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Hi. I'm running a vintage setup comprising a NAD C521i (with low jitter clock conversion), Pioneer SX-990 transistor receiver (re-capped etc.) KEF Uni-Q Q90 speakers and; a Wharfedale Power Cube 8 subwoofer.
I must confess from the off that I am not competent with electronics beyond a bit of soldering and therefore, didn't do any of the work myself.
I'm trying to get to grips with low frequency because I feel that there is something missing especially from the orchestral stuff I play. There's no problem with the more upbeat stuff which usually comes with a strong baseline anyway.
Both the KEF speakers and the sub are rated at 40 Hz at the bottom end +/-3 dB, but when I fed a YouTube test signal through the system via my tablet there was a distinct drop-off at around 65Hz on both and by the time the signal dropped to 55Hz there was virtually nothing coming out of the drivers at all. This happened with other test too! This raises two questions:
- Is this normal or is there a weak link that's cutting the signal at this point?
- Would a better sub give me the extra down to, say, 25Hz?
Sorry this first post is so long but any suggestions would be gratefully received
Thanks
Elgee
Follow Ups:
Did you measure it the same way?
.
"The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius
The subwoofer could actually be SUBTRACTING bass if it is not in phase with your main speakers at the listening position. See if the bass sounds better with the subwoofer off. If it does, it is out of phase.
If you can get a sound pressure meter like the Radio Shack model, it can measure the amplitude, and you can control the frequency by using a test CD where different frequencies are on different tracks. You can play a 40 Hz tone on 'repeat' and use the SPL meter to measure the response both with and without the subwoofer. Don't be surprised if the response measures lower with the subwoofer. If the SW doesn't have a continuous phase control (best) or phase reversal switch, you can still adjust the phase by moving it around in the room until you find a setting or position where it is increasing the amplitude instead of reducing it.
My subwoofer was reducing the amplitude when on, and it didn't have a phase switch. Since I didn't want to change the location, I opened it up and reversed the leads on the drivers (it had two). Then it increased the bass rather than decreased it. It is probably not exactly in phase (I would need a continuous phase control for that or change the location) but it is much better than it was before I reversed the leads.
The other thing I found was for planar main speakers (I have Magneplanar SMGc's) it sounds much better letting the main speakers run full range than to use the subwoofer's crossover to feed a high-pass signal to to the main speakers. For other types of speakers this may not be the case.
Thank you all for your suggestions -plenty of food for thought. I'm going to spend time experimenting with positioning etc. I am fairly limited in what I can do but I'll give it a try. Thank you again for your help. I'll let you know how I get on. Les G.
Elgee
d
Edits: 07/06/15
Phasing of the sub and its' location to the main speakers can effect your perception of bass.I have positioned speakers in a small area off the main listening room and been amazed at the loading of the bass.
Is it possible that you can either not load the room with the driver producing the bass or the driver cannot be driven hard enough to load the room with bass
I truly hope that some of this banter can help or partially assist in curing your sonic ills.
Tom:cat
LG, there are many considerations for your post as others point out. But here is another aspect to consider.
Your "upbeat" recordings, if rock or pop, will likely have and emphasis in the 60-120 Hz range, just above the apparent limits of your speakers. This is done in the mastering process so they will have apparent bass on "average" music systems. Orchestral recordings are more likely to be mastered with a flat or near flat response in that range. Therefore, no bass emphasis.
Many people have misconceptions about bass information. 60 Hz is really fairly deep as you would know if you ever heard a 60 cycle hum in your system. Only a few instruments extend below 40 Hz so very little music is written below that range.
Adding a sub to reach 25 Hz will likely come from a home theater product which may not necessarily be musical. After all, those are developed to reproduce special effects. You would be far better off (and spend less money) if you found a sub designed for music which might only extend to say 40-45 Hz.
"You can't know what the "best" is unless you have heard everything, and keep in mind that given individual tastes, there really isn't any such thing." HP
I disagree. I find that when my loudspeakers are designed to give me a good 30Hz low end, it really brings out the impact of a well recorded orchestra. There is a lot of bass drum energy and hall reverberation in the 30 Hz range.
Synergy is everything. And a good sales pitch doesn't hurt either.
charles
Ratings? Optimistic, best-case scenario maybe.You could try experimenting with seat and/or speaker positioning. If you or your speakers are sitting in a bass null zone, shoving things back or forth six inches at a time while you listen for the best bass could greatly change things for the better.
Edits: 06/12/15 06/12/15
and start backing up from the stereo while playing the same low frequency. You should see the meter rise and fall while the frequency is playing as you walk further from the stereo. If you then sit where the bass frequency rises, you should get the bass you expect.
However, if someone else could help, I think that two speakers producing the same frequency and at different distances from the listening position, could cause a cancellation at that frequency.
Finally an 8 inch woofer may not be able to produce enough volume at 40Hz while okay at higher frequencies. Of course, the Wharfedale speaker is supposed to be only -3Db at 40Hz.
You should realize that bass frequencies need ROOM to develop,Low frequencies need 20-30 feet of the listening room .You might try a sweep frequency CD and a SPL meter.
Don't EQ your system with this method or you will end up with mediocre sound.Stay under 100Hz.
Tom:cat
Perhaps you're thinking of room modes. The lowest frequency room mode occurs when the wavelength is equal to the longest room dimension. Below that frequency, there are no standing waves. But lower bass frequencies are still supported by the room. Think about the bass in your car. Or when listening to headphones. You don't need a big room to hear low bass.
what bass frequency I used. It was definitely below 100Hz from a Stereophile test CD. What I may wrongly call a decibel meter was what you call a SPL meter. My living room where the stereo is located is 37 feet long. I cannot recall how many nulls I measured, but there were at least three in that distance. The speakers were a stereo pair of HSU Research HSRW10 subwoofers.
I also used the SPL meter to use all the frequencies on the test CD to measure the frequency response of all of my speakers together(subs and bookshelf speakers).
I wonder how many of us look for and measure horizontal room modes while forgetting that vertical modes also exist?
Most furniture is not designed to be moved vertically. Too bad, huh?
You Tube is NOT an audio source
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