Hello
I have read all the threads about Martello Fr88ex and decided to build one my self. Right now I building a carbord modell but was wondering, is the model outdated? Are there any better elements right now? (2012)
2 x Fr88ex costs 100$ in Sweden.
If not what kind of amplifier and filter do you need?
A amp from Ebay maybe...
I have read all the threads about Martello Fr88ex and decided to build one my self. Right now I building a carbord modell but was wondering, is the model outdated? Are there any better elements right now? (2012)
2 x Fr88ex costs 100$ in Sweden.
If not what kind of amplifier and filter do you need?
A amp from Ebay maybe...
Member
Joined 2009
Paid Member
Thanks Bigun for sharing the awesome Martello.
I just built a cardboard model for fun, but I'm seriously thinking of using it with the Fr88ex.
Can you recommend an amp that's a value product like the Fr88ex. Maybe LM1875 ?
And about isolating the inside of a enclosure,what type of material do you recommend?
Member
Joined 2009
Paid Member
It looks a lot of fun to play around with this using cardboard.
As for amplifiers, I think your suggestion of a chip amp is a perfectly good one. I have never built one of these, having decided to build with discrete parts for the learning experience. But I wouldn't have any concerns about the sound quality from a chip amp if used within reasonable power levels - suitable for MARTELLO. If you do build a chip amp I would suggest you build a good solid power supply for it as the power supply is a key part of the amplifier and many people have reported that they tend to sound best when the amplifier has plenty of head-room. You may find more of interest here: http://www.diyaudio.com/forums/chip-amps/128561-chip-amp-power-supply-beginners-guide.html
One additional thing I would try if I were building a chip amp for my MARTELLO is to experiment with variable damping factor of the output - which you accomplish by putting a low value resistor in series with the speaker output and take the negative feedback from after this resistor. See here: http://sound.westhost.com/project56.htm
As for amplifiers, I think your suggestion of a chip amp is a perfectly good one. I have never built one of these, having decided to build with discrete parts for the learning experience. But I wouldn't have any concerns about the sound quality from a chip amp if used within reasonable power levels - suitable for MARTELLO. If you do build a chip amp I would suggest you build a good solid power supply for it as the power supply is a key part of the amplifier and many people have reported that they tend to sound best when the amplifier has plenty of head-room. You may find more of interest here: http://www.diyaudio.com/forums/chip-amps/128561-chip-amp-power-supply-beginners-guide.html
One additional thing I would try if I were building a chip amp for my MARTELLO is to experiment with variable damping factor of the output - which you accomplish by putting a low value resistor in series with the speaker output and take the negative feedback from after this resistor. See here: http://sound.westhost.com/project56.htm
Last edited:
Bigun what kind of isolation do you recommend using aside from felt?
You can see my work progress on imurl, just scroll down.
I just used the rope to temporarily test them. They sound good. Gonna do the hole for the air also.
I have to materials available. One is a kind of material people put in side-windows to make sure air can come in but debre and dust stay out. And the second one is a pillow from IKEA made of polyster fibres. Witch one would you recomend putting in the martellos. You can breath though bout of them, maybe there of same material.
Member
Joined 2009
Paid Member
I can see you've done a good job of the cutting and gluing up - well done!
The felt I used isn't ideal actually, it's really a bit on the thin side. I think what you have there looks a bit better, the roll of stuff sitting on top of the pillow looks pretty nice and I'd suggest trying that out. If you aren't sure, you could do an experiment of listening to the speaker without the material and with the material, just clamp the back on tightly instead of gluing it at first. But from the photo's looks like that stuff you have will work well.
The felt I used isn't ideal actually, it's really a bit on the thin side. I think what you have there looks a bit better, the roll of stuff sitting on top of the pillow looks pretty nice and I'd suggest trying that out. If you aren't sure, you could do an experiment of listening to the speaker without the material and with the material, just clamp the back on tightly instead of gluing it at first. But from the photo's looks like that stuff you have will work well.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.