[notoriousmatty]

Hey all

I currently have a denon 788 receiver with 5 psb b25 speakers that are rated at 4ohm minimum and 6 ohm nominal. This is my first setup and the receiver was a carry over from my pops sound room so im wondering what needs done. The sound doesnt get very loud and when I do try and push it I start to get distortion. Ive already blown out one psb and by the way the reviews praise the speakers it seems like these things should be incredible. Im thinking the speakers are too power hungry for the denon to handle. The system has been calibrated with an spl meter so its not that Im cranking them up to +10 each. What do you think? A 5 channel amp ( prob Emotiva) or going with a higher end receiver?

 

[fdiddy]

If you're happy with your receiver then get a power amp. If you're unhappy with your receiver, get a new receiver and a power amp. Moral of the story, if you want your sound loud, get a power amp. You will probably upgrade your receiver 5+ times before you upgrade your amp. Some people use amps that have been around for 30 years.


Amps put out power, and power will be the same thing next millenium. Receivers use algorithms and codecs. Don't expect to see the same ones you see today in 5 years. IMHO you can't go wrong by buying a separate amp.

 

[jostenmeat]

What's your total budget? You are using a subwoofer, and crossing over the B25s, yes?


These speakers have good sensitivity, but do have tougher impedance specs, namely nominal at 6 ohms, and minimal at 4 ohms. They don't mind having a strong amp behind them.


Unfortunately, it looks like your receiver doesn't have preouts to add an amp. The cheapest way to do this could be a new receiver with the minimal features you need, that ALSO has preouts, and add amp. The Yam 663 is about as affordable as it gets with preouts.


You don't have to use outboard amps with all 5 channels to begin with. You can amp, say, the front three, and use the receiver's power supply to power the rears, where high volumes will be very infrequent. And since the receiver is not powering the fronts, it will be better able to power those rears when needed.


Just an idea. It does sound like you need more power. The b25s can really crank.

 

[notoriousmatty]

I like that suggestion. I was dissapointed to hear that my denon didnt have preouts for an amp. Im looking at the emotiva xpa-3 that retails at 600 bucks to power my front soundstage. Ive heard great things about this amp and having never owned an amp im expecting big things from it. Looks like Ill need a new receiver however. I owned a yamaha 661 at one point and the hdmi didnt pass through without adding its own processing to the picture. In other words it made my hdmi pq look terrible. Maybe the 663 does something different? Any other suggestions for cheap receivers that have all this functionality that ill need? Thanks so far.

 

[TPnBobcats]



Quote:
Originally Posted by notoriousmatty /forum/post/15404478


I like that suggestion. I was dissapointed to hear that my denon didnt have preouts for an amp. Im looking at the emotiva xpa-3 that retails at 600 bucks to power my front soundstage. Ive heard great things about this amp and having never owned an amp im expecting big things from it. Looks like Ill need a new receiver however. I owned a yamaha 661 at one point and the hdmi didnt pass through without adding its own processing to the picture. In other words it made my hdmi pq look terrible. Maybe the 663 does something different? Any other suggestions for cheap receivers that have all this functionality that ill need? Thanks so far.

If you get it before the end of the year, the XPA-5 is only another $100 (or $50 normally). Then you can use the amps on the receiver to power two of the rear/side channels if you go 7.1.

 

[DonoMan]

No, don't go for an external amp just to drive B25s. Their excursion and thermal power handling aren't good enough to bother. If you want more then you need better speakers.

 

[dsmith901]

IMO it is never a good idea to drive 4 ohm speakers with a receiver, especially a mid-level one, except perhaps with a Harman Kardon or NAD. If you like those speakers then by all means get a power amp that will allow you to enjoy them to the max without damage. I recommend H/K receivers to use as a pre/pro and (except for the base AVR 1XX) will have preouts you need. The Emotiva or Outlaw amps will do fine, or the Sherwood Newcastle A-965, which is big and heavy but puts out a ton of current and sounds great for HT.

 

[notoriousmatty]

dsmith, do you agree with the poster above you to any extent? Those psbs are about all im willing to spend on speakers for a while so do you think an external amp will benefit? Whats your thoughts on the yamaha 663, or do you think I should still with HK however it will run me well over 1000. Also, Ive read alot of problems with hk receivers and a ps3 with audio dropouts and a few other things or else Id probably get the 254 plus an emotiva xpa-5.

 

[DonoMan]

You don't necessarily have to spend more to get more output. PSB's Image line is not overpriced but that doesn't mean you can't get more output for the money without going down in quality.


You can say the same thing about speakers as you can for engines: There's no replacement for displacement.

