Empire Grenadier 8000P


I would like to tap into the arsenal of knowledge on Audiogon and ask a question about the Empire Grenadier 8000P's. It involves something that has always confused me. On the back of the cabinet, there are 6 small ports. I've seen 8000P's with all sorts of configurations with regards to these ports. Some have all six ports plugged with a small plastic cap. Others have them all open and still others have every other combination of them plugged and un-plugged. Since I did not buy these new and have never seen an owners manual or any explanation for these ports, does anyone know what they are for and how or why you would use them, plugged versus un-plugged? Are they to be all removed, all installed or some combination based on speaker placement? Feedback would be appreciated. Thanks!
vintage_heath
I did find something about those ports on the Empire 8000P's. I'm now changing my mind and believe they were for more than packing and shipping. I found an old ad for them from 1966. It was on a French audio collectors website (of course it was all in French, but I understood the pictures), but the ad was in English. It made the following statement.

"Its exclusive dynamic reflex stop system allows you to adjust the bass and treble response to suit your individual room acoustics"

The crossover adjustment on the bottom is marked only for "High Frequency Control". Low, medium and high. So it looks like the only way to adjust the bass, would be to change the woofer load by removing some or all of the vent plugs or leaving them all in. There are six ports on each cabinet and right now I have four of the six ports plugged on each. Mainly because I only have 9 plugs total as the remaining 3 were missing. 

I also made at least one mistake in one of my ramblings above. The other Empire speaker I was trying to think of was the Jupiter, not the Neptune. I knew it was one of those planets! ;-) The cabinet looked like the head of "Robert" the robot from the old Gerry Anderson kids show Fireball XL5! Very unique!

I really like so much of the old equipment from the "golden era of audio" and before.

Regards,
Vintage_heath

Thanks everyone for the great information part of the discussion is taking them apart how is that achieved thanks for any help you can get does anybody have a manual on these things ?

Thanks again

Hi greystereoman,

I don't have a manual, but have rebuilt the crossovers in my pair of 8000P's. Everything is accessed through the bottom. So flip one upside down and take out the four screws. The wooden bottom will come off. Be careful of the golden grate as the edges are sharp and can damage the finish or the woofer. The wires from the crossover switch will need to be unsoldered. Keep track of where they go. The wires go through the edge/frame of the woofer. Undo the 4 studs and remove the woofer being careful to feed the wires from the switch you disconnected through the holes. Disconnect the woofer keeping track of which wires connect to it. Some fiberglass sound deadening material is stapled over the crossover. Remove the staples and the sound deadening material. There you will find the crossover components. Two inductors and a number of capacitors. You will need to replace all of the caps as they are guaranteed to be bad by now. You should be able to look down the enclosure following the wiring inside and see the mid-range and tweeter. I have a schematic of the crossover with values for all components and all the internal wiring and even ran some LTSpice simulations of the crossovers and generated a nice plot. Unfortunately, I don't see how to attach this information to this post as they are PDF's or JPEG files on my computer. Hope this information helps.

Happy New Year!

Hello,

I just picked up a pair of Grenadier 6000's.  The tweeter and midrange of one of them comes in and out.  I need to open up the speaker cabinet to take a look.  You mentioned that you have a schematic of the internal wiring.  Would it be possible to send me the PDF through email?  I dont' see a way to send you a private message.

Thanks,

Fortino

 

 

 

 

I do have a schematic for the Empire 8000P speaker system that I drew up while replacing the wax and paper capacitors in the crossover and to run LTspice simulations on the network. Unfortunately, I don't think this will help you as the crossovers used in the Grenadier 6000's are different than the ones used in the 8000P. Even though I have never owned a pair of the 6000s, if you look at eBay right now, there are a pair of these crossovers listed for sale. Looking at them, I can see there are components intentionally missing in this crossover design that are utilized in the 8000P. I have heard from other Empire owners who have the model 8000, 8000P and 9000 that a lot of problems with the midrange and tweeters in these units (which all use the same gold face plate array) that these components suffer from electrolytic corrosion problems which stem from the use of aluminum wire in the voice coils where they interface with the copper wire used for further interconnect. This causes intermittent problems with these drivers in the early stages of corrosion and permanent loss of functionality as the corrosion progresses to open circuit. They can be repaired, but it is a tricky and delicate repair. I can not say this same problem exists with the 6000 as I do not know what tweeter and midrange is used in this model and how they are constructed. This may not be the answer you wanted to hear, but hope it helps in tracking down your issue. If you take your speaker apart, you can use your DVM/VOM/VTVM to check for open circuit or high impedance through the midrange and tweeter components. That should give you a good idea where the problem is. Be sure to check all the solder connections of the wiring on the crossover board terminal strips and of course those pesky old capacitors. Best Regards.