Any reason for poor HU performance?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=87922
Printed Date: May 01, 2024 at 7:13 PM
Topic: Any reason for poor HU performance?
Posted By: Sad, little man
Subject: Any reason for poor HU performance?
Date Posted: December 28, 2006 at 9:52 AM
I have an Alpine CDA-9811 HU, and for some reason, for as long as I can remember, it's sounded terrible at anything past 2/3 volume. Any bass note dims the lights in the dials and just sounds like it's killing the deck. Were HUs just not meant to be turned up that high without an external amp? It has a 4 channel 23W RMS (50 max) amplifier in it, which is pretty decent for an HU, but it still strains to do door speakers.
Replies:
Posted By: DYohn
Date Posted: December 28, 2006 at 10:42 AM
What speakers are you using? What vehicle? ------------- Support the12volt.com
Posted By: boulderguy
Date Posted: December 28, 2006 at 10:44 AM
Sounds like it ain't getting enough juice - are you using the stock wiring assembly? Car details would be helpful.
Posted By: Sad, little man
Date Posted: December 28, 2006 at 11:28 AM
It's a 1996 Mazda Miata. The speakers are dayton audio 8 ohm woofers with 6 ohm tweeters run through a crossover. It also did this with the stock speakers, which for some odd reason consisted of a 2 ohm pioneer woofer with a 4 ohm tweeter in parallel. I thought maybe I blew the head unit unknowingly using it to play such low impedence speakers, or that the old speakers sounded so bad because they were too low impedence for the deck, but I tried the new speakers on another channel and it sounds the same as always. I even tried hard-wiring the deck to the battery, same problem. I tested the voltage at the deck... A constant 14V with the car running.
Posted By: DYohn
Date Posted: December 28, 2006 at 12:11 PM
Sounds like you are simply expecting too much from HU power. The part that intrigues me is you say the HU is causing lights to dim? This is why I asked about the speakers, as driving too low an impedance load might cause all sorts of HU issues. Perhaps driving the OEM speakers damaged the head amplifier as it is designed for no lower than a 4-ohm load. Your fault description indicates either faulty HU, faulty wiring or faulty vehicle electrical system. You may want also to get your alternator and battery tested at a car electrical shop. ------------- Support the12volt.com
Posted By: Sad, little man
Date Posted: December 28, 2006 at 12:52 PM
Well, it's the HU lights that are dimming, nothing else. Indicating that it's working pretty hard. I'll probably just have to go with a separate amp for the performance I want. Any opinions on the Alpine MRP-F250 as a nice basic amp briged to 2 channels for door speakers?
Posted By: DYohn
Date Posted: December 28, 2006 at 1:41 PM
If the HU lights are dimming, I bet your HU is defective. I do not normally recommend any 4-channel amp to be bridged to drive the stereo main set. Too much distortion that way. Use only 2-channels of a 4-channel amp or get a stereo amplifier. Alpine amps are decent. ------------- Support the12volt.com
Posted By: Sad, little man
Date Posted: December 28, 2006 at 3:19 PM
But pretty much everything in Alpine's current lineup is a four channel amp brigable down to two. Would you really suggest insisting on only a two channel amp?
Posted By: boulderguy
Date Posted: December 28, 2006 at 3:22 PM
Does it have to be Alpine? Lots of respectable & affordable 2 ch amps out there.
Posted By: Sad, little man
Date Posted: December 28, 2006 at 3:23 PM
Well, what would you guys suggest?
Posted By: boulderguy
Date Posted: December 28, 2006 at 3:28 PM
How about this - https://www.caraudiomag.com/testreports/0609_cae_eclipse_xa2000_amp/
Posted By: Sad, little man
Date Posted: December 28, 2006 at 3:40 PM
A little pricey. How about... https://www.pioneerelectronics.com/pna/v3/pg/product/details/0,,2076_310069933_291522415_tab=D,00.html?compName=PNA_V3_ProductDetailsComponent
Posted By: boulderguy
Date Posted: December 28, 2006 at 4:17 PM
Don't know what that is, can't open. How about this?
Posted By: haemphyst
Date Posted: December 28, 2006 at 4:36 PM
gt_mule has not answered me yet, so the Eclipse 3122 I have, is still up for grabs. 55X2 @ 4 ohms, 80X2 @ 2 ohms... I offered it to him for 120, including freight and insurance. Same offer for you! PM me and let me know.
All original packaging, including the 4 mounting screws it came with, and even the spare additional fuse... Like new, man! PM me, and let me know. Just trying to sell it, as I am not using it in my present system.
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It all reminds me of something that Moličre once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: DYohn
Date Posted: December 28, 2006 at 5:15 PM
That is a nice amp and a good price, haemphyst. FAR better than anything from Pioneer, little man. ------------- Support the12volt.com
Posted By: Sad, little man
Date Posted: December 28, 2006 at 5:21 PM
Is the crossover on that eclipse able to be shut off? Didn't sound like the first one was. I'd want that seeing as how I'll use my own passive crossovers. The one I posted was this.
https://www.epinions.com/Pioneer_GM_3200T_2_Channel_Power_Amplifier_Car_Audio_Amplifier
I'm trying to stay away from the cheap brands.
Posted By: boulderguy
Date Posted: December 28, 2006 at 5:32 PM
Haemphyst's amp is a good deal.
Posted By: DYohn
Date Posted: December 28, 2006 at 5:50 PM
Sad, little man, you seem to be confused. The crossover on the amplifier will have nothing to do with the required crossover for your component set. It is a HP or LP filter. The HP will limit the low frequency extension for your mains (which you will want) or a LP in the case it is used to drive subwoofers (which you will not do.) It has nothing to do with the crossover between your woofer and tweeter. And yes, most amplifier crossovers have a defeat or off position. Pioneer is, IMO, a cheap brand. I cannot recomend them. ------------- Support the12volt.com
Posted By: Sad, little man
Date Posted: December 28, 2006 at 6:07 PM
Ok, I understand now. You'll have to bear with me, I don't do a ton of car audio stuff.
Posted By: geepherder
Date Posted: December 28, 2006 at 6:40 PM
If I remember correctly the ground wire is not in the Miata harness, but is a female disconnect that slides onto a terminal behind the factory deck. If you didn't connect the ground wire, this could be the cause of your problem. With no seperate ground wire connected, the deck will source a ground through the outer conductor of the antenna lead. This is not a sufficient ground, and will provide you with the symptoms described above. Run your own ground first and see if this clears up your problem.
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My ex once told me I have a perfect face for radio.
Posted By: Sad, little man
Date Posted: December 28, 2006 at 7:32 PM
I had it grounded. There is a dedicated grounding wire that ran to the frame of the HU which I transfered over to the HU. I also clamped in the actual grounding wire from the wiring harness of the HU to this point on the frame of the HU. I think I've established that everything is ok with the HU wiring, it just isn't capable of performing how I want.
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