JBL cinema and other high sensitivity speakers hissing with pro amps - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #1 of 75 Old 04-12-2013, 07:54 AM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I have JBL 4722n's (104db@2.83v@1m) for LCR and recently bought some Peavey IPR3000DSP's to power them. After connecting the 4722's to the amps and powering the amps on there is quite a loud (can hear clearly from listening position) speaker hiss shhhhh noise coming out the horns. This is with no input connected to the amp and changing the amp gain/volume does not effect it.

Before I exchange these amps for another brand/type of pro amp I'm wondering if this is just an inherent issue with using a high powered pro amp with high sensitivity speakers. Do others running this kind of system have these issues? Any other amp recommendations in the IPR price range? I did a quick test and connected one of the 4722's to my Denon 4520 and there was a slight hiss but it could only be heard by sticking your head pretty much inside the horn.
rob4321 is offline  
Sponsored Links
Advertisement
 
post #2 of 75 Old 04-12-2013, 08:07 AM
AVS Addicted Member
 
MKtheater's Avatar
 
Join Date: Jul 2006
Location: New Hartford, NY
Posts: 14,204
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 93 Post(s)
Liked: 403
Try putting a cheat plug on the amp just to see what happens. It might just need to be grounded better.
MKtheater is online now  
post #3 of 75 Old 04-12-2013, 08:22 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1193
Quote:
Originally Posted by rob4321 View Post

Before I exchange these amps for another brand/type of pro amp I'm wondering if this is just an inherent issue with using a high powered pro amp with high sensitivity speakers.
It's an inherent issue with amps that have a poor S/N ratio, be they pro or otherwise. You hear it with a high sensitivity HF driver because that idle noise is up to 20dB louder than with a typical dome tweeter. Peavey claims the hum/noise is -92dB, and that's about 10dB less than I'd want.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #4 of 75 Old 04-12-2013, 08:34 AM
AVS Special Member
 
coctostan's Avatar
 
Join Date: Oct 2005
Location: Indy
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 127
Yep, it could be either a grounding issue or inherent to the amp in question. Do you have any other amps to try temporarily? I've not used any of the integrated DSP pro amps but I've heard complaints that they tend be a bit noisy. Of course, those complaints might have been due to something outside of the amp itself (ground loops, poor gain structure, faulty amp etc).
coctostan is offline  
post #5 of 75 Old 04-12-2013, 10:31 AM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks. I'll see if I can find a cheater plug to test. The amps are plugged into 2 dedicated 20 amp lines with nothing else on the line. There's a 15amp line nearby I could test running from that.

I actually didn't even order the DSP versions. They were out of stock so upgraded me to them for free. I see that the non DSP has a signal to noise ratio of -101.5db and the IPR1600 has -105db. Maybe I could exchange for that since I'm not using the DSP.
rob4321 is offline  
post #6 of 75 Old 04-12-2013, 01:03 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,925
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked: 835
signal to noise is a little tricky because of the different ways that it can be measured and reported.

peavey states -92db a weighted at rated power @ 4 ohms.

at 4 ohms, the amp is producing 815 watts.

so adjusting that down to 1 watt requires a 29.1 db add (log (815/1)*10).

that leaves roughly a 1w signal to noise rating of -63db. in my estimation that is a defective product.

the 4722n is 101db 1w1m, so 63db off that is about 38db of noise. that is much too high unless you sit about 50 back from the speakers. :-)

if you have a good clean signal going to the amp, most pro amps should be unheard even with high sensitivity speakers unless perhaps you put your ear right next to the driver.

Listen. It's All Good.
LTD02 is online now  
post #7 of 75 Old 04-12-2013, 03:31 PM
AVS Special Member
 
Wayne A. Pflughaupt's Avatar
 
Join Date: Mar 2001
Location: Katy, TX USA
Posts: 1,999
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12

Any piece of pro audio gear with an A-weighted noise spec should be approached with caution. An A-weighted spec is a less-rigorous standard than the unweighted specmost pro audio manufacturers adhere to (i.e. typically designated as xx dBu) . As you can see in the graph below, an A-weighted curve rolls out the upper and lower frequencies. By comparison, an unweighted spec is a flat-response reference with no roll-out of the bottom or top end.




