Crossover question/lack of bass

[DigitalHippie]

Hello all, my name is Luke and I have an increasing addiction to loud bass that I'm trying to feed. Currently my home setup consists of two Cerwin Vega 380SE towers powered by a QSC MX1500A amp, a Cerwin Vega 10" powered sub and a Kenwood 10" powered sub. My issue is with the 380SEs. The only way it seems to get the two 15" subs to put out is by turning the volume all the way up but by that point the mids and highs are deafening. Perhaps this is normal but I guess I was expecting better bass response at more reasonable volumes. So, I have two questions. 1; does it seem normal for the highs and mids to overpower the subs and 2; if that doesn't seem normal then what could be causing it? The only component I can think of is the crossover but the crossovers are working in the sense that they are filtering the signals properly it just seems like the subs are starved for power. Any suggestions on diagnostic ideas is greatly appreciated. If any more information is needed on my part feel free to ask. Thanks in advance for any help. I'm looking forward to my stay here at audioholics!

Cheers,
Luke

 

[markw]

The size of a speakers woofer is not an indicator as to how low it can go. For extention, you need powered subs.

these big ash are woofer, not subwoofers. There's a big difference. They are designed for mid/upper bass and to try to get more deep bass, you WILL have to drive the cheeses out of them and, by then, the entire range will be louder as well. For extention you need speakers designed to go lower than they can. Ergo, the term "sub" woofer.

Methinks you need bigger, badder powered subwoofers which aren't cheap.

 

[DigitalHippie]

Thanks for the response Mark. I suppose that does makes sense. I guess I assumed that since it has two midrange woofers as well as a high frequency horn in addition to the 15" woofer that the 15" was a subwoofer. So do you know what features of a woofer make it unstuitsble for deep bass? I mean, the 15" speakers certainly have the capability of hitting low so is it just a matter of redesigning the crossover to accommodate the lower frequencies better or is there something about the speaker itself that would restrict it. It certainly is a heavy duty speaker in a cast frame but I don't know much about how the voice coils work. The spec sheet still indicates a frequency response down to 25hz. If it's just a matter of using a different crossover to redistribute power I'd be ok with that.

 

[everettT]

Take manufacturer specs with a grain of salt, third party measurements are used for verification. They might say it plays to 25hz but a what level, how much distortion, etc. Speakers that play good into th 20s are costly and hard to find. Mark's suggestion to get a true subwoofer will get you the lower extension your looking for.

 

[markw]

not being an engineer, I'll just say there are physical differences between the two. Also, they are more directly created to operate in a a particular size enclosure designed to maximize their low end. If someone more eloquent on this subject feels free to chime in., then let him

That big ash 15" woofer may impress, it won't go down that low. It'll do a bang up job on mid/upper bass, but as rot the low lows, nah. As you will learn, size isn't everything. Knowing how to use what you've got counts more.

As for that 25 hz figure you quote, specs lie like a rug. How many decibels down is that 25 hz from a 50 hz tone is it? It may reproduce it but it'll be at a much lower level than a 50 hz tone is15:

Check out some subs from Hsu and SVS. they have some ten and 12 inchers that will blow the pants off your 15 incher.

http://www.hsuresearch.com/

https://www.svsound.com/pages/subwoofers?gclid=CIL-k8GCpM0CFQ6PaQodX-IOhg

There are others.

 

[DigitalHippie]

I seem to be having trouble posting now...

 

[DigitalHippie]

Something about my intended response is considered spam or inappropriate but I can't imagine what that is.

 

[DigitalHippie]

Basically I've been disappointed with these speakers since I got them. Other forums talk about how much booming bass these speakers have but that leaves me questioning what they consider "booming". I'm trying to squeeze as much out of them as possible even if that means modifying them.

 

[-Jim-]

Okay Luke, I'm going to commit Blasphemy here for an Audioholic.