 

[TPnBobcats]



Quote:
Originally Posted by notoriousmatty /forum/post/15407435


dsmith, do you agree with the poster above you to any extent? Those psbs are about all im willing to spend on speakers for a while so do you think an external amp will benefit? Whats your thoughts on the yamaha 663, or do you think I should still with HK however it will run me well over 1000.

I wouldn't worry about it that much with bookshelf speakers like you have. Its the lower mid-range/base that really takes the power in speakers. With a 6.5" mid-range driver, you just simply aren't going to be able to go that low.


I've run 4 ohm nominal speakers (LSi15, LSiC, LSiFX) off of a pioneer elite AVR for several years and it's worked just fine. Things definitely have more punch running them off of an XPA-5, but it's not like it didn't work at all before.


In short, you need better/bigger speakers before it's really going to make a huge difference.

 

[notoriousmatty]

in my 12x12 room im getting some distortion turning the receiver up to -12 which I listen at. Explosions / screaming. I use reference quality blurays in audio such as band of brothers and im still getting these almost a crackling ripping noise. All im trying to do is smooth this out im not really looking to start a rave club. 1000 bucks seems like a fair price to pay in order to improve the sound this way. Im not really looking to upgrade speakrs because at 400 bucks a pair its all im going to afford.


From stereophile a few years back:

I can't recall a single area where that older, more expensive speaker outperformed the Image B25it impressed me in many areas and let me down in none. I can't think of a single other speaker for less than $500/pair that outperforms the PSB Image B25. Congratulations, Paul.

 

[DougWinsor]



Quote:
in my 12x12 room im getting some distortion turning the receiver up to -12 which I listen at. Explosions / screaming.

If the amp is not clipping I think it is the speakers that are distorting.


PSB B25

Input Power RMS, Clipping
Recommended 10-100 Watts

Program 70 Watts

http://www.hometheaterhifi.com/proce...eceiver_6.html


The denon 689 put out 85 watts into 8 ohm.

 

[jnickrand]

What subwoofer are you using and what is your crossover set at?


Usually the first thing to crap out when pushing speakers is the bass. Both from the speakers and from the receiver.


You should have no problem filling that room with mind numbing SPL's, that is a tiny room. By contrast, I can play ONE pair of B25's well into the upper 90 dB's in a 25x15 room without noticing distortion.

 

[DonoMan]

That's not all that impressive. And cutting out the bass is a hack of an idea, not a real solution, IMO. You can/should only bring a subwoofer up so much....

 

[notoriousmatty]

im using a bic sub crossed at 80hz.

 

[jnickrand]



Quote:
Originally Posted by DonoMan /forum/post/15407882


That's not all that impressive. And cutting out the bass is a hack of an idea, not a real solution, IMO. You can/should only bring a subwoofer up so much....

If that is a response to me, please elaborate. Consider that I never said anything about maxing out the speakers in my much larger room, just that it was distortion free and getting uncomfortable for continuous listening (music). And taking the load off the receiver and placing it on a dedicated sub amp is far from a hack of an idea. It makes perfect sense.

Quote:
Originally Posted by notoriousmatty /forum/post/15407931


im using a bic sub crossed at 80hz.

Are you sure the speakers aren't playing

 

[jostenmeat]



Quote:
Originally Posted by DonoMan /forum/post/15404808


No, don't go for an external amp just to drive B25s. Their excursion and thermal power handling aren't good enough to bother. If you want more then you need better speakers.

What are the products that you would recommend? Seriously. I'm sure there's stuff, I just don't know it. However, the B25s are the largest bookshelves being had for $350 that I've seen, though I'm sure there's probably larger.

Quote:
Originally Posted by DonoMan /forum/post/15407492


You don't necessarily have to spend more to get more output. PSB's Image line is not overpriced but that doesn't mean you can't get more output for the money without going down in quality.


You can say the same thing about speakers as you can for engines: There's no replacement for displacement.

What are the recommendations? I'm curious!

Quote:
Originally Posted by TPnBobcats /forum/post/15407505


I wouldn't worry about it that much with bookshelf speakers like you have. Its the lower mid-range/base that really takes the power in speakers. With a 6.5" mid-range driver, you just simply aren't going to be able to go that low.


I've run 4 ohm nominal speakers (LSi15, LSiC, LSiFX) off of a pioneer elite AVR for several years and it's worked just fine. Things definitely have more punch running them off of an XPA-5, but it's not like it didn't work at all before.


In short, you need better/bigger speakers before it's really going to make a huge difference.

I agree with the last part. However, even if buying a beefy receiver, or outboard amp, is not the best way to go about this (which I agree with), if the OP doesn't have money for it, I'm not sure if I can recommend that receiver... the only other solution is to simply turn it down.