The problem with using an A-weighted curve to obtain a signal-to-noise spec, obviously, is that it “ignores” upper- or lower-frequency noise that may be present. So if a component happens to generate a bit more hum or hiss than it should, and this problematic component can only muster an unweighted spec of 88 dB, A-weighting would allow the manufacturer to “honestly” bump the figure up to a more respectable 94 dB. This is merely a hypothetical example of a component that’s only a bit worse than it should be; in reality A-weighting can “improve” a noise spec as much as 10 dB.

Regards,
Wayne A. Pflughaupt



Wayne A. Pflughaupt is offline  
post #8 of 75 Old 04-12-2013, 04:49 PM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks for the tips on calculating SNR. Should help when I have to pick out another amp. Any suggestions of one to look at? Maybe the non DSP versions since they have 10 - 13db better ratings. Lots of people on the Peavey forum claim the IPR's are dead silent for background noise so perhaps mine are just defective.

I tried a cheater plug and it made no difference. Also tried the 15 amp circuit also with no difference. I'm going to drop them off at the store on Monday for them to test.
rob4321 is offline  
post #9 of 75 Old 04-12-2013, 05:10 PM
AVS Special Member
 
tsloms's Avatar
 
Join Date: Dec 2005
Location: Wisconsin
Posts: 1,022
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 25
I was using an inuke3000dsp with my ewave style speakers using the de250 cd but it had quite a bit of hiss as well so it has been replaced. Even a cheater plug and/or external ground wire couldn't quiet it down. It's a great amp for subs but not so much for high efficiency speakers.
tsloms is offline  
post #10 of 75 Old 04-12-2013, 05:36 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,925
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked: 835
tsloms, was that stand alone or with other equipment plugged in?

Listen. It's All Good.
LTD02 is online now  
post #11 of 75 Old 04-12-2013, 05:46 PM
Advanced Member
 
auburnu008's Avatar
 
Join Date: Jun 2004
Location: Auburn, AL
Posts: 842
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 25
What about the Crown DSI amps? You have the passive so you dont need the built in crossover presets for the JBL speaks but since they are the "recommended" amps from JBL and Crown they might be better? That is what I plan to power my 4722's with.

War Eagle!
auburnu008 is offline  
post #12 of 75 Old 04-12-2013, 06:29 PM
AVS Special Member
 
tsloms's Avatar
 
Join Date: Dec 2005
Location: Wisconsin
Posts: 1,022
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 25
Quote:
Originally Posted by LTD02 View Post

tsloms, was that stand alone or with other equipment plugged in?

I tried several ways to eliminate the hiss. With all inputs disconnected from the amp and with or without a separate ground wire to the receiver the hiss was still present.
tsloms is offline  
post #13 of 75 Old 04-12-2013, 07:22 PM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
All speakers hiss.

Some causes of unacceptable hiss: bad balanced cable(s), bad jacks and a poor gain structure, which creates a poor SNR.

If the hiss is that annoying and all of the above causes are investigated with no satisfactory result, I would use a gate. IMO, any dead silent home audio components use a gate circuit. Without it, you'll always have some hiss.

2 and 4 channel gates run $120 to $1200 from all of the usual suspects (Sweetwater, Musician's Friend, Guitar Center, etc).

2 cents, FWIW.
bossobass is offline  
post #14 of 75 Old 04-12-2013, 07:51 PM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1193
Quote:
Originally Posted by bossobass View Post

All speakers hiss.
No speakers hiss. Electronics hiss, speakers reproduce it. If you've got an amp that produces high levels of hiss a gate won't help, as the gate only stops noise that's sourced prior to the amp, not in the amp. The cure is an amp with better S/N.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #15 of 75 Old 04-12-2013, 07:55 PM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by auburnu008 View Post

What about the Crown DSI amps?
Those would be great but at more than double the IPR price. I'll keep them in mind though.

