To Dope or NOT

[GD70]

Don't the speakers have to be mounted and the enclosure sealed closed to perform this test? I tried the test on my Advents. It's easy just to take off the grill and push down on the woofer. With the Utahs, the grill does not come off--you have to removed wood blocks on the inside that sandwich it in place. So, I'm just hoping I hear a fuller, tighter bass.

Yes, woofers, and all drivers need to be in place, cabs sealed.

 

[Katalyst]

Hello and thanks. Yes, it did it twice, brand new fuses. Only with the Utah speaker. Plays three other speaker types I have just fine.

If the fuse blows only with the Utah. The Utah is at fault. Check to see if the crossover or drivers are shorting .

 

[Grid]

If the fuse blows only with the Utah. The Utah is at fault. Check to see if the crossover or drivers are shorting .

That certainly makes sense. But if there was a short, why don't the other amps I connect the Utah to blow? I'm not arguing, just maybe inept.

 

[Grid]

Yes, woofers, and all drivers need to be in place, cabs sealed.

It's just that it seems a mess of a job to remove the grill so I can push in on the woofer. Let me ask this: if the surrounds are not working right, I'd hear a deficiency in bass, correct?

 

[westend]

I'd suggest to put an ohm meter across the speaker terminals and measure that value. You may have a bad connection or some other driver damage that is indicating itself by blowing the amp's protection fuse .

 

[Grid]

I'd suggest to put an ohm meter across the speaker terminals and measure that value. You may have a bad connection or some other driver damage that is indicating itself by blowing the amp's protection fuse .

thank you. that's 7.6 ohms. three other amps play this speaker with no problems. But you just gave me an idea. I have another set of these Utahs coming tomorrow. I will connect them and see if the Amp's fuse blows or not.

 

[Grid]

Update. Redoped. Not happy. No improvement in sub bass. The Advents put these to shame. For sale.

 

[Katalyst]

Most but not all speakers from the early stereo era roll off after 50hz.

 

[Grid]

Most but not all speakers from the early stereo era roll off after 50hz.

This was a waste of time and money. If anything, the dope seems to have stifled the bass. I should've listened to my gut: "If it ain't broke..." Well, at least when I sell them, I can say they were recapped and redoped!

I did learn a great deal though and I'm thankful for everyone's knowledge.

 

[Katalyst]

The audio hobby to me is a journey. Different components mixed to see how the combo sounds. Just like cooking. Some stuff has a bitter taste and you throw it out.

 

[Grid]

The audio hobby to me is a journey. Different components mixed to see how the combo sounds. Just like cooking. Some stuff has a bitter taste and you throw it out.

Yep, life long learning journey. I do get great satisfaction from learning, even from unpleasant lessons.

 

[StimpyWan]

Okay. I have to ask, since I guess this is a dead project now. How did you dope the surrounds, when you mentioned you couldn't remove the grills? Did you dope from inside the cabinets, to the back of the surrounds?

 

[Grid]

Got in from the rear and removed woofer. I meant that I could not remove the grill to do the push test. The grill is sandwiched in wood blocks, and there is even a caulk like sealant sealing the blocks--I would have had to break that seal to get the grills off then go out and buy whatever kind of stuff that is and replace it to reseal the blocks. I've had enough. Not worth anymore hassle. Time to sell, lug them to FedEx and move on to finishing the S-C ASR 444 I had intended to use these with. As usual, I'm ol' Mike cart before the horse. Should've just waited to see how the amp sounds with my Advents (OLA). I bet my Advents sound fine with that tube amp with 30 wps. They sound incredible with that 15 wps Advent 300 receiver.

Matter of fact, I'm wondering if those Advents are more efficient than most people here give them credit for.

Ha! Now that I look again at the photo, all those staples would have to come out too. So just to do the push test, now I'd need a wood stapler too. Enough!

 

[Katalyst]

Knight speakers have the same motor board mounting system. I built a set of "Frankenstein" speakers out of a pair. I pulled all the staples out and mirror imaged them. Sanyo 12" woofers with cloth surrounds. Piezo tweeters. Kept the closed back midrange. My stepson has them now. He likes them .

 

[Grid]

Knight speakers have the same motor board mounting system. I built a set of "Frankenstein" speakers out of a pair. I pulled all the staples out and mirror imaged them. Sanyo 12" woofers with cloth surrounds. Piezo tweeters. Kept the closed back midrange. My stepson has them now. He likes them .

Nice work. What does mirror imaged them mean? My crossovers don't have those transformers.

 

[Grid]

Most but not all speakers from the early stereo era roll off after 50hz.

Oh, also, I saw these in a 1970 catalog. But perhaps in this model A-100 Utah was using drivers they had manufactured earlier than 1970.

 

[Katalyst]

Nice work. What does mirror imaged them mean? My crossovers don't have those transformers.

When drivers are offset to one side on the baffle.The left and right are mirror images of each other .I removed the baffles and flipped one.The crossovers were radio shack three ways I had around.

 

[Grid]

When drivers are offset to one side on the baffle.The left and right are mirror images of each other .I removed the baffles and flipped one.The crossovers were radio shack three ways I had around.

i've often wondered about how configuration / orientation affects sound. these utah's apparently are meant to stand horizontally. what improvement did you hear after flipping?

 

[Katalyst]

Image more centered.

 

[N8Nagel]

How much power are you driving these with? I have several pairs of speakers that sound ''meh" on 30-40 WPC receivers but come alive on 100+ watt power amps or oddly, similar 30-40 WPC tube gear.