Quote:
Originally Posted by notoriousmatty /forum/post/15407621


in my 12x12 room im getting some distortion turning the receiver up to -12 which I listen at. Explosions / screaming. I use reference quality blurays in audio such as band of brothers and im still getting these almost a crackling ripping noise. All im trying to do is smooth this out im not really looking to start a rave club. 1000 bucks seems like a fair price to pay in order to improve the sound this way. Im not really looking to upgrade speakrs because at 400 bucks a pair its all im going to afford.

I've watched the entire BoB BD set already, and Carentan at least three times. Dude, these discs are extremely dynamic, and there is a LOT of serious midbass peaking going on during battles. I am using a 7.1 set PSB Images, sitting decently far, with -7.5 as the default for a while. As I recently induced some ringing of the ears, I've been taking it down to around -8.5/9 recently. The Images handles everything I throw at em, but the B25s are only doing surround duty.

Quote:
From stereophile a few years back:

I can't recall a single area where that older, more expensive speaker outperformed the Image B25—it impressed me in many areas and let me down in none. I can't think of a single other speaker for less than $500/pair that outperforms the PSB Image B25. Congratulations, Paul.

There was a somewhat recent shootout that Craigsub did, many of the details I do not remember. While the Images didn't finish first by any means, they were particularly noted for their ability to crank! However, there weren't any towers competing in the bookshelf shootout...

Quote:
Originally Posted by DonoMan /forum/post/15407882


That's not all that impressive. And cutting out the bass is a hack of an idea, not a real solution, IMO. You can/should only bring a subwoofer up so much....

My B25s have no problem at 80hz or even 60hz, but only as surrounds as aforementioned. Running full range, they do choke out for sure.



edit: I just wanted to reiterate that I think out of my entire collection, Band of Brothers probably has the most amount of serious midbass peaks. Its often the midbass where the minimal impedances are reached with modern speakers. I wouldnt' be surprised at all that the Denon just can't cut it. Like I said, my Images have handled EVERYTHING I throw at em in a multi row dedicated theater... but I am powering it with a NAD amp...

 

[jnickrand]



Quote:
Originally Posted by jostenmeat /forum/post/15408534



My B25s have no problem at 80hz or even 60hz, but only as surrounds as aforementioned. Running full range, they do choke out for sure.



edit: I just wanted to reiterate that I think out of my entire collection, Band of Brothers probably has the most amount of serious midbass peaks. Its often the midbass where the minimal impedances are reached with modern speakers. I wouldnt' be surprised at all that the Denon just can't cut it. Like I said, my Images have handled EVERYTHING I throw at em in a multi row dedicated theater... but I am powering it with a NAD amp...

Yep, that's why I asked about a sub. Any 6.5" bookshelf will crap out in the bass department once SPL's get quite high. A 6.5" woofer can only move so much air.


As for the impedence of the PSB B25's, stereophile had this to say about them:

Quote:
The very nicely finished PSB Image B25 offered a voltage sensitivity slightly higher than average, at an estimated 88dB(B)/2.83V/m, which is within the margin of error of the specified figure. Its impedance was also moderately high, dropping below 6 ohms only in the lower midrange and mid-treble, with a minimum value of 3.7 ohms at 177Hz (fig.1). Good 4-ohm-rated amplifiers and receivers will have no problems driving this speaker.

3.7 ohms at 177 hz (mid bass) could certainly bring some receivers to their knees at high output levels.

 

[notoriousmatty]

solution??? Accept that my speakers will never sound amazing with any external equipment I throw at them?? It seems like if you dont spend 5k on speakers people think the speakers arent worth it. Hell I should just go back to my 200 sony htib, at least then things didnt distort....of course it sounded like crap but I never heard any distortion.

 

[TPnBobcats]



Quote:
Originally Posted by notoriousmatty /forum/post/15410806


solution??? Accept that my speakers will never sound amazing with any external equipment I throw at them?? It seems like if you dont spend 5k on speakers people think the speakers arent worth it. Hell I should just go back to my 200 sony htib, at least then things didnt distort....of course it sounded like crap but I never heard any distortion.

You don't have to spend 5k, but you do have to spend more than $500. IF you want really good mid-bass and low bass. The simple fact is that there is only so much air a single 6.5" driver can move and that simply isn't ever going to be as much as larger speaker can. You can pump enough current into them to melt the speakers, but it won't change the laws of physics.


Generally speaking you are better off spending significantly more on your speakers than on your electronics. Probably at least something on the order of twice as much on the speakers than you do on the electronics. Since it doesn't matter how much power you have or how good a signal you can generate, if your speakers are incapable of recreating that signal.