Blow Tweeter SR6500

tntw6ms

I have a set that is only a little over a month old that I am running Bi amped with 75W rms @ 4 Ohm in Stereo Hi pass filter on set per polks spec's with the gain at just abovr half no loudness on and todau blew a tweeter. I am wondering why if anyone knows what would cause it. I checked everything to see if anything was bare or touching losse anything but it's not. anyone know what could Cause this????

MacLeod

Overpowering.

The SR's are rated at 120 watts RMS and your 75x4 amp likely makes a lot closer to 100 watts per channel, so your speakers were getting nearly double their rated power.

Now if you set the gains properly and use common sense with the volume, you should be alright but youre still taking a chance.

Were you using the passive crossovers? They have a protection bulb in there to protect the tweeters from overpowering. If you are using them, check the bulb to see if its blown.

If in fact you have blown a tweeter AND you bought them thru an authorized dealer and not off Ebay, call Polk customer service.

polkcs@polkaudio.com
9am - 6pm, M-F, EST (USA)
800-377-7655 toll free phone
410-764-5470 fax

1996blackmax

What is the preout voltage of your HU and what is the input sensitivity of your amplifier? Unles you have a HU with pretty weak preouts, the gain being at that level seems kind of high.

Thom

How did you set the high pass crossover? Many times just spinning the knob until it looks like it's at about 4k (or wherever) isn't accurate. Years ago I kept blowing Quart tweeters and it turned out that I was high passing them quite a bit lower than I thought. Once I fixed the crossover I never had another problem...

What amp are you using? Are you using that amp's crossover?

Can you verify your crossover point? Do you know anyone with an RTA?

nadams

When I was on the Polk Headquarters tour, I believe they said there was no easy way to blow the tweeter on the SR6500? That the crossover is designed to eliminate overpowering?

MacLeod

Thats true. The crossover does offer substantial protection for the tweeter however, if you dont use them and cross them over actively you lose that protection.

RBR

Hi guys, I'm new on this board and have some questions regarding my set-up.
Headunit: Alpine CDA-9855
Amp: Alpine PDX4.150
Speakers: Polk SR6500
I'm only using 2 of the channels on the amp, so not bi amping them, although some shops around the area recommed that I do in order to make them sound better / louder. I'm skeptical because this amp puts out 150 watts per channel and I don't want to blow the speakers. I'm also using the passive xovers that came with the speakers. In order to make the sound a bit richer, would you recommend that I mess around with the xover settings in the head unit? I'm under the impression that since I'm using the passive xovers, changing the xover settings via the headunit won't really change the sound much. Keep in mind, I'm new at all this, so don't rip on me. Any advice would be appreciated.
Thanks

MacLeod

RBR wrote:

Hi guys, I'm new on this board and have some questions regarding my set-up.
Headunit: Alpine CDA-9855
Amp: Alpine PDX4.150
Speakers: Polk SR6500

Excellent equipment!!

I'm only using 2 of the channels on the amp, so not bi amping them, although some shops around the area recommed that I do in order to make them sound better / louder. I'm skeptical because this amp puts out 150 watts per channel and I don't want to blow the speakers

The only benefit to bi-amping is to get the maximum flexibility in tuning the output of the tweeters and the ability to tune mid and tweeter independant of each other. Unless youre a tweek freak or planning on competing, Id leave well enough alone. You can still do plenty of tuning in 2 channel mode plus youre a lot less likely to blow something.

I'm also using the passive xovers that came with the speakers. In order to make the sound a bit richer, would you recommend that I mess around with the xover settings in the head unit? I'm under the impression that since I'm using the passive xovers, changing the xover settings via the headunit won't really change the sound much. Keep in mind, I'm new at all this, so don't rip on me. Any advice would be appreciated.
Thanks

The 9855 does have an excellent 3 way crossover that you could use but youd have to bi-amp for that. Ive found that the Polk engineers got it about right when designing the SR's crossovers. I played around with different crossover settings and finally did decide on 4000 Hz instead of 3100 Hz but the difference is extremely minimal.

In 2 channel mode you can adjust the crossover between the mid and sub (if you have one) and this would change the sound quite a bit.

Since youre new at this, I recommend leaving the system in 2 channel, leave the passive crossovers and if you have a sub low pass it at 80 Hz as well as the midrange.

Mess with the tweeters attenuation a little til you find the mix that sounds best then experiment with the low pass settings. Besides, you have a lot of EQ'ing that you can do with the HU's EQ and youll get better sound out of that than from crossover settings.

If you dont have a sub, get one!