950/7100 - Loud Enough...huh?

Posted by: BeethovenRocks

950/7100 - Loud Enough...huh? - 04/26/05 06:17 PM

I'm enjoying my 950/7100 very much! I have a question, though, maybe more about amps, but it's general enough, I think...

I have the Outlaws attached to a pair of Axiom M80s, and yeah, it's REALLY loud.

It's also REALLY hot (the amp). These speakers are 4 Ohms, which I don't believe is, technically, a problem. How hot is too hot?

And - I'm considering a pair of monoblocks, for running during Music Only sessions - at 300W/4 ohms. Only slightly louder, I understand, but what, if any, overall improvement might I hear? Is that change in balance at VERY loud levels the 7100 reaching 165W, or is it me going deaf?

It sounds GREAT, don't get me wrong. But there is a change in the mix when going from a "comfortable level" to, my RS DBmeter says, about 100db, with peaks of 102, 103...

Maybe the vocals step back a little, or that horn isn't near the top anymore...things like that.

Comments?
Posted by: NewBuyer

Re: 950/7100 - Loud Enough...huh? - 04/26/05 06:26 PM

Why is this in the 950 Feedback forum?
Posted by: BeethovenRocks

Re: 950/7100 - Loud Enough...huh? - 04/26/05 06:41 PM

Yikes...

"...I have a question...maybe more about amps, but it's general enough, I think...."

Because the answer to my Mix question may lie in something I'm not doing right with my 950.
Posted by: painttoad

Re: 950/7100 - Loud Enough...huh? - 04/26/05 09:16 PM

i'm not sure about axiom's,but many 'mid to high' end speakers have protection for the tweeters(i guess mids are possible) that are basically light bulbs that drain off excessive power to protect the drivers.i'm not sure but it's possible that's what you are hearing in the 'balance' of your speakers.
quick test,back off the treble on the 950,listen combfortably,then start to turn it up,see if the sound stays uniform.now it's possible that with the reduction in the treble circuit,the louder you go,you may get some tweeter gain at higher levels.it's possible you've reached the limit of the tweeters and the x-overs are trying to protect them,which can get annoying but it's better than replacing tweeters or getting up to reset the breaker(which i had to do with my d-9's years ago)
Posted by: gonk

Re: 950/7100 - Loud Enough...huh? - 04/26/05 11:57 PM

How hot is the air above your amp? Solid state power amps will generate a substantial amount of heat, especially when in an enclosed space, and it is not necessarily indicative of a problem.
Posted by: wingnut4772

Re: 950/7100 - Loud Enough...huh? - 04/27/05 05:23 AM

Beethoven, I have Polk LSIs which are 4ohms. I used to have the 7100 which sounded really nice with them but was HOT. I decided to get the 770 (300w at4 ohms) instead since I had read that with the LSIs the more power the better.

I noticed that the 770 opened them up a little more. They sounded better at higher volumes and slightly fuller with more detail..and now my 770 runs hot. It may be the 4 ohm thing. Just make sure you have a lot of room for ventilation. You may also want to consider a cooling fan. I picked up a couple from Ebay (not the one in my pics :p ).
Posted by: gonk

Re: 950/7100 - Loud Enough...huh? - 04/27/05 07:52 AM

Before resorting to mechanical ventilation, make sure you have a problem and it can't be solved in other ways. (I design large commercial HVAC systems, but I still don't like putting fans in home theater equipment racks if I can help it - possibly because I've dealt with fan noise so much at work.) I use a cheap indoor/outdoor digital thermometer to monitor two points in my equipment rack and to record peak temperatures (it has a memory of the highest and lowest temperature seen "inside" and "outside"). I prefer to keep the space above my gear below 95F if possible. I don't worry about temperatures up to and even a little past 105F, however. The 7100 is working hard with that 4 ohm load, but even with an 8 ohm load and efficient speakers it would generate noticeable heat. First, try to get as much free space around the amp as possible - if you can get 3" or even 4" clear above it, that will let the heat sinks work most effectively. An open back on the equipment rack will also help.
Posted by: NormanB

Re: 950/7100 - Loud Enough...huh? - 04/27/05 10:47 AM

Some of the shift you are hearing could be the amp running out of steam. As an amp gets near its end the sound stage collapes compression sets in etc. Since you have 4 ohm speakers and I don't know the efficiency of them I have to think this is a possiblility.
Posted by: BeethovenRocks

Re: 950/7100 - Loud Enough...huh? - 04/27/05 12:27 PM

I'm thinking the heat isn't so bad. I measure just over 100 degrees average, with 105 when I go loud and long. There is plenty of space, top, back and sides, no fans.