Quote:
Originally Posted by tsloms View Post

I tried several ways to eliminate the hiss. With all inputs disconnected from the amp and with or without a separate ground wire to the receiver the hiss was still present.
Did you find an amp that worked?
rob4321 is offline  
post #16 of 75 Old 04-12-2013, 07:56 PM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Bill Fitzmaurice View Post

No speakers hiss. Electronics hiss, speakers reproduce it. If you've got an amp that produces high levels of hiss a gate won't help, as the gate only stops noise that's sourced prior to the amp, not in the amp. The cure is an amp with better S/N.

Thanks, yes there is no input connected to the amp and they are hissing big time. I guess a gate wouldn't help.
rob4321 is offline  
post #17 of 75 Old 04-12-2013, 08:28 PM
Advanced Member
 
auburnu008's Avatar
 
Join Date: Jun 2004
Location: Auburn, AL
Posts: 842
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 25
Quote:
Originally Posted by rob4321 View Post

Those would be great but at more than double the IPR price. I'll keep them in mind though.
Did you find an amp that worked?

You can get the DSI1000 on ebay for about $350. They are refurbs but the still carry the full Crown warranty.

War Eagle!
auburnu008 is offline  
post #18 of 75 Old 04-12-2013, 08:37 PM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by auburnu008 View Post

You can get the DSI1000 on ebay for about $350. They are refurbs but the still carry the full Crown warranty.

I'll keep an eye out. I see one for $450. I'm in Canada so the shipping may kill the deal.
rob4321 is offline  
post #19 of 75 Old 04-12-2013, 09:01 PM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1193
Quote:
Originally Posted by rob4321 View Post

I'll keep an eye out. I see one for $450. I'm in Canada so the shipping may kill the deal.
Plenty of good old heavy iron amps are out there, as their owners are looking to replace them with compact lightweight amps.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #20 of 75 Old 04-12-2013, 09:10 PM
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,358
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 155 Post(s)
Liked: 427
Check out Axe music for decent prices on amps in Canada. I find amps to be a pain to find for a good price here. Ill probably buy one next time I'm down in the states. Maybe next weekend. If I can find a good deal. Where in Canada do you live
tuxedocivic is online now  
post #21 of 75 Old 04-12-2013, 09:59 PM - Thread Starter
Member
 
rob4321's Avatar
 
Join Date: Aug 2006
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Edmonton. Axe is where I got these from.
rob4321 is offline  
post #22 of 75 Old 04-12-2013, 10:13 PM
AVS Special Member
 
tsloms's Avatar
 
Join Date: Dec 2005
Location: Wisconsin
Posts: 1,022
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 25
Quote:
Originally Posted by rob4321 View Post

Did you find an amp that worked?

I ended up using an old Rane MA6S 6 Channel amp bridged which is rated at 300 watts into 3 channels. Running sine waves showed that the 3000DSP could only output 50V into 8ohms where the Rane can do over 60V into 8 ohms on one channel. The Rane is much quieter and more powerful. Old school iron wins again!
tsloms is offline  
post #23 of 75 Old 04-13-2013, 12:31 AM
AVS Special Member
 
maxcooper's Avatar
 
Join Date: Jul 2003
Location: Silicon Valley, CA
Posts: 1,646
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 16
Another data point: My seos build had noticeable hiss when running active with an unbalanced minidsp and an inuke3000dsp (not using inuke's DSP). In contrast, it's nearly silent and totally acceptable when connected directly to my receiver with a passive xover.