But here goes...If you want to see just how much Bass you can get out of your main speakers, the easiest way is to EQ the sound above your targeted frequencies down, while boosting the Bass frequencies up. Something like the image below is a good starting point - although you may want to make the slope even steeper. Just be careful with the volume and go easy so you don't blow the woofers.

Can you advise what Pre Amp you use, and/or if you use a Computer for a source for playing lossless (Like FLAC) tunes?

 

[tyhjaarpa]

You need bigger subs to get your big bass. I dont know how those speakers do but what I have read Cerwin Vegas arent that great speakers in first place and I wouldn't expect too much from them. Getting quality 12-15" subs would get you where you want. Other option is to sell your speakers/subs and get different speakers with good subs.

 

[DigitalHippie]

Thanks again for the replies. I have adjusted the equalizer slightly, 20-50hz at 10db, 63hz at 5 db and 100hz+ at 0 db. Beyond that it just starts sounding too muddy (forgive me if i use the terms "punchy", "boomy" and "muddy" incorrectly when referring to bass. I don't actually know what sound they refer too I only know what I imagine them to sound like). My pre-amp is basically my TV/computer. I have my computer connected to the TV via HDMI and then audio out from the TV to the power amp. The TV volume is set to max and I do all of the volume control from my computer. I'm not sure what you are referring to by "lossless". I have seen the term FLAC before but don;t know what it is. I have noticed that using my phone as an audio source provides much better sound than my TV but still not improved enough that I blame the TV for everything. One final tidbit I noticed was when I played two specific tracks on Youtube from my computer. Both were bass tests, one was a song that was pretty much just a deep bass kick beat and the other was a steady 40Hz tone. Both videos nearly tore the speakers away from the surround but as soon has I put on a normal hardcore techno track that encompasses a full range of frequencies that hard kicking becomes severely diminished. Someday I will invest in better audio but since everything I have was either given to me or acquired very cheaply I am just trying to make do. Plus I am a tinkerer and like to explore the inner workings of things while also trying to improve them where possible. Perhaps in this case the only improvement is to replace the whole thing. I have heard that the newer Cerwin Vega stuff is sub par but everyone I've come across seems to speak highly of the vintage stuff. I think my 380s were made in 1991 so I think that just barely qualifies as vintage

 

[TLS Guy]

Okay Luke, I'm going to commit Blasphemy here for an Audioholic.

But here goes...If you want to see just how much Bass you can get out of your main speakers, the easiest way is to EQ the sound above your targeted frequencies down, while boosting the Bass frequencies up. Something like the image below is a good starting point - although you may want to make the slope even steeper. Just be careful with the volume and go easy so you don't blow the woofers.

Can you advise what Pre Amp you use, and/or if you use a Computer for a source for playing lossless (Like FLAC) tunes?

That won't work. You can not Eq a ported speaker to extend the bass. The driver decouples from the box below tuning. The result of boosting the low frequencies is to get useless cone excursion which does not produce sound. This muddies the sound and can damage the driver.

 

[TLS Guy]

Thanks again for the replies. I have adjusted the equalizer slightly, 20-50hz at 10db, 63hz at 5 db and 100hz+ at 0 db. Beyond that it just starts sounding too muddy (forgive me if i use the terms "punchy", "boomy" and "muddy" incorrectly when referring to bass. I don't actually know what sound they refer too I only know what I imagine them to sound like). My pre-amp is basically my TV/computer. I have my computer connected to the TV via HDMI and then audio out from the TV to the power amp. The TV volume is set to max and I do all of the volume control from my computer. I'm not sure what you are referring to by "lossless". I have seen the term FLAC before but don;t know what it is. I have noticed that using my phone as an audio source provides much better sound than my TV but still not improved enough that I blame the TV for everything. One final tidbit I noticed was when I played two specific tracks on Youtube from my computer. Both were bass tests, one was a song that was pretty much just a deep bass kick beat and the other was a steady 40Hz tone. Both videos nearly tore the speakers away from the surround but as soon has I put on a normal hardcore techno track that encompasses a full range of frequencies that hard kicking becomes severely diminished. Someday I will invest in better audio but since everything I have was either given to me or acquired very cheaply I am just trying to make do. Plus I am a tinkerer and like to explore the inner workings of things while also trying to improve them where possible. Perhaps in this case the only improvement is to replace the whole thing. I have heard that the newer Cerwin Vega stuff is sub par but everyone I've come across seems to speak highly of the vintage stuff. I think my 380s were made in 1991 so I think that just barely qualifies as vintage

