midwoofer distortion

CornellAlum · « **on:** 13 Jun 2005, 04:36 pm »

Over the weekend I was playing some serious bass of a recent live moe recording I did. The bass is quite heavy in the recording, though nothing that is ear shattering or anything like that. It was heavy at the show for that matter, and my recording gear pretty much captures everything the way it is produced. Anyway, I am running the 626r's via a bolder modded panny xr-45. As I was playing the music, I got the panny to around -15 or so on the dial, and all hell broke loose with the midwoofers. They were visably strained, moving back and forth to the point where I was afraid they were going to straight up pop, though I doubt that was possible. The sound was audibly distorted until I turned the levels on the panny back to about -20-25. Any ideas on the weak link or what I can do to stop this? The larger gives me plenty of bass fwiw.

Thanks in advance for the help,

Daryan

csero · « **Reply #1 on:** 13 Jun 2005, 05:25 pm »

The panny is "unity digital gain" at -20 db volume setting.
It means if you play a digital source, where the peaks reach 0dB, you will get hard digital clipping if the volume is above -20dB, or even lower, if you use any processing in the panny.

Tyson · « **Reply #2 on:** 13 Jun 2005, 05:35 pm »

Are you running the 626R's full range, or are you high-passing the bass? ANY ported speaker is going to have serious problems if you play loud bass at below it's resonance point. For the 626R's, that means if you play loud bass below 40hz, it will cause the woofers problems. Only solution is to high-pass them, or get a speaker with a lower tuning and greater overall output capability.

zybar · « **Reply #3 on:** 13 Jun 2005, 05:45 pm »

Daryan,

Aren't you using that nice sub I just sold you?

George

John Casler · « **Reply #4 on:** 13 Jun 2005, 06:41 pm »

Quote from: Tyson

Are you running the 626R's full range, or are you high-passing the bass? ANY ported speaker is going to have serious problems if you play loud bass at below it's resonance point. For the 626R's, that means if you play loud bass below 40hz, it will cause the woofers problems. Only solution is to high-pass them, or get a speaker with a lower tuning and greater overall output capability.

Let me give our AC friend, Mike from ACI, a plug.

He offers a couple "passive inline" filters that are inexpensive and do a great job of doing just that.

If you problem is the amp clipping then it won't help, but if you are "overdriving" the woofer, the filter will allow you to play things "much" louder, without distress, simply by putting these in the line.
,
Look here:

http://www.audioc.com/accessories1/misc/hipass.htm

This is a bargain for $29, and will relieve the 626R woofer by passing (hi passsing) above either 65Hz or 85Hz.

Tyson · « **Reply #5 on:** 13 Jun 2005, 07:33 pm »

With the Panny, he's gonna need a speaker level high-pass, not the line level high pass. I believe ACI sells speaker level high pass filters too....

CornellAlum · « **Reply #6 on:** 13 Jun 2005, 07:41 pm »

I attempt to bounce of of zero on all of my recordings fwiw, so I am guessing you guys are right on with the info provided. Thanks for all of the help thus far, I am sure I will have at least 2 more questions

To answer the other questions...

I am running the speakers full range, with the bass crossover at it's lowest setting to mate with the absolutely SWEET and HUGE subwoofer from George which now occupies my entire living room

If I change from full range to small on the panny, can I avoid what I am hearing? It did NOT sound like digital clipping to me, as I have heard digital clipping and it sounds a lot more like a click than a thud!

Thanks guys!

Daryan

Tyson · « **Reply #7 on:** 13 Jun 2005, 08:05 pm »

Yes, using the Panny to high pass the 626R's should prevent what you are hearing. The downside is the only crossover point for high passing from the panny is at 100hz, which is too high for good integration with a subwoofer, IMO.

CornellAlum · « **Reply #8 on:** 13 Jun 2005, 11:51 pm »

So what do you guys feel will be the best solution for me at this point? I am not adverse to going to seperates if that will help, though the prospect seems rather exspensive unfortunately.

zybar · « **Reply #9 on:** 14 Jun 2005, 12:25 am »

Quote from: CornellAlum

So what do you guys feel will be the best solution for me at this point? I am not adverse to going to seperates if that will help, though the prospect seems rather exspensive unfortunately.

Why not see if you can blend the Larger with the 100hz crossover?

