hello,
first post so bear with me!
I've done live sound in pubs and clubs over the years, mainly small acts up to 500 people.
otherwise used to work sound in nightclubs.
now I have a small HK compact classic p.a. 2 subs 150w each and 2 12 inch plus horn tops. Run this off 1400w thomanns amp.
nice and compact but I find the subs seem crossed over very low, resulting in some rumble, but between them and the tops there is virtually no bass drum apparent ( not in pure volume, it just seems to be lacking( if that makes sense!). the crossovers are built in to cabs are non adjustable.
anyway this p.a is just for my pub band and I just use a 15 band graphic to eq it as it's all I have these days!
it's o.k, but just adding an old 15 inch reflex bass guitar can I had lying around seems to give me the bass drum I require.
as I do the odd pub and church hall gig for jazz and Rick bands and I do enjoy making stuff I would like to build 2 compact tops and a single sub capable of being run from my 1400 w amp and possibly a cloud 200w amp I happen to have.
I have no idea what I should look at and wondered if you kind people had any thoughts? Im keen to build for the enjoyment of it. Budget not huge ( under a grand if possible!
first post so bear with me!
I've done live sound in pubs and clubs over the years, mainly small acts up to 500 people.
otherwise used to work sound in nightclubs.
now I have a small HK compact classic p.a. 2 subs 150w each and 2 12 inch plus horn tops. Run this off 1400w thomanns amp.
nice and compact but I find the subs seem crossed over very low, resulting in some rumble, but between them and the tops there is virtually no bass drum apparent ( not in pure volume, it just seems to be lacking( if that makes sense!). the crossovers are built in to cabs are non adjustable.
anyway this p.a is just for my pub band and I just use a 15 band graphic to eq it as it's all I have these days!
it's o.k, but just adding an old 15 inch reflex bass guitar can I had lying around seems to give me the bass drum I require.
as I do the odd pub and church hall gig for jazz and Rick bands and I do enjoy making stuff I would like to build 2 compact tops and a single sub capable of being run from my 1400 w amp and possibly a cloud 200w amp I happen to have.
I have no idea what I should look at and wondered if you kind people had any thoughts? Im keen to build for the enjoyment of it. Budget not huge ( under a grand if possible!
Before replacing cabs, you could buy a DSP like Behringer 2496 or dBX PA2 upgrading your system from passive to active, this device will give you a lot more freedom to change the crossover and also to add delay where you need. You can still use your amp for a while (1400w) , one channel for subs, the other channels for tops, and the second amp for horns (200w).
Additionally, you could by a mic and using REW/RTA softwere to measure your system setups investigating what you consider as an issue.
This exercice will give you better idea about what you need.
Additionally, you could by a mic and using REW/RTA softwere to measure your system setups investigating what you consider as an issue.
This exercice will give you better idea about what you need.
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Hi,
Thanks! Thinking about it I have got an old crossover in the attic, so will try to play with crossover point to see if that will in some way assist the HK system.
I'll have a play around with what I have.
Ultimately looking for a different set up but would be interesting to see results,
Many thanks,
Al
Thanks! Thinking about it I have got an old crossover in the attic, so will try to play with crossover point to see if that will in some way assist the HK system.
I'll have a play around with what I have.
Ultimately looking for a different set up but would be interesting to see results,
Many thanks,
Al
hi,
yes it's one sub and top per channel. I'll bypass the passive crossover in the sub and try as you suggest.
it's weird how it operates currently, I'm boosting 45 to 100 Hz by 12dB on the graphic but just not getting any kick drum at all, just low rumble. almost like the crossove point currently in use has a hole in the area between the two cabs.
cheers for the good advice, will try that before I sell the cabs on !
yes it's one sub and top per channel. I'll bypass the passive crossover in the sub and try as you suggest.
it's weird how it operates currently, I'm boosting 45 to 100 Hz by 12dB on the graphic but just not getting any kick drum at all, just low rumble. almost like the crossove point currently in use has a hole in the area between the two cabs.
cheers for the good advice, will try that before I sell the cabs on !
Don't forget the B string on a bass is near to 31hZ and the kick drum resonates at around 80hZ when tuned so no need for the sub to go more than 100hZ but rule of thumb is a sub needs twice the useable power of bass that needs twice the useable power of mid that needs twice the useable power of treble. So with only 150W of sub, there is no power available for a reasonable balance.
Cheers,
Yes , good point, I was suspect about the subs being 150w only...
I guess I'll be selling these on soon...
Any ideas of an efficient top and sub combination for DIY?
Criteria is to fit in car(!), Cover small pub and hall gigs up to maybe 100 odd people, for live band not DJ use.
Bands will be from rock to jazz , no electronic( synth) bass.
Cheers!
Al
Yes , good point, I was suspect about the subs being 150w only...
I guess I'll be selling these on soon...
Any ideas of an efficient top and sub combination for DIY?
Criteria is to fit in car(!), Cover small pub and hall gigs up to maybe 100 odd people, for live band not DJ use.
Bands will be from rock to jazz , no electronic( synth) bass.
Cheers!
Al
Personal seat of the pants observation, YMMV of course.
*Hi Fi cabinets are designed for smooth , flat response and efficiency be d*mned.
*Old PA cabinets tried to be efficient since in the old days power was relatively expensive and not that much available, so they tried to make them efficient and "as flat as possible" as long as it this did not hurt the first requirement.
* nowadays power is dirt cheap and plentiful , so efficiency requirements are relaxed and "better curves" are sought.