The size of the woofer relates very little to not at all as to how low the speaker will play. Larger speakers tend to higher output.

The spec that really determines how low a speaker will play is the free air resonance: - Fs. The Fs of the driver effectively sets the lowest frequency it will reproduce. In fact it is a little above Fs ported and significantly above for a sealed alignment. If the driver has enough excursion a sealed speaker can be equalized, a ported one can not.

Those older type of speakers that were popular from the seventies to early nineties had drivers with Fs usually close to 60 Hz actually, so they did not play all that low. They were built for output, as amps were not so powerful then and if they were they were expensive.

As I have pointed out many times before, there is an inverse relationship between sensitivity/efficiency and bass extension. Back then it was about output rather than bass extension.

You can not modify those speakers to get bass extension. To add bass extension you need a powered sub woofer and powerful one at that to keep up with those Vegas. Cerwin Vega speakers are basically party speakers and have never been known for refined sound.

 

[-Jim-]

Folks don't get my suggestion wrong here. I never said that EQing the output from a preamp would defy the limitations of his speakers, and magically convert the Woofers into Subs. (Physics is physics you know...) It will allow him diminish the output of those sounds above the output of the Woofer's normal limits; so he won't be saying "the mids and highs are deafening" and then he can hear what the Woofer is capable of producing. Boosting the Bass may not result in what he is looking for, but he should be able to see if the output approaches the lower limit of the 380SE woofer's specification (20Hz). (It is crossed over @ 250 Hz.) Tweaking these settings is all reversible.

Luke, thanks for the info "I have my computer connected to the TV via HDMI and then audio out from the TV to the power amp." I'm a little concerned for the quality of the sound headed into the Amp. You can't make decent sound without good material, and a clean pathway for it (Garbage in /garbage out).

A couple more questions. Please advise what drives the HDMI output in your PC. Please advise what soundcard is in your PC. And just how do you hook up your TV to the Amp. And lastly, do you have an optical drive in your PC with a CD or two you can use as source material? (I'm assuming you use a lossy file format like MP3s on your PC. Please advise details.) FLAC files are slightly compressed audio files that, unlike MP3s, are not missing any of the original information of the source material. When you play a FLAC File it's like playing the CD (if the FLAC File was created from a CD) and sounds identical to it. ( From xiph.org => FLAC stands for Free Lossless Audio Codec, an audio format similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality.) My intent would be to go direct from your PC to the Amp to eliminate the TV (for now) in the equation. Let's try to get some clean source material and go from there.

 

[DigitalHippie]

I'm almost embarrassed to reveal anymore regarding my connection from the TV... It is certainly far from ideal and I am aware of that. Originally I had been using RCA audio out from the rear of the TV to the amp, however I noticed the signal to the left channel speakers was significantly weaker than the right channel. Additionally, I get the best results when the TV volume is at max so this posed a problem. The solution was to use the 3.5mm headphone jack on the side of the TV which overrides the TVs speakers so I could have the volume maxed without the TV speakers blaring.. So at the moment I'm using a 3.5mm headphone jack to RCA, then RCA to 1/8 inch jack for the amp. The HDMI is connected to a MSI Radeon R9 280X graphics card. I spent hours the other day trying to connect the amp directly to the audio ports on the rear of the computer but I can't get any sound from them or the front headphone jack. Playback devices recognizes that there are speakers connected but no sound makes it through. I ended up giving up on it and plugging it back into the TV. As is turns out even the left channel from the headphone jack in the TV sends a weak signal so there is definitely an issue internally somewhere which is why I get better sound from my phone. I'll investigate some more when I can connect a normal pair of computer speakers to the computer and see if they work or not. I would definitely love to bypass the TV altogether and send the signal directly from the computer to the power amp.