You might want to consider getting the RDES by AV123 in order to be able to control the peaks and valleys with the sub.

Also, can you put the sub between the speakers?

George

warnerwh · « **Reply #10 on:** 14 Jun 2005, 12:30 am »

How do you delete a double post?

warnerwh · « **Reply #11 on:** 14 Jun 2005, 12:31 am »

George hit the nail on the head and at no cost to you:

"Also, can you put the sub between the speakers? " Or you could get another sub and put the 626's on top, that of course would be more money. If you're driving the sub and the 626's with that little receiver I'd be surprised if you didn't run out of power very fast especially if you have been playing with much volume at all. Clipping will make bass sound loose and mushy btw.

Wayne1 · « **Reply #12 on:** 14 Jun 2005, 12:31 am »

First try the Panny with the high pass crossover.

See if that takes care of your problem.

You can then look into a passive high pass filter for the 626Rs.

You could also spend a LOT of money and get into separates with a DAC, preamp, electronic crossover, and power amp.

I believe some of the TACT preamps have a crossover built into them and they will keep the signal digital. They will also provide room and speaker correction.

zybar · « **Reply #13 on:** 14 Jun 2005, 12:33 am »

Quote from: warnerwh

George hit the nail on the head and at no cost to you:

"Also, can you put the sub between the speakers? " Or you could get another sub and put the 626's on top, that of course would be more money. If you're driving the sub and the 626's with that little receiver I'd be surprised if you didn't run out of power very fast especially if you have been playing with much volume at all. Clipping will make bass sound loose and mushy btw.

Darayan is more than welcome to buy my other Larger sub.

George

zybar · « **Reply #14 on:** 14 Jun 2005, 12:37 am »

Quote from: Wayne1

First try the Panny with the high pass crossover.

See if that takes care of your problem.

You can then look into a passive high pass filter for the 626Rs.

You could also spend a LOT of money and get into separates with a DAC, preamp, electronic crossover, and power amp.

I believe some of the TACT preamps have a crossover built into them and they will keep the signal digital. They will also provide room and speaker correction.

The TacT indeed has crossover functionality that would handle this plus the correction capabilities. It made a very big impact on my old VMPS setup of RM 40's + Larger subs.

The only negative is that the TacT isn't cheap.

But if you consider that is an excellent preamp, dac, and crossover (especially with the upgraded power supply) with room correction capabilities, it doesn't look that expensive anymore.

George

CornellAlum · « **Reply #15 on:** 14 Jun 2005, 12:52 am »

Exspense is certainly a large consideration now that I have a big ass car payment

I will fool around with all of this and report back. The sub is currently dead center between the two speakers so it will certainly integrate that way. How do I set the crossover at 100 on the panny?

Wayne1 · « **Reply #16 on:** 14 Jun 2005, 01:00 am »

Go into the setup menu and change the front speakers to small.

You should then be able to change what frequency they crossover. It will be the same as the sub crossover point.

CornellAlum · « **Reply #17 on:** 14 Jun 2005, 01:05 am »

Thanks Wayne. Check your PM's...

Daryan

John Casler · « **Reply #18 on:** 14 Jun 2005, 01:37 am »

If the x-over is actually 100Hz (I'm not familiar with that unit) you will probably need to place the LARGER exactly between the speakers in order not to get a "pull" towards the sub. If it is not in the center when crossed that high, male voices will will be pulled toward the sub.

Quote

Darayan is more than welcome to buy my other Larger sub.

I can vouch for this combo (using the LARGERs as speaker stands) as being one of the best BUDGET systems as far as performance.

I had mine dialed in so precisely it was absolutley "scary"

zybar · « **Reply #19 on:** 14 Jun 2005, 01:46 am »

Quote from: John Casler

If the x-over is actually 100Hz (I'm not familiar with that unit) you will probably need to place the LARGER exactly between the speakers in order not to get a "pull" towards the sub. If it is not in the center when crossed that high, male voices will will be pulled toward the sub.

John,

When using something such as the TacT that does time and phase alignment as well as the room correction, you can have your crossover set higher and still not detect the sub.

When I had people over, they would ask me if the subs were even on!!

I had the Largers crossed over as high as 120hz or 130hz using a 10th order crossover at times.

George