Converting Magnepan MG10QR's to DSP crossover

[SoundMods]

After all that work please do not keep those cheap-ass fuses. Here is a link for some nice sand-filled fuses that enable the best possible sound quality.

https://www.ebay.com/itm/154043810677?h ... R-qO09SpYg

Thanks! Will give them a try.

You're very welcome!

[Roscoe Primrose]

The best sounding fuse is no fuse at all... The tweeters can handle a lot of power if it's clean...

Roscoe

[HAL]

Roscoe,
I had a pair of MGIIB's in the '80s with a fuse. Used Hafler DH220 on the MGIIB's and DH200 amps on the subs. It was clean, but still managed to blow the fuse. Since the passive line level crossover was only 6dB/oct probably still to much low frequencies to the mid panel when I added the VMPS Standard subs with their DH220 amp.

Should not be a problem with an 8 pole L-R acoustic alignment when I get things measured on both the mid and tweeter panels. Works well with the Radian LM10n planars.

[HAL]

Well the new fuses maybe here by September, so will be using the originals until then.

Reworking the listening area and then start setup. The 2x12 servo subs are ready for amp and wiring.

Still waiting to hear about the Magna Risers shipping.

[HAL]

Well, the tracking was wrong.

The fuses are here to put in the MG10/QR's.

Now I just need a room to set them up.

New drywall is installed and hopefully painted Friday. Then new floor goes in Monday. Then time to start the next step of Audio Room V2.0

Attachments

[SoundMods]

The best sounding fuse is no fuse at all... The tweeters can handle a lot of power if it's clean...

Roscoe

Roscoe? No! The "tweeter Voice Coils" are very small gauge and for the speakers to operate reliably the current through them should no exceed 3.2-amps (80% of 4-amp fuses). That's 40 watts.

You increase the volume level 3-db and you are demanding 80-watts. OUCH! During my evil past I had a pair of Manepans with the copper "voice Coils." I thought I was doing the audiophile thing by installing jumpers to replace the fuses.

The speakers did sound better without the fuses -- no question. Then POOF!! The voice coil in one speaker became the fuse. Lesson learned. The sand-filled fuses are a nice find and they do make a difference.

[tomp]

The main reason for the sand filled fuses is to have higher interrupting capacity on very low impedance circuits. For example a 3 amp ABC fuse has a current interrupting capability of 10,000 amps. No audio amplifier can ever come close to that. Otherwise there is no difference.

[HAL]

tomp,
When I had my MGIIB's in the '80s it was fascinating to watch the fuse element physically move inside the glass tube. This was at higher volume listening levels, but not as loud as one would think.

Physically constraining the fuse element by damping might be interesting. I know after some period of time, the MGIIB speakers would not sound as good even with periodic cleaning of the contacts. Replacing the fuse restored the sound quality.

This will be an interesting trial.

In the mean time, my room has new drywall installed, the walls painted and floor installed. Sounds like a giant echo chamber.

Talked to SonitusUSA and asked about if they had east coast installers for the Ultra Package for my room. Waiting on response. I did get copies of the material specs to review.

I also talked to Bay Acoustics in Baltimore and they are sending an estimate to measure the room acoustics of the room for a 3D model to suggest an appropriate acoustic installation for my listening room. Waiting on that now.

One step at a time.

[HAL]

A pair of Magna Risers for the MG10/QR speakers arrived.

Time to start setup and start moving back into the audio room.

[tomp]

tomp,
When I had my MGIIB's in the '80s it was fascinating to watch the fuse element physically move inside the glass tube. This was at higher volume listening levels, but not as loud as one would think.

Physically constraining the fuse element by damping might be interesting. I know after some period of time, the MGIIB speakers would not sound as good even with periodic cleaning of the contacts. Replacing the fuse restored the sound quality.

This will be an interesting trial.

In the mean time, my room has new drywall installed, the walls painted and floor installed. Sounds like a giant echo chamber.

Talked to SonitusUSA and asked about if they had east coast installers for the Ultra Package for my room. Waiting on response. I did get copies of the material specs to review.

I also talked to Bay Acoustics in Baltimore and they are sending an estimate to measure the room acoustics of the room for a 3D model to suggest an appropriate acoustic installation for my listening room. Waiting on that now.

One step at a time.

A typical AGC 3 amp fuse has a resistance of 0.045 ohms. Even if the resistance rose to 1 ohm the fuse would blow at 0.3A which represents 1/3W into 4 ohms. Hard to determine the mechanism that could cause an audible change.