-Max
maxcooper is offline  
post #24 of 75 Old 04-13-2013, 05:06 AM
AVS Special Member
 
coctostan's Avatar
 
Join Date: Oct 2005
Location: Indy
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 127
Max, did u get hiss with the iNuke plugged into the speaker and nothing on the input? I believe that even if your aren't using any of the DSP settings it is still running through the DSP chip and circuitry which I'm guessing might be the issue. These Behringer and Peavey DSP amps likely have the absolute cheapest DSP chip and circuit known to man. If it saves them $5 per amp and they lose 10db of actual S/N it is likely worth it for them. If their DSP amps are spec'd at 10db worse than their non-DSP mates it is possibly even worse given how generous some of these companies sometimes are with specs.
coctostan is offline  
post #25 of 75 Old 04-13-2013, 08:57 AM
AVS Special Member
 
DS-21's Avatar
 
Join Date: Jun 2005
Posts: 3,334
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked: 155
Quote:
Originally Posted by bossobass View Post

All speakers hiss.

Perhaps on some theoretical level your statement (as corrected by BFM) is true, but as a practical matter good electronics competently set up don't produce audlble hiss even with one's ear a few inches from the diaphragm. The catch there is that many electronics aren't "good" in that way. My amp test is to take a cheap efficient tweeter (Eminence APT) and hook up the amp to my phone and the tweeter. Then I grab the tweeter and slowly move it closer to my ear. If I can hear hiss with my arm bent more than 90deg, then I simply reject the amp as unsuitable for me.
Quote:
Originally Posted by maxcooper View Post

Another data point: My seos build had noticeable hiss when running active with an unbalanced minidsp and an inuke3000dsp (not using inuke's DSP). In contrast, it's nearly silent and totally acceptable when connected directly to my receiver with a passive xover.

Not surprising to me. The unbalanced miniDSP isn't the quietest piece, and the Inuke (even when not using the DSP) adds an extra DA conversion as well as an amp section with rather high gain and "extremely quiet" way down on the list of design goals. You'll get a lower noise floor results with a balanced miniDSP and/or (preferably "and") a quieter amp. You don't need much power for SEOS-based speakers at home. 30W/ch is likely sufficient. Save the Inuke for subs, and if you're running the SEOS's active consider something with less power and a lower noise floor. Then if noise is still an issue replace the miniDSP with a balanced (or "x8") one. (My 8x8 board in a 10x10HD case is MUCH quieter than my 2x4 unbalanced. I've never compared it directly to my 2x4 balanced miniDSPs, though.)

--
"In many cases there aren’t two sides unless one side is 'reality' and the other is 'nonsense.'" - Phil Plait
Serious Audio Blog 
Multichannel music (and video) urban loft living room system 
DS-21 is offline  
post #26 of 75 Old 04-13-2013, 02:25 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,925
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked: 835
"Running sine waves showed that the 3000DSP could only output 50V into 8ohms..."

50 volts into 8 ohms is 50^2/8 = 312.5 watts.

behringer specs that amp for 315 watts into 8 ohms.



http://www.behringer.com/assets/NU1000_NU3000_NU6000_NU12000_NU1000DSP_NU3000DSP_NU6000DSP_NU12000DSP_WebBrochure.pdf

Listen. It's All Good.
LTD02 is online now  
post #27 of 75 Old 04-13-2013, 03:36 PM
Member
 
Dezmond's Avatar
 
Join Date: Jan 2010
Location: WNY
Posts: 168
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by tsloms View Post

I ended up using an old Rane MA6S 6 Channel amp bridged which is rated at 300 watts into 3 channels. Running sine waves showed that the 3000DSP could only output 50V into 8ohms where the Rane can do over 60V into 8 ohms on one channel. The Rane is much quieter and more powerful. Old school iron wins again!

