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Adding midrange to Infinity Qa?

Natrik

Natrik

Member
I have a set of Infinity Qa's that I love. The imaging is fantastic, and they seem to be a great match for my Sansui receiver. However, they are lacking in the midrange department. The Qb line had a midrange driver added, but upgrading to another speaker altogether is out of my price range. Can anyone suggest what kind of driver would be a good addition to this speaker? Parts Express has several different options, and I don't want to buy "blind" and just guess. I want something balanced, not something that will bring out the vocals and guitar slightly. Thanks for your input!
 
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How about just adjusting the EQ to bring out the mids? Unless you're adept at designing and building a new crossover, that may be your only option...
 
You'll need to find drivers that match, replace the crossovers and cut holes in the baffles of your Qa's. It will probably cost over $100 plus a bunch of time and you'll end up with something that might not be great. And you will have ruined the speakers that you love.

You might do OK if you can find the midranges and crossovers for a set of Qb's, assuming the tweeters and midranges are the same. Otherwise I think you should save your money until you can trade up.
 
Ohighway said:
Sell the Qa. Buy the Qb.
Click to expand...

Next best thing would be to find the mids and crossovers from a pair of Qb and install them. However keep in mind, the tweeter placement on the Qa and Qb are different, so that would be more holes to cut and patch....

I still think sell the Qa and buy some Qb would be best.
 
Next best thing would be to find the mids and crossovers from a pair of Qb and install them. However keep in mind, the tweeter placement on the Qa and Qb are different, so that would be more holes to cut and patch....
Click to expand...

Tweeter placement is the same in both models, attached is a picture showing both speakers.

I would get a pair of original Philips AD5060 midranges,(the mid-range comes with a closed enclosure, as shown on the left of the tech sheet) they are quite cheap when available, and modify the crossover, you need 2 coils, 1 resistor and 2 capacitors. I think the pot is the same.

Or, get a Qb crossover (compare prices with the new components, since you'll need to change the 12 uF cap at least)

My Qb crossover is a model with a mid-range pot only, no pot in the tweeter. (picture attached)

Of course, selling the Qa and buying a Qb is much easier.
 

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elnaldo said:
Tweeter placement is the same in both models, attached is a picture showing both speakers.
Click to expand...

Yep, you're right. I was getting the Qa confused with the RSa.

elnaldo said:
My Qb crossover is a model with a mid-range pot only, no pot in the tweeter.
Click to expand...

Hmm. Didn't know there were two versions. My Qb crossover has midrange and tweeter pots. (reference SN 8119597 FWIW)
 
i didn't know about the tweeter pot, until I googled "Infinity Qb" a couple of years ago :)

But my Qb don't have it .... (picture is from my own Qb's before the recap...)

6_P1060617.jpg
 
Upgrading the cabinet damping may be your most cost effective choice to help the mids. A recap may help a bit too.
 
I would do just what the others have suggested, sell your speakers and upgrade them with the money. I purchased my pair of Quantum 5's for like 150 dollars they have the Phillips 5060 mid, the EMIT, and the 12 inch Watkins and the front baffle is veneered in walnut as well, I doubt you will be able to modifiy yours for that cost.
 
Has anyone on the forum ever tested and documented the T/S parameters for the 5060/w? It would certainly make a lot of Dahlquist Dq-10 owners happy if the could fine a modern replacement when this driver gives up the ghost.
 
Ohighway said:
If it's the pair I just looked at over there, check out the sky high shipping charge.....
Click to expand...
Oooops, don't know how I missed that.
I guess I was so happy to see a pair for the OP to look into I forgot to check the shipping fees.
 
Thanks for the input! I really appreciate being able to get ideas before doing something stupid/regrettable/pointless. I'm going to re-cap these Qa's and keep my eyes open for a set of Qb's or something similar. Dave1027, what do you mean by upgrading the cabinet dampening exactly? Do you mean like acoustic fill material?
 
Something I mention to Qa and Qb owners. Check your cabinets for air leaks. I bought a set of Qb brand new in the late 70's. Within a few years they started sounding bad.... bass was flat and muddy. Turns out the cabinets had developed air leaks. (Fatal flaw for an acoustic suspension speaker) Once I sealed them back up, they sounded good again!
 
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