RM-7500 problems

jedelman

Hi,

I've had a set of RM 7500 speakers for about 2.5 years now and I've been vaguely unsatisfied with them since the beginning. I also happened to move into a new house at the same time, so I was never sure whether it was the room, the speaker setup or the speakers themselves.

Well, since then I got my previous speakers back from the friend I gave them to.

I'm really not exactly sure how to describe the problem except to say that they are not "bright" enough. When I listen to my other speakers I can localize sounds, and it just sounds fuller.

I guess my question is, could it be a problem with the speakers? Or could it be just the normal sound of these speakers?

I disconnected the tweeters and I get even less highs. Any suggestions would be appreciated.

Thanks,

-Jim

Dennis Gardner

I am not familiar with the 7500 satellites, but some of the more recent offerings from Polk have gone to a silk dome tweeter instead of the tri-laminate design that they used for a number of years.

This tweeter does give a more neutral sound described by those that like it as "Sweet" or "Mellow" and by those that dislike it as "Dull" or "Veiled".

I have both in my system and find that in a room with hard materials around, floors and walls, they are nice, but if I was in a heavily carpeted or curtained room, I might wish for more of the sound that you describe as bright.

The tweeter does seem to make a larger noticeable difference in speaker characteristics, than do the woofers.

You may be a listener that just prefers the brighter sounds of metal or metallic designed tweeters. What brand or type of tweeter does your other speaker have that you prefer?

Dennis

fireshoes

What equipment are you using and how is it hooked up>?

jedelman

Thanks for the replies.

Please forgive my ignorance if I use any terms incorrectly.

My old speakers are not Polk, they are large bookshelf speakers from Jensen. They are Jensen Concert Series Model 1030, if that means anything to anyone. They are about 15 years old IIRC. The tweeters seem to be 2.5 inch paper cones(?).

My receiver is a (putting on my flame suit) Sony V555ES. I have the sub connected via the sub out on my receiver and have it connected to the LFE in on the sub. The system is in a very large carpeted room.

For me dull is a good way to describe them. I was watching a movie yesterday and during one of the scenes a car drove by in the background. On the old speakers I could hear it drive across the room. On the 7500s I could hear it, but I could barely tell it was moving.

What are my options? Should I just sell my current speakers on eBay and save up for new speakers? Can I trade in my tweeters, or would I have to buy a set of the newest ones and what might that cost me? I'm not sure I want to spend any more money on these speakers.

Oh my, I seem to have a lot of questions. I guess I'm just a bit frustrated and its nice to hear Someone validating my opinion. My wife can't seem to hear the difference and tends to tell me that I'm crazy.


Thanks again,

-Jim

Dennis Gardner

You are experiencing a normal finding that many have when trying to compare "Large Bookshelf Speakers" with small sats.
The Jensens are probably a more efficient speaker that has a full range sound compared to the small sats that the Polk has.I went from my Polk sats in my 7300 setup to RT-25 bookshelf models to RT55 models and ended up with RTi70 tower models to get the fuller sound that I felt I wanted. You could simply upgrade the left and right speakers to get the fuller sound, but at the expense of size. Just realize that the upgrade path could be long and expensive if you can't find what you desire in a couple of moves.

I would do a little more testing your system before you discard it as a bad sounding set of speakers.

You may think that the Jensens sound better to you, and I am sure that they do, but you may be hearing what is an enhanced sound from them that may not be very true to the original intention of the recorded material. Let me say again that this isn't bad or good, just different and not accurate.

You could get an spl meter (Radio Shack carries them for around $35) and download some test tone sweeps to see which speaker reproduces the flattest reponse curve throughout the frequency ranges. This would let you know what type of response you prefer. I would also look into different subwoofer settings such as crossover points, phase adjustments and volume. The larger Jensens may be making up for poor sub tuning with the full range they offer. A properly matched sub setting may be your problem with your satellites. A sub setting that is too hot can make all dialogue and higher frequencies seem to be simply background noise instead the point of focus.

I know that this sounds like alot of work ( it is), but if you could avoid the pain of selling ( at a loss) and buying new, by simply tweaking, you may find a good solution.

Then again, maybe you just want a new set of speakers,:D

Dennis

jedelman

I actually have a radio shack SPL meter(it's been collecting dust).

I've never done this before so the results are probably a bit off. I especially had trouble with the 1500 hz measurement, every time I blinked, the mesurement changed. It fluctuated from 60-70 depending where I stood.

Anyway it looks like you were right. It seems that the Polks are much flatter, but not totally flat. The polks seem to drop off fast at the high end. Is that normal?

I don't think the sub tuning is my problem, though I know the sub is not tuned correctly. The reson I say this is that I have listened with the sub off and I have the same complaint.

F1nut

Wow, a 20dB flux between 200 Hz and 300Hz is way too much. Dennis hit the nail on the head about enhanced sound. Actually neither speaker looks that good. Might be time to demo some new ones, eh?

Dennis Gardner

The 20 db difference at 1.5khz & 4khz may be what your are hearing. That is a major difference between the two speakers. The Jensens actually are hot from 1.5khz (voices) to 5khz, while the Polks have begun their natural rolloff.

They look kinda dead to me when compared to the Jensen.

Listen to the Jensens in your system for a couple of weeks and see if you still prefer the brighter highs. If you do, the answers to your situation are either trying some EQ to boost the highs a little or try speakers with a different high end profile like Klipsch.

Sometimes people find that after they use speakers with intense highs, they tend to tire easily in the listening experience, and the added presence of the highs is too much for comfort. Others just love it and call it very detailed and crisp. Maybe that is your cup of tea.

Based on your charts, you aren't just imagining the difference. It is very real!

DG

jedelman

Dennis,

I want to thank you for taking the time to answer my questions. You have really helped me get a handle on the situation.

I actually used the Jensens for quite a while in my old home so I think I really do enjoy speakers with a bit more intense highs.

The problem is that I really don't have the money to replace the whole system. I don't even know if it would even be possible, but it would be great if I could just replace the tweeters.

Anyway, thanks again.

-Jim