construction pics here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=53971&perpage=10&highlight=&pagenumber=12
Heres a plot next to the single cab plot from prosound web.:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=53971&perpage=10&highlight=&pagenumber=12
Heres a plot next to the single cab plot from prosound web.:
Attachments
Paul, the measurement was taken at 2m with the mic on the ground, in the middle of my garden.
Behringer ecm8000 mic, trueRTA software.
Hopefully tonight I'll have help to stack them and be able to measure them in room, corner loaded.
Will hopefully have enough horsepower in the dcx to do all eq'ing. Otherwise I have a DEQ2496 aswell (am hoping not to need it and sell it on though)
Looking forwards to hearing them in my system.....
Have to build new boxes to fit my tempests in now though
Cheers,
Rob.
Behringer ecm8000 mic, trueRTA software.
Hopefully tonight I'll have help to stack them and be able to measure them in room, corner loaded.
Will hopefully have enough horsepower in the dcx to do all eq'ing. Otherwise I have a DEQ2496 aswell (am hoping not to need it and sell it on though)
Looking forwards to hearing them in my system.....
Have to build new boxes to fit my tempests in now though
Cheers,
Rob.
paulspencer said:Rob, you haven't tried them out in your system yet?
I've had some personal rubbish to deal with the last 2 weeks (car crash was one of the things) so the labs went on the back burner. The day I installed the drivers I tried test tones through them (in my garage)
Bear in mind it takes 2 people to carry 1 if it's not on wheels, and I was stupid enough not to put carry handles on them...
Basically last night was the first time I could move them into my garden to measure, then into the middle of my living room.I've just got them stacked, corner loaded and am about to do the in room measurements. Once I've had a breather that is...
Simon5 - that was careless of me to crop the scale off... here you go :
Rob.
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slowmotion said:
Thanks Jan,
Just me in my car, 1 person in the other. Not a big crash everybody ok, just had to spend the last 2 weeks repairing my car in between working etc... Just about finished..
Day after the accident my dad went into hospital so stopped work on car and labs to be with him... Bad things always happen together.. Anyways:
Some in room plots..
Clearly showing the usual lovely room modes, but also the change from 24dB/oct roll off to 12dB/oct in room.
The measurements were taken across my couch in 3 places (1/2/3), and again (4/5/6) a few foot in front as the couch moves backwards and forwards a bit day to day.
No eq btw....
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Paul,
Initial listening is very promising, but I won't commit to anything until I've eq'd everything properly.
Obviously they go amazingly loud. I've adjusted levels to match the mains, and xo'd in a pair of tempests below 30Hz. Haven't eq'd the tempests flat before xo'ing so theres a bit of a bump from them at 50Hz, which should mess with the labs sound quality. My wife commented that the bass seems to start and stop very quickly, and I would agree - it's tight as can be. I also noticed that with dvd's I seem to me rattling more stuff in the house with apparently less output. I'm assuming the lack of distortion makes the bass seem less 'hearable' while actually being louder.
Going back to an older thread, it seems I can set these up level with the mains and they still sound tight, whereas my old subs seemed to 'boom'.
I feel these sound better than the scanspeaks / tempest combo, but that also takes my mains into cosideration.
Will post a proper 'review' after a weeks playing with eq / xo stuff.
1st step - eq'ing the tempests and labs flat before xo'ing.
It's been a long night - it's 2am here and I get up for work in 5 hours
Cheers,
Rob.
Initial listening is very promising, but I won't commit to anything until I've eq'd everything properly.
Obviously they go amazingly loud. I've adjusted levels to match the mains, and xo'd in a pair of tempests below 30Hz. Haven't eq'd the tempests flat before xo'ing so theres a bit of a bump from them at 50Hz, which should mess with the labs sound quality. My wife commented that the bass seems to start and stop very quickly, and I would agree - it's tight as can be. I also noticed that with dvd's I seem to me rattling more stuff in the house with apparently less output. I'm assuming the lack of distortion makes the bass seem less 'hearable' while actually being louder.
Going back to an older thread, it seems I can set these up level with the mains and they still sound tight, whereas my old subs seemed to 'boom'.
I feel these sound better than the scanspeaks / tempest combo, but that also takes my mains into cosideration.
