Ua721 Mod

[RJMELKON]

I have built the UA721 DIY kits from PE for my RCL speakers
in my HT.My concern is that sometimes the tweeter seems
too bright.I was wondering if anybody here knows of any mods
to this kit that will help.TIA.

[JimHRB]

Looks like there is a 1.5 ohm resistor used to pad down the tweeter. Replacing that with one with higher resistance would reduce the tweeter output. Since this is a prebuilt crossover, you would have to remove the resistor from the circuit board and replace it with another. Not the easiest job unless you have some experience doing this.

[Pete Schumacher ®]

I have built the UA721 DIY kits from PE for my RCL speakers
in my HT.My concern is that sometimes the tweeter seems
too bright.I was wondering if anybody here knows of any mods
to this kit that will help.TIA.

Does your receiver have Audessey? It should be able to EQ the extra highs away.

[RJMELKON]

Thanks for the responses guys.
No I do not have audessy and is there another way
to implement a different resistor,say 2 ohm for the tweeter,
rather than at the board.Maybe at the tweeter terminals
themselves?Sorry if that sounds stupid but as you can tell
I am not an experienced speaker builder.

[Pete Schumacher ®]

Thanks for the responses guys.
No I do not have audessy and is there another way
to implement a different resistor,say 2 ohm for the tweeter,
rather than at the board.Maybe at the tweeter terminals
themselves?Sorry if that sounds stupid but as you can tell
I am not an experienced speaker builder.

If you put the resistor between the board, and the tweeter terminal, then you will be able to pad the tweeter a bit, but that way may also change the XO point somewhat. An additional resistor across the terminals, AND in between the board and tweeter could succeed (L-pad).

[RJMELKON]

Thanks again Pete for your time.
Be patient with me please but are you saying a resistor across the
terminals on the tweeter assy itself?If so how is this done,soldering
the resistor across the two terminals?

[RJMELKON]

Actually does Parts Express offer a prebuilt XO that
could replace what was in the original kit and will
tame the tweeter?

[Brewski]

Actually does Parts Express offer a prebuilt XO that
could replace what was in the original kit and will
tame the tweeter?

I don't think you'll find another crossover that would be more optimized for those drivers sold as a pre-made crossover. Your best bet would be tweaking the value of the 1.5 ohm resistor trying 2 ohms and 2.5 ohm in that location to see if they they are more appealing.

One somewhat easier way of trying it while testing it out would be to add a .5 or 1 ohm resistor into the positive wire lead for the tweeter after the crossover board.

Take it easy
Jay

[jclin4]

Actually does Parts Express offer a prebuilt XO that
could replace what was in the original kit and will
tame the tweeter?

The answer to your question is Yes and No. There probably is a pre-built XO that will tame the top end...but it will most likely ruin everything else unfortunately.

Your best bet is to follow Pete S.'s suggestion (actually he made two): A) take the wire that leads to the tweeter's positive terminal and splice in a small value resistor, like .5 ohms temporarily. Then give it a listen. If it is still too bright, then try .75 or 1 ohm.

OR

B) do the above AND add a resistor connecting the positive and negative terminals of the tweeter. To get the appropriate values for both resistors will require some crossover modeling with the data for your specific tweeter and woofer, or maybe someone can suggest the values to start with. This method will more precisely adjust the level of your tweeter without changing your crossover point significantly.

But either way, I would definitely keep the XO you have and tweak it with the above methods. A pre-built XO is not going to help you...

[RJMELKON]

Got it,thanks again guys.
If I decide to do this will report back.

[JimHRB]

Before you go modifying things, I would carefully check that you put the kit together correctly. That kit uses high quality Usher drivers and was designed by someone very well known, Dr. D'Appolito. The FR curve looks very flat. Also check that you don't have something set incorrectly on your receiver. Turn off all surround sound modes, equalizer settings, etc. And consider room placement. If after all that it still sounds hot to you, then consider padding down the tweeter.