* I bet your "old 15 inch reflex bass guitar (cabinet)" is LOUD (very efficient) , punchy, .... and not that flat at all .... , most probably has some noticeable bass bump/peak , between, say, 60 and 90 or even 100Hz which makes it even louder than what its higher efficiency already offers, and probably drops like a brick below 60 or 70 Hz.
Now we hear these frequencies very well, so they nicely add to the perceived mix, while deep extended modern subwoofer curves may measure very flat, very deep (say flat to 35/40 Hz), but we are near the practical limits of audibility and sound in that area, specially in a large untreated room, can very well be perceived as "rumble".
What´s my point? ... I am agreeing with your observation, I have listened the same many times in live sound situations, and might suggest something: have you considered cloning that "old 15" bass cabinet"? ... using modern but efficient and higher power handling speakers?
It might be a worthwhile addition to your system.
If it is an old American made cabinet by any of the major manufacturers (Ampeg/Peavey/Fender/etc.) it most probably has some variation of Eminence speaker inside, and if British, it might be a Celestion ... you may research a little and find the modern equivalent, basically same specs but higher power handling.
*Hi Fi cabinets are designed for smooth , flat response and efficiency be d*mned.
*Old PA cabinets tried to be efficient since in the old days power was relatively expensive and not that much available, so they tried to make them efficient and "as flat as possible" as long as it this did not hurt the first requirement.
* nowadays power is dirt cheap and plentiful , so efficiency requirements are relaxed and "better curves" are sought.
* I bet your "old 15 inch reflex bass guitar (cabinet)" is LOUD (very efficient) , punchy, .... and not that flat at all .... , most probably has some noticeable bass bump/peak , between, say, 60 and 90 or even 100Hz which makes it even louder than what its higher efficiency already offers, and probably drops like a brick below 60 or 70 Hz.
Now we hear these frequencies very well, so they nicely add to the perceived mix, while deep extended modern subwoofer curves may measure very flat, very deep (say flat to 35/40 Hz), but we are near the practical limits of audibility and sound in that area, specially in a large untreated room, can very well be perceived as "rumble".
What´s my point? ... I am agreeing with your observation, I have listened the same many times in live sound situations, and might suggest something: have you considered cloning that "old 15" bass cabinet"? ... using modern but efficient and higher power handling speakers?
It might be a worthwhile addition to your system.
If it is an old American made cabinet by any of the major manufacturers (Ampeg/Peavey/Fender/etc.) it most probably has some variation of Eminence speaker inside, and if British, it might be a Celestion ... you may research a little and find the modern equivalent, basically same specs but higher power handling.
ALt, you can use the equation and the example below to balance your system, or at least to undertand the current situation and the desired one.
Sound Pressure Level (SPL) = Cab sensitivity (@1W) + 10 * Log (Cab Power).
Considering 120dB as target @ 1m for all frequencies = flat response
For bass (Subwoofer)
Note: How much dynamics you need to mage is up to you, drivers manufactores recomend a power amp at least having the double of program power and this recomendation was used in the equation. If you need higher headroom your SPL will be lower so you will need to increase the amount of power to rise it again
Sound Pressure Level (SPL) = Cab sensitivity (@1W) + 10 * Log (Cab Power).
Considering 120dB as target @ 1m for all frequencies = flat response
For bass (Subwoofer)
120db = 96db + 10 * Log (300W) - In this case you need 600W to manage dynamics
For mids120db = 99db + 10 * Log (125W) - In this case you need 250W to manage dynamics
For trebble (Horn)120db = 108db + 10 * Log (16W) - In this case you need 32W to manage dynamics
Note: How much dynamics you need to mage is up to you, drivers manufactores recomend a power amp at least having the double of program power and this recomendation was used in the equation. If you need higher headroom your SPL will be lower so you will need to increase the amount of power to rise it again
Hi , thanks for the continued advice! On occasions I've had to put kick at low levels through 15s and tops (in the past) sometimes was o.k but often, possibly due to lack of compressors could get a bit hairy!
I think that maybe making a good 15 inch reflex box for sub and a couple of decent 12 tops would be a goer. I do like kick, even at low level, through the p.a to add some beef and as we like him play at low levels on stage do often d.i my bass to the p.a.
At the moment the HK p.a is not really cutting sadly. I've noticed it needs a fair bit of eq on the Tops to get a smoother sound, nasty 4k peaks in particular..
Install head over to the sub forum and see if there are any recommended sub designs..
Been a while since a built a cab, last was a huge scoop with 18 inch speaker, 1000w amp. Was a laugh til I tried to move it 😂
I think that maybe making a good 15 inch reflex box for sub and a couple of decent 12 tops would be a goer. I do like kick, even at low level, through the p.a to add some beef and as we like him play at low levels on stage do often d.i my bass to the p.a.
At the moment the HK p.a is not really cutting sadly. I've noticed it needs a fair bit of eq on the Tops to get a smoother sound, nasty 4k peaks in particular..
Install head over to the sub forum and see if there are any recommended sub designs..
Been a while since a built a cab, last was a huge scoop with 18 inch speaker, 1000w amp. Was a laugh til I tried to move it 😂
That suggest you have some of the speakers out of polarity with the others, if the speaker cables have 1/4" jacks or speakon connectors they may be wired incorrectly and you will have to open them up to fix it.
Start with just 1 sub connected and then bring in the other sub, do you get more bass when the second sub is added? If so good, if not the second sub is out of polarity so switch the speaker wires on that box positive for negative.
Now go back to one channel by turning down the amp control for the other channel. Connect the top and listen to the bass, if that hole reappears flip polarity on the speaker wire to the top. Repeat that for the other side and you should be good.
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