replaced with the 18uf cap and 3.4ohm resister. For high-pass remove the 4.7uf cap and replace with 2.7uf. The 3.3ohm and 5.6ohm resisters are eliminated. Remove and replace with some 18awg wire as jumpers. Thats it for the details on this rebuild. Here is the modified crossover and simulated response.
- New crossover circuit
- Onaxis summation - hmm doesn't look great what the hell
- Summation at listening distance - ahh the summation at a typical listening distance evens them out. The 3db dip between 2-6k relaxes them a little. Perfect for rock music.
- Reverse null
Conclusion
Between this guide and the previious one there are multiple crossovers to choose from so which one is the best? Well that depends. Previous guide has the minimalist and perfectionist crossovers and now this one. My take is follows:
Minimalist - great for someone who just wants to get them running as quick as possible or if the level of complexity of the others is too much. Use whichever tweeter you can find on sale. They sound decent but you will likely miss the original Paradigm tweeters.
Perfectionist - For those of you who prefer a speaker with a flatter response, ie more "accurate". Great for non-amplified music or lower level listening. They will show you bad recordings. Go with the Scan-Speak D2606 or Peerless H26TG4506
This build - Do you like rock music? Do you like it loud? Use this design and the Peerless H26TG4506 or Scan-Speak D2606/9220. You'll wish the stock tweeters died sooner!
lord_darkhelmet at accesscomm dot ca