 

[herbu]

I have an increasing addiction to loud bass... better bass response at more reasonable volumes.

Luke, the answer has been given. You need a good sub(s), and some bass management. Mark gave you a couple good places to look for subs. For bass mgmt, the easiest may be a Receiver. Lots of good choices from Denon/Marantz/Yamaha.

A receiver will let you define the frequency you want signals to split between your speakers and subs, and control the volume of each separately. That means you can get "better bass response at more reasonable volumes". A decent sub or two can reproduce the signal you send, at the volume you want.

 

[Dan Madden]

Sounds like you have a compromised set up there. Ditch the TV as an audio conduit. Use the TV as a video display only and send the audio signal directly to your amp. If your playing lossy MP3 files from your computer you are going to get crappy sound. Spin some CD's from your computer (If you must use a computer to play your music) directly to your amp and you should get vastly improved performance audio wise.

 

[markw]

Okay Luke, I'm going to commit Blasphemy here for an Audioholic.

But here goes...If you want to see just how much Bass you can get out of your main speakers, the easiest way is to EQ the sound above your targeted frequencies down, while boosting the Bass frequencies up. Something like the image below is a good starting point - although you may want to make the slope even steeper. Just be careful with the volume and go easy so you don't blow the woofers.

Can you advise what Pre Amp you use, and/or if you use a Computer for a source for playing lossless (Like FLAC) tunes?

Several things should be noted on this graph.

Think about the power you're currently using.

That ten decibel gain, which is about twice as loud, requires ten times the power you are currently using.

That 20 decibel gain, which is about four times as loud, requires one hundred times the your current power..

...just a little something to think about.

 

[-Jim-]

I'm almost embarrassed to reveal anymore regarding my connection from the TV... It is certainly far from ideal and I am aware of that. Originally I had been using RCA audio out from the rear of the TV to the amp, however I noticed the signal to the left channel speakers was significantly weaker than the right channel. Additionally, I get the best results when the TV volume is at max so this posed a problem. The solution was to use the 3.5mm headphone jack on the side of the TV which overrides the TVs speakers so I could have the volume maxed without the TV speakers blaring.. So at the moment I'm using a 3.5mm headphone jack to RCA, then RCA to 1/8 inch jack for the amp. The HDMI is connected to a MSI Radeon R9 280X graphics card. I spent hours the other day trying to connect the amp directly to the audio ports on the rear of the computer but I can't get any sound from them or the front headphone jack. Playback devices recognizes that there are speakers connected but no sound makes it through. I ended up giving up on it and plugging it back into the TV. As is turns out even the left channel from the headphone jack in the TV sends a weak signal so there is definitely an issue internally somewhere which is why I get better sound from my phone. I'll investigate some more when I can connect a normal pair of computer speakers to the computer and see if they work or not. I would definitely love to bypass the TV altogether and send the signal directly from the computer to the power amp.

IMHO your immediate need is to get good sound from your PC to the Amp. (Don't worry about the details in the graph I posted - it was just to give you an indication of what direction to adjust the EQ if you wanted to hear mostly bass from your main speakers. It's not meant to be absolute. Just something indicative I quickly found on the web to post here.)

Your CW 380SEs should put out some reasonable amount of Bass without massive EQ adjustments if the input source is full range and clean. Then you can blend in the existing Subs to support them before spend more coin on new ones. Can you advise the Model of the PC, or it's Motherboard, or the sound card if it has a separate one? If I have that detail I may be able to figure out how to connect your PC directly to the Amp.

I hope this is helpful.