EV sentry III SOUNDS very baddddd help!

[Assman68]

Hello,
I ve just purchased all original EV Sentry III mkii from 80’s for 2k.
Initially I had triangle lyrr genese speakers drived by Arc pre ls17+arc d70 mkii and Dac smsl d300 with excellent results.
I wanted to improve my config and I loved so much the Cornwalls but I had no money for such equipment.I realised Sentry’s could be a good cheaper alternative.
So I tryed this with my arc amps and the result was…horrible…I didn’t expected that.I can t believe that s this so reputated speaker!
The sound is brilliant agressiv,bass are poor,better are my lyrr genese with three 8’ sub,music is flat,no dynamics,no big scene ,foggy,looks anemic with no précisions…
I v checked the component:all is original,crossover,trebble mid and sub are in good shape.
I can t imagine such a result with research 70 watts tubes amp.
Do you think it could be aged component of the crossover which killed the sound?Actually,no repairs in the past on this crossover I think.I let you photos about that
What to do now?
Thank you for help me back

 

[MasterTech]

double check value of crossover caps - they definitely can drift over decades

 

[Assman68]

Easy to do?what material needed?

 

[Assman68]

I ve a multimeter only

 

[robiles]

That does not sound right. Are you sure that the bass drivers are original? Are the surrounds in a good shape? The original bass drivers have foam surrounds that goes bad with the time. That might be a food place to start.
You should try getting your hands on an eq (for other models can also be used by replacing a couple of resistors per channel) and in any case try to vover the lower bass reflex opening (a plate should be found on the bottom of the cabinet).

 

[wmgwizard]

I only see one electrolytic cap in the pics you posted, doubtful re capping will make much improvement.

Is it possible you wired them out of phase ??

That would certaily reduce the bass output and can therefore cause the mids/highs to sound shrill or exaggerated.

 

[Assman68]

That does not sound right. Are you sure that the bass drivers are original? Are the surrounds in a good shape? The original bass drivers have foam surrounds that goes bad with the time. That might be a food place to start.
You should try getting your hands on an eq (for other models can also be used by replacing a couple of resistors per channel) and in any case try to vover the lower bass reflex opening (a plate should be found on the bottom of the cabinet).

No surrounds issue.They seems intact.Yes I ve no eq.But it doesn’t explain the poor bass I think.My mosscade 10’ sub does better.It s impossible vs two 15’.by the way the 2 bass reflex are open…

 

[Assman68]

I only see one electrolytic cap in the pics you posted, doubtful re capping will make much improvement.

Is it possible you wired them out of phase ??

That would certaily reduce the bass output and can therefore cause the mids/highs to sound shrill or exaggerated.

I ve just wired them as usual with two red and black cables in the good place.no bi amp.How to cable them out of phase ?
I ve a good space to sonorise.about 50m2 .I think this is perfect space and amps context for use.I m not an extrem hifi specialist.but I have good ear.Even my wife said it s sound crappy .i can t imagine this piece of sound history sounding like that.My lyrr genese are far far away from it.It s not really rational.I found the inside cable very thin and poor.Maybe because of it?Do you see on my pictures some electronics maybe to replace?

 

[Assman68]

In the story I know the last owner had tested active amp on them.And touched éther cables.Look at my last cross over photo.in the center it seems that there is a problem with appairement cables I think.Red with blue,and not red with red and blue with blue…

 

[Assman68]

Seems to be incorrect

 

[robiles]

You seem to be right regarding the wiring, but if that is the case, i think you should check all the wiring and crossover components. A crossover schematic should be easy to find.

You can find a few phase test with a short description at the following site:

Online Stereo Polarity (Phase) Sound Test

Checks your loudpeakers wiring.

www.audiocheck.net

 

[djnagle]

Can you post pix of the front and back of each driver?

 

[Assman68]

Thanks a lot for your help.I ll give you more pics about that soon.I understand that if it sounds bad,and that all the drivers are working properly and are originals,should the issues be only on a wrong cables associations or a defect crossover components .exact for you?
Last question to be sure :I expected to obtain good space scene and dynamics from these speakers ,in the way of a cornwall.I ve read lots of good things about these sentry.In your opinion,and experience,we can have excellent musical feeling with them?Not possible that my recents triangle genese at 3k are so gooood that they explode literally these old machines?it ll be incredible and not rational…only to know if my intents are not to high

 

[Assman68]

What are these components on this photo?they seems very old…but maybe not to change

 

[robiles]

From what i have seen, your gear is superior to what i have used with mine, so your results should be superior. In my limited experience horns are a different animal to dome tweeters and mids. The sound that they produce should be really thick - a pair of good bookshelf speakers sound like small computer speakers compared to the sentries.
Positioning could also have an influence on the sound. The recommended position is in the corner of the room, close to the walls.
Also do you have another higher powered amp that you could try with them? From what I saw, your amp has 60w per channel at 16 ohms, which could not be enough to fill a room as large as yours.

 

[Assman68]

I put them against the wall in my configuration.The arc d70 is also 60W rms in 8ohms.and these speakers are high sensitivity at 97db I think.The lake of power is possible.But I read that some little 15watts tubes amp give good results too.But I will try big ss amp if I can.all that story is not clear …

 

[Assman68]

New pics.Drivers seems to be all originals and perfect state…

 

[robiles]

IIRC the sensitivity is 87db, but i might also be wrong. In troubleshooting it is important to take a stept by step approach and change only 1 variable at a time. Your amp might be perfectly fine, but at the same time trying something else is not a bad idea. If you have the possibility, go the biamp route, with a ss amp for the bass. Have heard that it is a step up compared to non bi-amp.
There are a lot of aspects of this speakers that are a bit misterious. Sorry to break it to you but the bass drivers are not original (rare as hens teeth), but fortunately are the closest alternative that you can get - i do not think your problems are because of the drivers. Also you have the earlier midrange drivers, which are the more desireable ones.
Have you tried switching the wires that are not color matched? If they are unmatched only in 1 speaker, they would be out of phase and would be a plausible explanation to the lack of bass that you are hearing.

 

[Assman68]

It s a lack of everything in the sound !medium or not full too.I will try to match the cable.Why do you think it s not original sub?i ve compared them to the original photos on the web,and it seems to be.By the way it s possible they have been restored in deutsch factory for sure

 

[robiles]

The code that is imprinted on the speakers correspond to the Sorry, the code is in fact correct, but they might have been reconned with a DL15w kit (which is also written on the magnet with a sharpie). They look the same indeed, but looks aren't everything. If you google a bit about the sentry woofers, you can find a lot of information.

Do you live in Germany, and if yes, where exactly?

Here is a foto i stole with original woofers, you can see the code on them (815-9062):



Also here are the parameters, for future reference (also copied from a website, so they might not be 100% correct):
Thiele Small Parameter
Fs (Hz)35
Qms8.01
Qes0.32
Qts0.31
Vas (Liter)260
RMS (ohm)2.59
Mms (kg)86
SPL (dB)97.23999999999999
Bl17.21
Re (ohm)5.4