Will post a proper 'review' after a weeks playing with eq / xo stuff.
1st step - eq'ing the tempests and labs flat before xo'ing.
It's been a long night - it's 2am here and I get up for work in 5 hours
Cheers,
Rob.
I've found it interesting to read posts by Tom Danley regarding the Lab horn regarding power handling. Apparently the power handling actually can be a lot more than the thermal rating of the drivers due to the increased electrical impedance caused by horn loading when used above fc. I think they have a power handling of ~1kw per lab horn, however 2kw or more can be achieved with stacks of 4 or more.
Hi Paul,
you're right.
A 1% efficient speaker puts 99% of the input out as heat into the voice coil. So 400W input = 396W of heat.
A 50% efficient speaker puts 50% of input out as heat. It follows that if the Labhorn is as efficient as this you can double the input power PROVIDED you stay in band and do not drive the bass unit below it's active bandwidth (about 28Hz to 34Hz).
So a pair stacked could theoretically take 3.2kW.
What are we trying to do to Rob's hearing?
you're right.
A 1% efficient speaker puts 99% of the input out as heat into the voice coil. So 400W input = 396W of heat.
A 50% efficient speaker puts 50% of input out as heat. It follows that if the Labhorn is as efficient as this you can double the input power PROVIDED you stay in band and do not drive the bass unit below it's active bandwidth (about 28Hz to 34Hz).
So a pair stacked could theoretically take 3.2kW.
What are we trying to do to Rob's hearing?
AndrewT said:
Hi Andrew,
I built 2 labhorns, and have them one on top of the other. I chose this over 1 with a flare extension as they had to fit behind behind my screen, and they fit well like this. I've also read a fair number of threads about using a pair 'floor to ceiling' as being an ideal match to the corner loading.
Mark Seaton post here
and here
Theres a number by Tom Danley aswell, but I couldn't find them today.
I've eq'd my tempests that I'm using below 30Hz, and its all working pretty seamlessly. With music they disappear nicely, and with dvd's they light up the room when theres bass content. I was stunned by the output with just a 30W nad amp and test tones in my garage. With a 600W per lab QSC RMX1850HD and Finding Nemo I just get a huge grin on my face..
Although the amp will not get the last 3dB from the labs, it's designed to handle the low impedance that the labs have. I'm pretty sure they drop to 2.7 Ohm at some points.(from memory so I could be wrong there)
I cut the wood for 4 labhorns, but cannot see how I'd ever need 4. However, if I ever win the lotto then they're there, flat packed, ready to go.
Thanks to Mark Seaton for taking time out to answer my questions about which amp I should get
Cheers,
Rob.
Hi Coolin,
I'm still playing with the balance of levels, but am loving the quality of the labs. They are very clean sounding, with the usual descritions such as 'fast' that people don't like using here. Compared to the tempests its the lack of bloat I like best.
Acoustic double bass sounds good on them, and that seems to be quite a hard instrument to reproduce well.
They remind me of servo type subs, so maybe it's the low distortion helping out.
I still use the tempests below 30Hz, and am about to rebuild the boxes with 2 drivers per box, magnet out on 1 to lower the harmonic distortion a bit.
The downsides -
a pain to move them about. Very heavy.
They need eq'ing to get a flat response - I wouldn't use them without parametric eq.
They take up a lot of space.
Not the easiest things to build.
will post an in room plot with the eq in place when I get home.
cheers,
Rob.
I'm still playing with the balance of levels, but am loving the quality of the labs. They are very clean sounding, with the usual descritions such as 'fast' that people don't like using here. Compared to the tempests its the lack of bloat I like best.
Acoustic double bass sounds good on them, and that seems to be quite a hard instrument to reproduce well.
They remind me of servo type subs, so maybe it's the low distortion helping out.
I still use the tempests below 30Hz, and am about to rebuild the boxes with 2 drivers per box, magnet out on 1 to lower the harmonic distortion a bit.
The downsides -
a pain to move them about. Very heavy.
They need eq'ing to get a flat response - I wouldn't use them without parametric eq.
They take up a lot of space.
Not the easiest things to build.
will post an in room plot with the eq in place when I get home.
cheers,
Rob.
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