I'm planning to run the PN4.320 to power a pair of Biketronics 7.1 speakers in the fairing of a Street Glide.

Questions:

What specifically is the issue with bridging the PN4.520?

Are there any know issue with bridging the PN4.320?

Is anyone experiencing problems with RF interference with the PN4.320?

 

I wouldn't do it until it is all resolved. Trust me I blew a set of speakers because of this. Do not bridge the amp or you might end up like me.

Personally if I had the money at the moment I'd be shelling it out for the BT 4x180 amp I plan on it in the future lifetime warranty and made in USA. And I know they will stand behind it for fact.

 

What's a BT amp?

 

BikeTronics...........

http://www.biketronics.com/categories/Amplifiers/

 

car audio amps produce an AC voltage output to the speakers that operates within a certain range (your gain controls) designed by the manufacturer. These voltage outputs can be measured with a DMM and are usually somewhere between 1vac to roughly 45vac is the highest I've seen them. This SS amp is no exception to that when run in a normal mode (either front or rear channels or all 4 channels) and in fact there is a direct correlation between the input voltage into the amp on the RCA inputs, the measureable signal being piped through the amp (test tone), the load applied to the outputs, and the output voltages. This is how you determine what the amp is actually putting out in wattage. I will say that a lot of amp manufacturers spec their products at a certain wattage only to be tested and they don't. This amp is spot on with it's output power ratings and in 4 different tests a couple of nights ago, I was getting consistent 128 to 131 watt outputs ratings on all 4 channels with a 2 ohm load applied.

However, in bridged mode with my scope connected to take a peak at the waveform being generated, I started seeing some really oddball peaks. If you want to go through all the calculations to figure out what the peaks are with a scope knock yourself out. I simply removed the scope and attached my DMM to measure AC voltages and I was quite surprised at what I discovered; Voltages in excess of 70vac! This is enough to toast even the best speakers out there. So I contacted a couple of folks that I know who are not necessarily audio engineers but they do know their stuff and confirmed with them exactly what I was seeing. This is exactly the reason that Strait toasted his speakers, and the 2 installs I did myself in bridged mode toasted the speakers as well within a few hours.

So I took all my documented test information and went to SS yesterday and I wasn't going to talk to some level 1 tech support person with this. So I persisted until I got Vincent who is the Technical Product Manager for the Picaso Nano series amps on the phone. We discussed this for about an hour along with the FM issues and he assured me that he would take it back to the engineers to test what I was seeing.

I'll wait to see what he comes back with, but for some oddball reason I have this sneaky suspicion that the printed manual and what is stamped on the amp itself for a bridged wiring diagram is not correct. I say this because I've never seen an amp bridged with the speaker outputs the way that the SS manual says to do it. It just doesn't look right to me. And it's no secret that with the older style PN4.520D amp (with the black speaker output plug), they did misprint the wiring diagram in the manual for the high level inputs.

 

It's good to know and understand what's going on with the bridging problem. Hopefully, Soundstream can figure it out.

I have the newer style PN4.520D on my Ultra Classic. The wiring diagram that came with it is also incorrect, having the high level input + and - reversed, as compared to what's printed on the end of the amp.

If someone were to connect the speaker according to the wiring diagram showing reversed polarity, what would be the consequences?

Also, in the meantime, what would be the best choice for a 2 channel amp just to run a set of Biketronics 7.1 fairing speakers?

 

according to SS and I've tested it to be true as well; it really doesn't matter on the high level inputs. I'm just **** about the way I do things. Always go by what's printed on the amp.

The PBR300x2 is great amp
Dragonfly is offering 30% off right now so that makes ARC very attractive
Biketronics BT2180
If you're simply looking to improve a bit over stock with something like MM651, Focal CA165, etc. the Alpine KTP445U is a good choice as well (not for these monsters you mentioned though)

Still have no ETA on release of the PN2.350D.

 

I originally ran the Alpine KTP-445U with 6.5" Titan IIs in the fairing of my Ultra (before going the SS + Polk route) and it drove those speakers just fine.

So, are you thinking the Alpine may be a little under-powered for the 7.1's ?

I saw bench test the RF PBR300X2 & Alpine KTP on the Internet and since it was on the Internet, it MUST BE TRUE.

PBR300X2 = 92.83 watts @ 4 ohms (driving both channels)

KTP-445U = 95.24 watts @ 4 ohms ("bridged" - driving both channels)

Based on these test, it appears that the RF is a little over-rated (100 watts RMS @ 4 ohms) and the KTP is a little under-rated (90 watts RMS @ 4 ohms).

Of course, since the final determining factor is "How does it sound to your ears?", it is hard for me to compare them, since I haven't ever heard the PBR300X2.

I'm sure that the Biketronics amps are Top-Shelf, but they are out of my "stereo upgrade" budget, especially for my second bike.

The Arc 2-channel mini is a viable option, but it too is priced up above my budget and the power rating on it driving 4 ohm speakers is only 70 watts, which was surprising to me.

 

The last PBR300x2 I installed over the weekend had a "birth" sheet with it as RF has always done with their amps. Although it was rated at 100x2 at 4 ohms, the birth sheet stated it spec'd out at 198x2 at 4 ohms and the way it sounded (didn't actually bench test it) I tend to believe 125+w x2 easily. Any of the PBR300x2 amps I've installed were like this.

Me personally yes I think the KTP is not enough power to make these monsters shine.

The correct power ratings on the amps are

PBR300x2 - 100x2 @ 4ohms
150x2 @ 2ohms
KTP445U - 45x4 @ 4 ohms
45x4 @ 2 ohms


The PBR300x2 will outshine that KTP amp hands down.

 

I knew you would steer me in the right direction, again:

This is part of your post to my thread: Rockford Fosgate PBR300X2 or PBR300X4:

The amp choice is directly dependent upon what your future plans are. If you're wanting to power your front speakers only, then the X2 is a no brainer.

That was last September, so the RF appears to be tried & true and hard to beat.

Sounds like the PBR300X2 will be powering my Biketronics 7.1's!

Thanks UltraNutZ!