my living room is on the low end of the room size spectrum. 10'x 12. and yeah that is a bit too close. I did find a 8'x10' heavy weave rug to put on on the far wall, where we sit. it sure helped.
So speakers are built, sounding great. Nice deep bass, yet not overpowering. It's real. Most speakers out there have what I call fake bass, they over emphasize it to satisfy the bass hungry US market. The horn L-pads are set on a little less than 2. Which makes them smooth and seem to play the easy going music I am into, beautifully.
I'm not sure of the sensitivity but with just 8 watts of 300b power I can get the volume maybe to 25% and that is house shaking. The jbl woofers are rated at 103db.
My dampening is not totally covering inside the cabinets. The front face has none, and the rear door has none either. Just top bottom and sides. I added some insulation in the corners so there is no sharp areas. I'm ordering a couple packs of acoustic wadding this week to try it on the back and maybe the face.
Problem is when I really crank up the volume, it is harsh and hot.
I'm going to build the 1200hz xover and test side by side with my present 800hz xover. I'm adding the dampening. Is there anything else I can do to tone this down a bit. Aside from turning down the volume
My room is small and there isn't a whole lot of room to spread them out. I think bouncing off the walls could be part of it. Should I dampen the 511 at all?
I just figured I would ask since I'm sure some of you could have gone through this before.
For the record my room is only 11 ft wide and I sit 13ft from front wall.
Inside speaker dimension is 22w x18d x29h and are 3/4" MDF and solid and heavy.
Drivers are 902-8a/511b and 15" jbl d130
N801-8a xover w/ Jantzen caps
Thanks for any thoughts
my living room is on the low end of the room size spectrum. 10'x 12. and yeah that is a bit too close. I did find a 8'x10' heavy weave rug to put on on the far wall, where we sit. it sure helped.
Sonic Barbarian
Good call, I was just reaching back and could feel the vibrations, but unfortunately that's where my front door is. Lol. But I may be able to figure something out. And I definitely need something other than hardwood floor in between me and the speakers.
Thx
Sounds to me like you're running out of power.
"crank it up" and SET's are somewhat conflicting terms.
You may also need to dial in the room a bit.
Last edited by bowtie427ss; December 4th, 2016 at 08:05 PM.
Not all vegetables make good leaders.
since your running the 800 hz cross-over the responce in the room will seem overly bright. use the 1200 hz cross-over with the 2500-3000 hz cut and you'll be happy. look at the fletcher munson curve and itl'll make sense !
Thanks guys, the room is definitely an issue. Im not sure it's the power because ive run this amp with 90db @ 6ohm and would run out of power regularly, so I know what that sounds like.
I'm going to build the 1200hz xover pretty soon. Parts express seems to be out of stock on 1/2 the items in my cart.
Thanks I'll work on the room and eventually xover. See how that works out.
Petro - I've enjoyed watching your progress on your speaker system. Do you have any means for measuring the frequency response of the speakers as they now stand? I'm by no means the expert here, and I'll look forward to seeing what others have to say on this idea, but I'll bet you are encountering the typically accentuated frequency response of an un-equalized compression driver in the upper midranges when you refer to the higher-volume "harshness."
Have you followed BillWojo's post about using the Altec 30904 EQ/attenuator? (30904 attenuator works!) This little crossover addition brings those frequencies down (about 6dB, if memory serves) and smooths that harshness you are referring to. It's a cheap and easy addition to your crossover and certainly worth the try.
I intend to use the 30904 on my upcoming build (A7 components). If that sends me in the right direction, I'll be using some of the on line calculators to add more/less attenuation to smooth that horn response in the normally-hot upper midrange frequencies.
GeeDeeEmm
Unfortunately I don't have any measuring software or anything yet. I'm working on changing my whole room around and will definitely include room for my computer this time. I do think my 801 xover could use another adjustment, I want to build the same xover BillWojo is building. I've been talking about it with him. On another note. Just a thick blanket across the rear wall has helped alot. A nice throw rug and a 1200hz xover is next. Also need to finish some boxes for the 4"deep vents, with a decent looking lip around it.Originally Posted by gdmoore28
I was curious about dampening at least part of the 511. Maybe I'll get some thick rubber padding and experiment this weekend.
Thank you !!!!
Steve
I use duct seal from home depot. It comes in 1 lbs blocks and is a non hardening clay like material. I used one block per horn. My horns are also bolted to the top of the cabs
Nice!!! That's what I was looking for, I actually had 2 couch pillows folded and shoved underneath the 511's lol. It works but looks like crap. Thanks!!
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