I recently picked up a rane ma6s myself, I am using it to biamp some jbl l7's, sounds great .
Dezmond is offline  
post #28 of 75 Old 04-13-2013, 05:06 PM
AVS Special Member
 
maxcooper's Avatar
 
Join Date: Jul 2003
Location: Silicon Valley, CA
Posts: 1,646
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 16
Quote:
Originally Posted by coctostan View Post

Max, did u get hiss with the iNuke plugged into the speaker and nothing on the input? I believe that even if your aren't using any of the DSP settings it is still running through the DSP chip and circuitry which I'm guessing might be the issue. These Behringer and Peavey DSP amps likely have the absolute cheapest DSP chip and circuit known to man. If it saves them $5 per amp and they lose 10db of actual S/N it is likely worth it for them. If their DSP amps are spec'd at 10db worse than their non-DSP mates it is possibly even worse given how generous some of these companies sometimes are with specs.

I think I did some testing with different combinations of things plugged in or not. I was using a switch-mode USB charger to power the miniDSP, but I think I found that this was not the cause of the noise. I don't remember exactly what else I tested or how it turned out. I was just running active to get some experience with it, but planned to build passive crossovers anyway (in pursuit of simplicity).

I mentioned that I wasn't using the iNuke's DSP mainly to indicate that I was aware that it had the capability, even though I was using the miniDSP with it. I was using the miniDSP because that's what I had settings for, and programming the iNuke DSP is less convenient for me because it requires Windows (or hopefully, Wine).

That is a good point that the iNuke does another set of ADC/DAC conversions. I wonder if the non-DSP versions do that, too? I always considered the DSP versions "better" since I figured it just added DSP features, with no drawbacks -- but maybe that isn't the case.
Quote:
Originally Posted by DS-21 View Post

Not surprising to me. The unbalanced miniDSP isn't the quietest piece, and the Inuke (even when not using the DSP) adds an extra DA conversion as well as an amp section with rather high gain and "extremely quiet" way down on the list of design goals. You'll get a lower noise floor results with a balanced miniDSP and/or (preferably "and") a quieter amp. You don't need much power for SEOS-based speakers at home. 30W/ch is likely sufficient. Save the Inuke for subs, and if you're running the SEOS's active consider something with less power and a lower noise floor. Then if noise is still an issue replace the miniDSP with a balanced (or "x8") one. (My 8x8 board in a 10x10HD case is MUCH quieter than my 2x4 unbalanced. I've never compared it directly to my 2x4 balanced miniDSPs, though.)

I've got a balanced miniDSP that I could try, also, but I already built the passive crossover for my SEOS speaker. Maybe I'll try it with my next speaker project. I'm also working on a bike project that will eventually include speakers, and I plan to use the miniDSP to save weight over a passive crossover.

I have an Onkyo 805 receiver, which I am quite satisfied with to power my SEOS speaker(s) directly at home. Also, very little hiss -- you have to put your ear up to the driver to hear any. :-)
maxcooper is offline  
post #29 of 75 Old 04-14-2013, 09:31 AM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by Bill Fitzmaurice View Post

No speakers hiss. Electronics hiss, speakers reproduce it. If you've got an amp that produces high levels of hiss a gate won't help, as the gate only stops noise that's sourced prior to the amp, not in the amp. The cure is an amp with better S/N.

Yeah, no speakers play music content either. So, a horn is a dome and sensitivity is irrelevant... gotcha.

A gate is just a fancy (or not so fancy) mute circuit and it's simple enough to work into an amplifier, once the source is identified. Hiss might be as simple as the outlet the amp is plugged into. Without data other than "hiss is loud", tossing the amp for a "better' one would not be my course of action... especially not for a used big iron amp.

I agree that the IPR is not a very good choice, but I disagree that blaming it wholesale for a hiss that's unacceptable and buying a used amp to replace it is the way to go.
bossobass is offline  
post #30 of 75 Old 04-14-2013, 12:35 PM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1193
Quote:
Originally Posted by bossobass View Post

Yeah, no speakers play music content either..
Not when there's no signal applied. I feel quite confident that the OPs speakers will not hiss when there is no amplifier connected to them. And since they do hiss when the amp is connected to them and powered up but with no signal being input to the amp then one need not be Sherlock Holmes to deduce that the source of the hiss is the amp.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off