Bought an Hartke 7000 used, problem detected.

[clorets123]

Hi,

I'm new to this forum. I read a lot of posts and reply and I feel I have a good chance to get really great information from its members.

I just bought a used Hartke 7000. Everything works great when it is used in mono mode. As soon as I press the back switch to enable the crossover (for Hi and Low setup), the woofers of the two cabs (210XL and 4.5XL) begin to dance and wave (like a sin wave), no sound just movement of the woofers in such a way that they reach max excursion and back. The frequency seems to be 5-10 hertz max.

I repeated this behavior two times now. As soon as the "dance" begins I hit the power switch to prevent damage to the cabs.
Any ideas?

[Jazz P Bass]

Woofer movement in both cabs is without a signal?

I would start by turning the preamp inputs OFF. the EQ OFF & the Compressor OFF.
Set the Contour, Balance & Crossover at 12 oclock.

If none of the front panel controls change the woofer behaviour, then you may have a Crossover circuit that is bad.

http://www.samsontech.com/site_media...000_manual.pdf

http://elektrotanya.com/hartke_ha500.../download.html

[J M Fahey]

Agree and add: I'm somewhat intrigued about what you are trying to do.

Although one is larger than the other, both cabinets are full range and basically the same; I fail to see the advantage of using one of them for "bass" (in which case you lose its tweeters) and the other for "treble" , in which case you severely compromise the use of its woofers.

One case where the total is less than the sum of parts.

The idea behind active crossovers and biamping is to get a range that a cabinet by itself will not supply.
Examples: you have the 410 which already is full range, and want to add wall shaking bass, then you add , say, 1 or 2 15" or 18" subwoofers, and split frequencies at, say, 80 to 120Hz ... or the contrary, you have, say, a warm and woofy classic 2 x 15"cabinet and add a 2 x 10" plus horns and cross over at 450 Hz or straioght horns and drivers and cross over at 2500 Hz.

But using 2 so similar cabinets ... it's better to use both full range.

I have an idea bothering me in the back of my mind, but I'd prefer to hear from you first: please describe the wiring, how you connect those speakers to the head.

Just by chance, do they have biamp inputs?

If so, do you use them?

[clorets123]

Thanks for the help, it is appreciated.

You are absolutely right, there is no need for me to use this feature, although since I just got it, I wanted to test all the features.

The 210XL is plugged in the "High" channel, jack #1. The 4.5XL is plugged into the "Low" channel, also jack #1. There is nothing plugged into jacks #2 of any channel.

With no input plugged in, I put both preamps to 0, turned the EQ off, left contour untouched and dialed the Balance and Crossover to 12 o'clock.
I turned the master volume to 0, and fired up the amp. Nothing appends.
Then I played with the Crossover knob, still nothing.
Then, I put the preamps to 1, nothing.
Then I put Master volume to 2 and all hell broke loose, lots of woofer movements and very loud "Pop" sounds. I decided to end the test at that point.

I know for general day-to-day use, the logical setup is to use the amp at "Mono" setting and bypass the crossover section. Since I only paid 500$ CAD (450$ US) for the whole rig, I can live with the problem.

[g1]

So turning down the master stops the movements and pops?
And in mono mode you have no such issues even when master is up?

Edit: In response to JM's question, neither cab has biamp inputs, they are both full range.

[clorets123]

Absolutely, no movement when master is off. Everything sounds really good in mono mode, great sound and dynamic.

Since this is a feature that I don't really need, I do not think this is something worth putting money in to get it fixed.

Thanks for your great input guys!

[Jazz P Bass]

Dollars to donuts says you have a bad IC on the Xover board.

[J M Fahey]

You're forgetting Inflation

I bet 1 donut today costs at least a Dollar, if not more

And if it still doesn't ... just wait a little

[clorets123]

Eating my Tim Horton's donuts while reading this thread

Thanks for the schematics, I will save it in my archives. Thanks for sharing your knowledge and ideas.