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MB Quart 3 floor

robv60

robv60

Member
So, I have a pair of speakers that I cant really find much info on so thought Id ask here for info. They are MB Quart Three floor standing speakers circa 1990something. Hold 2 ~6" cones and one tweeter. They seem nice and sound pretty decent to my ears. Whats better is that I traded my Onkyo hts-790 system's front L&R speakers for them, lol. Quite a trade up. However......
These are 4ohm speakers @ 90w rms (best i can tell) with a max of 170w. My Onkyo HT-R540 receiver puts out 110w per channel @ 8 Ohms. Now, to my knowledge, in a perfect world the rec should therefore pump out 220w rms to a 4ohm speaker. Am I going to ruin something running things this way? Afraid Im either 1. gonna blow the speakers or at the very least 2. not getting optimal sound from them. Any thoughts or suggestions? I know my receiver is OLD and not that great but its what I have and has served me well.

edit:: I understand the amp could likely get warmer under this load but other than that what kind of issues, if any might I expect?
 
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Hi Rob, and welcome to AK.

You are right, your Three's seem to be a bit rare, I can't find any info on them, only Ones and Two's.

Having said that, I had a pair of 800's that had 2x 6.5" and a 25mm tweeter. Great sounding speakers. I use MBQ 1000's in my home theater system now.

I wouldn't worry all that much about overloading your amp. I just went to HiFi Engine and downloaded the owners and service manuals.
https://www.hifiengine.com/manual_library/onkyo/ht-r540.shtml

First, I wouldn't call an amp built in 2006 old. But that's just me. :) Looking at the listed specs they are engaging in the typical modern spec bloat. But reading the 2-channel rating of:
"All channels:
110 watts minimum continuous power
per channel, 8 ohm loads, 2 channels
driven at 1 kHz, with a maximum total
harmonic distortion of 0.9%"

I'd make the WAG that with a full 20hz -> 20khz driven at the 0.08%THD shown farther down in the listing that you could probably consider it to be around a 75->80wpc/RMS amp driving 8 ohms with 2 channels, perhaps 85->90wpc/rms@4ohms. Just guessing.

Note that they do show Dynamic ratings driving 2-channels into 3, 4 and 8 ohm loads, so they seem to be saying that it can do that.

I've pretty much only owned 4 ohm speakers over the last 40 years and have never had a problem with damaging either amps or speakers. I don't think that you are going to have any problems. Just be careful with that axe Eugene. ;)

FYI, when I was given the MBQ-800's both tweeters were dead. With a bit of searching and a lot of help from members here I learned that MB Quart sold their name sometime after your speakers were made, and then the original MBQ re-named themselves German Maestro. I contacted them and was able to send the tweeters to them for repair. Cost me ~€50 per tweeter and the came back like new. Just in case you ever need to know that.

Cheers,
James
 
Thanks so much for your thorough reply! I had looked through the manual previously (although thanks for providing a link) but my limited knowledge of the specs didn't tell me much so i appreciate your input. They appear to be quality speakers. All the driver seem to be in working order and they sound pretty good to me. Still, i wonder if newer, more up to date speakers would sound better. I doubt I'd get much improvement without shelling out more than grand for new ones. Ive been toying with the idea of just getting some cheapo elac debuts or something. I doubt really know the history of the set i have, hiw they were treated,etc., but they were essentially free so I'm not going to do much better at that price point, haha. I just wonder how they compare to something new that's better matched to my amp with a higher efficiency rating, is all. Hard to tell at Beast Buy.
 
Happy to help.

If the speakers are working well they are every bit as good as "newer, more up to date speakers". If you take the "Two" for instance...
https://www.hifi-wiki.de/index.php/MB_Quart_Two
...and translate DM into Euros, adjust for inflation, switch to Dollars (if you are in the States), then you would need to spend a good bit more than what you just mentioned to buy a "Three".

I'd say that you fell into a fine pair of speakers, much better than a cheap pair of Elac's will ever be.

If they are built like my 800's were and 1000's are, the mid will be in a sealed section working as an acoustic suspension, with only the woofer in the ported section.
https://www.hifi-wiki.de/index.php/MB_Quart_800
https://www.audiokarma.org/forums/index.php?threads/mb-quart-800-project.638282/
https://www.hifi-wiki.de/index.php/MB_Quart_1000
https://audiokarma.org/forums/index.php?threads/mb-quart-1000-speaker-thread.824228/

I can state for a fact that MBQ's sound really good with a nice Yamaha 2-channel amp driving them. ;):) Just in case you were thinking of a new amp.

Enjoy them. Oh, and if you feel like it, we love photos!

Cheers,
James
 
Well, I cant say they sound bad. They don't get very loud without distorting, but loud enough for normal listening; something where I guess a new pair of something like a Klipsch R-26F might be better. I have no real need to spend the money on something new for a marginal, at best improvement. Id like a little more treble as these are pretty warm but I bet I'd have to spend $2-3k to get noticeably better.These will certainly do me well for now. Mine differ from the MBQ2 in that mine have 2, 6" drivers in addition to the 1" tweeter, similar to the 800's in form. Ill get some pics tomorrow! We all love pics.....
 
robv60 said:
I did run across this:
http://www.hifi-review.com/153419-mb-quart-quart-three.html
Click to expand...

The review pretty much describes what I thought of the 800's, without the measuring.

Looking at your photos, and reading that review, it looks to me like the Threes are a USA produced 800 with simplified cabinets. I'm going to guess that the internal volumes are the same, and that the 120hz/2900hz crossover points will be similar or the same.

The mid is a closed box. If you look how the tweeter is closer to the mid than the woofer, that lower gap is where the bulkhead dividing the upper and lower chambers is.

Tip: Check that the sealant on the cables for the mid/tweeter where they go through the separation bulkhead is still intact. In my 800's one speaker had loose wires and the other had sorta kinda sealed plugged. For the mid to work correctly the upper chamber must be sealed.

Tip 2: If the crossover doesn't have film caps on the tweeters replacing them with film caps will improve things. Likewise when I used a film cap on the upper end of the mid it sounded better to me.

Cheers,
James
 
Dang, now I need to start pulling it apart, haha. Kidding of course. But i MIGHT- because I can never leave well enough alone. Thanks so much for your input, man. I really do appreciate you taking the time to help and point out these things.
 
Cool thread. I have a pair of the MB Quart 500's. Smaller bookshelf speakers. But I've never heard them yet. They were yet another item from my estate score. And you're right, not much info online.
 
robv60 said:
Dang, now I need to start pulling it apart, haha. Kidding of course. But i MIGHT- because I can never leave well enough alone. Thanks so much for your input, man. I really do appreciate you taking the time to help and point out these things.
Click to expand...

Very happy to be of use. Have fun!

Cheers,
James
 
5395333C-2938-43F0-A50C-CC201FEAE749.jpeg 52E39E5A-481B-45BF-9132-07F3DE65BEED.jpeg Resurrecting this thread a bit to chime in and say that I just picked up some very clean model 500s yesterday. Impressive build quality, and after a days worth of listening now, definite keepers. They’re so nicely built it’s like looking at art, the baffle is covered in black cloth looking a little like corduroy in white cabinets. Nice weight for their size, about 17” tall.

Artie, did you ever listen to yours?
 
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