Quantcast

Renaissance 15A Keep Going Quiet

MartinLogan Owners (MLO)

Help Support MartinLogan Owners (MLO):

Moltar

New member
Joined
Nov 15, 2020
Messages
4
Reaction score
1
Let me try to explain this. At high volumes my 15A, both of them, will cut out and then come back on with audio. They don’t turn off as I’ve watched the lights on the back and the light never flashes. I have no idea what is causing this. Volume is in excess of 95db I’d say, but I don’t have an SPL meter. Each 15A is powered by its own Behringer A800 in bridged mode so I know they have enough power. Is the ohm dropping to fair as I’ve heard they can drop to 1 ohm. Do they have a protection mode that would be causing this?

Any thoughts?
 

spkrdctr

Well-known member
Joined
Dec 23, 2017
Messages
216
Reaction score
98
Location
Clearwater Florida USA
It does sound at first glance like the amp shutting down. I would check the amp temp to see if you can put your hand on it without it being real hot. If it is quite hot, then you probably found the culprit and need to buy a beefier amp bridged or not. But if it is not hot than you probably have another problem with the amp unrelated to power. It would need to be repaired, but intermittent problems are VERY, VERY hard to find and fix. Good Luck and let us know what you find.
 

Gordon Gray

Well-known member
Joined
Jan 18, 2005
Messages
3,986
Reaction score
12
Location
Alto, NM
95db is pretty friggin loud and, if sustained, can cause permanent hearing damage. Nonetheless, one can borrow another amp to determine if that's the source of the issue. Same strategy goes for the pre and other gear. In my view, that's the simplest, most bomb proof way to locate the cause and the fix. I would start with the amp.

As an aside and with all due respect to the OP, powering a $25K speaker with two amps totaling $500 seems a bit of a mismatch. Reinforces my view of the problem source.
 
Last edited:

spkrdctr

Well-known member
Joined
Dec 23, 2017
Messages
216
Reaction score
98
Location
Clearwater Florida USA
I read a test review of the A800. You most likely are hitting its limits with your setup. If you back it down in volume some, it should not shut down. If you try it and it doesn't shut down, you found your problem. If you are up for buying another amp, I would suggest a Crown XLI 3500 ($560) which should easily take care of your needs without bridging. Also if you are shutting down your amp, you are clipping the hell out of it and will ultimately destroy your speakers. I'm surprised you have not fried a voice coil yet on your bass woofer. Let us know what you end up doing.
 

ttocs

Well-known member
MLO Supporter
Joined
Aug 10, 2014
Messages
408
Reaction score
85
Location
Highland Park, IL
I agree with above, amp is hitting limits.

From Behringer manual:
"2 x 400 Watts into 4 Ohms,
800 Watts into 8 Ohms in bridged mono operation"

In bridged mono the impedance limit goes in the wrong direction, same as other bridged amps I've owned. As soon as they're bridged, they don't like low impedance.
 

fordste

Member
Joined
Sep 15, 2007
Messages
12
Reaction score
3
Location
Ocoee TN
The speakers do not have the ability to cut off. The panel has no protective relays. If you unplug the speakers you will still get some sound from the panels, you just loose all the bass. I agree with everyone that it is your amps. There are many amps that are not to be bridged on anything but an 8 ohm or higher load. Sounds like that is your problem.
 

Gordon Gray

Well-known member
Joined
Jan 18, 2005
Messages
3,986
Reaction score
12
Location
Alto, NM
The source of the problem seems pretty obvious. And without sounding too judgmental, why would anyone buy a $25K speaker system and spend $500 on amps to drive it? Seems to be a major disconnect. Perhaps the OP can explain his reasons.
 
Last edited:

cfa88

Member
Joined
Dec 31, 2020
Messages
5
Reaction score
0
Looks like the amps are the issues, some mis-match there. Again, 95db is super loud. I run only 40db on mine and they are loud.
 

18000rpm

Well-known member
Joined
Dec 6, 2018
Messages
80
Reaction score
20
Location
Singapore
And without sounding too judgmental, why would anyone buy a $25K speaker system and spend $500 on amps to drive it?
Based on the SINAD and THD measurements here Behringer A800 Stereo Amplifier Review this is a terrible amp in an audiophile context.