The speakers are what I'd call "mid-efficient," with claims of 95db/w@1m in-room, 91 anechoic.

They're dang loud, I can tell ya that!

But being pushed - maybe they are being compressed (the amp, not the speakers)?

Should I expect my ears to respond the same, regardless of level, until deafness sets in?

I'm considering two monoblocks for an experiment.

While it IS loud in my small-ish room, I hope to move soon, and then the room will be large, and what is loud now will not be as much - and if I'm pushing the amps now, I wanna figure it out before Day 30 goes by!
Posted by: curegeorg

Re: 950/7100 - Loud Enough...huh? - 04/27/05 12:42 PM

if you push almost any amp to near its limits you will have distortion, if you push it longer at near its limits you have a greater chance of distortion. if 200watts isnt enough, bi-amp for 400watts or something similar... obviously if you are pushing a 200watt amp to its max, it will not perform as well as a 300 watt amp pushing 200watts. yeah, some may, but none that most people own.
Posted by: NormanB

Re: 950/7100 - Loud Enough...huh? - 04/28/05 09:25 AM

Another thing to consider is the impedance curve of your speakers. With them starting at 4 ohms I would be suprised if at certain frequencies they don't drop below 4 and possibly as low a 2 ohms. If that is the case your 7100 may be very unhappy driving those loads.
Posted by: BeethovenRocks

Re: 950/7100 - Loud Enough...huh? - 04/28/05 09:18 PM

Thanks for the ideas.

Outlaw says 4 ohms is no problem, they accounted for the 2-ohm possibility.

I doubt I'm nearing 165Watts on these things, so I'm not clipping. There's no distortion that I can hear. It's still clear as can be.

It's just that details start to fade a little. The music still sounds GREAT, but the relative levels of everything shifts some.
Posted by: curegeorg

Re: 950/7100 - Loud Enough...huh? - 04/29/05 10:11 AM

Quote:
Originally posted by BeethovenRocks:

It's just that details start to fade a little. The music still sounds GREAT, but the relative levels of everything shifts some.
That sounds like distortion to me. I assume you never had this problem with these SPEAKERS before?
Posted by: BeethovenRocks

Re: 950/7100 - Loud Enough...huh? - 04/29/05 12:35 PM

It may indeed be distortion, if that's how you'd define it.

I was expecting some fuzzy sound, some choppy-ness, some Stratocaster-in-a-Fender-Twin kinda sound. THAT kinda distortion.

I never heard it before because the speakers, too, are brand new.

Now, my OLD speakers - THEY have distortion. I may have to bump my standards up a notch or three to become an appropriately critical listener.
Posted by: NormanB

Re: 950/7100 - Loud Enough...huh? - 05/10/05 01:54 PM

Loss of detail sounds like compression to me.
Posted by: BeethovenRocks

Re: 950/7100 - Loud Enough...huh? - 05/10/05 03:59 PM

Not to worry now...I just traded up to the 770.

: ))
Posted by: readster

Re: 950/7100 - Loud Enough...huh? - 06/06/05 05:56 PM

I'm considering a pair of monoblocks, for running during Music Only sessions - at 300W/4 ohms. Only slightly louder, I understand

Incorrect, Will Robinson, ALOT LOUDER !!!!! (and clearer too !! )
Posted by: MeanGene

Re: 950/7100 - Loud Enough...huh? - 06/20/05 10:15 PM

I have found that the limits of my system are really the limits of the room. It just gets filled with sound and adding more defeats the desired results. I can reach a certain level of SPL and realize that the room needs to be larger to accommidate the volume or room treatments are needed to "gain" control. Something to take into consideration anyway.

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