Please get something better for these big speakers!

I've been using a Bryston 4B-SST with my Prodigies for about 10 years and during all that time it has never shutdown or had ANY issue even once. And I play it seriously LOUD.
 

Lightloopy

Well-known member
Joined
Jan 25, 2010
Messages
167
Reaction score
52
Location
Delaware
Agree with above comments. Curious as to how your journey came to this combination?
Maybe reevaluate what your goal is regarding volume and type of music, etc and then can make choices to make that happen. Could save yourself a lot of headache too.
 

18000rpm

Well-known member
Joined
Dec 6, 2018
Messages
80
Reaction score
20
Location
Singapore
Again, 95db is super loud. I run only 40db on mine and they are loud.
FYI you're probably referring to the 40dB setting on your preamp or receiver, not actual 40dB sound level. 40dB sound level is barely above ambient noise. It's about the hum of a running fridge.
 

twich54

Forum Administrator
Moderator
Joined
Nov 25, 2005
Messages
6,706
Reaction score
97
Location
SE Pa
The source of the problem seems pretty obvious. And without sounding too judgmental, why would anyone buy a $25K speaker system and spend $500 on amps to drive it? Seems to be a major disconnect. Perhaps the OP can explain his reasons.
agreed Gordon, almost as bad as spending 25k on an amp to drive $500 speakers !

Although it would be interesting as spkrdctr suggests to put a Crown $500 amp up against the panels. Might just have some audiophiles gasping for air, LOL !
 

cfa88

Member
Joined
Dec 31, 2020
Messages
5
Reaction score
0
FYI you're probably referring to the 40dB setting on your preamp or receiver, not actual 40dB sound level. 40dB sound level is barely above ambient noise. It's about the hum of a running fridge.
Yep, misread the OP's post, lol.
 

Bernard

Well-known member
Joined
Aug 14, 2007
Messages
4,458
Reaction score
10
Location
Ottawa, Canada
95db is pretty friggin loud and, if sustained, can cause permanent hearing damage.
On another site recently a guy was pleased that he was able to listen at concert levels, and had a picture of an SPL meter registering 130 dB. I wonder if the ringing in his ears has stopped yet! Or .... maybe the meter was defective and it was really not that loud?
 

ttocs

Well-known member
MLO Supporter
Joined
Aug 10, 2014
Messages
408
Reaction score
85
Location
Highland Park, IL
Big speakers in tiny rooms can make big numbers.

That story reminds me of the movie Ruthless People when Judge Reinhold is selling stereo speakers. These are the speakers that made that SPL meter peak! The Dominator MX10!
 

spkrdctr

Well-known member
Joined
Dec 23, 2017
Messages
216
Reaction score
98
Location
Clearwater Florida USA
Twich, to be exact I recommend putting a "real" amp against that Behringer. The Crown makes huge power without any bridging. It will handle any load that the OP would ask of it. But as usual, we get one post and he is gone. I guess he really didn't want to know how to "fix" his problem. We gave him an inexpensive fix up to fairly expensive $4000 fixes. I guess he wanted the "free" fix. Oh well, if there is one thing about decent audio it is that it is not dirt cheap. If he can't even spend $550 bucks than he is pretty much out of luck. Oh well, we tried to help him.......
 

18000rpm

Well-known member
Joined
Dec 6, 2018
Messages
80
Reaction score
20
Location
Singapore
The $500 Crown amp is fine for subwoofers or budget speakers but please get something better for these 15As...

Just my opinion, I don't want to get into that whole watts is watts debate.
 

spkrdctr

Well-known member
Joined
Dec 23, 2017
Messages
216
Reaction score
98
Location
Clearwater Florida USA
The $500 Crown amp is fine for subwoofers or budget speakers but please get something better for these 15As...

Just my opinion, I don't want to get into that whole watts is watts debate.
I was giving him the cheapest option as what he had was not working at all. I think he was pulling our legs. To jump on here and post something that stupid (15A's?) and never return means he was bored and probably thought, "I will go to the ML forums and tweak them up a bit". Boredom gets many of us in trouble, especially when I was young!
 
Top